示例#1
0
/*! \brief Print the blocking parameters.
 */
void print_sp_ienv_dist(superlu_options_t *options)
{
    if ( options->PrintStat == NO ) return;

    printf("**************************************************\n");
    printf(".. blocking parameters from sp_ienv():\n");
    printf("**    relaxation           : " IFMT "\n", sp_ienv_dist(2));
    printf("**    max supernode        : " IFMT "\n", sp_ienv_dist(3));
    printf("**    estimated fill ratio : " IFMT "\n", sp_ienv_dist(6));
    printf("**************************************************\n");
}
示例#2
0
/*! \brief
 *
 * <pre>
 * mem_usage consists of the following fields:
 *    - for_lu (float)
 *      The amount of space used in bytes for the L\U data structures.
 *    - total (float)
 *      The amount of space needed in bytes to perform factorization.
 *    - expansions (int)
 *      Number of memory expansions during the LU factorization.
 * </pre>
 */
int_t dQuerySpace_dist(int_t n, LUstruct_t *LUstruct, gridinfo_t *grid,
		       mem_usage_t *mem_usage)
{
    register int_t dword, gb, iword, k, maxsup, nb, nsupers;
    int_t *index, *xsup;
    int iam, mycol, myrow;
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    LocalLU_t *Llu = LUstruct->Llu;

    iam = grid->iam;
    myrow = MYROW( iam, grid );
    mycol = MYCOL( iam, grid );
    iword = sizeof(int_t);
    dword = sizeof(double);
    maxsup = sp_ienv_dist(3);
    nsupers = Glu_persist->supno[n-1] + 1;
    xsup = Glu_persist->xsup;
    mem_usage->for_lu = 0;

    /* For L factor */
    nb = CEILING( nsupers, grid->npcol ); /* Number of local column blocks */
    for (k = 0; k < nb; ++k) {
	gb = k * grid->npcol + mycol; /* Global block number. */
	if ( gb < nsupers ) {
	    index = Llu->Lrowind_bc_ptr[k];
	    if ( index ) {
		mem_usage->for_lu += (float)
		    ((BC_HEADER + index[0]*LB_DESCRIPTOR + index[1]) * iword);
		mem_usage->for_lu += (float)(index[1]*SuperSize( gb )*dword);
	    }
	}
    }

    /* For U factor */
    nb = CEILING( nsupers, grid->nprow ); /* Number of local row blocks */
    for (k = 0; k < nb; ++k) {
	gb = k * grid->nprow + myrow; /* Global block number. */
	if ( gb < nsupers ) {
	    index = Llu->Ufstnz_br_ptr[k];
	    if ( index ) {
		mem_usage->for_lu += (float)(index[2] * iword);
		mem_usage->for_lu += (float)(index[1] * dword);
	    }
	}
    }

    /* Working storage to support factorization */
    mem_usage->total = mem_usage->for_lu;
    mem_usage->total +=
	(float)(( Llu->bufmax[0] + Llu->bufmax[2] ) * iword +
		( Llu->bufmax[1] + Llu->bufmax[3] + maxsup ) * dword );
    /**** another buffer to use mpi_irecv in pdgstrf_irecv.c ****/
    mem_usage->total +=
	(float)( Llu->bufmax[0] * iword +  Llu->bufmax[1] * dword );
    mem_usage->total += (float)( maxsup * maxsup + maxsup) * iword;
    k = CEILING( nsupers, grid->nprow );
    mem_usage->total += (float)(2 * k * iword);

    return 0;
} /* dQuerySpace_dist */
示例#3
0
float
ddistribute(fact_t fact, int_t n, SuperMatrix *A, 
            Glu_freeable_t *Glu_freeable,
	    LUstruct_t *LUstruct, gridinfo_t *grid)
{
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    LocalLU_t *Llu = LUstruct->Llu;
    int_t bnnz, fsupc, fsupc1, i, ii, irow, istart, j, jb, jj, k, 
          len, len1, nsupc;
    int_t ljb;  /* local block column number */
    int_t nrbl; /* number of L blocks in current block column */
    int_t nrbu; /* number of U blocks in current block column */
    int_t gb;   /* global block number; 0 < gb <= nsuper */
    int_t lb;   /* local block number; 0 < lb <= ceil(NSUPERS/Pr) */
    int iam, jbrow, kcol, mycol, myrow, pc, pr;
    int_t mybufmax[NBUFFERS];
    NCPformat *Astore;
    double *a;
    int_t *asub;
    int_t *xa_begin, *xa_end;
    int_t *xsup = Glu_persist->xsup;    /* supernode and column mapping */
    int_t *supno = Glu_persist->supno;   
    int_t *lsub, *xlsub, *usub, *xusub;
    int_t nsupers;
    int_t next_lind;      /* next available position in index[*] */
    int_t next_lval;      /* next available position in nzval[*] */
    int_t *index;         /* indices consist of headers and row subscripts */
    int   *index1;        /* temporary pointer to array of int */
    double *lusup, *uval; /* nonzero values in L and U */
    double **Lnzval_bc_ptr;  /* size ceil(NSUPERS/Pc) */
    int_t  **Lrowind_bc_ptr; /* size ceil(NSUPERS/Pc) */
    double **Unzval_br_ptr;  /* size ceil(NSUPERS/Pr) */
    int_t  **Ufstnz_br_ptr;  /* size ceil(NSUPERS/Pr) */

    /*-- Counts to be used in factorization. --*/
    int  *ToRecv, *ToSendD, **ToSendR;

    /*-- Counts to be used in lower triangular solve. --*/
    int_t  *fmod;          /* Modification count for L-solve.        */
    int_t  **fsendx_plist; /* Column process list to send down Xk.   */
    int_t  nfrecvx = 0;    /* Number of Xk I will receive.           */
    int_t  nfsendx = 0;    /* Number of Xk I will send               */
    int_t  kseen;

    /*-- Counts to be used in upper triangular solve. --*/
    int_t  *bmod;          /* Modification count for U-solve.        */
    int_t  **bsendx_plist; /* Column process list to send down Xk.   */
    int_t  nbrecvx = 0;    /* Number of Xk I will receive.           */
    int_t  nbsendx = 0;    /* Number of Xk I will send               */
    int_t  *ilsum;         /* starting position of each supernode in 
			      the full array (local)                 */

    /*-- Auxiliary arrays; freed on return --*/
    int_t *rb_marker;  /* block hit marker; size ceil(NSUPERS/Pr)           */
    int_t *Urb_length; /* U block length; size ceil(NSUPERS/Pr)             */
    int_t *Urb_indptr; /* pointers to U index[]; size ceil(NSUPERS/Pr)      */
    int_t *Urb_fstnz;  /* # of fstnz in a block row; size ceil(NSUPERS/Pr)  */
    int_t *Ucbs;       /* number of column blocks in a block row            */
    int_t *Lrb_length; /* L block length; size ceil(NSUPERS/Pr)             */
    int_t *Lrb_number; /* global block number; size ceil(NSUPERS/Pr)        */
    int_t *Lrb_indptr; /* pointers to L index[]; size ceil(NSUPERS/Pr)      */
    int_t *Lrb_valptr; /* pointers to L nzval[]; size ceil(NSUPERS/Pr)      */
    double *dense, *dense_col; /* SPA */
    double zero = 0.0;
    int_t  ldaspa;     /* LDA of SPA */
    int_t iword, dword;
    float mem_use = 0.0;

#if ( PRNTlevel>=1 )
    int_t nLblocks = 0, nUblocks = 0;
#endif
#if ( PROFlevel>=1 ) 
    double t, t_u, t_l;
    int_t u_blks;
#endif

    /* Initialization. */
    iam = grid->iam;
    myrow = MYROW( iam, grid );
    mycol = MYCOL( iam, grid );
    for (i = 0; i < NBUFFERS; ++i) mybufmax[i] = 0;
    nsupers  = supno[n-1] + 1;
    Astore   = A->Store;
    a        = Astore->nzval;
    asub     = Astore->rowind;
    xa_begin = Astore->colbeg;
    xa_end   = Astore->colend;
#if ( PRNTlevel>=1 )
    iword = sizeof(int_t);
    dword = sizeof(double);
#endif

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter ddistribute()");
#endif

    if ( fact == SamePattern_SameRowPerm ) {
        /* ---------------------------------------------------------------
         * REUSE THE L AND U DATA STRUCTURES FROM A PREVIOUS FACTORIZATION.
         * --------------------------------------------------------------- */

#if ( PROFlevel>=1 )
	t_l = t_u = 0; u_blks = 0;
#endif
	/* We can propagate the new values of A into the existing
	   L and U data structures.            */
	ilsum = Llu->ilsum;
	ldaspa = Llu->ldalsum;
	if ( !(dense = doubleCalloc_dist(((size_t)ldaspa) * sp_ienv_dist(3))) )
	    ABORT("Calloc fails for SPA dense[].");
	nrbu = CEILING( nsupers, grid->nprow ); /* No. of local block rows */
	if ( !(Urb_length = intCalloc_dist(nrbu)) )
	    ABORT("Calloc fails for Urb_length[].");
	if ( !(Urb_indptr = intMalloc_dist(nrbu)) )
	    ABORT("Malloc fails for Urb_indptr[].");
	Lrowind_bc_ptr = Llu->Lrowind_bc_ptr;
	Lnzval_bc_ptr = Llu->Lnzval_bc_ptr;
	Ufstnz_br_ptr = Llu->Ufstnz_br_ptr;
	Unzval_br_ptr = Llu->Unzval_br_ptr;
#if ( PRNTlevel>=1 )
	mem_use += 2.0*nrbu*iword + ldaspa*sp_ienv_dist(3)*dword;
#endif
#if ( PROFlevel>=1 )
	t = SuperLU_timer_();
#endif

	/* Initialize Uval to zero. */
	for (lb = 0; lb < nrbu; ++lb) {
	    Urb_indptr[lb] = BR_HEADER; /* Skip header in U index[]. */
	    index = Ufstnz_br_ptr[lb];
	    if ( index ) {
		uval = Unzval_br_ptr[lb];
		len = index[1];
		for (i = 0; i < len; ++i) uval[i] = zero;
	    } /* if index != NULL */
	} /* for lb ... */

	for (jb = 0; jb < nsupers; ++jb) { /* Loop through each block column */
	    pc = PCOL( jb, grid );
	    if ( mycol == pc ) { /* Block column jb in my process column */
		fsupc = FstBlockC( jb );
		nsupc = SuperSize( jb );

 		/* Scatter A into SPA (for L), or into U directly. */
		for (j = fsupc, dense_col = dense; j < FstBlockC(jb+1); ++j) {
		    for (i = xa_begin[j]; i < xa_end[j]; ++i) {
			irow = asub[i];
			gb = BlockNum( irow );
			if ( myrow == PROW( gb, grid ) ) {
			    lb = LBi( gb, grid );
 			    if ( gb < jb ) { /* in U */
 				index = Ufstnz_br_ptr[lb];
 				uval = Unzval_br_ptr[lb];
 				while (  (k = index[Urb_indptr[lb]]) < jb ) {
 				    /* Skip nonzero values in this block */
 				    Urb_length[lb] += index[Urb_indptr[lb]+1];
 				    /* Move pointer to the next block */
 				    Urb_indptr[lb] += UB_DESCRIPTOR
 					+ SuperSize( k );
 				}
 				/*assert(k == jb);*/
 				/* start fstnz */
 				istart = Urb_indptr[lb] + UB_DESCRIPTOR;
 				len = Urb_length[lb];
 				fsupc1 = FstBlockC( gb+1 );
 				k = j - fsupc;
 				/* Sum the lengths of the leading columns */
 				for (jj = 0; jj < k; ++jj)
				    len += fsupc1 - index[istart++];
				/*assert(irow>=index[istart]);*/
				uval[len + irow - index[istart]] = a[i];
			    } else { /* in L; put in SPA first */
  				irow = ilsum[lb] + irow - FstBlockC( gb );
  				dense_col[irow] = a[i];
  			    }
  			}
		    } /* for i ... */
  		    dense_col += ldaspa;
		} /* for j ... */

#if ( PROFlevel>=1 )
		t_u += SuperLU_timer_() - t;
		t = SuperLU_timer_();
#endif

		/* Gather the values of A from SPA into Lnzval[]. */
		ljb = LBj( jb, grid ); /* Local block number */
		index = Lrowind_bc_ptr[ljb];
		if ( index ) {
		    nrbl = index[0];   /* Number of row blocks. */
		    len = index[1];    /* LDA of lusup[]. */
		    lusup = Lnzval_bc_ptr[ljb];
		    next_lind = BC_HEADER;
		    next_lval = 0;
		    for (jj = 0; jj < nrbl; ++jj) {
			gb = index[next_lind++];
			len1 = index[next_lind++]; /* Rows in the block. */
			lb = LBi( gb, grid );
			for (bnnz = 0; bnnz < len1; ++bnnz) {
			    irow = index[next_lind++]; /* Global index. */
			    irow = ilsum[lb] + irow - FstBlockC( gb );
			    k = next_lval++;
			    for (j = 0, dense_col = dense; j < nsupc; ++j) {
				lusup[k] = dense_col[irow];
				dense_col[irow] = zero;
				k += len;
				dense_col += ldaspa;
			    }
			} /* for bnnz ... */
		    } /* for jj ... */
		} /* if index ... */
#if ( PROFlevel>=1 )
		t_l += SuperLU_timer_() - t;
#endif
	    } /* if mycol == pc */
	} /* for jb ... */

	SUPERLU_FREE(dense);
	SUPERLU_FREE(Urb_length);
	SUPERLU_FREE(Urb_indptr);
#if ( PROFlevel>=1 )
	if ( !iam ) printf(".. 2nd distribute time: L %.2f\tU %.2f\tu_blks %d\tnrbu %d\n",
			   t_l, t_u, u_blks, nrbu);
#endif

    } else { 
        /* --------------------------------------------------
         * FIRST TIME CREATING THE L AND U DATA STRUCTURE. 
         * -------------------------------------------------- */

#if ( PROFlevel>=1 )
	t_l = t_u = 0; u_blks = 0;
#endif
	/* No L and U data structures are available yet.
	   We need to set up the L and U data structures and propagate
	   the values of A into them.          */
	lsub = Glu_freeable->lsub;    /* compressed L subscripts */
	xlsub = Glu_freeable->xlsub;
	usub = Glu_freeable->usub;    /* compressed U subscripts */
	xusub = Glu_freeable->xusub;
    
	if ( !(ToRecv = SUPERLU_MALLOC(nsupers * sizeof(int))) )
	    ABORT("Malloc fails for ToRecv[].");
	for (i = 0; i < nsupers; ++i) ToRecv[i] = 0;

	k = CEILING( nsupers, grid->npcol );/* Number of local column blocks */
	if ( !(ToSendR = (int **) SUPERLU_MALLOC(k*sizeof(int*))) )
	    ABORT("Malloc fails for ToSendR[].");
	j = k * grid->npcol;
	if ( !(index1 = SUPERLU_MALLOC(j * sizeof(int))) )
	    ABORT("Malloc fails for index[].");
#if ( PRNTlevel>=1 )
	mem_use += (float) k*sizeof(int_t*) + (j + nsupers)*iword;
#endif
	for (i = 0; i < j; ++i) index1[i] = EMPTY;
	for (i = 0,j = 0; i < k; ++i, j += grid->npcol) ToSendR[i] = &index1[j];
	k = CEILING( nsupers, grid->nprow ); /* Number of local block rows */

	/* Pointers to the beginning of each block row of U. */
	if ( !(Unzval_br_ptr = 
               (double**)SUPERLU_MALLOC(k * sizeof(double*))) )
	    ABORT("Malloc fails for Unzval_br_ptr[].");
	if ( !(Ufstnz_br_ptr = (int_t**)SUPERLU_MALLOC(k * sizeof(int_t*))) )
	    ABORT("Malloc fails for Ufstnz_br_ptr[].");
	
	if ( !(ToSendD = SUPERLU_MALLOC(k * sizeof(int))) )
	    ABORT("Malloc fails for ToSendD[].");
	for (i = 0; i < k; ++i) ToSendD[i] = NO;
	if ( !(ilsum = intMalloc_dist(k+1)) )
	    ABORT("Malloc fails for ilsum[].");

	/* Auxiliary arrays used to set up U block data structures.
	   They are freed on return. */
	if ( !(rb_marker = intCalloc_dist(k)) )
	    ABORT("Calloc fails for rb_marker[].");
	if ( !(Urb_length = intCalloc_dist(k)) )
	    ABORT("Calloc fails for Urb_length[].");
	if ( !(Urb_indptr = intMalloc_dist(k)) )
	    ABORT("Malloc fails for Urb_indptr[].");
	if ( !(Urb_fstnz = intCalloc_dist(k)) )
	    ABORT("Calloc fails for Urb_fstnz[].");
	if ( !(Ucbs = intCalloc_dist(k)) )
	    ABORT("Calloc fails for Ucbs[].");
#if ( PRNTlevel>=1 )	
	mem_use += 2.0*k*sizeof(int_t*) + (7.0*k+1)*iword;
#endif
	/* Compute ldaspa and ilsum[]. */
	ldaspa = 0;
	ilsum[0] = 0;
	for (gb = 0; gb < nsupers; ++gb) {
	    if ( myrow == PROW( gb, grid ) ) {
		i = SuperSize( gb );
		ldaspa += i;
		lb = LBi( gb, grid );
		ilsum[lb + 1] = ilsum[lb] + i;
	    }
	}
	
            
	/* ------------------------------------------------------------
	   COUNT NUMBER OF ROW BLOCKS AND THE LENGTH OF EACH BLOCK IN U.
	   THIS ACCOUNTS FOR ONE-PASS PROCESSING OF G(U).
	   ------------------------------------------------------------*/
	
	/* Loop through each supernode column. */
	for (jb = 0; jb < nsupers; ++jb) {
	    pc = PCOL( jb, grid );
	    fsupc = FstBlockC( jb );
	    nsupc = SuperSize( jb );
	    /* Loop through each column in the block. */
	    for (j = fsupc; j < fsupc + nsupc; ++j) {
		/* usub[*] contains only "first nonzero" in each segment. */
		for (i = xusub[j]; i < xusub[j+1]; ++i) {
		    irow = usub[i]; /* First nonzero of the segment. */
		    gb = BlockNum( irow );
		    kcol = PCOL( gb, grid );
		    ljb = LBj( gb, grid );
		    if ( mycol == kcol && mycol != pc ) ToSendR[ljb][pc] = YES;
		    pr = PROW( gb, grid );
		    lb = LBi( gb, grid );
		    if ( mycol == pc ) {
			if  ( myrow == pr ) {
			    ToSendD[lb] = YES;
			    /* Count nonzeros in entire block row. */
			    Urb_length[lb] += FstBlockC( gb+1 ) - irow;
			    if (rb_marker[lb] <= jb) {/* First see the block */
				rb_marker[lb] = jb + 1;
				Urb_fstnz[lb] += nsupc;
				++Ucbs[lb]; /* Number of column blocks
					       in block row lb. */
#if ( PRNTlevel>=1 )
				++nUblocks;
#endif
			    }
			    ToRecv[gb] = 1;
			} else ToRecv[gb] = 2; /* Do I need 0, 1, 2 ? */
		    }
		} /* for i ... */
	    } /* for j ... */
	} /* for jb ... */
	
	/* Set up the initial pointers for each block row in U. */
	nrbu = CEILING( nsupers, grid->nprow );/* Number of local block rows */
	for (lb = 0; lb < nrbu; ++lb) {
	    len = Urb_length[lb];
	    rb_marker[lb] = 0; /* Reset block marker. */
	    if ( len ) {
		/* Add room for descriptors */
		len1 = Urb_fstnz[lb] + BR_HEADER + Ucbs[lb] * UB_DESCRIPTOR;
		if ( !(index = intMalloc_dist(len1+1)) )
		    ABORT("Malloc fails for Uindex[].");
		Ufstnz_br_ptr[lb] = index;
		if ( !(Unzval_br_ptr[lb] = doubleMalloc_dist(len)) )
		    ABORT("Malloc fails for Unzval_br_ptr[*][].");
		mybufmax[2] = SUPERLU_MAX( mybufmax[2], len1 );
		mybufmax[3] = SUPERLU_MAX( mybufmax[3], len );
		index[0] = Ucbs[lb]; /* Number of column blocks */
		index[1] = len;      /* Total length of nzval[] */
		index[2] = len1;     /* Total length of index[] */
		index[len1] = -1;    /* End marker */
	    } else {
		Ufstnz_br_ptr[lb] = NULL;
		Unzval_br_ptr[lb] = NULL;
	    }
	    Urb_length[lb] = 0; /* Reset block length. */
	    Urb_indptr[lb] = BR_HEADER; /* Skip header in U index[]. */
 	    Urb_fstnz[lb] = BR_HEADER;
	} /* for lb ... */

	SUPERLU_FREE(Ucbs);

#if ( PROFlevel>=1 )
	t = SuperLU_timer_() - t;
	if ( !iam) printf(".. Phase 2 - setup U strut time: %.2f\t\n", t);
#endif
#if ( PRNTlevel>=1 )
        mem_use -= 2.0*k * iword;
#endif
	/* Auxiliary arrays used to set up L block data structures.
	   They are freed on return.
	   k is the number of local row blocks.   */
	if ( !(Lrb_length = intCalloc_dist(k)) )
	    ABORT("Calloc fails for Lrb_length[].");
	if ( !(Lrb_number = intMalloc_dist(k)) )
	    ABORT("Malloc fails for Lrb_number[].");
	if ( !(Lrb_indptr = intMalloc_dist(k)) )
	    ABORT("Malloc fails for Lrb_indptr[].");
	if ( !(Lrb_valptr = intMalloc_dist(k)) )
	    ABORT("Malloc fails for Lrb_valptr[].");
	if (!(dense=doubleCalloc_dist(SUPERLU_MAX(1,((size_t)ldaspa)
              *sp_ienv_dist(3)))))
	    ABORT("Calloc fails for SPA dense[].");

	/* These counts will be used for triangular solves. */
	if ( !(fmod = intCalloc_dist(k)) )
	    ABORT("Calloc fails for fmod[].");
	if ( !(bmod = intCalloc_dist(k)) )
	    ABORT("Calloc fails for bmod[].");
#if ( PRNTlevel>=1 )	
	mem_use += 6.0*k*iword + ldaspa*sp_ienv_dist(3)*dword;
#endif
	k = CEILING( nsupers, grid->npcol );/* Number of local block columns */

	/* Pointers to the beginning of each block column of L. */
	if ( !(Lnzval_bc_ptr = (double**)SUPERLU_MALLOC(k * sizeof(double*))) )
	    ABORT("Malloc fails for Lnzval_bc_ptr[].");
	if ( !(Lrowind_bc_ptr = (int_t**)SUPERLU_MALLOC(k * sizeof(int_t*))) )
	    ABORT("Malloc fails for Lrowind_bc_ptr[].");
	Lrowind_bc_ptr[k-1] = NULL;

	/* These lists of processes will be used for triangular solves. */
	if ( !(fsendx_plist = (int_t **) SUPERLU_MALLOC(k*sizeof(int_t*))) )
	    ABORT("Malloc fails for fsendx_plist[].");
	len = k * grid->nprow;
	if ( !(index = intMalloc_dist(len)) )
	    ABORT("Malloc fails for fsendx_plist[0]");
	for (i = 0; i < len; ++i) index[i] = EMPTY;
	for (i = 0, j = 0; i < k; ++i, j += grid->nprow)
	    fsendx_plist[i] = &index[j];
	if ( !(bsendx_plist = (int_t **) SUPERLU_MALLOC(k*sizeof(int_t*))) )
	    ABORT("Malloc fails for bsendx_plist[].");
	if ( !(index = intMalloc_dist(len)) )
	    ABORT("Malloc fails for bsendx_plist[0]");
	for (i = 0; i < len; ++i) index[i] = EMPTY;
	for (i = 0, j = 0; i < k; ++i, j += grid->nprow)
	    bsendx_plist[i] = &index[j];
#if ( PRNTlevel>=1 )
	mem_use += 4.0*k*sizeof(int_t*) + 2.0*len*iword;
#endif
	/*------------------------------------------------------------
	  PROPAGATE ROW SUBSCRIPTS AND VALUES OF A INTO L AND U BLOCKS.
	  THIS ACCOUNTS FOR ONE-PASS PROCESSING OF A, L AND U.
	  ------------------------------------------------------------*/

	for (jb = 0; jb < nsupers; ++jb) {
	    pc = PCOL( jb, grid );
	    if ( mycol == pc ) { /* Block column jb in my process column */
		fsupc = FstBlockC( jb );
		nsupc = SuperSize( jb );
		ljb = LBj( jb, grid ); /* Local block number */
		
		/* Scatter A into SPA. */
		for (j = fsupc, dense_col = dense; j < FstBlockC( jb+1 ); ++j){
		    for (i = xa_begin[j]; i < xa_end[j]; ++i) {
			irow = asub[i];
			gb = BlockNum( irow );
			if ( myrow == PROW( gb, grid ) ) {
			    lb = LBi( gb, grid );
			    irow = ilsum[lb] + irow - FstBlockC( gb );
			    dense_col[irow] = a[i];
			}
		    }
		    dense_col += ldaspa;
		}

		jbrow = PROW( jb, grid );

#if ( PROFlevel>=1 )
		t = SuperLU_timer_();
#endif
		/*------------------------------------------------
		 * SET UP U BLOCKS.
		 *------------------------------------------------*/
		kseen = 0;
		dense_col = dense;
		/* Loop through each column in the block column. */
		for (j = fsupc; j < FstBlockC( jb+1 ); ++j) {
		    istart = xusub[j];
		    /* NOTE: Only the first nonzero index of the segment
		       is stored in usub[]. */
		    for (i = istart; i < xusub[j+1]; ++i) {
			irow = usub[i]; /* First nonzero in the segment. */
			gb = BlockNum( irow );
			pr = PROW( gb, grid );
			if ( pr != jbrow &&
			     myrow == jbrow &&  /* diag. proc. owning jb */
			     bsendx_plist[ljb][pr] == EMPTY ) {
			    bsendx_plist[ljb][pr] = YES;
			    ++nbsendx;
                        }
			if ( myrow == pr ) {
			    lb = LBi( gb, grid ); /* Local block number */
			    index = Ufstnz_br_ptr[lb];
			    uval = Unzval_br_ptr[lb];
			    fsupc1 = FstBlockC( gb+1 );
			    if (rb_marker[lb] <= jb) { /* First time see 
							  the block       */
				rb_marker[lb] = jb + 1;
				Urb_indptr[lb] = Urb_fstnz[lb];;
				index[Urb_indptr[lb]] = jb; /* Descriptor */
				Urb_indptr[lb] += UB_DESCRIPTOR;
				/* Record the first location in index[] of the
				   next block */
				Urb_fstnz[lb] = Urb_indptr[lb] + nsupc;
				len = Urb_indptr[lb];/* Start fstnz in index */
				index[len-1] = 0;
				for (k = 0; k < nsupc; ++k)
				    index[len+k] = fsupc1;
				if ( gb != jb )/* Exclude diagonal block. */
				    ++bmod[lb];/* Mod. count for back solve */
				if ( kseen == 0 && myrow != jbrow ) {
				    ++nbrecvx;
				    kseen = 1;
				}
			    } else { /* Already saw the block */
				len = Urb_indptr[lb];/* Start fstnz in index */
			    }
			    jj = j - fsupc;
			    index[len+jj] = irow;
			    /* Load the numerical values */
			    k = fsupc1 - irow; /* No. of nonzeros in segment */
			    index[len-1] += k; /* Increment block length in
						  Descriptor */
			    irow = ilsum[lb] + irow - FstBlockC( gb );
			    for (ii = 0; ii < k; ++ii) {
				uval[Urb_length[lb]++] = dense_col[irow + ii];
				dense_col[irow + ii] = zero;
			    }
			} /* if myrow == pr ... */
		    } /* for i ... */
                    dense_col += ldaspa;
		} /* for j ... */

#if ( PROFlevel>=1 )
		t_u += SuperLU_timer_() - t;
		t = SuperLU_timer_();
#endif

		/*------------------------------------------------
		 * SET UP L BLOCKS.
		 *------------------------------------------------*/

		/* Count number of blocks and length of each block. */
		nrbl = 0;
		len = 0; /* Number of row subscripts I own. */
		kseen = 0;
		istart = xlsub[fsupc];
		for (i = istart; i < xlsub[fsupc+1]; ++i) {
		    irow = lsub[i];
		    gb = BlockNum( irow ); /* Global block number */
		    pr = PROW( gb, grid ); /* Process row owning this block */
		    if ( pr != jbrow &&
			 myrow == jbrow &&  /* diag. proc. owning jb */
			 fsendx_plist[ljb][pr] == EMPTY /* first time */ ) {
			fsendx_plist[ljb][pr] = YES;
			++nfsendx;
                    }
		    if ( myrow == pr ) {
			lb = LBi( gb, grid );  /* Local block number */
			if (rb_marker[lb] <= jb) { /* First see this block */
			    rb_marker[lb] = jb + 1;
			    Lrb_length[lb] = 1;
			    Lrb_number[nrbl++] = gb;
			    if ( gb != jb ) /* Exclude diagonal block. */
				++fmod[lb]; /* Mod. count for forward solve */
			    if ( kseen == 0 && myrow != jbrow ) {
				++nfrecvx;
				kseen = 1;
			    }
#if ( PRNTlevel>=1 )
			    ++nLblocks;
#endif
			} else {
			    ++Lrb_length[lb];
			}
			++len;
		    }
		} /* for i ... */

		if ( nrbl ) { /* Do not ensure the blocks are sorted! */
		    /* Set up the initial pointers for each block in 
		       index[] and nzval[]. */
		    /* Add room for descriptors */
		    len1 = len + BC_HEADER + nrbl * LB_DESCRIPTOR;
		    if ( !(index = intMalloc_dist(len1)) ) 
			ABORT("Malloc fails for index[]");
		    Lrowind_bc_ptr[ljb] = index;
		    if (!(Lnzval_bc_ptr[ljb] = doubleMalloc_dist(((size_t)len)*nsupc))) {
			fprintf(stderr, "col block " IFMT " ", jb);
			ABORT("Malloc fails for Lnzval_bc_ptr[*][]");
		    }
		    mybufmax[0] = SUPERLU_MAX( mybufmax[0], len1 );
		    mybufmax[1] = SUPERLU_MAX( mybufmax[1], len*nsupc );
		    mybufmax[4] = SUPERLU_MAX( mybufmax[4], len );
		    index[0] = nrbl;  /* Number of row blocks */
		    index[1] = len;   /* LDA of the nzval[] */
		    next_lind = BC_HEADER;
		    next_lval = 0;
		    for (k = 0; k < nrbl; ++k) {
			gb = Lrb_number[k];
			lb = LBi( gb, grid );
			len = Lrb_length[lb];
			Lrb_length[lb] = 0;  /* Reset vector of block length */
			index[next_lind++] = gb; /* Descriptor */
			index[next_lind++] = len; 
			Lrb_indptr[lb] = next_lind;
			Lrb_valptr[lb] = next_lval;
			next_lind += len;
			next_lval += len;
		    }
		    /* Propagate the compressed row subscripts to Lindex[], and
		       the initial values of A from SPA into Lnzval[]. */
		    lusup = Lnzval_bc_ptr[ljb];
		    len = index[1];  /* LDA of lusup[] */
		    for (i = istart; i < xlsub[fsupc+1]; ++i) {
			irow = lsub[i];
			gb = BlockNum( irow );
			if ( myrow == PROW( gb, grid ) ) {
			    lb = LBi( gb, grid );
			    k = Lrb_indptr[lb]++; /* Random access a block */
			    index[k] = irow;
			    k = Lrb_valptr[lb]++;
			    irow = ilsum[lb] + irow - FstBlockC( gb );
			    for (j = 0, dense_col = dense; j < nsupc; ++j) {
				lusup[k] = dense_col[irow];
				dense_col[irow] = 0.0;
				k += len;
				dense_col += ldaspa;
			    }
			}
		    } /* for i ... */
		} else {
		    Lrowind_bc_ptr[ljb] = NULL;
		    Lnzval_bc_ptr[ljb] = NULL;
		} /* if nrbl ... */
#if ( PROFlevel>=1 )
		t_l += SuperLU_timer_() - t;
#endif
	    } /* if mycol == pc */

	} /* for jb ... */

	Llu->Lrowind_bc_ptr = Lrowind_bc_ptr;
	Llu->Lnzval_bc_ptr = Lnzval_bc_ptr;
	Llu->Ufstnz_br_ptr = Ufstnz_br_ptr;
	Llu->Unzval_br_ptr = Unzval_br_ptr;
	Llu->ToRecv = ToRecv;
	Llu->ToSendD = ToSendD;
	Llu->ToSendR = ToSendR;
	Llu->fmod = fmod;
	Llu->fsendx_plist = fsendx_plist;
	Llu->nfrecvx = nfrecvx;
	Llu->nfsendx = nfsendx;
	Llu->bmod = bmod;
	Llu->bsendx_plist = bsendx_plist;
	Llu->nbrecvx = nbrecvx;
	Llu->nbsendx = nbsendx;
	Llu->ilsum = ilsum;
	Llu->ldalsum = ldaspa;
	
#if ( PRNTlevel>=1 )
	if ( !iam ) printf(".. # L blocks " IFMT "\t# U blocks " IFMT "\n",
			   nLblocks, nUblocks);
#endif

	SUPERLU_FREE(rb_marker);
	SUPERLU_FREE(Urb_fstnz);
	SUPERLU_FREE(Urb_length);
	SUPERLU_FREE(Urb_indptr);
	SUPERLU_FREE(Lrb_length);
	SUPERLU_FREE(Lrb_number);
	SUPERLU_FREE(Lrb_indptr);
	SUPERLU_FREE(Lrb_valptr);
	SUPERLU_FREE(dense);

	k = CEILING( nsupers, grid->nprow );/* Number of local block rows */
	if ( !(Llu->mod_bit = intMalloc_dist(k)) )
	    ABORT("Malloc fails for mod_bit[].");

	/* Find the maximum buffer size. */
	MPI_Allreduce(mybufmax, Llu->bufmax, NBUFFERS, mpi_int_t, 
		      MPI_MAX, grid->comm);

#if ( PROFlevel>=1 )
	if ( !iam ) printf(".. 1st distribute time:\n "
			   "\tL\t%.2f\n\tU\t%.2f\n"
			   "\tu_blks %d\tnrbu %d\n--------\n",
  			   t_l, t_u, u_blks, nrbu);
#endif

    } /* else fact != SamePattern_SameRowPerm */

#if ( DEBUGlevel>=1 )
    /* Memory allocated but not freed:
       ilsum, fmod, fsendx_plist, bmod, bsendx_plist  */
    CHECK_MALLOC(iam, "Exit ddistribute()");
#endif

    return (mem_use);
} /* DDISTRIBUTE */
示例#4
0
void
pzgsrfs_ABXglobal(int_t n, SuperMatrix *A, double anorm, LUstruct_t *LUstruct,
		  gridinfo_t *grid, doublecomplex *B, int_t ldb,
		  doublecomplex *X, int_t ldx, int nrhs, double *berr,
		  SuperLUStat_t *stat, int *info)
{
/* 
 * Purpose
 * =======
 *
 * pzgsrfs_ABXglobal improves the computed solution to a system of linear   
 * equations and provides error bounds and backward error estimates
 * for the solution. 
 *
 * Arguments
 * =========
 *
 * n      (input) int (global)
 *        The order of the system of linear equations.
 *
 * A      (input) SuperMatrix*
 *	  The original matrix A, or the scaled A if equilibration was done.
 *        A is also permuted into the form Pc*Pr*A*Pc', where Pr and Pc
 *        are permutation matrices. The type of A can be:
 *        Stype = NCP; Dtype = Z; Mtype = GE.
 *
 *        NOTE: Currently, A must reside in all processes when calling
 *              this routine.
 *
 * anorm  (input) double
 *        The norm of the original matrix A, or the scaled A if
 *        equilibration was done.
 *
 * LUstruct (input) LUstruct_t*
 *        The distributed data structures storing L and U factors.
 *        The L and U factors are obtained from pzgstrf for
 *        the possibly scaled and permuted matrix A.
 *        See superlu_ddefs.h for the definition of 'LUstruct_t'.
 *
 * grid   (input) gridinfo_t*
 *        The 2D process mesh. It contains the MPI communicator, the number
 *        of process rows (NPROW), the number of process columns (NPCOL),
 *        and my process rank. It is an input argument to all the
 *        parallel routines.
 *        Grid can be initialized by subroutine SUPERLU_GRIDINIT.
 *        See superlu_ddefs.h for the definition of 'gridinfo_t'.
 *
 * B      (input) doublecomplex* (global)
 *        The N-by-NRHS right-hand side matrix of the possibly equilibrated
 *        and row permuted system.
 *       
 *        NOTE: Currently, B must reside on all processes when calling
 *              this routine.
 *
 * ldb    (input) int (global)
 *        Leading dimension of matrix B.
 *
 * X      (input/output) doublecomplex* (global)
 *        On entry, the solution matrix X, as computed by pzgstrs.
 *        On exit, the improved solution matrix X.
 *        If DiagScale = COL or BOTH, X should be premultiplied by diag(C)
 *        in order to obtain the solution to the original system.
 *
 *        NOTE: Currently, X must reside on all processes when calling
 *              this routine.
 *
 * ldx    (input) int (global)
 *        Leading dimension of matrix X.
 *
 * nrhs   (input) int
 *        Number of right-hand sides.
 *
 * berr   (output) double*, dimension (nrhs)
 *         The componentwise relative backward error of each solution   
 *         vector X(j) (i.e., the smallest relative change in   
 *         any element of A or B that makes X(j) an exact solution).
 *
 * stat   (output) SuperLUStat_t*
 *        Record the statistics about the refinement steps.
 *        See util.h for the definition of SuperLUStat_t.
 *
 * info   (output) int*
 *        = 0: successful exit
 *        < 0: if info = -i, the i-th argument had an illegal value
 *        
 * Internal Parameters   
 * ===================   
 *
 * ITMAX is the maximum number of steps of iterative refinement.   
 *
 */

#define ITMAX 20
    
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    LocalLU_t *Llu = LUstruct->Llu;
    /* 
     * Data structures used by matrix-vector multiply routine.
     */
    int_t  N_update; /* Number of variables updated on this process */
    int_t  *update;  /* vector elements (global index) updated 
			on this processor.                     */
    int_t  *bindx;
    doublecomplex *val;
    int_t *mv_sup_to_proc;  /* Supernode to process mapping in
			       matrix-vector multiply.  */
    /*-- end data structures for matrix-vector multiply --*/
    doublecomplex *b, *ax, *R, *B_col, *temp, *work, *X_col,
                  *x_trs, *dx_trs;
    double *rwork;
    int_t count, ii, j, jj, k, knsupc, lk, lwork,
          nprow, nsupers, notran, nz, p;
    int   i, iam, pkk;
    int_t *ilsum, *xsup;
    double eps, lstres;
    double s, safmin, safe1, safe2;

    /* NEW STUFF */
    int_t num_diag_procs, *diag_procs; /* Record diagonal process numbers. */
    int_t *diag_len; /* Length of the X vector on diagonal processes. */

    /*-- Function prototypes --*/
    extern void pzgstrs1(int_t, LUstruct_t *, gridinfo_t *,
			 doublecomplex *, int, SuperLUStat_t *, int *);
    extern double dlamch_(char *);
    
    /* Test the input parameters. */
    *info = 0;
    if ( n < 0 ) *info = -1;
    else if ( A->nrow != A->ncol || A->nrow < 0 ||
	      A->Stype != SLU_NCP || A->Dtype != SLU_Z || A->Mtype != SLU_GE )
	*info = -2;
    else if ( ldb < SUPERLU_MAX(0, n) ) *info = -10;
    else if ( ldx < SUPERLU_MAX(0, n) )	*info = -12;
    else if ( nrhs < 0 ) *info = -13;
    if (*info != 0) {
	i = -(*info);
	xerbla_("pzgsrfs_ABXglobal", &i);
	return;
    }

    /* Quick return if possible. */
    if ( n == 0 || nrhs == 0 ) {
	return;
    }

    /* Initialization. */
    iam = grid->iam;
    nprow = grid->nprow;
    nsupers = Glu_persist->supno[n-1] + 1;
    xsup = Glu_persist->xsup;
    ilsum = Llu->ilsum;
    notran = 1;

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter pzgsrfs_ABXglobal()");
#endif

    get_diag_procs(n, Glu_persist, grid, &num_diag_procs,
		   &diag_procs, &diag_len);
#if ( PRNTlevel>=1 )
    if ( !iam ) {
	printf(".. number of diag processes = %d\n", num_diag_procs);
	PrintInt10("diag_procs", num_diag_procs, diag_procs);
	PrintInt10("diag_len", num_diag_procs, diag_len);
    }
#endif

    if ( !(mv_sup_to_proc = intCalloc_dist(nsupers)) )
	ABORT("Calloc fails for mv_sup_to_proc[]");

    pzgsmv_AXglobal_setup(A, Glu_persist, grid, &N_update, &update,
			  &val, &bindx, mv_sup_to_proc);

    i = CEILING( nsupers, nprow ); /* Number of local block rows */
    ii = Llu->ldalsum + i * XK_H;
    k = SUPERLU_MAX(N_update, sp_ienv_dist(3));
    jj = diag_len[0];
    for (j = 1; j < num_diag_procs; ++j) jj = SUPERLU_MAX( jj, diag_len[j] );
    jj = SUPERLU_MAX( jj, N_update );
    lwork = N_update         /* For ax and R */
	  + ii               /* For dx_trs */
	  + ii               /* For x_trs */
          + k                /* For b */
	  + jj;              /* for temp */
    if ( !(work = doublecomplexMalloc_dist(lwork)) )
	ABORT("Malloc fails for work[]");
    ax = R = work;
    dx_trs = work + N_update;
    x_trs  = dx_trs + ii;
    b      = x_trs + ii;
    temp   = b + k;
    if ( !(rwork = SUPERLU_MALLOC(N_update * sizeof(double))) )
	ABORT("Malloc fails for rwork[]");

#if ( DEBUGlevel>=2 )
    {
	doublecomplex *dwork = doublecomplexMalloc_dist(n);
	for (i = 0; i < n; ++i) {
	    if ( i & 1 ) dwork[i].r = 1.;
	    else dwork[i].r = 2.;
	    dwork[i].i = 0.;
	}
	/* Check correctness of matrix-vector multiply. */
	pzgsmv_AXglobal(N_update, update, val, bindx, dwork, ax);
	PrintDouble5("Mult A*x", N_update, ax);
	SUPERLU_FREE(dwork);
    }
#endif


    /* NZ = maximum number of nonzero elements in each row of A, plus 1 */
    nz     = A->ncol + 1;
    eps    = dlamch_("Epsilon");
    safmin = dlamch_("Safe minimum");
    safe1  = nz * safmin;
    safe2  = safe1 / eps;

#if ( DEBUGlevel>=1 )
    if ( !iam ) printf(".. eps = %e\tanorm = %e\tsafe1 = %e\tsafe2 = %e\n",
		       eps, anorm, safe1, safe2);
#endif

    /* Do for each right-hand side ... */
    for (j = 0; j < nrhs; ++j) {
	count = 0;
	lstres = 3.;

	/* Copy X into x on the diagonal processes. */
	B_col = &B[j*ldb];
	X_col = &X[j*ldx];
	for (p = 0; p < num_diag_procs; ++p) {
	    pkk = diag_procs[p];
	    if ( iam == pkk ) {
		for (k = p; k < nsupers; k += num_diag_procs) {
		    knsupc = SuperSize( k );
		    lk = LBi( k, grid );
		    ii = ilsum[lk] + (lk+1)*XK_H;
		    jj = FstBlockC( k );
		    for (i = 0; i < knsupc; ++i) x_trs[i+ii] = X_col[i+jj];
		    dx_trs[ii-XK_H].r = k;/* Block number prepended in header. */
		}
	    }
	}
	/* Copy B into b distributed the same way as matrix-vector product. */
	ii = update[0];
	for (i = 0; i < N_update; ++i) b[i] = B_col[i + ii];

	while (1) { /* Loop until stopping criterion is satisfied. */

	    /* Compute residual R = B - op(A) * X,   
	       where op(A) = A, A**T, or A**H, depending on TRANS. */

	    /* Matrix-vector multiply. */
	    pzgsmv_AXglobal(N_update, update, val, bindx, X_col, ax);
	    
	    /* Compute residual. */
	    for (i = 0; i < N_update; ++i) z_sub(&R[i], &b[i], &ax[i]);

	    /* Compute abs(op(A))*abs(X) + abs(B). */
	    pzgsmv_AXglobal_abs(N_update, update, val, bindx, X_col, rwork);
	    for (i = 0; i < N_update; ++i) rwork[i] += z_abs1(&b[i]);
	    
	    s = 0.0;
	    for (i = 0; i < N_update; ++i) {
		if ( rwork[i] > safe2 )
		    s = SUPERLU_MAX(s, z_abs1(&R[i]) / rwork[i]);
		else
		    s = SUPERLU_MAX(s, (z_abs1(&R[i])+safe1)/(rwork[i]+safe1));
	    }
	    MPI_Allreduce( &s, &berr[j], 1, MPI_DOUBLE, MPI_MAX, grid->comm );
		
#if ( PRNTlevel>= 1 )
	    if ( !iam )
		printf("(%2d) .. Step %2d: berr[j] = %e\n", iam, count, berr[j]);
#endif
	    if ( berr[j] > eps && berr[j] * 2 <= lstres && count < ITMAX ) {
		/* Compute new dx. */
		redist_all_to_diag(n, R, Glu_persist, Llu, grid,
				   mv_sup_to_proc, dx_trs);
		pzgstrs1(n, LUstruct, grid, dx_trs, 1, stat, info);

		/* Update solution. */
		for (p = 0; p < num_diag_procs; ++p) 
		    if ( iam == diag_procs[p] )
			for (k = p; k < nsupers; k += num_diag_procs) {
			    lk = LBi( k, grid );
			    ii = ilsum[lk] + (lk+1)*XK_H;
			    knsupc = SuperSize( k );
			    for (i = 0; i < knsupc; ++i)
				z_add(&x_trs[i + ii], &x_trs[i + ii], 
				      &dx_trs[i + ii]);
			}
		lstres = berr[j];
		++count;
		/* Transfer x_trs (on diagonal processes) into X
		   (on all processes). */
		gather_1rhs_diag_to_all(n, x_trs, Glu_persist, Llu, grid, 
					num_diag_procs, diag_procs, diag_len,
					X_col, temp);
	    } else {
		break;
	    }
	} /* end while */

	stat->RefineSteps = count;

    } /* for j ... */


    /* Deallocate storage used by matrix-vector multiplication. */
    SUPERLU_FREE(diag_procs);
    SUPERLU_FREE(diag_len);
    if ( N_update ) {
	SUPERLU_FREE(update);
	SUPERLU_FREE(bindx);
	SUPERLU_FREE(val);
    }
    SUPERLU_FREE(mv_sup_to_proc);
    SUPERLU_FREE(work);
    SUPERLU_FREE(rwork);

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Exit pzgsrfs_ABXglobal()");
#endif

} /* PZGSRFS_ABXGLOBAL */
示例#5
0
void
pdgssvx(superlu_options_t *options, SuperMatrix *A, 
	ScalePermstruct_t *ScalePermstruct,
	double B[], int ldb, int nrhs, gridinfo_t *grid,
	LUstruct_t *LUstruct, SOLVEstruct_t *SOLVEstruct, double *berr,
	SuperLUStat_t *stat, int *info)
{
/* 
 * -- Distributed SuperLU routine (version 2.2) --
 * Lawrence Berkeley National Lab, Univ. of California Berkeley.
 * November 1, 2007
 * Feburary 20, 2008
 *
 *
 * Purpose
 * =======
 *
 * PDGSSVX solves a system of linear equations A*X=B,
 * by using Gaussian elimination with "static pivoting" to
 * compute the LU factorization of A.
 *
 * Static pivoting is a technique that combines the numerical stability
 * of partial pivoting with the scalability of Cholesky (no pivoting),
 * to run accurately and efficiently on large numbers of processors.
 * See our paper at http://www.nersc.gov/~xiaoye/SuperLU/ for a detailed
 * description of the parallel algorithms.
 *
 * The input matrices A and B are distributed by block rows.
 * Here is a graphical illustration (0-based indexing):
 *
 *                        A                B
 *               0 ---------------       ------
 *                   |           |        |  |
 *                   |           |   P0   |  |
 *                   |           |        |  |
 *                 ---------------       ------
 *        - fst_row->|           |        |  |
 *        |          |           |        |  |
 *       m_loc       |           |   P1   |  |
 *        |          |           |        |  |
 *        -          |           |        |  |
 *                 ---------------       ------
 *                   |    .      |        |. |
 *                   |    .      |        |. |
 *                   |    .      |        |. |
 *                 ---------------       ------
 * 
 * where, fst_row is the row number of the first row,
 *        m_loc is the number of rows local to this processor
 * These are defined in the 'SuperMatrix' structure, see supermatrix.h.
 *
 *
 * Here are the options for using this code:
 *
 *   1. Independent of all the other options specified below, the
 *      user must supply
 *
 *      -  B, the matrix of right-hand sides, distributed by block rows,
 *            and its dimensions ldb (local) and nrhs (global)
 *      -  grid, a structure describing the 2D processor mesh
 *      -  options->IterRefine, which determines whether or not to
 *            improve the accuracy of the computed solution using 
 *            iterative refinement
 *
 *      On output, B is overwritten with the solution X.
 *
 *   2. Depending on options->Fact, the user has four options
 *      for solving A*X=B. The standard option is for factoring
 *      A "from scratch". (The other options, described below,
 *      are used when A is sufficiently similar to a previously 
 *      solved problem to save time by reusing part or all of 
 *      the previous factorization.)
 *
 *      -  options->Fact = DOFACT: A is factored "from scratch"
 *
 *      In this case the user must also supply
 *
 *        o  A, the input matrix
 *
 *        as well as the following options to determine what matrix to
 *        factorize.
 *
 *        o  options->Equil,   to specify how to scale the rows and columns
 *                             of A to "equilibrate" it (to try to reduce its
 *                             condition number and so improve the
 *                             accuracy of the computed solution)
 *
 *        o  options->RowPerm, to specify how to permute the rows of A
 *                             (typically to control numerical stability)
 *
 *        o  options->ColPerm, to specify how to permute the columns of A
 *                             (typically to control fill-in and enhance
 *                             parallelism during factorization)
 *
 *        o  options->ReplaceTinyPivot, to specify how to deal with tiny
 *                             pivots encountered during factorization
 *                             (to control numerical stability)
 *
 *      The outputs returned include
 *         
 *        o  ScalePermstruct,  modified to describe how the input matrix A
 *                             was equilibrated and permuted:
 *          .  ScalePermstruct->DiagScale, indicates whether the rows and/or
 *                                         columns of A were scaled
 *          .  ScalePermstruct->R, array of row scale factors
 *          .  ScalePermstruct->C, array of column scale factors
 *          .  ScalePermstruct->perm_r, row permutation vector
 *          .  ScalePermstruct->perm_c, column permutation vector
 *
 *          (part of ScalePermstruct may also need to be supplied on input,
 *           depending on options->RowPerm and options->ColPerm as described 
 *           later).
 *
 *        o  A, the input matrix A overwritten by the scaled and permuted
 *              matrix diag(R)*A*diag(C)*Pc^T, where 
 *              Pc is the row permutation matrix determined by
 *                  ScalePermstruct->perm_c
 *              diag(R) and diag(C) are diagonal scaling matrices determined
 *                  by ScalePermstruct->DiagScale, ScalePermstruct->R and 
 *                  ScalePermstruct->C
 *
 *        o  LUstruct, which contains the L and U factorization of A1 where
 *
 *                A1 = Pc*Pr*diag(R)*A*diag(C)*Pc^T = L*U
 *
 *               (Note that A1 = Pc*Pr*Aout, where Aout is the matrix stored
 *                in A on output.)
 *
 *   3. The second value of options->Fact assumes that a matrix with the same
 *      sparsity pattern as A has already been factored:
 *     
 *      -  options->Fact = SamePattern: A is factored, assuming that it has
 *            the same nonzero pattern as a previously factored matrix. In
 *            this case the algorithm saves time by reusing the previously
 *            computed column permutation vector stored in
 *            ScalePermstruct->perm_c and the "elimination tree" of A
 *            stored in LUstruct->etree
 *
 *      In this case the user must still specify the following options
 *      as before:
 *
 *        o  options->Equil
 *        o  options->RowPerm
 *        o  options->ReplaceTinyPivot
 *
 *      but not options->ColPerm, whose value is ignored. This is because the
 *      previous column permutation from ScalePermstruct->perm_c is used as
 *      input. The user must also supply 
 *
 *        o  A, the input matrix
 *        o  ScalePermstruct->perm_c, the column permutation
 *        o  LUstruct->etree, the elimination tree
 *
 *      The outputs returned include
 *         
 *        o  A, the input matrix A overwritten by the scaled and permuted
 *              matrix as described above
 *        o  ScalePermstruct, modified to describe how the input matrix A was
 *                            equilibrated and row permuted
 *        o  LUstruct, modified to contain the new L and U factors
 *
 *   4. The third value of options->Fact assumes that a matrix B with the same
 *      sparsity pattern as A has already been factored, and where the
 *      row permutation of B can be reused for A. This is useful when A and B
 *      have similar numerical values, so that the same row permutation
 *      will make both factorizations numerically stable. This lets us reuse
 *      all of the previously computed structure of L and U.
 *
 *      -  options->Fact = SamePattern_SameRowPerm: A is factored,
 *            assuming not only the same nonzero pattern as the previously
 *            factored matrix B, but reusing B's row permutation.
 *
 *      In this case the user must still specify the following options
 *      as before:
 *
 *        o  options->Equil
 *        o  options->ReplaceTinyPivot
 *
 *      but not options->RowPerm or options->ColPerm, whose values are
 *      ignored. This is because the permutations from ScalePermstruct->perm_r
 *      and ScalePermstruct->perm_c are used as input.
 *
 *      The user must also supply 
 *
 *        o  A, the input matrix
 *        o  ScalePermstruct->DiagScale, how the previous matrix was row
 *                                       and/or column scaled
 *        o  ScalePermstruct->R, the row scalings of the previous matrix,
 *                               if any
 *        o  ScalePermstruct->C, the columns scalings of the previous matrix, 
 *                               if any
 *        o  ScalePermstruct->perm_r, the row permutation of the previous
 *                                    matrix
 *        o  ScalePermstruct->perm_c, the column permutation of the previous 
 *                                    matrix
 *        o  all of LUstruct, the previously computed information about
 *                            L and U (the actual numerical values of L and U
 *                            stored in LUstruct->Llu are ignored)
 *
 *      The outputs returned include
 *         
 *        o  A, the input matrix A overwritten by the scaled and permuted
 *              matrix as described above
 *        o  ScalePermstruct,  modified to describe how the input matrix A was
 *                             equilibrated (thus ScalePermstruct->DiagScale,
 *                             R and C may be modified)
 *        o  LUstruct, modified to contain the new L and U factors
 *
 *   5. The fourth and last value of options->Fact assumes that A is
 *      identical to a matrix that has already been factored on a previous 
 *      call, and reuses its entire LU factorization
 *
 *      -  options->Fact = Factored: A is identical to a previously
 *            factorized matrix, so the entire previous factorization
 *            can be reused.
 *
 *      In this case all the other options mentioned above are ignored
 *      (options->Equil, options->RowPerm, options->ColPerm, 
 *       options->ReplaceTinyPivot)
 *
 *      The user must also supply 
 *
 *        o  A, the unfactored matrix, only in the case that iterative
 *              refinment is to be done (specifically A must be the output
 *              A from the previous call, so that it has been scaled and permuted)
 *        o  all of ScalePermstruct
 *        o  all of LUstruct, including the actual numerical values of
 *           L and U
 *
 *      all of which are unmodified on output.
 *         
 * Arguments
 * =========
 *
 * options (input) superlu_options_t* (global)
 *         The structure defines the input parameters to control
 *         how the LU decomposition will be performed.
 *         The following fields should be defined for this structure:
 *         
 *         o Fact (fact_t)
 *           Specifies whether or not the factored form of the matrix
 *           A is supplied on entry, and if not, how the matrix A should
 *           be factorized based on the previous history.
 *
 *           = DOFACT: The matrix A will be factorized from scratch.
 *                 Inputs:  A
 *                          options->Equil, RowPerm, ColPerm, ReplaceTinyPivot
 *                 Outputs: modified A
 *                             (possibly row and/or column scaled and/or 
 *                              permuted)
 *                          all of ScalePermstruct
 *                          all of LUstruct
 *
 *           = SamePattern: the matrix A will be factorized assuming
 *             that a factorization of a matrix with the same sparsity
 *             pattern was performed prior to this one. Therefore, this
 *             factorization will reuse column permutation vector 
 *             ScalePermstruct->perm_c and the elimination tree
 *             LUstruct->etree
 *                 Inputs:  A
 *                          options->Equil, RowPerm, ReplaceTinyPivot
 *                          ScalePermstruct->perm_c
 *                          LUstruct->etree
 *                 Outputs: modified A
 *                             (possibly row and/or column scaled and/or 
 *                              permuted)
 *                          rest of ScalePermstruct (DiagScale, R, C, perm_r)
 *                          rest of LUstruct (GLU_persist, Llu)
 *
 *           = SamePattern_SameRowPerm: the matrix A will be factorized
 *             assuming that a factorization of a matrix with the same
 *             sparsity	pattern and similar numerical values was performed
 *             prior to this one. Therefore, this factorization will reuse
 *             both row and column scaling factors R and C, and the
 *             both row and column permutation vectors perm_r and perm_c,
 *             distributed data structure set up from the previous symbolic
 *             factorization.
 *                 Inputs:  A
 *                          options->Equil, ReplaceTinyPivot
 *                          all of ScalePermstruct
 *                          all of LUstruct
 *                 Outputs: modified A
 *                             (possibly row and/or column scaled and/or 
 *                              permuted)
 *                          modified LUstruct->Llu
 *           = FACTORED: the matrix A is already factored.
 *                 Inputs:  all of ScalePermstruct
 *                          all of LUstruct
 *
 *         o Equil (yes_no_t)
 *           Specifies whether to equilibrate the system.
 *           = NO:  no equilibration.
 *           = YES: scaling factors are computed to equilibrate the system:
 *                      diag(R)*A*diag(C)*inv(diag(C))*X = diag(R)*B.
 *                  Whether or not the system will be equilibrated depends
 *                  on the scaling of the matrix A, but if equilibration is
 *                  used, A is overwritten by diag(R)*A*diag(C) and B by
 *                  diag(R)*B.
 *
 *         o RowPerm (rowperm_t)
 *           Specifies how to permute rows of the matrix A.
 *           = NATURAL:   use the natural ordering.
 *           = LargeDiag: use the Duff/Koster algorithm to permute rows of
 *                        the original matrix to make the diagonal large
 *                        relative to the off-diagonal.
 *           = MY_PERMR:  use the ordering given in ScalePermstruct->perm_r
 *                        input by the user.
 *           
 *         o ColPerm (colperm_t)
 *           Specifies what type of column permutation to use to reduce fill.
 *           = NATURAL:       natural ordering.
 *           = MMD_AT_PLUS_A: minimum degree ordering on structure of A'+A.
 *           = MMD_ATA:       minimum degree ordering on structure of A'*A.
 *           = MY_PERMC:      the ordering given in ScalePermstruct->perm_c.
 *         
 *         o ReplaceTinyPivot (yes_no_t)
 *           = NO:  do not modify pivots
 *           = YES: replace tiny pivots by sqrt(epsilon)*norm(A) during 
 *                  LU factorization.
 *
 *         o IterRefine (IterRefine_t)
 *           Specifies how to perform iterative refinement.
 *           = NO:     no iterative refinement.
 *           = DOUBLE: accumulate residual in double precision.
 *           = EXTRA:  accumulate residual in extra precision.
 *
 *         NOTE: all options must be indentical on all processes when
 *               calling this routine.
 *
 * A (input/output) SuperMatrix* (local)
 *         On entry, matrix A in A*X=B, of dimension (A->nrow, A->ncol).
 *           The number of linear equations is A->nrow. The type of A must be:
 *           Stype = SLU_NR_loc; Dtype = SLU_D; Mtype = SLU_GE.
 *           That is, A is stored in distributed compressed row format.
 *           See supermatrix.h for the definition of 'SuperMatrix'.
 *           This routine only handles square A, however, the LU factorization
 *           routine PDGSTRF can factorize rectangular matrices.
 *         On exit, A may be overwtirren by diag(R)*A*diag(C)*Pc^T,
 *           depending on ScalePermstruct->DiagScale and options->ColPerm:
 *             if ScalePermstruct->DiagScale != NOEQUIL, A is overwritten by
 *                diag(R)*A*diag(C).
 *             if options->ColPerm != NATURAL, A is further overwritten by
 *                diag(R)*A*diag(C)*Pc^T.
 *           If all the above condition are true, the LU decomposition is
 *           performed on the matrix Pc*Pr*diag(R)*A*diag(C)*Pc^T.
 *
 * ScalePermstruct (input/output) ScalePermstruct_t* (global)
 *         The data structure to store the scaling and permutation vectors
 *         describing the transformations performed to the matrix A.
 *         It contains the following fields:
 *
 *         o DiagScale (DiagScale_t)
 *           Specifies the form of equilibration that was done.
 *           = NOEQUIL: no equilibration.
 *           = ROW:     row equilibration, i.e., A was premultiplied by
 *                      diag(R).
 *           = COL:     Column equilibration, i.e., A was postmultiplied
 *                      by diag(C).
 *           = BOTH:    both row and column equilibration, i.e., A was 
 *                      replaced by diag(R)*A*diag(C).
 *           If options->Fact = FACTORED or SamePattern_SameRowPerm,
 *           DiagScale is an input argument; otherwise it is an output
 *           argument.
 *
 *         o perm_r (int*)
 *           Row permutation vector, which defines the permutation matrix Pr;
 *           perm_r[i] = j means row i of A is in position j in Pr*A.
 *           If options->RowPerm = MY_PERMR, or
 *           options->Fact = SamePattern_SameRowPerm, perm_r is an
 *           input argument; otherwise it is an output argument.
 *
 *         o perm_c (int*)
 *           Column permutation vector, which defines the 
 *           permutation matrix Pc; perm_c[i] = j means column i of A is 
 *           in position j in A*Pc.
 *           If options->ColPerm = MY_PERMC or options->Fact = SamePattern
 *           or options->Fact = SamePattern_SameRowPerm, perm_c is an
 *           input argument; otherwise, it is an output argument.
 *           On exit, perm_c may be overwritten by the product of the input
 *           perm_c and a permutation that postorders the elimination tree
 *           of Pc*A'*A*Pc'; perm_c is not changed if the elimination tree
 *           is already in postorder.
 *
 *         o R (double*) dimension (A->nrow)
 *           The row scale factors for A.
 *           If DiagScale = ROW or BOTH, A is multiplied on the left by 
 *                          diag(R).
 *           If DiagScale = NOEQUIL or COL, R is not defined.
 *           If options->Fact = FACTORED or SamePattern_SameRowPerm, R is
 *           an input argument; otherwise, R is an output argument.
 *
 *         o C (double*) dimension (A->ncol)
 *           The column scale factors for A.
 *           If DiagScale = COL or BOTH, A is multiplied on the right by 
 *                          diag(C).
 *           If DiagScale = NOEQUIL or ROW, C is not defined.
 *           If options->Fact = FACTORED or SamePattern_SameRowPerm, C is
 *           an input argument; otherwise, C is an output argument.
 *         
 * B       (input/output) double* (local)
 *         On entry, the right-hand side matrix of dimension (m_loc, nrhs),
 *           where, m_loc is the number of rows stored locally on my
 *           process and is defined in the data structure of matrix A.
 *         On exit, the solution matrix if info = 0;
 *
 * ldb     (input) int (local)
 *         The leading dimension of matrix B.
 *
 * nrhs    (input) int (global)
 *         The number of right-hand sides.
 *         If nrhs = 0, only LU decomposition is performed, the forward
 *         and back substitutions are skipped.
 *
 * grid    (input) gridinfo_t* (global)
 *         The 2D process mesh. It contains the MPI communicator, the number
 *         of process rows (NPROW), the number of process columns (NPCOL),
 *         and my process rank. It is an input argument to all the
 *         parallel routines.
 *         Grid can be initialized by subroutine SUPERLU_GRIDINIT.
 *         See superlu_ddefs.h for the definition of 'gridinfo_t'.
 *
 * LUstruct (input/output) LUstruct_t*
 *         The data structures to store the distributed L and U factors.
 *         It contains the following fields:
 *
 *         o etree (int*) dimension (A->ncol) (global)
 *           Elimination tree of Pc*(A'+A)*Pc' or Pc*A'*A*Pc'.
 *           It is computed in sp_colorder() during the first factorization,
 *           and is reused in the subsequent factorizations of the matrices
 *           with the same nonzero pattern.
 *           On exit of sp_colorder(), the columns of A are permuted so that
 *           the etree is in a certain postorder. This postorder is reflected
 *           in ScalePermstruct->perm_c.
 *           NOTE:
 *           Etree is a vector of parent pointers for a forest whose vertices
 *           are the integers 0 to A->ncol-1; etree[root]==A->ncol.
 *
 *         o Glu_persist (Glu_persist_t*) (global)
 *           Global data structure (xsup, supno) replicated on all processes,
 *           describing the supernode partition in the factored matrices
 *           L and U:
 *	       xsup[s] is the leading column of the s-th supernode,
 *             supno[i] is the supernode number to which column i belongs.
 *
 *         o Llu (LocalLU_t*) (local)
 *           The distributed data structures to store L and U factors.
 *           See superlu_ddefs.h for the definition of 'LocalLU_t'.
 *
 * SOLVEstruct (input/output) SOLVEstruct_t*
 *         The data structure to hold the communication pattern used
 *         in the phases of triangular solution and iterative refinement.
 *         This pattern should be intialized only once for repeated solutions.
 *         If options->SolveInitialized = YES, it is an input argument.
 *         If options->SolveInitialized = NO and nrhs != 0, it is an output
 *         argument. See superlu_ddefs.h for the definition of 'SOLVEstruct_t'.
 *
 * berr    (output) double*, dimension (nrhs) (global)
 *         The componentwise relative backward error of each solution   
 *         vector X(j) (i.e., the smallest relative change in   
 *         any element of A or B that makes X(j) an exact solution).
 *
 * stat   (output) SuperLUStat_t*
 *        Record the statistics on runtime and floating-point operation count.
 *        See util.h for the definition of 'SuperLUStat_t'.
 *
 * info    (output) int*
 *         = 0: successful exit
 *         > 0: if info = i, and i is
 *             <= A->ncol: U(i,i) is exactly zero. The factorization has
 *                been completed, but the factor U is exactly singular,
 *                so the solution could not be computed.
 *             > A->ncol: number of bytes allocated when memory allocation
 *                failure occurred, plus A->ncol.
 *
 * See superlu_ddefs.h for the definitions of varioous data types.
 *
 */
    NRformat_loc *Astore;
    SuperMatrix GA;      /* Global A in NC format */
    NCformat *GAstore;
    double   *a_GA;
    SuperMatrix GAC;      /* Global A in NCP format (add n end pointers) */
    NCPformat *GACstore;
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    Glu_freeable_t *Glu_freeable;
            /* The nonzero structures of L and U factors, which are
	       replicated on all processrs.
	           (lsub, xlsub) contains the compressed subscript of
		                 supernodes in L.
          	   (usub, xusub) contains the compressed subscript of
		                 nonzero segments in U.
	      If options->Fact != SamePattern_SameRowPerm, they are 
	      computed by SYMBFACT routine, and then used by PDDISTRIBUTE
	      routine. They will be freed after PDDISTRIBUTE routine.
	      If options->Fact == SamePattern_SameRowPerm, these
	      structures are not used.                                  */
    fact_t   Fact;
    double   *a;
    int_t    *colptr, *rowind;
    int_t    *perm_r; /* row permutations from partial pivoting */
    int_t    *perm_c; /* column permutation vector */
    int_t    *etree;  /* elimination tree */
    int_t    *rowptr, *colind;  /* Local A in NR*/
    int_t    *rowind_loc, *colptr_loc;
    int_t    colequ, Equil, factored, job, notran, rowequ, need_value;
    int_t    i, iinfo, j, irow, m, n, nnz, permc_spec, dist_mem_use;
    int_t    nnz_loc, m_loc, fst_row, icol;
    int      iam;
    int      ldx;  /* LDA for matrix X (local). */
    char     equed[1], norm[1];
    double   *C, *R, *C1, *R1, amax, anorm, colcnd, rowcnd;
    double   *X, *b_col, *b_work, *x_col;
    double   t;
    static mem_usage_t num_mem_usage, symb_mem_usage;
#if ( PRNTlevel>= 2 )
    double   dmin, dsum, dprod;
#endif
    int_t procs;

    /* Structures needed for parallel symbolic factorization */
    int_t *sizes, *fstVtxSep, parSymbFact;
    int   noDomains, nprocs_num;
    MPI_Comm symb_comm; /* communicator for symbolic factorization */
    int   col, key; /* parameters for creating a new communicator */
    Pslu_freeable_t Pslu_freeable;
    float  flinfo;

    /* Initialization. */
    m       = A->nrow;
    n       = A->ncol;
    Astore  = (NRformat_loc *) A->Store;
    nnz_loc = Astore->nnz_loc;
    m_loc   = Astore->m_loc;
    fst_row = Astore->fst_row;
    a       = (double *) Astore->nzval;
    rowptr  = Astore->rowptr;
    colind  = Astore->colind;
    sizes   = NULL;
    fstVtxSep = NULL;
    symb_comm = MPI_COMM_NULL;

    /* Test the input parameters. */
    *info = 0;
    Fact = options->Fact;
    if ( Fact < 0 || Fact > FACTORED )
	*info = -1;
    else if ( options->RowPerm < 0 || options->RowPerm > MY_PERMR )
	*info = -1;
    else if ( options->ColPerm < 0 || options->ColPerm > MY_PERMC )
	*info = -1;
    else if ( options->IterRefine < 0 || options->IterRefine > EXTRA )
	*info = -1;
    else if ( options->IterRefine == EXTRA ) {
	*info = -1;
	fprintf(stderr, "Extra precise iterative refinement yet to support.");
    } else if ( A->nrow != A->ncol || A->nrow < 0 || A->Stype != SLU_NR_loc
		|| A->Dtype != SLU_D || A->Mtype != SLU_GE )
	*info = -2;
    else if ( ldb < m_loc )
	*info = -5;
    else if ( nrhs < 0 )
	*info = -6;
    if ( *info ) {
	i = -(*info);
	pxerbla("pdgssvx", grid, -*info);
	return;
    }

    factored = (Fact == FACTORED);
    Equil = (!factored && options->Equil == YES);
    notran = (options->Trans == NOTRANS);
    iam = grid->iam;
    job = 5;
    if ( factored || (Fact == SamePattern_SameRowPerm && Equil) ) {
	rowequ = (ScalePermstruct->DiagScale == ROW) ||
	         (ScalePermstruct->DiagScale == BOTH);
	colequ = (ScalePermstruct->DiagScale == COL) ||
	         (ScalePermstruct->DiagScale == BOTH);
    } else rowequ = colequ = FALSE;

    /* The following arrays are replicated on all processes. */
    perm_r = ScalePermstruct->perm_r;
    perm_c = ScalePermstruct->perm_c;
    etree = LUstruct->etree;
    R = ScalePermstruct->R;
    C = ScalePermstruct->C;
    /********/

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter pdgssvx()");
#endif

    /* Not factored & ask for equilibration */
    if ( Equil && Fact != SamePattern_SameRowPerm ) { 
	/* Allocate storage if not done so before. */
	switch ( ScalePermstruct->DiagScale ) {
	    case NOEQUIL:
		if ( !(R = (double *) doubleMalloc_dist(m)) )
		    ABORT("Malloc fails for R[].");
	        if ( !(C = (double *) doubleMalloc_dist(n)) )
		    ABORT("Malloc fails for C[].");
		ScalePermstruct->R = R;
		ScalePermstruct->C = C;
		break;
	    case ROW: 
	        if ( !(C = (double *) doubleMalloc_dist(n)) )
		    ABORT("Malloc fails for C[].");
		ScalePermstruct->C = C;
		break;
	    case COL: 
		if ( !(R = (double *) doubleMalloc_dist(m)) )
		    ABORT("Malloc fails for R[].");
		ScalePermstruct->R = R;
		break;
	}
    }

    /* ------------------------------------------------------------
       Diagonal scaling to equilibrate the matrix.
       ------------------------------------------------------------*/
    if ( Equil ) {
#if ( DEBUGlevel>=1 )
	CHECK_MALLOC(iam, "Enter equil");
#endif
	t = SuperLU_timer_();

	if ( Fact == SamePattern_SameRowPerm ) {
	    /* Reuse R and C. */
	    switch ( ScalePermstruct->DiagScale ) {
	      case NOEQUIL:
		break;
	      case ROW:
		irow = fst_row;
		for (j = 0; j < m_loc; ++j) {
		    for (i = rowptr[j]; i < rowptr[j+1]; ++i) {
			a[i] *= R[irow];       /* Scale rows. */
		    }
		    ++irow;
		}
		break;
	      case COL:
		for (j = 0; j < m_loc; ++j)
		    for (i = rowptr[j]; i < rowptr[j+1]; ++i){
		        icol = colind[i];
			a[i] *= C[icol];          /* Scale columns. */
		    }
		break;
	      case BOTH:
		irow = fst_row;
		for (j = 0; j < m_loc; ++j) {
		    for (i = rowptr[j]; i < rowptr[j+1]; ++i) {
			icol = colind[i];
			a[i] *= R[irow] * C[icol]; /* Scale rows and cols. */
		    }
		    ++irow;
		}
	        break;
	    }
	} else { /* Compute R & C from scratch */
            /* Compute the row and column scalings. */
	    pdgsequ(A, R, C, &rowcnd, &colcnd, &amax, &iinfo, grid);

	    /* Equilibrate matrix A if it is badly-scaled. */
	    pdlaqgs(A, R, C, rowcnd, colcnd, amax, equed);

	    if ( lsame_(equed, "R") ) {
		ScalePermstruct->DiagScale = rowequ = ROW;
	    } else if ( lsame_(equed, "C") ) {
		ScalePermstruct->DiagScale = colequ = COL;
	    } else if ( lsame_(equed, "B") ) {
		ScalePermstruct->DiagScale = BOTH;
		rowequ = ROW;
		colequ = COL;
	    } else ScalePermstruct->DiagScale = NOEQUIL;

#if ( PRNTlevel>=1 )
	    if ( !iam ) {
		printf(".. equilibrated? *equed = %c\n", *equed);
		/*fflush(stdout);*/
	    }
#endif
	} /* if Fact ... */

	stat->utime[EQUIL] = SuperLU_timer_() - t;
#if ( DEBUGlevel>=1 )
	CHECK_MALLOC(iam, "Exit equil");
#endif
    } /* if Equil ... */

    if ( !factored ) { /* Skip this if already factored. */
        /*
         * Gather A from the distributed compressed row format to
         * global A in compressed column format.
         * Numerical values are gathered only when a row permutation
         * for large diagonal is sought after.
         */
	if ( Fact != SamePattern_SameRowPerm ) {
            need_value = (options->RowPerm == LargeDiag);
            pdCompRow_loc_to_CompCol_global(need_value, A, grid, &GA);
            GAstore = (NCformat *) GA.Store;
            colptr = GAstore->colptr;
            rowind = GAstore->rowind;
            nnz = GAstore->nnz;
            if ( need_value ) a_GA = (double *) GAstore->nzval;
            else assert(GAstore->nzval == NULL);
	}

        /* ------------------------------------------------------------
           Find the row permutation for A.
           ------------------------------------------------------------*/
        if ( options->RowPerm != NO ) {
	    t = SuperLU_timer_();
	    if ( Fact != SamePattern_SameRowPerm ) {
	        if ( options->RowPerm == MY_PERMR ) { /* Use user's perm_r. */
	            /* Permute the global matrix GA for symbfact() */
	            for (i = 0; i < colptr[n]; ++i) {
	            	irow = rowind[i]; 
		    	rowind[i] = perm_r[irow];
	            }
	        } else { /* options->RowPerm == LargeDiag */
	            /* Get a new perm_r[] */
	            if ( job == 5 ) {
		        /* Allocate storage for scaling factors. */
		        if ( !(R1 = doubleMalloc_dist(m)) )
		            ABORT("SUPERLU_MALLOC fails for R1[]");
		    	if ( !(C1 = doubleMalloc_dist(n)) )
		            ABORT("SUPERLU_MALLOC fails for C1[]");
	            }

	            if ( !iam ) {
		        /* Process 0 finds a row permutation */
		        dldperm(job, m, nnz, colptr, rowind, a_GA,
		                perm_r, R1, C1);
		
		        MPI_Bcast( perm_r, m, mpi_int_t, 0, grid->comm );
		        if ( job == 5 && Equil ) {
		            MPI_Bcast( R1, m, MPI_DOUBLE, 0, grid->comm );
		            MPI_Bcast( C1, n, MPI_DOUBLE, 0, grid->comm );
		        }
	            } else {
		        MPI_Bcast( perm_r, m, mpi_int_t, 0, grid->comm );
		        if ( job == 5 && Equil ) {
		            MPI_Bcast( R1, m, MPI_DOUBLE, 0, grid->comm );
		            MPI_Bcast( C1, n, MPI_DOUBLE, 0, grid->comm );
		        }
	            }

#if ( PRNTlevel>=2 )
	            dmin = dlamch_("Overflow");
	            dsum = 0.0;
	            dprod = 1.0;
#endif
	            if ( job == 5 ) {
		        if ( Equil ) {
		            for (i = 0; i < n; ++i) {
			        R1[i] = exp(R1[i]);
			        C1[i] = exp(C1[i]);
		            }

		            /* Scale the distributed matrix */
		            irow = fst_row;
		            for (j = 0; j < m_loc; ++j) {
			        for (i = rowptr[j]; i < rowptr[j+1]; ++i) {
			            icol = colind[i];
			            a[i] *= R1[irow] * C1[icol];
#if ( PRNTlevel>=2 )
			            if ( perm_r[irow] == icol ) { /* New diagonal */
			              if ( job == 2 || job == 3 )
				        dmin = SUPERLU_MIN(dmin, fabs(a[i]));
			              else if ( job == 4 )
				        dsum += fabs(a[i]);
			              else if ( job == 5 )
				        dprod *= fabs(a[i]);
			            }
#endif
			        }
			        ++irow;
		            }

		            /* Multiply together the scaling factors. */
		            if ( rowequ ) for (i = 0; i < m; ++i) R[i] *= R1[i];
		            else for (i = 0; i < m; ++i) R[i] = R1[i];
		            if ( colequ ) for (i = 0; i < n; ++i) C[i] *= C1[i];
		            else for (i = 0; i < n; ++i) C[i] = C1[i];
		    
		            ScalePermstruct->DiagScale = BOTH;
		            rowequ = colequ = 1;

		        } /* end Equil */

                        /* Now permute global A to prepare for symbfact() */
                        for (j = 0; j < n; ++j) {
		            for (i = colptr[j]; i < colptr[j+1]; ++i) {
	                        irow = rowind[i];
		                rowind[i] = perm_r[irow];
		            }
		        }
		        SUPERLU_FREE (R1);
		        SUPERLU_FREE (C1);
	            } else { /* job = 2,3,4 */
		        for (j = 0; j < n; ++j) {
		            for (i = colptr[j]; i < colptr[j+1]; ++i) {
			        irow = rowind[i];
			        rowind[i] = perm_r[irow];
		            } /* end for i ... */
		        } /* end for j ... */
	            } /* end else job ... */

#if ( PRNTlevel>=2 )
	            if ( job == 2 || job == 3 ) {
		        if ( !iam ) printf("\tsmallest diagonal %e\n", dmin);
	            } else if ( job == 4 ) {
		        if ( !iam ) printf("\tsum of diagonal %e\n", dsum);
	            } else if ( job == 5 ) {
		        if ( !iam ) printf("\t product of diagonal %e\n", dprod);
	            }
#endif
	    
                } /* end if options->RowPerm ... */

	        t = SuperLU_timer_() - t;
	        stat->utime[ROWPERM] = t;
#if ( PRNTlevel>=1 )
	        if ( !iam ) printf(".. LDPERM job %d\t time: %.2f\n", job, t);
#endif
            } /* end if Fact ... */
        } else { /* options->RowPerm == NOROWPERM */
            for (i = 0; i < m; ++i) perm_r[i] = i;
        }

#if ( DEBUGlevel>=2 )
        if ( !iam ) PrintInt10("perm_r",  m, perm_r);
#endif
    } /* end if (!factored) */

    if ( !factored || options->IterRefine ) {
	/* Compute norm(A), which will be used to adjust small diagonal. */
	if ( notran ) *(unsigned char *)norm = '1';
	else *(unsigned char *)norm = 'I';
	anorm = pdlangs(norm, A, grid);
#if ( PRNTlevel>=1 )
	if ( !iam ) printf(".. anorm %e\n", anorm);
#endif
    }

    /* ------------------------------------------------------------
       Perform the LU factorization.
       ------------------------------------------------------------*/
    if ( !factored ) {
	t = SuperLU_timer_();
	/*
	 * Get column permutation vector perm_c[], according to permc_spec:
	 *   permc_spec = NATURAL:  natural ordering 
	 *   permc_spec = MMD_AT_PLUS_A: minimum degree on structure of A'+A
	 *   permc_spec = MMD_ATA:  minimum degree on structure of A'*A
	 *   permc_spec = METIS_AT_PLUS_A: METIS on structure of A'+A
	 *   permc_spec = PARMETIS: parallel METIS on structure of A'+A
	 *   permc_spec = MY_PERMC: the ordering already supplied in perm_c[]
	 */
	permc_spec = options->ColPerm;
	parSymbFact = options->ParSymbFact;

#if ( PRNTlevel>=1 )
	if ( parSymbFact && permc_spec != PARMETIS )
	    if ( !iam ) printf(".. Parallel symbolic factorization"
			       " only works wth ParMetis!\n");
#endif

	if ( parSymbFact == YES || permc_spec == PARMETIS ) {	
	    nprocs_num = grid->nprow * grid->npcol;
  	    noDomains = (int) ( pow(2, ((int) LOG2( nprocs_num ))));

	    /* create a new communicator for the first noDomains processors in
	       grid->comm */
	    key = iam;
    	    if (iam < noDomains) col = 0;
	    else col = MPI_UNDEFINED;
	    MPI_Comm_split (grid->comm, col, key, &symb_comm );

	    permc_spec = PARMETIS; /* only works with PARMETIS */
        }

	if ( permc_spec != MY_PERMC && Fact == DOFACT ) {
	  if ( permc_spec == PARMETIS ) {
	      /* Get column permutation vector in perm_c.                    *
	       * This routine takes as input the distributed input matrix A  *
	       * and does not modify it.  It also allocates memory for       *
	       * sizes[] and fstVtxSep[] arrays, that contain information    *
	       * on the separator tree computed by ParMETIS.                 */
	      flinfo = get_perm_c_parmetis(A, perm_r, perm_c, nprocs_num,
                                  	   noDomains, &sizes, &fstVtxSep,
                                           grid, &symb_comm);
	      if (flinfo > 0)
	          ABORT("ERROR in get perm_c parmetis.");
	  } else {
	      get_perm_c_dist(iam, permc_spec, &GA, perm_c);
          }
        }

	stat->utime[COLPERM] = SuperLU_timer_() - t;

	/* Compute the elimination tree of Pc*(A'+A)*Pc' or Pc*A'*A*Pc'
	   (a.k.a. column etree), depending on the choice of ColPerm.
	   Adjust perm_c[] to be consistent with a postorder of etree.
	   Permute columns of A to form A*Pc'. */
	if ( Fact != SamePattern_SameRowPerm ) {
	    if ( parSymbFact == NO ) {
	        int_t *GACcolbeg, *GACcolend, *GACrowind;

	        sp_colorder(options, &GA, perm_c, etree, &GAC); 

	        /* Form Pc*A*Pc' to preserve the diagonal of the matrix GAC. */
	        GACstore = (NCPformat *) GAC.Store;
	        GACcolbeg = GACstore->colbeg;
	        GACcolend = GACstore->colend;
	        GACrowind = GACstore->rowind;
	        for (j = 0; j < n; ++j) {
	            for (i = GACcolbeg[j]; i < GACcolend[j]; ++i) {
		        irow = GACrowind[i];
		        GACrowind[i] = perm_c[irow];
	            }
	        }

	        /* Perform a symbolic factorization on Pc*Pr*A*Pc' and set up
                   the nonzero data structures for L & U. */
#if ( PRNTlevel>=1 ) 
                if ( !iam )
		  printf(".. symbfact(): relax %4d, maxsuper %4d, fill %4d\n",
		          sp_ienv_dist(2), sp_ienv_dist(3), sp_ienv_dist(6));
#endif
  	        t = SuperLU_timer_();
	        if ( !(Glu_freeable = (Glu_freeable_t *)
		      SUPERLU_MALLOC(sizeof(Glu_freeable_t))) )
		    ABORT("Malloc fails for Glu_freeable.");

	    	/* Every process does this. */
	    	iinfo = symbfact(options, iam, &GAC, perm_c, etree, 
			     	 Glu_persist, Glu_freeable);

	    	stat->utime[SYMBFAC] = SuperLU_timer_() - t;
	    	if ( iinfo < 0 ) { /* Successful return */
		    QuerySpace_dist(n, -iinfo, Glu_freeable, &symb_mem_usage);
#if ( PRNTlevel>=1 )
		    if ( !iam ) {
		    	printf("\tNo of supers %ld\n", Glu_persist->supno[n-1]+1);
		    	printf("\tSize of G(L) %ld\n", Glu_freeable->xlsub[n]);
		    	printf("\tSize of G(U) %ld\n", Glu_freeable->xusub[n]);
		    	printf("\tint %d, short %d, float %d, double %d\n", 
			       sizeof(int_t), sizeof(short), sizeof(float),
			       sizeof(double));
		    	printf("\tSYMBfact (MB):\tL\\U %.2f\ttotal %.2f\texpansions %d\n",
			   	symb_mem_usage.for_lu*1e-6, 
			   	symb_mem_usage.total*1e-6,
			   	symb_mem_usage.expansions);
		    }
#endif
	    	} else {
		    if ( !iam ) {
		        fprintf(stderr,"symbfact() error returns %d\n",iinfo);
		    	exit(-1);
		    }
	        }
	    } /* end if serial symbolic factorization */
	    else {  /* parallel symbolic factorization */
	    	t = SuperLU_timer_();
	    	flinfo = symbfact_dist(nprocs_num, noDomains, A, perm_c, perm_r,
				       sizes, fstVtxSep, &Pslu_freeable, 
				       &(grid->comm), &symb_comm,
				       &symb_mem_usage); 
	    	stat->utime[SYMBFAC] = SuperLU_timer_() - t;
	    	if (flinfo > 0) 
	      	    ABORT("Insufficient memory for parallel symbolic factorization.");
	    }
	} /* end if Fact ... */

#if ( PRNTlevel>=1 )
	if (!iam) printf("\tSYMBfact time: %.2f\n", stat->utime[SYMBFAC]);
#endif
        if (sizes) SUPERLU_FREE (sizes);
        if (fstVtxSep) SUPERLU_FREE (fstVtxSep);
	if (symb_comm != MPI_COMM_NULL)
	  MPI_Comm_free (&symb_comm); 

	if (parSymbFact == NO || Fact == SamePattern_SameRowPerm) {
  	    /* Apply column permutation to the original distributed A */
	    for (j = 0; j < nnz_loc; ++j) colind[j] = perm_c[colind[j]];

	    /* Distribute Pc*Pr*diag(R)*A*diag(C)*Pc' into L and U storage. 
	       NOTE: the row permutation Pc*Pr is applied internally in the
  	       distribution routine. */
	    t = SuperLU_timer_();
	    dist_mem_use = pddistribute(Fact, n, A, ScalePermstruct,
                                      Glu_freeable, LUstruct, grid);
	    stat->utime[DIST] = SuperLU_timer_() - t;

  	    /* Deallocate storage used in symbolic factorization. */
	    if ( Fact != SamePattern_SameRowPerm ) {
	        iinfo = symbfact_SubFree(Glu_freeable);
	        SUPERLU_FREE(Glu_freeable);
	    }
	} else {
	    /* Distribute Pc*Pr*diag(R)*A*diag(C)*Pc' into L and U storage. 
	       NOTE: the row permutation Pc*Pr is applied internally in the
	       distribution routine. */
	    /* Apply column permutation to the original distributed A */
	    for (j = 0; j < nnz_loc; ++j) colind[j] = perm_c[colind[j]];

    	    t = SuperLU_timer_();
	    dist_mem_use = ddist_psymbtonum(Fact, n, A, ScalePermstruct,
		  			   &Pslu_freeable, LUstruct, grid);
	    if (dist_mem_use > 0)
	        ABORT ("Not enough memory available for dist_psymbtonum\n");
	    stat->utime[DIST] = SuperLU_timer_() - t;
	}

#if ( PRNTlevel>=1 )
	if (!iam) printf ("\tDISTRIBUTE time    %8.2f\n", stat->utime[DIST]);
#endif

	/* Perform numerical factorization in parallel. */
	t = SuperLU_timer_();
	pdgstrf(options, m, n, anorm, LUstruct, grid, stat, info);
	stat->utime[FACT] = SuperLU_timer_() - t;

#if ( PRNTlevel>=1 )
	{
	    int_t TinyPivots;
	    float for_lu, total, max, avg, temp;
	    dQuerySpace_dist(n, LUstruct, grid, &num_mem_usage);
	    MPI_Reduce( &num_mem_usage.for_lu, &for_lu,
		       1, MPI_FLOAT, MPI_SUM, 0, grid->comm );
	    MPI_Reduce( &num_mem_usage.total, &total,
		       1, MPI_FLOAT, MPI_SUM, 0, grid->comm );
	    temp = SUPERLU_MAX(symb_mem_usage.total,
			       symb_mem_usage.for_lu +
			       (float)dist_mem_use + num_mem_usage.for_lu);
	    if (parSymbFact == TRUE)
	      /* The memory used in the redistribution routine
		 includes the memory used for storing the symbolic
		 structure and the memory allocated for numerical
		 factorization */
	      temp = SUPERLU_MAX(symb_mem_usage.total,
				 (float)dist_mem_use);
	    temp = SUPERLU_MAX(temp, num_mem_usage.total);
	    MPI_Reduce( &temp, &max,
		       1, MPI_FLOAT, MPI_MAX, 0, grid->comm );
	    MPI_Reduce( &temp, &avg,
		       1, MPI_FLOAT, MPI_SUM, 0, grid->comm );
	    MPI_Allreduce( &stat->TinyPivots, &TinyPivots, 1, mpi_int_t,
			  MPI_SUM, grid->comm );
	    stat->TinyPivots = TinyPivots;
	    if ( !iam ) {
		printf("\tNUMfact (MB) all PEs:\tL\\U\t%.2f\tall\t%.2f\n",
		       for_lu*1e-6, total*1e-6);
		printf("\tAll space (MB):"
		       "\t\ttotal\t%.2f\tAvg\t%.2f\tMax\t%.2f\n",
		       avg*1e-6, avg/grid->nprow/grid->npcol*1e-6, max*1e-6);
		printf("\tNumber of tiny pivots: %10d\n", stat->TinyPivots);
	    }
	}
#endif
    
        /* Destroy GA */
        if ( Fact != SamePattern_SameRowPerm )
            Destroy_CompCol_Matrix_dist(&GA);
    } /* end if (!factored) */
	
    /* ------------------------------------------------------------
       Compute the solution matrix X.
       ------------------------------------------------------------*/
    if ( nrhs ) {

	if ( !(b_work = doubleMalloc_dist(n)) )
	    ABORT("Malloc fails for b_work[]");

	/* ------------------------------------------------------------
	   Scale the right-hand side if equilibration was performed. 
	   ------------------------------------------------------------*/
	if ( notran ) {
	    if ( rowequ ) {
		b_col = B;
		for (j = 0; j < nrhs; ++j) {
		    irow = fst_row;
		    for (i = 0; i < m_loc; ++i) {
		        b_col[i] *= R[irow];
		        ++irow;
		    }
		    b_col += ldb;
		}
	    }
	} else if ( colequ ) {
	    b_col = B;
	    for (j = 0; j < nrhs; ++j) {
	        irow = fst_row;
		for (i = 0; i < m_loc; ++i) {
		    b_col[i] *= C[irow];
		    ++irow;
		}
		b_col += ldb;
	    }
	}

	/* Save a copy of the right-hand side. */
	ldx = ldb;
	if ( !(X = doubleMalloc_dist(((size_t)ldx) * nrhs)) )
	    ABORT("Malloc fails for X[]");
	x_col = X;  b_col = B;
	for (j = 0; j < nrhs; ++j) {
	    for (i = 0; i < m_loc; ++i) x_col[i] = b_col[i];
	    x_col += ldx;  b_col += ldb;
	}

	/* ------------------------------------------------------------
	   Solve the linear system.
	   ------------------------------------------------------------*/
	if ( options->SolveInitialized == NO ) {
	    dSolveInit(options, A, perm_r, perm_c, nrhs, LUstruct, grid,
		       SOLVEstruct);
	}

	pdgstrs(n, LUstruct, ScalePermstruct, grid, X, m_loc, 
		fst_row, ldb, nrhs, SOLVEstruct, stat, info);

	/* ------------------------------------------------------------
	   Use iterative refinement to improve the computed solution and
	   compute error bounds and backward error estimates for it.
	   ------------------------------------------------------------*/
	if ( options->IterRefine ) {
	    /* Improve the solution by iterative refinement. */
	    int_t *it, *colind_gsmv = SOLVEstruct->A_colind_gsmv;
	    SOLVEstruct_t *SOLVEstruct1;  /* Used by refinement. */

	    t = SuperLU_timer_();
	    if ( options->RefineInitialized == NO || Fact == DOFACT ) {
	        /* All these cases need to re-initialize gsmv structure */
	        if ( options->RefineInitialized )
		    pdgsmv_finalize(SOLVEstruct->gsmv_comm);
	        pdgsmv_init(A, SOLVEstruct->row_to_proc, grid,
			    SOLVEstruct->gsmv_comm);
	       
                /* Save a copy of the transformed local col indices
		   in colind_gsmv[]. */
	        if ( colind_gsmv ) SUPERLU_FREE(colind_gsmv);
	        if ( !(it = intMalloc_dist(nnz_loc)) )
		    ABORT("Malloc fails for colind_gsmv[]");
	        colind_gsmv = SOLVEstruct->A_colind_gsmv = it;
	        for (i = 0; i < nnz_loc; ++i) colind_gsmv[i] = colind[i];
	        options->RefineInitialized = YES;
	    } else if ( Fact == SamePattern ||
			Fact == SamePattern_SameRowPerm ) {
	        double at;
	        int_t k, jcol, p;
	        /* Swap to beginning the part of A corresponding to the
		   local part of X, as was done in pdgsmv_init() */
	        for (i = 0; i < m_loc; ++i) { /* Loop through each row */
		    k = rowptr[i];
		    for (j = rowptr[i]; j < rowptr[i+1]; ++j) {
		        jcol = colind[j];
		        p = SOLVEstruct->row_to_proc[jcol];
		        if ( p == iam ) { /* Local */
		            at = a[k]; a[k] = a[j]; a[j] = at;
		            ++k;
		        }
		    }
	        }
	      
	        /* Re-use the local col indices of A obtained from the
		   previous call to pdgsmv_init() */
	        for (i = 0; i < nnz_loc; ++i) colind[i] = colind_gsmv[i];
	    }

	    if ( nrhs == 1 ) { /* Use the existing solve structure */
	        SOLVEstruct1 = SOLVEstruct;
	    } else { /* For nrhs > 1, since refinement is performed for RHS
			one at a time, the communication structure for pdgstrs
			is different than the solve with nrhs RHS. 
			So we use SOLVEstruct1 for the refinement step.
		     */
	        if ( !(SOLVEstruct1 = (SOLVEstruct_t *) 
		                       SUPERLU_MALLOC(sizeof(SOLVEstruct_t))) )
		    ABORT("Malloc fails for SOLVEstruct1");
	        /* Copy the same stuff */
	        SOLVEstruct1->row_to_proc = SOLVEstruct->row_to_proc;
	        SOLVEstruct1->inv_perm_c = SOLVEstruct->inv_perm_c;
	        SOLVEstruct1->num_diag_procs = SOLVEstruct->num_diag_procs;
	        SOLVEstruct1->diag_procs = SOLVEstruct->diag_procs;
	        SOLVEstruct1->diag_len = SOLVEstruct->diag_len;
	        SOLVEstruct1->gsmv_comm = SOLVEstruct->gsmv_comm;
	        SOLVEstruct1->A_colind_gsmv = SOLVEstruct->A_colind_gsmv;
		
		/* Initialize the *gstrs_comm for 1 RHS. */
		if ( !(SOLVEstruct1->gstrs_comm = (pxgstrs_comm_t *)
		       SUPERLU_MALLOC(sizeof(pxgstrs_comm_t))) )
		    ABORT("Malloc fails for gstrs_comm[]");
		pxgstrs_init(n, m_loc, 1, fst_row, perm_r, perm_c, grid, 
			     Glu_persist, SOLVEstruct1);
	    }

	    pdgsrfs(n, A, anorm, LUstruct, ScalePermstruct, grid,
		    B, ldb, X, ldx, nrhs, SOLVEstruct1, berr, stat, info);

            /* Deallocate the storage associated with SOLVEstruct1 */
	    if ( nrhs > 1 ) {
	        pxgstrs_finalize(SOLVEstruct1->gstrs_comm);
	        SUPERLU_FREE(SOLVEstruct1);
	    }

	    stat->utime[REFINE] = SuperLU_timer_() - t;
	}

	/* Permute the solution matrix B <= Pc'*X. */
	pdPermute_Dense_Matrix(fst_row, m_loc, SOLVEstruct->row_to_proc,
			       SOLVEstruct->inv_perm_c,
			       X, ldx, B, ldb, nrhs, grid);
#if ( DEBUGlevel>=2 )
	printf("\n (%d) .. After pdPermute_Dense_Matrix(): b =\n", iam);
	for (i = 0; i < m_loc; ++i)
	  printf("\t(%d)\t%4d\t%.10f\n", iam, i+fst_row, B[i]);
#endif
	
	/* Transform the solution matrix X to a solution of the original
	   system before the equilibration. */
	if ( notran ) {
	    if ( colequ ) {
		b_col = B;
		for (j = 0; j < nrhs; ++j) {
		    irow = fst_row;
		    for (i = 0; i < m_loc; ++i) {
		        b_col[i] *= C[irow];
		        ++irow;
		    }
		    b_col += ldb;
		}
	    }
	} else if ( rowequ ) {
	    b_col = B;
	    for (j = 0; j < nrhs; ++j) {
	        irow = fst_row;
		for (i = 0; i < m_loc; ++i) {
		    b_col[i] *= R[irow];
		    ++irow;
		}
		b_col += ldb;
	    }
	}

	SUPERLU_FREE(b_work);
	SUPERLU_FREE(X);

    } /* end if nrhs != 0 */

#if ( PRNTlevel>=1 )
    if ( !iam ) printf(".. DiagScale = %d\n", ScalePermstruct->DiagScale);
#endif

    /* Deallocate R and/or C if it was not used. */
    if ( Equil && Fact != SamePattern_SameRowPerm ) {
	switch ( ScalePermstruct->DiagScale ) {
	    case NOEQUIL:
	        SUPERLU_FREE(R);
		SUPERLU_FREE(C);
		break;
	    case ROW: 
		SUPERLU_FREE(C);
		break;
	    case COL: 
		SUPERLU_FREE(R);
		break;
	}
    }
    if ( !factored && Fact != SamePattern_SameRowPerm && !parSymbFact)
 	Destroy_CompCol_Permuted_dist(&GAC);

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Exit pdgssvx()");
#endif

}
示例#6
0
void
pzgstrs(int_t n, LUstruct_t *LUstruct, 
	ScalePermstruct_t *ScalePermstruct,
	gridinfo_t *grid, doublecomplex *B,
	int_t m_loc, int_t fst_row, int_t ldb, int nrhs,
	SOLVEstruct_t *SOLVEstruct,
	SuperLUStat_t *stat, int *info)
{
/*
 * Purpose
 * =======
 *
 * PZGSTRS solves a system of distributed linear equations
 * A*X = B with a general N-by-N matrix A using the LU factorization
 * computed by PZGSTRF.
 * If the equilibration, and row and column permutations were performed,
 * the LU factorization was performed for A1 where
 *     A1 = Pc*Pr*diag(R)*A*diag(C)*Pc^T = L*U
 * and the linear system solved is
 *     A1 * Y = Pc*Pr*B1, where B was overwritten by B1 = diag(R)*B, and
 * the permutation to B1 by Pc*Pr is applied internally in this routine.
 * 
 * Arguments
 * =========
 *
 * n      (input) int (global)
 *        The order of the system of linear equations.
 *
 * LUstruct (input) LUstruct_t*
 *        The distributed data structures storing L and U factors.
 *        The L and U factors are obtained from PZGSTRF for
 *        the possibly scaled and permuted matrix A.
 *        See superlu_zdefs.h for the definition of 'LUstruct_t'.
 *        A may be scaled and permuted into A1, so that
 *        A1 = Pc*Pr*diag(R)*A*diag(C)*Pc^T = L*U
 *
 * grid   (input) gridinfo_t*
 *        The 2D process mesh. It contains the MPI communicator, the number
 *        of process rows (NPROW), the number of process columns (NPCOL),
 *        and my process rank. It is an input argument to all the
 *        parallel routines.
 *        Grid can be initialized by subroutine SUPERLU_GRIDINIT.
 *        See superlu_defs.h for the definition of 'gridinfo_t'.
 *
 * B      (input/output) doublecomplex*
 *        On entry, the distributed right-hand side matrix of the possibly
 *        equilibrated system. That is, B may be overwritten by diag(R)*B.
 *        On exit, the distributed solution matrix Y of the possibly
 *        equilibrated system if info = 0, where Y = Pc*diag(C)^(-1)*X,
 *        and X is the solution of the original system.
 *
 * m_loc  (input) int (local)
 *        The local row dimension of matrix B.
 *
 * fst_row (input) int (global)
 *        The row number of B's first row in the global matrix.
 *
 * ldb    (input) int (local)
 *        The leading dimension of matrix B.
 *
 * nrhs   (input) int (global)
 *        Number of right-hand sides.
 * 
 * SOLVEstruct (output) SOLVEstruct_t* (global)
 *        Contains the information for the communication during the
 *        solution phase.
 *
 * stat   (output) SuperLUStat_t*
 *        Record the statistics about the triangular solves.
 *        See util.h for the definition of 'SuperLUStat_t'.
 *
 * info   (output) int*
 * 	   = 0: successful exit
 *	   < 0: if info = -i, the i-th argument had an illegal value
 *        
 */
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    LocalLU_t *Llu = LUstruct->Llu;
    doublecomplex alpha = {1.0, 0.0};
    doublecomplex zero = {0.0, 0.0};
    doublecomplex *lsum;  /* Local running sum of the updates to B-components */
    doublecomplex *x;     /* X component at step k. */
		    /* NOTE: x and lsum are of same size. */
    doublecomplex *lusup, *dest;
    doublecomplex *recvbuf, *tempv;
    doublecomplex *rtemp; /* Result of full matrix-vector multiply. */
    int_t  **Ufstnz_br_ptr = Llu->Ufstnz_br_ptr;
    int_t  *Urbs, *Urbs1; /* Number of row blocks in each block column of U. */
    Ucb_indptr_t **Ucb_indptr;/* Vertical linked list pointing to Uindex[] */
    int_t  **Ucb_valptr;      /* Vertical linked list pointing to Unzval[] */
    int_t  iam, kcol, krow, mycol, myrow;
    int_t  i, ii, il, j, jj, k, lb, ljb, lk, lptr, luptr;
    int_t  nb, nlb, nub, nsupers;
    int_t  *xsup, *supno, *lsub, *usub;
    int_t  *ilsum;    /* Starting position of each supernode in lsum (LOCAL)*/
    int_t  Pc, Pr;
    int    knsupc, nsupr;
    int    ldalsum;   /* Number of lsum entries locally owned. */
    int    maxrecvsz, p, pi;
    int_t  **Lrowind_bc_ptr;
    doublecomplex **Lnzval_bc_ptr;
    MPI_Status status;
#ifdef ISEND_IRECV
    MPI_Request *send_req, recv_req;
#endif
    pxgstrs_comm_t *gstrs_comm = SOLVEstruct->gstrs_comm;

    /*-- Counts used for L-solve --*/
    int_t  *fmod;         /* Modification count for L-solve --
                             Count the number of local block products to
                             be summed into lsum[lk]. */
    int_t  **fsendx_plist = Llu->fsendx_plist;
    int_t  nfrecvx = Llu->nfrecvx; /* Number of X components to be recv'd. */
    int_t  *frecv;        /* Count of lsum[lk] contributions to be received
                             from processes in this row. 
                             It is only valid on the diagonal processes. */
    int_t  nfrecvmod = 0; /* Count of total modifications to be recv'd. */
    int_t  nleaf = 0, nroot = 0;

    /*-- Counts used for U-solve --*/
    int_t  *bmod;         /* Modification count for U-solve. */
    int_t  **bsendx_plist = Llu->bsendx_plist;
    int_t  nbrecvx = Llu->nbrecvx; /* Number of X components to be recv'd. */
    int_t  *brecv;        /* Count of modifications to be recv'd from
			     processes in this row. */
    int_t  nbrecvmod = 0; /* Count of total modifications to be recv'd. */
    double t;
#if ( DEBUGlevel>=2 )
    int_t Ublocks = 0;
#endif

    t = SuperLU_timer_();

    /* Test input parameters. */
    *info = 0;
    if ( n < 0 ) *info = -1;
    else if ( nrhs < 0 ) *info = -9;
    if ( *info ) {
	pxerbla("PZGSTRS", grid, -*info);
	return;
    }
	
    /*
     * Initialization.
     */
    iam = grid->iam;
    Pc = grid->npcol;
    Pr = grid->nprow;
    myrow = MYROW( iam, grid );
    mycol = MYCOL( iam, grid );
    xsup = Glu_persist->xsup;
    supno = Glu_persist->supno;
    nsupers = supno[n-1] + 1;
    Lrowind_bc_ptr = Llu->Lrowind_bc_ptr;
    Lnzval_bc_ptr = Llu->Lnzval_bc_ptr;
    nlb = CEILING( nsupers, Pr ); /* Number of local block rows. */

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter pzgstrs()");
#endif

    stat->ops[SOLVE] = 0.0;
    Llu->SolveMsgSent = 0;

    /* Save the count to be altered so it can be used by
       subsequent call to PDGSTRS. */
    if ( !(fmod = intMalloc_dist(nlb)) )
	ABORT("Calloc fails for fmod[].");
    for (i = 0; i < nlb; ++i) fmod[i] = Llu->fmod[i];
    if ( !(frecv = intMalloc_dist(nlb)) )
	ABORT("Malloc fails for frecv[].");
    Llu->frecv = frecv;

#ifdef ISEND_IRECV
    k = SUPERLU_MAX( Llu->nfsendx, Llu->nbsendx ) + nlb;
    if ( !(send_req = (MPI_Request*) SUPERLU_MALLOC(k*sizeof(MPI_Request))) )
	ABORT("Malloc fails for send_req[].");
#endif

#ifdef _CRAY
    ftcs1 = _cptofcd("L", strlen("L"));
    ftcs2 = _cptofcd("N", strlen("N"));
    ftcs3 = _cptofcd("U", strlen("U"));
#endif


    /* Obtain ilsum[] and ldalsum for process column 0. */
    ilsum = Llu->ilsum;
    ldalsum = Llu->ldalsum;

    /* Allocate working storage. */
    knsupc = sp_ienv_dist(3);
    maxrecvsz = knsupc * nrhs + SUPERLU_MAX( XK_H, LSUM_H );
    if ( !(lsum = doublecomplexCalloc_dist(((size_t)ldalsum)*nrhs + nlb*LSUM_H)) )
	ABORT("Calloc fails for lsum[].");
    if ( !(x = doublecomplexMalloc_dist(ldalsum * nrhs + nlb * XK_H)) )
	ABORT("Malloc fails for x[].");
    if ( !(recvbuf = doublecomplexMalloc_dist(maxrecvsz)) )
	ABORT("Malloc fails for recvbuf[].");
    if ( !(rtemp = doublecomplexCalloc_dist(maxrecvsz)) )
	ABORT("Malloc fails for rtemp[].");

    
    /*---------------------------------------------------
     * Forward solve Ly = b.
     *---------------------------------------------------*/
    /* Redistribute B into X on the diagonal processes. */
    pzReDistribute_B_to_X(B, m_loc, nrhs, ldb, fst_row, ilsum, x, 
			  ScalePermstruct, Glu_persist, grid, SOLVEstruct);

    /* Set up the headers in lsum[]. */
    ii = 0;
    for (k = 0; k < nsupers; ++k) {
	knsupc = SuperSize( k );
	krow = PROW( k, grid );
	if ( myrow == krow ) {
	    lk = LBi( k, grid );   /* Local block number. */
	    il = LSUM_BLK( lk );
	    lsum[il - LSUM_H].r = k;/* Block number prepended in the header.*/
	    lsum[il - LSUM_H].i = 0;
	}
	ii += knsupc;
    }

    /*
     * Compute frecv[] and nfrecvmod counts on the diagonal processes.
     */
    {
	superlu_scope_t *scp = &grid->rscp;

	for (k = 0; k < nsupers; ++k) {
	    krow = PROW( k, grid );
	    if ( myrow == krow ) {
		lk = LBi( k, grid );    /* Local block number. */
		kcol = PCOL( k, grid ); /* Root process in this row scope. */
		if ( mycol != kcol && fmod[lk] )
		    i = 1;  /* Contribution from non-diagonal process. */
		else i = 0;
		MPI_Reduce( &i, &frecv[lk], 1, mpi_int_t,
			   MPI_SUM, kcol, scp->comm );
		if ( mycol == kcol ) { /* Diagonal process. */
		    nfrecvmod += frecv[lk];
		    if ( !frecv[lk] && !fmod[lk] ) ++nleaf;
#if ( DEBUGlevel>=2 )
		    printf("(%2d) frecv[%4d]  %2d\n", iam, k, frecv[lk]);
		    assert( frecv[lk] < Pc );
#endif
		}
	    }
	}
    }

    /* ---------------------------------------------------------
       Solve the leaf nodes first by all the diagonal processes.
       --------------------------------------------------------- */
#if ( DEBUGlevel>=2 )
    printf("(%2d) nleaf %4d\n", iam, nleaf);
#endif
    for (k = 0; k < nsupers && nleaf; ++k) {
	krow = PROW( k, grid );
	kcol = PCOL( k, grid );
	if ( myrow == krow && mycol == kcol ) { /* Diagonal process */
	    knsupc = SuperSize( k );
	    lk = LBi( k, grid );
	    if ( frecv[lk]==0 && fmod[lk]==0 ) {
		fmod[lk] = -1;  /* Do not solve X[k] in the future. */
		ii = X_BLK( lk );
		lk = LBj( k, grid ); /* Local block number, column-wise. */
		lsub = Lrowind_bc_ptr[lk];
		lusup = Lnzval_bc_ptr[lk];
		nsupr = lsub[1];
#ifdef _CRAY
		CTRSM(ftcs1, ftcs1, ftcs2, ftcs3, &knsupc, &nrhs, &alpha,
		      lusup, &nsupr, &x[ii], &knsupc);
#elif defined (USE_VENDOR_BLAS)
		ztrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
		       lusup, &nsupr, &x[ii], &knsupc, 1, 1, 1, 1);
#else
		ztrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
		       lusup, &nsupr, &x[ii], &knsupc);
#endif
		stat->ops[SOLVE] += 4 * knsupc * (knsupc - 1) * nrhs
		    + 10 * knsupc * nrhs; /* complex division */
		--nleaf;
#if ( DEBUGlevel>=2 )
		printf("(%2d) Solve X[%2d]\n", iam, k);
#endif
		
		/*
		 * Send Xk to process column Pc[k].
		 */
		for (p = 0; p < Pr; ++p) {
		    if ( fsendx_plist[lk][p] != EMPTY ) {
			pi = PNUM( p, kcol, grid );
#ifdef ISEND_IRECV
			MPI_Isend( &x[ii - XK_H], knsupc * nrhs + XK_H,
				   SuperLU_MPI_DOUBLE_COMPLEX, pi, Xk, grid->comm,
                                   &send_req[Llu->SolveMsgSent++]);
#else
			MPI_Send( &x[ii - XK_H], knsupc * nrhs + XK_H,
				 SuperLU_MPI_DOUBLE_COMPLEX, pi, Xk, grid->comm );
#endif
#if ( DEBUGlevel>=2 )
			printf("(%2d) Sent X[%2.0f] to P %2d\n",
			       iam, x[ii-XK_H], pi);
#endif
		    }
		}
		/*
		 * Perform local block modifications: lsum[i] -= L_i,k * X[k]
		 */
		nb = lsub[0] - 1;
		lptr = BC_HEADER + LB_DESCRIPTOR + knsupc;
		luptr = knsupc; /* Skip diagonal block L(k,k). */
		
		zlsum_fmod(lsum, x, &x[ii], rtemp, nrhs, knsupc, k,
			   fmod, nb, lptr, luptr, xsup, grid, Llu, 
			   send_req, stat);
	    }
	} /* if diagonal process ... */
    } /* for k ... */

    /* -----------------------------------------------------------
       Compute the internal nodes asynchronously by all processes.
       ----------------------------------------------------------- */
#if ( DEBUGlevel>=2 )
    printf("(%2d) nfrecvx %4d,  nfrecvmod %4d,  nleaf %4d\n",
	   iam, nfrecvx, nfrecvmod, nleaf);
#endif

    while ( nfrecvx || nfrecvmod ) { /* While not finished. */

	/* Receive a message. */
#ifdef ISEND_IRECV
	/* -MPI- FATAL: Remote protocol queue full */
	MPI_Irecv( recvbuf, maxrecvsz, SuperLU_MPI_DOUBLE_COMPLEX,
                 MPI_ANY_SOURCE, MPI_ANY_TAG, grid->comm, &recv_req );
	MPI_Wait( &recv_req, &status );
#else
	MPI_Recv( recvbuf, maxrecvsz, SuperLU_MPI_DOUBLE_COMPLEX,
                  MPI_ANY_SOURCE, MPI_ANY_TAG, grid->comm, &status );
#endif

        k = (*recvbuf).r;

#if ( DEBUGlevel>=2 )
	printf("(%2d) Recv'd block %d, tag %2d\n", iam, k, status.MPI_TAG);
#endif
	
	switch ( status.MPI_TAG ) {
	  case Xk:
	      --nfrecvx;
	      lk = LBj( k, grid ); /* Local block number, column-wise. */
	      lsub = Lrowind_bc_ptr[lk];
	      lusup = Lnzval_bc_ptr[lk];
	      if ( lsub ) {
		  nb   = lsub[0];
		  lptr = BC_HEADER;
		  luptr = 0;
		  knsupc = SuperSize( k );

		  /*
		   * Perform local block modifications: lsum[i] -= L_i,k * X[k]
		   */
		  zlsum_fmod(lsum, x, &recvbuf[XK_H], rtemp, nrhs, knsupc, k,
			     fmod, nb, lptr, luptr, xsup, grid, Llu, 
			     send_req, stat);
	      } /* if lsub */

	      break;

	  case LSUM: /* Receiver must be a diagonal process */
	      --nfrecvmod;
	      lk = LBi( k, grid ); /* Local block number, row-wise. */
	      ii = X_BLK( lk );
	      knsupc = SuperSize( k );
	      tempv = &recvbuf[LSUM_H];
	      RHS_ITERATE(j) {
		  for (i = 0; i < knsupc; ++i)
		      z_add(&x[i + ii + j*knsupc],
			    &x[i + ii + j*knsupc],
			    &tempv[i + j*knsupc]);
	      }

	      if ( (--frecv[lk])==0 && fmod[lk]==0 ) {
		  fmod[lk] = -1; /* Do not solve X[k] in the future. */
		  lk = LBj( k, grid ); /* Local block number, column-wise. */
		  lsub = Lrowind_bc_ptr[lk];
		  lusup = Lnzval_bc_ptr[lk];
		  nsupr = lsub[1];
#ifdef _CRAY
		  CTRSM(ftcs1, ftcs1, ftcs2, ftcs3, &knsupc, &nrhs, &alpha,
			lusup, &nsupr, &x[ii], &knsupc);
#elif defined (USE_VENDOR_BLAS)
		  ztrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
			 lusup, &nsupr, &x[ii], &knsupc, 1, 1, 1, 1);
#else
		  ztrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
			 lusup, &nsupr, &x[ii], &knsupc);
#endif
		  stat->ops[SOLVE] += 4 * knsupc * (knsupc - 1) * nrhs
		      + 10 * knsupc * nrhs; /* complex division */
#if ( DEBUGlevel>=2 )
		  printf("(%2d) Solve X[%2d]\n", iam, k);
#endif
		
		  /*
		   * Send Xk to process column Pc[k].
		   */
		  kcol = PCOL( k, grid );
		  for (p = 0; p < Pr; ++p) {
		      if ( fsendx_plist[lk][p] != EMPTY ) {
			  pi = PNUM( p, kcol, grid );
#ifdef ISEND_IRECV
			  MPI_Isend( &x[ii-XK_H], knsupc * nrhs + XK_H,
                                     SuperLU_MPI_DOUBLE_COMPLEX, pi, Xk, grid->comm,
                                     &send_req[Llu->SolveMsgSent++]);
#else
			  MPI_Send( &x[ii - XK_H], knsupc * nrhs + XK_H,
				    SuperLU_MPI_DOUBLE_COMPLEX, pi, Xk, grid->comm );
#endif
#if ( DEBUGlevel>=2 )
			  printf("(%2d) Sent X[%2.0f] to P %2d\n",
				 iam, x[ii-XK_H], pi);
#endif
		      }
                  }
		  /*
		   * Perform local block modifications.
		   */
		  nb = lsub[0] - 1;
		  lptr = BC_HEADER + LB_DESCRIPTOR + knsupc;
		  luptr = knsupc; /* Skip diagonal block L(k,k). */

		  zlsum_fmod(lsum, x, &x[ii], rtemp, nrhs, knsupc, k,
			     fmod, nb, lptr, luptr, xsup, grid, Llu,
			     send_req, stat);
	      } /* if */

	      break;

#if ( DEBUGlevel>=2 )
	    default:
	      printf("(%2d) Recv'd wrong message tag %4d\n", status.MPI_TAG);
	      break;
#endif
	  } /* switch */

    } /* while not finished ... */


#if ( PRNTlevel>=2 )
    t = SuperLU_timer_() - t;
    if ( !iam ) printf(".. L-solve time\t%8.2f\n", t);
    t = SuperLU_timer_();
#endif

#if ( DEBUGlevel==2 )
    {
      printf("(%d) .. After L-solve: y =\n", iam);
      for (i = 0, k = 0; k < nsupers; ++k) {
	  krow = PROW( k, grid );
	  kcol = PCOL( k, grid );
	  if ( myrow == krow && mycol == kcol ) { /* Diagonal process */
	      knsupc = SuperSize( k );
	      lk = LBi( k, grid );
	      ii = X_BLK( lk );
	      for (j = 0; j < knsupc; ++j)
		printf("\t(%d)\t%4d\t%.10f\n", iam, xsup[k]+j, x[ii+j]);
	      fflush(stdout);
	  }
	  MPI_Barrier( grid->comm );
      }
    }
#endif

    SUPERLU_FREE(fmod);
    SUPERLU_FREE(frecv);
    SUPERLU_FREE(rtemp);

#ifdef ISEND_IRECV
    for (i = 0; i < Llu->SolveMsgSent; ++i) MPI_Request_free(&send_req[i]);
    Llu->SolveMsgSent = 0;
#endif


    /*---------------------------------------------------
     * Back solve Ux = y.
     *
     * The Y components from the forward solve is already
     * on the diagonal processes.
     *---------------------------------------------------*/

    /* Save the count to be altered so it can be used by
       subsequent call to PZGSTRS. */
    if ( !(bmod = intMalloc_dist(nlb)) )
	ABORT("Calloc fails for bmod[].");
    for (i = 0; i < nlb; ++i) bmod[i] = Llu->bmod[i];
    if ( !(brecv = intMalloc_dist(nlb)) )
	ABORT("Malloc fails for brecv[].");
    Llu->brecv = brecv;

    /*
     * Compute brecv[] and nbrecvmod counts on the diagonal processes.
     */
    {
	superlu_scope_t *scp = &grid->rscp;

	for (k = 0; k < nsupers; ++k) {
	    krow = PROW( k, grid );
	    if ( myrow == krow ) {
		lk = LBi( k, grid );    /* Local block number. */
		kcol = PCOL( k, grid ); /* Root process in this row scope. */
		if ( mycol != kcol && bmod[lk] )
		    i = 1;  /* Contribution from non-diagonal process. */
		else i = 0;
		MPI_Reduce( &i, &brecv[lk], 1, mpi_int_t,
			   MPI_SUM, kcol, scp->comm );
		if ( mycol == kcol ) { /* Diagonal process. */
		    nbrecvmod += brecv[lk];
		    if ( !brecv[lk] && !bmod[lk] ) ++nroot;
#if ( DEBUGlevel>=2 )
		    printf("(%2d) brecv[%4d]  %2d\n", iam, k, brecv[lk]);
		    assert( brecv[lk] < Pc );
#endif
		}
	    }
	}
    }

    /* Re-initialize lsum to zero. Each block header is already in place. */
    for (k = 0; k < nsupers; ++k) {
	krow = PROW( k, grid );
	if ( myrow == krow ) {
	    knsupc = SuperSize( k );
	    lk = LBi( k, grid );
	    il = LSUM_BLK( lk );
	    dest = &lsum[il];
	    RHS_ITERATE(j) {
		for (i = 0; i < knsupc; ++i) dest[i + j*knsupc] = zero;
	    }
	}
    }
示例#7
0
void
pzgstrs_Bglobal(int_t n, LUstruct_t *LUstruct, gridinfo_t *grid,
                doublecomplex *B, int_t ldb, int nrhs,
                SuperLUStat_t *stat, int *info)
{
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    LocalLU_t *Llu = LUstruct->Llu;
    doublecomplex alpha = {1.0, 0.0};
    doublecomplex zero = {0.0, 0.0};
    doublecomplex *lsum;  /* Local running sum of the updates to B-components */
    doublecomplex *x;     /* X component at step k. */
    doublecomplex *lusup, *dest;
    doublecomplex *recvbuf, *tempv;
    doublecomplex *rtemp; /* Result of full matrix-vector multiply. */
    int_t  **Ufstnz_br_ptr = Llu->Ufstnz_br_ptr;
    int_t  *Urbs, *Urbs1; /* Number of row blocks in each block column of U. */
    Ucb_indptr_t **Ucb_indptr;/* Vertical linked list pointing to Uindex[] */
    int_t  **Ucb_valptr;      /* Vertical linked list pointing to Unzval[] */
    int_t  kcol, krow, mycol, myrow;
    int_t  i, ii, il, j, jj, k, lb, ljb, lk, lptr, luptr;
    int_t  nb, nlb, nub, nsupers;
    int_t  *xsup, *lsub, *usub;
    int_t  *ilsum;    /* Starting position of each supernode in lsum (LOCAL)*/
    int    Pc, Pr, iam;
    int    knsupc, nsupr;
    int    ldalsum;   /* Number of lsum entries locally owned. */
    int    maxrecvsz, p, pi;
    int_t  **Lrowind_bc_ptr;
    doublecomplex **Lnzval_bc_ptr;
    MPI_Status status;
#if defined (ISEND_IRECV) || defined (BSEND)
    MPI_Request *send_req, recv_req;
#endif

    /*-- Counts used for L-solve --*/
    int_t  *fmod;         /* Modification count for L-solve. */
    int_t  **fsendx_plist = Llu->fsendx_plist;
    int_t  nfrecvx = Llu->nfrecvx; /* Number of X components to be recv'd. */
    int_t  *frecv;        /* Count of modifications to be recv'd from
			     processes in this row. */
    int_t  nfrecvmod = 0; /* Count of total modifications to be recv'd. */
    int_t  nleaf = 0, nroot = 0;

    /*-- Counts used for U-solve --*/
    int_t  *bmod;         /* Modification count for L-solve. */
    int_t  **bsendx_plist = Llu->bsendx_plist;
    int_t  nbrecvx = Llu->nbrecvx; /* Number of X components to be recv'd. */
    int_t  *brecv;        /* Count of modifications to be recv'd from
			     processes in this row. */
    int_t  nbrecvmod = 0; /* Count of total modifications to be recv'd. */
    double t;
#if ( DEBUGlevel>=2 )
    int_t Ublocks = 0;
#endif

    int_t *mod_bit = Llu->mod_bit; /* flag contribution from each row block */

    t = SuperLU_timer_();

    /* Test input parameters. */
    *info = 0;
    if ( n < 0 ) *info = -1;
    else if ( nrhs < 0 ) *info = -9;
    if ( *info ) {
	pxerr_dist("PZGSTRS_BGLOBAL", grid, -*info);
	return;
    }

    /*
     * Initialization.
     */
    iam = grid->iam;
    Pc = grid->npcol;
    Pr = grid->nprow;
    myrow = MYROW( iam, grid );
    mycol = MYCOL( iam, grid );
    nsupers = Glu_persist->supno[n-1] + 1;
    xsup = Glu_persist->xsup;
    Lrowind_bc_ptr = Llu->Lrowind_bc_ptr;
    Lnzval_bc_ptr = Llu->Lnzval_bc_ptr;
    nlb = CEILING( nsupers, Pr ); /* Number of local block rows. */
    stat->ops[SOLVE] = 0.0;
    Llu->SolveMsgSent = 0;

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter pzgstrs_Bglobal()");
#endif

    /* Save the count to be altered so it can be used by
       subsequent call to PDGSTRS_BGLOBAL. */
    if ( !(fmod = intMalloc_dist(nlb)) )
	ABORT("Calloc fails for fmod[].");
    for (i = 0; i < nlb; ++i) fmod[i] = Llu->fmod[i];
    if ( !(frecv = intMalloc_dist(nlb)) )
	ABORT("Malloc fails for frecv[].");
    Llu->frecv = frecv;

#if defined (ISEND_IRECV) || defined (BSEND)
    k = SUPERLU_MAX( Llu->nfsendx, Llu->nbsendx ) + nlb;
    if ( !(send_req = (MPI_Request*) SUPERLU_MALLOC(k*sizeof(MPI_Request))) )
	ABORT("Malloc fails for send_req[].");
#endif

#ifdef _CRAY
    ftcs1 = _cptofcd("L", strlen("L"));
    ftcs2 = _cptofcd("N", strlen("N"));
    ftcs3 = _cptofcd("U", strlen("U"));
#endif


    /* Obtain ilsum[] and ldalsum for process column 0. */
    ilsum = Llu->ilsum;
    ldalsum = Llu->ldalsum;

    /* Allocate working storage. */
    knsupc = sp_ienv_dist(3);
    maxrecvsz = knsupc * nrhs + SUPERLU_MAX( XK_H, LSUM_H );
    if ( !(lsum = doublecomplexCalloc_dist(((size_t)ldalsum) * nrhs
        + nlb * LSUM_H)) )
	ABORT("Calloc fails for lsum[].");
    if ( !(x = doublecomplexMalloc_dist(((size_t)ldalsum) * nrhs
        + nlb * XK_H)) )
	ABORT("Malloc fails for x[].");
    if ( !(recvbuf = doublecomplexMalloc_dist(maxrecvsz)) )
	ABORT("Malloc fails for recvbuf[].");
    if ( !(rtemp = doublecomplexCalloc_dist(maxrecvsz)) )
	ABORT("Malloc fails for rtemp[].");


    /*---------------------------------------------------
     * Forward solve Ly = b.
     *---------------------------------------------------*/

    /*
     * Copy B into X on the diagonal processes.
     */
    ii = 0;
    for (k = 0; k < nsupers; ++k) {
	knsupc = SuperSize( k );
	krow = PROW( k, grid );
	if ( myrow == krow ) {
	    lk = LBi( k, grid );   /* Local block number. */
	    il = LSUM_BLK( lk );
	    lsum[il - LSUM_H].r = k;/* Block number prepended in the header. */
	    lsum[il - LSUM_H].i = 0;
	    kcol = PCOL( k, grid );
	    if ( mycol == kcol ) { /* Diagonal process. */
		jj = X_BLK( lk );
		x[jj - XK_H].r = k; /* Block number prepended in the header. */
		x[jj - XK_H].i = 0;
		RHS_ITERATE(j)
		    for (i = 0; i < knsupc; ++i) /* X is stored in blocks. */
			x[i + jj + j*knsupc] = B[i + ii + j*ldb];
	    }
	}
示例#8
0
void
pdgsrfs_ABXglobal(int_t n, SuperMatrix *A, double anorm, LUstruct_t *LUstruct,
		  gridinfo_t *grid, double *B, int_t ldb, double *X, int_t ldx,
		  int nrhs, double *berr, SuperLUStat_t *stat, int *info)
{


#define ITMAX 20

    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    LocalLU_t *Llu = LUstruct->Llu;
    /*
     * Data structures used by matrix-vector multiply routine.
     */
    int_t  N_update; /* Number of variables updated on this process */
    int_t  *update;  /* vector elements (global index) updated
			on this processor.                     */
    int_t  *bindx;
    double *val;
    int_t *mv_sup_to_proc;  /* Supernode to process mapping in
			       matrix-vector multiply.  */
    /*-- end data structures for matrix-vector multiply --*/
    double *b, *ax, *R, *B_col, *temp, *work, *X_col,
           *x_trs, *dx_trs;
    int_t count, ii, j, jj, k, knsupc, lk, lwork,
          nprow, nsupers, nz, p;
    int   i, iam, pkk;
    int_t *ilsum, *xsup;
    double eps, lstres;
    double s, safmin, safe1, safe2;

    /* NEW STUFF */
    int_t num_diag_procs, *diag_procs; /* Record diagonal process numbers. */
    int_t *diag_len; /* Length of the X vector on diagonal processes. */

    /*-- Function prototypes --*/
    extern void pdgstrs1(int_t, LUstruct_t *, gridinfo_t *,
			 double *, int, SuperLUStat_t *, int *);

    /* Test the input parameters. */
    *info = 0;
    if ( n < 0 ) *info = -1;
    else if ( A->nrow != A->ncol || A->nrow < 0 ||
	      A->Stype != SLU_NCP || A->Dtype != SLU_D || A->Mtype != SLU_GE )
	*info = -2;
    else if ( ldb < SUPERLU_MAX(0, n) ) *info = -10;
    else if ( ldx < SUPERLU_MAX(0, n) )	*info = -12;
    else if ( nrhs < 0 ) *info = -13;
    if (*info != 0) {
	i = -(*info);
	pxerr_dist("pdgsrfs_ABXglobal", grid, i);
	return;
    }

    /* Quick return if possible. */
    if ( n == 0 || nrhs == 0 ) {
	return;
    }

    /* Initialization. */
    iam = grid->iam;
    nprow = grid->nprow;
    nsupers = Glu_persist->supno[n-1] + 1;
    xsup = Glu_persist->xsup;
    ilsum = Llu->ilsum;

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter pdgsrfs_ABXglobal()");
#endif

    get_diag_procs(n, Glu_persist, grid, &num_diag_procs,
		   &diag_procs, &diag_len);
#if ( PRNTlevel>=1 )
    if ( !iam ) {
	printf(".. number of diag processes = " IFMT "\n", num_diag_procs);
	PrintInt10("diag_procs", num_diag_procs, diag_procs);
	PrintInt10("diag_len", num_diag_procs, diag_len);
    }
#endif

    if ( !(mv_sup_to_proc = intCalloc_dist(nsupers)) )
	ABORT("Calloc fails for mv_sup_to_proc[]");

    pdgsmv_AXglobal_setup(A, Glu_persist, grid, &N_update, &update,
		          &val, &bindx, mv_sup_to_proc);

    i = CEILING( nsupers, nprow ); /* Number of local block rows */
    ii = Llu->ldalsum + i * XK_H;
    k = SUPERLU_MAX(N_update, sp_ienv_dist(3));
    jj = diag_len[0];
    for (j = 1; j < num_diag_procs; ++j) jj = SUPERLU_MAX( jj, diag_len[j] );
    jj = SUPERLU_MAX( jj, N_update );
    lwork = N_update         /* For ax and R */
	  + ii               /* For dx_trs */
	  + ii               /* For x_trs */
          + k                /* For b */
	  + jj;              /* for temp */
    if ( !(work = doubleMalloc_dist(lwork)) )
	ABORT("Malloc fails for work[]");
    ax = R = work;
    dx_trs = work + N_update;
    x_trs  = dx_trs + ii;
    b      = x_trs + ii;
    temp   = b + k;

#if ( DEBUGlevel>=2 )
    {
	double *dwork = doubleMalloc_dist(n);
	for (i = 0; i < n; ++i) {
	    if ( i & 1 ) dwork[i] = 1.;
	    else dwork[i] = 2.;
        }
	/* Check correctness of matrix-vector multiply. */
	pdgsmv_AXglobal(N_update, update, val, bindx, dwork, ax);
	PrintDouble5("Mult A*x", N_update, ax);
	SUPERLU_FREE(dwork);
    }
#endif


    /* NZ = maximum number of nonzero elements in each row of A, plus 1 */
    nz     = A->ncol + 1;
    eps    = dmach_dist("Epsilon");
    safmin = dmach_dist("Safe minimum");

    /* Set SAFE1 essentially to be the underflow threshold times the
       number of additions in each row. */
    safe1  = nz * safmin;
    safe2  = safe1 / eps;

#if ( DEBUGlevel>=1 )
    if ( !iam ) printf(".. eps = %e\tanorm = %e\tsafe1 = %e\tsafe2 = %e\n",
		       eps, anorm, safe1, safe2);
#endif

    /* Do for each right-hand side ... */
    for (j = 0; j < nrhs; ++j) {
	count = 0;
	lstres = 3.;

	/* Copy X into x on the diagonal processes. */
	B_col = &B[j*ldb];
	X_col = &X[j*ldx];
	for (p = 0; p < num_diag_procs; ++p) {
	    pkk = diag_procs[p];
	    if ( iam == pkk ) {
		for (k = p; k < nsupers; k += num_diag_procs) {
		    knsupc = SuperSize( k );
		    lk = LBi( k, grid );
		    ii = ilsum[lk] + (lk+1)*XK_H;
		    jj = FstBlockC( k );
		    for (i = 0; i < knsupc; ++i) x_trs[i+ii] = X_col[i+jj];
		    dx_trs[ii-XK_H] = k;/* Block number prepended in header. */
		}
	    }
	}
	/* Copy B into b distributed the same way as matrix-vector product. */
        if ( N_update ) ii = update[0];
	for (i = 0; i < N_update; ++i) b[i] = B_col[i + ii];

	while (1) { /* Loop until stopping criterion is satisfied. */

	    /* Compute residual R = B - op(A) * X,
	       where op(A) = A, A**T, or A**H, depending on TRANS. */

	    /* Matrix-vector multiply. */
	    pdgsmv_AXglobal(N_update, update, val, bindx, X_col, ax);

	    /* Compute residual. */
	    for (i = 0; i < N_update; ++i) R[i] = b[i] - ax[i];

	    /* Compute abs(op(A))*abs(X) + abs(B). */
	    pdgsmv_AXglobal_abs(N_update, update, val, bindx, X_col, temp);
	    for (i = 0; i < N_update; ++i) temp[i] += fabs(b[i]);

	    s = 0.0;
	    for (i = 0; i < N_update; ++i) {
		if ( temp[i] > safe2 ) {
		    s = SUPERLU_MAX(s, fabs(R[i]) / temp[i]);
		} else if ( temp[i] != 0.0 ) {
                    /* Adding SAFE1 to the numerator guards against
                       spuriously zero residuals (underflow). */
		    s = SUPERLU_MAX(s, (safe1 + fabs(R[i])) / temp[i]);
                }
                /* If temp[i] is exactly 0.0 (computed by PxGSMV), then
                   we know the true residual also must be exactly 0.0. */
	    }
	    MPI_Allreduce( &s, &berr[j], 1, MPI_DOUBLE, MPI_MAX, grid->comm );

#if ( PRNTlevel>= 1 )
	    if ( !iam )
		printf("(%2d) .. Step " IFMT ": berr[j] = %e\n", iam, count, berr[j]);
#endif
	    if ( berr[j] > eps && berr[j] * 2 <= lstres && count < ITMAX ) {
		/* Compute new dx. */
		redist_all_to_diag(n, R, Glu_persist, Llu, grid,
				   mv_sup_to_proc, dx_trs);
		pdgstrs1(n, LUstruct, grid, dx_trs, 1, stat, info);

		/* Update solution. */
		for (p = 0; p < num_diag_procs; ++p)
		    if ( iam == diag_procs[p] )
			for (k = p; k < nsupers; k += num_diag_procs) {
			    lk = LBi( k, grid );
			    ii = ilsum[lk] + (lk+1)*XK_H;
			    knsupc = SuperSize( k );
			    for (i = 0; i < knsupc; ++i)
				x_trs[i + ii] += dx_trs[i + ii];
			}
		lstres = berr[j];
		++count;
		/* Transfer x_trs (on diagonal processes) into X
		   (on all processes). */
		gather_1rhs_diag_to_all(n, x_trs, Glu_persist, Llu, grid,
					num_diag_procs, diag_procs, diag_len,
					X_col, temp);
	    } else {
		break;
	    }
	} /* end while */

	stat->RefineSteps = count;

    } /* for j ... */


    /* Deallocate storage used by matrix-vector multiplication. */
    SUPERLU_FREE(diag_procs);
    SUPERLU_FREE(diag_len);
    if ( N_update ) {
	SUPERLU_FREE(update);
	SUPERLU_FREE(bindx);
	SUPERLU_FREE(val);
    }
    SUPERLU_FREE(mv_sup_to_proc);
    SUPERLU_FREE(work);

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Exit pdgsrfs_ABXglobal()");
#endif

} /* PDGSRFS_ABXGLOBAL */
示例#9
0
void pdgstrs1(int_t n, LUstruct_t *LUstruct, gridinfo_t *grid,
	      double *x, int nrhs, SuperLUStat_t *stat, int *info)
{
/*
 * Purpose
 * =======
 *
 * PDGSTRS1 solves a system of distributed linear equations
 *
 *                   op( sub(A) ) * X = sub( B )
 *
 * with a general N-by-N distributed matrix sub( A ) using the LU
 * factorization computed by PDGSTRF.
 * 
 * Arguments
 * =========
 *
 * n      (input) int (global)
 *        The order of the system of linear equations.
 *
 * LUstruct (input) LUstruct_t*
 *        The distributed data structures to store L and U factors,
 *        and the permutation vectors.
 *        See superlu_ddefs.h for the definition of 'LUstruct_t' structure.
 *
 * grid   (input) gridinfo_t*
 *        The 2D process mesh.
 *
 * x      (input/output) double*
 *        On entry, the right hand side matrix.
 *        On exit, the solution matrix if info = 0;
 *
 *        NOTE: the right-hand side matrix is already distributed on
 *              the diagonal processes.
 *
 * nrhs   (input) int (global)
 *        Number of right-hand sides.
 *
 * stat   (output) SuperLUStat_t*
 *        Record the statistics about the triangular solves; 
 *        See SuperLUStat_t structure defined in util.h.
 *
 * info   (output) int*
 * 	   = 0: successful exit
 *	   < 0: if info = -i, the i-th argument had an illegal value
 *        
 */
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    LocalLU_t *Llu = LUstruct->Llu;
    double alpha = 1.0;
    double *lsum;  /* Local running sum of the updates to B-components */
    double *lusup, *dest;
    double *recvbuf, *tempv;
    double *rtemp; /* Result of full matrix-vector multiply. */
    int_t  **Ufstnz_br_ptr = Llu->Ufstnz_br_ptr;
    int_t  *Urbs, *Urbs1; /* Number of row blocks in each block column of U. */
    Ucb_indptr_t **Ucb_indptr;/* Vertical linked list pointing to Uindex[] */
    int_t  **Ucb_valptr;      /* Vertical linked list pointing to Unzval[] */
    int_t  iam, kcol, krow, mycol, myrow;
    int_t  i, ii, il, j, k, lb, ljb, lk, lptr, luptr;
    int_t  nb, nlb, nub, nsupers;
    int_t  *xsup, *lsub, *usub;
    int_t  *ilsum;    /* Starting position of each supernode in lsum (LOCAL)*/
    int_t  Pc, Pr;
    int    knsupc, nsupr;
    int    ldalsum;   /* Number of lsum entries locally owned. */
    int    maxrecvsz, p, pi;
    int_t  **Lrowind_bc_ptr;
    double **Lnzval_bc_ptr;
    MPI_Status status;
#ifdef ISEND_IRECV
    MPI_Request *send_req, recv_req;
#endif

    /*-- Counts used for L-solve --*/
    int_t  *fmod;         /* Modification count for L-solve. */
    int_t  **fsendx_plist = Llu->fsendx_plist;
    int_t  nfrecvx = Llu->nfrecvx; /* Number of X components to be recv'd. */
    int_t  *frecv;        /* Count of modifications to be recv'd from
			     processes in this row. */
    int_t  nfrecvmod = 0; /* Count of total modifications to be recv'd. */
    int_t  nleaf = 0, nroot = 0;

    /*-- Counts used for U-solve --*/
    int_t  *bmod;         /* Modification count for L-solve. */
    int_t  **bsendx_plist = Llu->bsendx_plist;
    int_t  nbrecvx = Llu->nbrecvx; /* Number of X components to be recv'd. */
    int_t  *brecv;        /* Count of modifications to be recv'd from
			     processes in this row. */
    int_t  nbrecvmod = 0; /* Count of total modifications to be recv'd. */
    double t;
#if ( DEBUGlevel>=2 )
    int_t Ublocks = 0;
#endif

    t = SuperLU_timer_();

    /* Test input parameters. */
    *info = 0;
    if ( n < 0 ) *info = -1;
    else if ( nrhs < 0 ) *info = -8;
    if ( *info ) {
	pxerbla("PDGSTRS1", grid, -*info);
	return;
    }
	
    /*
     * Initialization.
     */
    iam = grid->iam;
    Pc = grid->npcol;
    Pr = grid->nprow;
    myrow = MYROW( iam, grid );
    mycol = MYCOL( iam, grid );
    nsupers = Glu_persist->supno[n-1] + 1;
    xsup = Glu_persist->xsup;
    Lrowind_bc_ptr = Llu->Lrowind_bc_ptr;
    Lnzval_bc_ptr = Llu->Lnzval_bc_ptr;
    nlb = CEILING( nsupers, Pr ); /* Number of local block rows. */
    Llu->SolveMsgSent = 0;

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter pdgstrs1()");
#endif

    /* Save the count to be altered so it can be used by
       subsequent call to PDGSTRS1. */
    if ( !(fmod = intMalloc_dist(nlb)) )
	ABORT("Calloc fails for fmod[].");
    for (i = 0; i < nlb; ++i) fmod[i] = Llu->fmod[i];
    if ( !(frecv = intMalloc_dist(nlb)) )
	ABORT("Malloc fails for frecv[].");
    Llu->frecv = frecv;

#ifdef ISEND_IRECV
    k = SUPERLU_MAX( Llu->nfsendx, Llu->nbsendx ) + nlb;
    if ( !(send_req = (MPI_Request*) SUPERLU_MALLOC(k*sizeof(MPI_Request))) )
	ABORT("Malloc fails for send_req[].");
#endif

#ifdef _CRAY
    ftcs1 = _cptofcd("L", strlen("L"));
    ftcs2 = _cptofcd("N", strlen("N"));
    ftcs3 = _cptofcd("U", strlen("U"));
#endif


    /* Compute ilsum[] and ldalsum for process column 0. */
    ilsum = Llu->ilsum;
    ldalsum = Llu->ldalsum;

    /* Allocate working storage. */
    knsupc = sp_ienv_dist(3);
    if ( !(lsum = doubleCalloc_dist(((size_t)ldalsum) * nrhs 
        + nlb * LSUM_H)) )
	ABORT("Calloc fails for lsum[].");
    maxrecvsz = knsupc * nrhs + SUPERLU_MAX(XK_H, LSUM_H);
    if ( !(recvbuf = doubleMalloc_dist(maxrecvsz)) )
	ABORT("Malloc fails for recvbuf[].");
    if ( !(rtemp = doubleCalloc_dist(maxrecvsz)) )
	ABORT("Malloc fails for rtemp[].");

    
    /*---------------------------------------------------
     * Forward solve Ly = b.
     *---------------------------------------------------*/

    /*
     * Prepended the block number in the header for lsum[].
     */
    for (k = 0; k < nsupers; ++k) {
	knsupc = SuperSize( k );
	krow = PROW( k, grid );
	if ( myrow == krow ) {
	    lk = LBi( k, grid );   /* Local block number. */
	    il = LSUM_BLK( lk );
	    lsum[il - LSUM_H] = k; 
	}
    }

    /*
     * Compute frecv[] and nfrecvmod counts on the diagonal processes.
     */
    {
	superlu_scope_t *scp = &grid->rscp;

	for (k = 0; k < nsupers; ++k) {
	    krow = PROW( k, grid );
	    if ( myrow == krow ) {
		lk = LBi( k, grid );    /* Local block number. */
		kcol = PCOL( k, grid ); /* Root process in this row scope. */
		if ( mycol != kcol && fmod[lk] )
		    i = 1;  /* Contribution from non-diagonal process. */
		else i = 0;
		MPI_Reduce( &i, &frecv[lk], 1, mpi_int_t,
			   MPI_SUM, kcol, scp->comm );
		if ( mycol == kcol ) { /* Diagonal process. */
		    nfrecvmod += frecv[lk];
		    if ( !frecv[lk] && !fmod[lk] ) ++nleaf;
#if ( DEBUGlevel>=2 )
		    printf("(%2d) frecv[%4d]  %2d\n", iam, k, frecv[lk]);
		    assert( frecv[lk] < Pc );
#endif
		}
	    }
	}
    }

    /* ---------------------------------------------------------
       Solve the leaf nodes first by all the diagonal processes.
       --------------------------------------------------------- */
#if ( DEBUGlevel>=2 )
    printf("(%2d) nleaf %4d\n", iam, nleaf);
#endif
    for (k = 0; k < nsupers && nleaf; ++k) {
	krow = PROW( k, grid );
	kcol = PCOL( k, grid );
	if ( myrow == krow && mycol == kcol ) { /* Diagonal process */
	    knsupc = SuperSize( k );
	    lk = LBi( k, grid );
	    if ( !frecv[lk] && !fmod[lk] ) {
		fmod[lk] = -1;  /* Do not solve X[k] in the future. */
		ii = X_BLK( lk );
		lk = LBj( k, grid ); /* Local block number, column-wise. */
		lsub = Lrowind_bc_ptr[lk];
		lusup = Lnzval_bc_ptr[lk];
		nsupr = lsub[1];
#ifdef _CRAY
		STRSM(ftcs1, ftcs1, ftcs2, ftcs3, &knsupc, &nrhs, &alpha,
		      lusup, &nsupr, &x[ii], &knsupc);
#elif defined (USE_VENDOR_BLAS)
		dtrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
		       lusup, &nsupr, &x[ii], &knsupc, 1, 1, 1, 1);
#else
		dtrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
		       lusup, &nsupr, &x[ii], &knsupc);
#endif
		/*stat->ops[SOLVE] += knsupc * (knsupc - 1) * nrhs;*/
		--nleaf;
#if ( DEBUGlevel>=2 )
		printf("(%2d) Solve X[%2d]\n", iam, k);
#endif
		
		/*
		 * Send Xk to process column Pc[k].
		 */
		for (p = 0; p < Pr; ++p)
		    if ( fsendx_plist[lk][p] != EMPTY ) {
			pi = PNUM( p, kcol, grid );
#ifdef ISEND_IRECV
			MPI_Isend( &x[ii - XK_H], knsupc * nrhs + XK_H,
                                   MPI_DOUBLE, pi, Xk, grid->comm,
                                   &send_req[Llu->SolveMsgSent++]);
#else
			MPI_Send( &x[ii - XK_H], knsupc * nrhs + XK_H,
				 MPI_DOUBLE, 
                                 pi, Xk, grid->comm );
#endif
#if ( DEBUGlevel>=2 )
			printf("(%2d) Sent X[%2.0f] to P %2d\n",
			       iam, x[ii-XK_H], pi);
#endif
		    }
		
		/*
		 * Perform local block modifications: lsum[i] -= L_i,k * X[k]
		 */
		nb = lsub[0] - 1;
		lptr = BC_HEADER + LB_DESCRIPTOR + knsupc;
		luptr = knsupc; /* Skip diagonal block L(k,k). */
		
		dlsum_fmod(lsum, x, &x[ii], rtemp, nrhs, knsupc, k,
			   fmod, nb, lptr, luptr, xsup, grid, Llu,
			   send_req, stat);
	    }
	} /* if diagonal process ... */
    } /* for k ... */

    /*
     * Compute the internal nodes asynchronously by all processes.
     */
#if ( DEBUGlevel>=2 )
    printf("(%2d) nfrecvx %4d,  nfrecvmod %4d,  nleaf %4d\n",
	   iam, nfrecvx, nfrecvmod, nleaf);
#endif

    while ( nfrecvx || nfrecvmod ) { /* While not finished. */

	/* Receive a message. */
#ifdef ISEND_IRECV
	/* -MPI- FATAL: Remote protocol queue full */
	MPI_Irecv( recvbuf, maxrecvsz, MPI_DOUBLE, MPI_ANY_SOURCE,
		 MPI_ANY_TAG, grid->comm, &recv_req );
	MPI_Wait( &recv_req, &status );
#else
	MPI_Recv( recvbuf, maxrecvsz, MPI_DOUBLE, MPI_ANY_SOURCE,
		 MPI_ANY_TAG, grid->comm, &status );
#endif

	k = *recvbuf;

#if ( DEBUGlevel>=2 )
	printf("(%2d) Recv'd block %d, tag %2d\n", iam, k, status.MPI_TAG);
#endif
	
	switch ( status.MPI_TAG ) {
	  case Xk:
	      --nfrecvx;
	      lk = LBj( k, grid ); /* Local block number, column-wise. */
	      lsub = Lrowind_bc_ptr[lk];
	      lusup = Lnzval_bc_ptr[lk];
	      if ( lsub ) {
		  nb   = lsub[0];
		  lptr = BC_HEADER;
		  luptr = 0;
		  knsupc = SuperSize( k );

		  /*
		   * Perform local block modifications: lsum[i] -= L_i,k * X[k]
		   */
		  dlsum_fmod(lsum, x, &recvbuf[XK_H], rtemp, nrhs, knsupc, k,
			     fmod, nb, lptr, luptr, xsup, grid, Llu,
			     send_req, stat);
	      } /* if lsub */

	      break;

	  case LSUM:
	      --nfrecvmod;
	      lk = LBi( k, grid ); /* Local block number, row-wise. */
	      ii = X_BLK( lk );
	      knsupc = SuperSize( k );
	      tempv = &recvbuf[LSUM_H];
	      RHS_ITERATE(j)
		  for (i = 0; i < knsupc; ++i)
		      x[i + ii + j*knsupc] += tempv[i + j*knsupc];

	      if ( (--frecv[lk])==0 && fmod[lk]==0 ) {
		  fmod[lk] = -1; /* Do not solve X[k] in the future. */
		  lk = LBj( k, grid ); /* Local block number, column-wise. */
		  lsub = Lrowind_bc_ptr[lk];
		  lusup = Lnzval_bc_ptr[lk];
		  nsupr = lsub[1];
#ifdef _CRAY
		  STRSM(ftcs1, ftcs1, ftcs2, ftcs3, &knsupc, &nrhs, &alpha,
			lusup, &nsupr, &x[ii], &knsupc);
#elif defined (USE_VENDOR_BLAS)
		  dtrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
			 lusup, &nsupr, &x[ii], &knsupc, 1, 1, 1, 1);
#else
		  dtrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
			 lusup, &nsupr, &x[ii], &knsupc);
#endif
		  /*stat->ops[SOLVE] += knsupc * (knsupc - 1) * nrhs;*/
#if ( DEBUGlevel>=2 )
		  printf("(%2d) Solve X[%2d]\n", iam, k);
#endif
		
		  /*
		   * Send Xk to process column Pc[k].
		   */
		  kcol = PCOL( k, grid );
		  for (p = 0; p < Pr; ++p)
		      if ( fsendx_plist[lk][p] != EMPTY ) {
			  pi = PNUM( p, kcol, grid );
#ifdef ISEND_IRECV
			  MPI_Isend( &x[ii - XK_H], knsupc * nrhs + XK_H,
                                     MPI_DOUBLE, pi, Xk, grid->comm,
				     &send_req[Llu->SolveMsgSent++] );
#else
			  MPI_Send( &x[ii - XK_H], knsupc * nrhs + XK_H,
				   MPI_DOUBLE, pi, Xk, grid->comm );
#endif
#if ( DEBUGlevel>=2 )
			  printf("(%2d) Sent X[%2.0f] to P %2d\n",
				 iam, x[ii-XK_H], pi);
#endif
		      }

		  /*
		   * Perform local block modifications.
		   */
		  nb = lsub[0] - 1;
		  lptr = BC_HEADER + LB_DESCRIPTOR + knsupc;
		  luptr = knsupc; /* Skip diagonal block L(k,k). */

		  dlsum_fmod(lsum, x, &x[ii], rtemp, nrhs, knsupc, k,
			     fmod, nb, lptr, luptr, xsup, grid, Llu,
			     send_req, stat);
	      } /* if */

	      break;

#if ( DEBUGlevel>=2 )
	    default:
	      printf("(%2d) Recv'd wrong message tag %4d\n", status.MPI_TAG);
	      break;
#endif
	  } /* switch */

    } /* while not finished ... */


#if ( PRNTlevel>=2 )
    t = SuperLU_timer_() - t;
    if ( !iam ) printf(".. L-solve time\t%8.2f\n", t);
    t = SuperLU_timer_();
#endif

#if ( DEBUGlevel>=2 )
    if ( !iam ) printf("\n.. After L-solve: y =\n");
    for (i = 0, k = 0; k < nsupers; ++k) {
	krow = PROW( k, grid );
	kcol = PCOL( k, grid );
	if ( myrow == krow && mycol == kcol ) { /* Diagonal process */
	    knsupc = SuperSize( k );
	    lk = LBi( k, grid );
	    ii = X_BLK( lk );
	    for (j = 0; j < knsupc; ++j)
		printf("\t(%d)\t%4d\t%.10f\n", iam, xsup[k]+j, x[ii+j]);
	}
	MPI_Barrier( grid->comm );
    }
#endif

    SUPERLU_FREE(fmod);
    SUPERLU_FREE(frecv);
    SUPERLU_FREE(rtemp);

#ifdef ISEND_IRECV
    for (i = 0; i < Llu->SolveMsgSent; ++i) MPI_Request_free(&send_req[i]);
    Llu->SolveMsgSent = 0;
#endif


    /*---------------------------------------------------
     * Back solve Ux = y.
     *
     * The Y components from the forward solve is already
     * on the diagonal processes.
     *---------------------------------------------------*/

    /* Save the count to be altered so it can be used by
       subsequent call to PDGSTRS1. */
    if ( !(bmod = intMalloc_dist(nlb)) )
	ABORT("Calloc fails for bmod[].");
    for (i = 0; i < nlb; ++i) bmod[i] = Llu->bmod[i];
    if ( !(brecv = intMalloc_dist(nlb)) )
	ABORT("Malloc fails for brecv[].");
    Llu->brecv = brecv;

    /*
     * Compute brecv[] and nbrecvmod counts on the diagonal processes.
     */
    {
	superlu_scope_t *scp = &grid->rscp;

	for (k = 0; k < nsupers; ++k) {
	    krow = PROW( k, grid );
	    if ( myrow == krow ) {
		lk = LBi( k, grid );    /* Local block number. */
		kcol = PCOL( k, grid ); /* Root process in this row scope. */
		if ( mycol != kcol && bmod[lk] )
		    i = 1;  /* Contribution from non-diagonal process. */
		else i = 0;
		MPI_Reduce( &i, &brecv[lk], 1, mpi_int_t,
			   MPI_SUM, kcol, scp->comm );
		if ( mycol == kcol ) { /* Diagonal process. */
		    nbrecvmod += brecv[lk];
		    if ( !brecv[lk] && !bmod[lk] ) ++nroot;
#if ( DEBUGlevel>=2 )
		    printf("(%2d) brecv[%4d]  %2d\n", iam, k, brecv[lk]);
		    assert( brecv[lk] < Pc );
#endif
		}
	    }
	}
    }

    /* Re-initialize lsum to zero. Each block header is already in place. */
    for (k = 0; k < nsupers; ++k) {
	krow = PROW( k, grid );
	if ( myrow == krow ) {
	    knsupc = SuperSize( k );
	    lk = LBi( k, grid );
	    il = LSUM_BLK( lk );
	    dest = &lsum[il];
	    RHS_ITERATE(j)
		for (i = 0; i < knsupc; ++i) dest[i + j*knsupc] = 0.0;
	}
    }
void
pzgstrs(int_t n, LUstruct_t *LUstruct, 
	ScalePermstruct_t *ScalePermstruct,
	gridinfo_t *grid, doublecomplex *B,
	int_t m_loc, int_t fst_row, int_t ldb, int nrhs,
	SOLVEstruct_t *SOLVEstruct,
	SuperLUStat_t *stat, int *info)
{
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    LocalLU_t *Llu = LUstruct->Llu;
    doublecomplex alpha = {1.0, 0.0};
    doublecomplex zero = {0.0, 0.0};
    doublecomplex *lsum;  /* Local running sum of the updates to B-components */
    doublecomplex *x;     /* X component at step k. */
		    /* NOTE: x and lsum are of same size. */
    doublecomplex *lusup, *dest;
    doublecomplex *recvbuf, *tempv;
    doublecomplex *rtemp; /* Result of full matrix-vector multiply. */
    int_t  **Ufstnz_br_ptr = Llu->Ufstnz_br_ptr;
    int_t  *Urbs, *Urbs1; /* Number of row blocks in each block column of U. */
    Ucb_indptr_t **Ucb_indptr;/* Vertical linked list pointing to Uindex[] */
    int_t  **Ucb_valptr;      /* Vertical linked list pointing to Unzval[] */
    int_t  iam, kcol, krow, mycol, myrow;
    int_t  i, ii, il, j, jj, k, lb, ljb, lk, lptr, luptr;
    int_t  nb, nlb, nub, nsupers;
    int_t  *xsup, *supno, *lsub, *usub;
    int_t  *ilsum;    /* Starting position of each supernode in lsum (LOCAL)*/
    int_t  Pc, Pr;
    int    knsupc, nsupr;
    int    ldalsum;   /* Number of lsum entries locally owned. */
    int    maxrecvsz, p, pi;
    int_t  **Lrowind_bc_ptr;
    doublecomplex **Lnzval_bc_ptr;
    MPI_Status status;
    MPI_Request *send_req, recv_req;
    pxgstrs_comm_t *gstrs_comm = SOLVEstruct->gstrs_comm;

    /*-- Counts used for L-solve --*/
    int_t  *fmod;         /* Modification count for L-solve --
                             Count the number of local block products to
                             be summed into lsum[lk]. */
    int_t  **fsendx_plist = Llu->fsendx_plist;
    int_t  nfrecvx = Llu->nfrecvx; /* Number of X components to be recv'd. */
    int_t  *frecv;        /* Count of lsum[lk] contributions to be received
                             from processes in this row. 
                             It is only valid on the diagonal processes. */
    int_t  nfrecvmod = 0; /* Count of total modifications to be recv'd. */
    int_t  nleaf = 0, nroot = 0;

    /*-- Counts used for U-solve --*/
    int_t  *bmod;         /* Modification count for U-solve. */
    int_t  **bsendx_plist = Llu->bsendx_plist;
    int_t  nbrecvx = Llu->nbrecvx; /* Number of X components to be recv'd. */
    int_t  *brecv;        /* Count of modifications to be recv'd from
			     processes in this row. */
    int_t  nbrecvmod = 0; /* Count of total modifications to be recv'd. */
    double t;
#if ( DEBUGlevel>=2 )
    int_t Ublocks = 0;
#endif

    int_t *mod_bit = Llu->mod_bit; /* flag contribution from each row block */
 
    t = SuperLU_timer_();

    /* Test input parameters. */
    *info = 0;
    if ( n < 0 ) *info = -1;
    else if ( nrhs < 0 ) *info = -9;
    if ( *info ) {
	pxerbla("PZGSTRS", grid, -*info);
	return;
    }
	
    /*
     * Initialization.
     */
    iam = grid->iam;
    Pc = grid->npcol;
    Pr = grid->nprow;
    myrow = MYROW( iam, grid );
    mycol = MYCOL( iam, grid );
    xsup = Glu_persist->xsup;
    supno = Glu_persist->supno;
    nsupers = supno[n-1] + 1;
    Lrowind_bc_ptr = Llu->Lrowind_bc_ptr;
    Lnzval_bc_ptr = Llu->Lnzval_bc_ptr;
    nlb = CEILING( nsupers, Pr ); /* Number of local block rows. */

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter pzgstrs()");
#endif

    stat->ops[SOLVE] = 0.0;
    Llu->SolveMsgSent = 0;

    /* Save the count to be altered so it can be used by
       subsequent call to PDGSTRS. */
    if ( !(fmod = intMalloc_dist(nlb)) )
	ABORT("Calloc fails for fmod[].");
    for (i = 0; i < nlb; ++i) fmod[i] = Llu->fmod[i];
    if ( !(frecv = intMalloc_dist(nlb)) )
	ABORT("Malloc fails for frecv[].");
    Llu->frecv = frecv;

    k = SUPERLU_MAX( Llu->nfsendx, Llu->nbsendx ) + nlb;
    if ( !(send_req = (MPI_Request*) SUPERLU_MALLOC(k*sizeof(MPI_Request))) )
	ABORT("Malloc fails for send_req[].");

#ifdef _CRAY
    ftcs1 = _cptofcd("L", strlen("L"));
    ftcs2 = _cptofcd("N", strlen("N"));
    ftcs3 = _cptofcd("U", strlen("U"));
#endif


    /* Obtain ilsum[] and ldalsum for process column 0. */
    ilsum = Llu->ilsum;
    ldalsum = Llu->ldalsum;

    /* Allocate working storage. */
    knsupc = sp_ienv_dist(3);
    maxrecvsz = knsupc * nrhs + SUPERLU_MAX( XK_H, LSUM_H );
    if ( !(lsum = doublecomplexCalloc_dist(((size_t)ldalsum)*nrhs + nlb*LSUM_H)) )
	ABORT("Calloc fails for lsum[].");
    if ( !(x = doublecomplexMalloc_dist(ldalsum * nrhs + nlb * XK_H)) )
	ABORT("Malloc fails for x[].");
    if ( !(recvbuf = doublecomplexMalloc_dist(maxrecvsz)) )
	ABORT("Malloc fails for recvbuf[].");
    if ( !(rtemp = doublecomplexCalloc_dist(maxrecvsz)) )
	ABORT("Malloc fails for rtemp[].");

    
    /*---------------------------------------------------
     * Forward solve Ly = b.
     *---------------------------------------------------*/
    /* Redistribute B into X on the diagonal processes. */
    pzReDistribute_B_to_X(B, m_loc, nrhs, ldb, fst_row, ilsum, x, 
			  ScalePermstruct, Glu_persist, grid, SOLVEstruct);

    /* Set up the headers in lsum[]. */
    ii = 0;
    for (k = 0; k < nsupers; ++k) {
	knsupc = SuperSize( k );
	krow = PROW( k, grid );
	if ( myrow == krow ) {
	    lk = LBi( k, grid );   /* Local block number. */
	    il = LSUM_BLK( lk );
	    lsum[il - LSUM_H].r = k;/* Block number prepended in the header.*/
	    lsum[il - LSUM_H].i = 0;
	}
	ii += knsupc;
    }

    /*
     * Compute frecv[] and nfrecvmod counts on the diagonal processes.
     */
    {
	superlu_scope_t *scp = &grid->rscp;

#if 1
	for (k = 0; k < nlb; ++k) mod_bit[k] = 0;
	for (k = 0; k < nsupers; ++k) {
	    krow = PROW( k, grid );
	    if ( myrow == krow ) {
		lk = LBi( k, grid );    /* local block number */
		kcol = PCOL( k, grid );
		if ( mycol != kcol && fmod[lk] )
		    mod_bit[lk] = 1;  /* contribution from off-diagonal */
	    }
	}
	/*PrintInt10("mod_bit", nlb, mod_bit);*/
	
#if ( PROFlevel>=2 )
	t_reduce_tmp = SuperLU_timer_();
#endif
	/* Every process receives the count, but it is only useful on the
	   diagonal processes.  */
	MPI_Allreduce( mod_bit, frecv, nlb, mpi_int_t, MPI_SUM, scp->comm );

#if ( PROFlevel>=2 )
	t_reduce += SuperLU_timer_() - t_reduce_tmp;
#endif

	for (k = 0; k < nsupers; ++k) {
	    krow = PROW( k, grid );
	    if ( myrow == krow ) {
		lk = LBi( k, grid );    /* local block number */
		kcol = PCOL( k, grid );
		if ( mycol == kcol ) { /* diagonal process */
		    nfrecvmod += frecv[lk];
		    if ( !frecv[lk] && !fmod[lk] ) ++nleaf;
		}
	    }
	}

#else /* old */

	for (k = 0; k < nsupers; ++k) {
	    krow = PROW( k, grid );
	    if ( myrow == krow ) {
		lk = LBi( k, grid );    /* Local block number. */
		kcol = PCOL( k, grid ); /* Root process in this row scope. */
		if ( mycol != kcol && fmod[lk] )
		    i = 1;  /* Contribution from non-diagonal process. */
		else i = 0;
		MPI_Reduce( &i, &frecv[lk], 1, mpi_int_t,
			   MPI_SUM, kcol, scp->comm );
		if ( mycol == kcol ) { /* Diagonal process. */
		    nfrecvmod += frecv[lk];
		    if ( !frecv[lk] && !fmod[lk] ) ++nleaf;
#if ( DEBUGlevel>=2 )
		    printf("(%2d) frecv[%4d]  %2d\n", iam, k, frecv[lk]);
		    assert( frecv[lk] < Pc );
#endif
		}
	    }
	}
#endif
    }

    /* ---------------------------------------------------------
       Solve the leaf nodes first by all the diagonal processes.
       --------------------------------------------------------- */
#if ( DEBUGlevel>=2 )
    printf("(%2d) nleaf %4d\n", iam, nleaf);
#endif
    for (k = 0; k < nsupers && nleaf; ++k) {
	krow = PROW( k, grid );
	kcol = PCOL( k, grid );
	if ( myrow == krow && mycol == kcol ) { /* Diagonal process */
	    knsupc = SuperSize( k );
	    lk = LBi( k, grid );
	    if ( frecv[lk]==0 && fmod[lk]==0 ) {
		fmod[lk] = -1;  /* Do not solve X[k] in the future. */
		ii = X_BLK( lk );
		lk = LBj( k, grid ); /* Local block number, column-wise. */
		lsub = Lrowind_bc_ptr[lk];
		lusup = Lnzval_bc_ptr[lk];
		nsupr = lsub[1];
#ifdef _CRAY
		CTRSM(ftcs1, ftcs1, ftcs2, ftcs3, &knsupc, &nrhs, &alpha,
		      lusup, &nsupr, &x[ii], &knsupc);
#elif defined (USE_VENDOR_BLAS)
		ztrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
		       lusup, &nsupr, &x[ii], &knsupc, 1, 1, 1, 1);
#else
		ztrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
		       lusup, &nsupr, &x[ii], &knsupc);
#endif
		stat->ops[SOLVE] += 4 * knsupc * (knsupc - 1) * nrhs
		    + 10 * knsupc * nrhs; /* complex division */
		--nleaf;
#if ( DEBUGlevel>=2 )
		printf("(%2d) Solve X[%2d]\n", iam, k);
#endif
		
		/*
		 * Send Xk to process column Pc[k].
		 */
		for (p = 0; p < Pr; ++p) {
		    if ( fsendx_plist[lk][p] != EMPTY ) {
			pi = PNUM( p, kcol, grid );

			MPI_Isend( &x[ii - XK_H], knsupc * nrhs + XK_H,
				   SuperLU_MPI_DOUBLE_COMPLEX, pi, Xk, grid->comm,
                                   &send_req[Llu->SolveMsgSent++]);
#if 0
			MPI_Send( &x[ii - XK_H], knsupc * nrhs + XK_H,
				 SuperLU_MPI_DOUBLE_COMPLEX, pi, Xk, grid->comm );
#endif
#if ( DEBUGlevel>=2 )
			printf("(%2d) Sent X[%2.0f] to P %2d\n",
			       iam, x[ii-XK_H], pi);
#endif
		    }
		}
		/*
		 * Perform local block modifications: lsum[i] -= L_i,k * X[k]
		 */
		nb = lsub[0] - 1;
		lptr = BC_HEADER + LB_DESCRIPTOR + knsupc;
		luptr = knsupc; /* Skip diagonal block L(k,k). */
		
		zlsum_fmod(lsum, x, &x[ii], rtemp, nrhs, knsupc, k,
			   fmod, nb, lptr, luptr, xsup, grid, Llu, 
			   send_req, stat);
	    }
	} /* if diagonal process ... */
    } /* for k ... */

    /* -----------------------------------------------------------
       Compute the internal nodes asynchronously by all processes.
       ----------------------------------------------------------- */
#if ( DEBUGlevel>=2 )
    printf("(%2d) nfrecvx %4d,  nfrecvmod %4d,  nleaf %4d\n",
	   iam, nfrecvx, nfrecvmod, nleaf);
#endif

    while ( nfrecvx || nfrecvmod ) { /* While not finished. */

	/* Receive a message. */
	MPI_Recv( recvbuf, maxrecvsz, SuperLU_MPI_DOUBLE_COMPLEX,
                  MPI_ANY_SOURCE, MPI_ANY_TAG, grid->comm, &status );

        k = (*recvbuf).r;

#if ( DEBUGlevel>=2 )
	printf("(%2d) Recv'd block %d, tag %2d\n", iam, k, status.MPI_TAG);
#endif
	
	switch ( status.MPI_TAG ) {
	  case Xk:
	      --nfrecvx;
	      lk = LBj( k, grid ); /* Local block number, column-wise. */
	      lsub = Lrowind_bc_ptr[lk];
	      lusup = Lnzval_bc_ptr[lk];
	      if ( lsub ) {
		  nb   = lsub[0];
		  lptr = BC_HEADER;
		  luptr = 0;
		  knsupc = SuperSize( k );

		  /*
		   * Perform local block modifications: lsum[i] -= L_i,k * X[k]
		   */
		  zlsum_fmod(lsum, x, &recvbuf[XK_H], rtemp, nrhs, knsupc, k,
			     fmod, nb, lptr, luptr, xsup, grid, Llu, 
			     send_req, stat);
	      } /* if lsub */

	      break;

	  case LSUM: /* Receiver must be a diagonal process */
	      --nfrecvmod;
	      lk = LBi( k, grid ); /* Local block number, row-wise. */
	      ii = X_BLK( lk );
	      knsupc = SuperSize( k );
	      tempv = &recvbuf[LSUM_H];
	      RHS_ITERATE(j) {
		  for (i = 0; i < knsupc; ++i)
		      z_add(&x[i + ii + j*knsupc],
			    &x[i + ii + j*knsupc],
			    &tempv[i + j*knsupc]);
	      }

	      if ( (--frecv[lk])==0 && fmod[lk]==0 ) {
		  fmod[lk] = -1; /* Do not solve X[k] in the future. */
		  lk = LBj( k, grid ); /* Local block number, column-wise. */
		  lsub = Lrowind_bc_ptr[lk];
		  lusup = Lnzval_bc_ptr[lk];
		  nsupr = lsub[1];
#ifdef _CRAY
		  CTRSM(ftcs1, ftcs1, ftcs2, ftcs3, &knsupc, &nrhs, &alpha,
			lusup, &nsupr, &x[ii], &knsupc);
#elif defined (USE_VENDOR_BLAS)
		  ztrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
			 lusup, &nsupr, &x[ii], &knsupc, 1, 1, 1, 1);
#else
		  ztrsm_("L", "L", "N", "U", &knsupc, &nrhs, &alpha, 
			 lusup, &nsupr, &x[ii], &knsupc);
#endif
		  stat->ops[SOLVE] += 4 * knsupc * (knsupc - 1) * nrhs
		      + 10 * knsupc * nrhs; /* complex division */
#if ( DEBUGlevel>=2 )
		  printf("(%2d) Solve X[%2d]\n", iam, k);
#endif
		
		  /*
		   * Send Xk to process column Pc[k].
		   */
		  kcol = PCOL( k, grid );
		  for (p = 0; p < Pr; ++p) {
		      if ( fsendx_plist[lk][p] != EMPTY ) {
			  pi = PNUM( p, kcol, grid );

			  MPI_Isend( &x[ii-XK_H], knsupc * nrhs + XK_H,
                                     SuperLU_MPI_DOUBLE_COMPLEX, pi, Xk, grid->comm,
                                     &send_req[Llu->SolveMsgSent++]);
#if 0
			  MPI_Send( &x[ii - XK_H], knsupc * nrhs + XK_H,
				    SuperLU_MPI_DOUBLE_COMPLEX, pi, Xk, grid->comm );
#endif
#if ( DEBUGlevel>=2 )
			  printf("(%2d) Sent X[%2.0f] to P %2d\n",
				 iam, x[ii-XK_H], pi);
#endif
		      }
                  }
		  /*
		   * Perform local block modifications.
		   */
		  nb = lsub[0] - 1;
		  lptr = BC_HEADER + LB_DESCRIPTOR + knsupc;
		  luptr = knsupc; /* Skip diagonal block L(k,k). */

		  zlsum_fmod(lsum, x, &x[ii], rtemp, nrhs, knsupc, k,
			     fmod, nb, lptr, luptr, xsup, grid, Llu,
			     send_req, stat);
	      } /* if */

	      break;

#if ( DEBUGlevel>=2 )
	    default:
	      printf("(%2d) Recv'd wrong message tag %4d\n", status.MPI_TAG);
	      break;
#endif
	  } /* switch */

    } /* while not finished ... */


#if ( PRNTlevel>=2 )
    t = SuperLU_timer_() - t;
    if ( !iam ) printf(".. L-solve time\t%8.2f\n", t);
    t = SuperLU_timer_();
#endif

#if ( DEBUGlevel==2 )
    {
      printf("(%d) .. After L-solve: y =\n", iam);
      for (i = 0, k = 0; k < nsupers; ++k) {
	  krow = PROW( k, grid );
	  kcol = PCOL( k, grid );
	  if ( myrow == krow && mycol == kcol ) { /* Diagonal process */
	      knsupc = SuperSize( k );
	      lk = LBi( k, grid );
	      ii = X_BLK( lk );
	      for (j = 0; j < knsupc; ++j)
		printf("\t(%d)\t%4d\t%.10f\n", iam, xsup[k]+j, x[ii+j]);
	      fflush(stdout);
	  }
	  MPI_Barrier( grid->comm );
      }
    }
#endif

    SUPERLU_FREE(fmod);
    SUPERLU_FREE(frecv);
    SUPERLU_FREE(rtemp);

    /*for (i = 0; i < Llu->SolveMsgSent; ++i) MPI_Request_free(&send_req[i]);*/

    for (i = 0; i < Llu->SolveMsgSent; ++i) MPI_Wait(&send_req[i], &status);
    Llu->SolveMsgSent = 0;

    MPI_Barrier( grid->comm );


    /*---------------------------------------------------
     * Back solve Ux = y.
     *
     * The Y components from the forward solve is already
     * on the diagonal processes.
     *---------------------------------------------------*/

    /* Save the count to be altered so it can be used by
       subsequent call to PZGSTRS. */
    if ( !(bmod = intMalloc_dist(nlb)) )
	ABORT("Calloc fails for bmod[].");
    for (i = 0; i < nlb; ++i) bmod[i] = Llu->bmod[i];
    if ( !(brecv = intMalloc_dist(nlb)) )
	ABORT("Malloc fails for brecv[].");
    Llu->brecv = brecv;

    /*
     * Compute brecv[] and nbrecvmod counts on the diagonal processes.
     */
    {
	superlu_scope_t *scp = &grid->rscp;

#if 1
	for (k = 0; k < nlb; ++k) mod_bit[k] = 0;
	for (k = 0; k < nsupers; ++k) {
	    krow = PROW( k, grid );
	    if ( myrow == krow ) {
		lk = LBi( k, grid );    /* local block number */
		kcol = PCOL( k, grid ); /* root process in this row scope */
		if ( mycol != kcol && bmod[lk] )
		    mod_bit[lk] = 1;  /* Contribution from off-diagonal */
	    }
	}

	/* Every process receives the count, but it is only useful on the
	   diagonal processes.  */
	MPI_Allreduce( mod_bit, brecv, nlb, mpi_int_t, MPI_SUM, scp->comm );

	for (k = 0; k < nsupers; ++k) {
	    krow = PROW( k, grid );
	    if ( myrow == krow ) {
		lk = LBi( k, grid );    /* local block number */
		kcol = PCOL( k, grid ); /* root process in this row scope. */
		if ( mycol == kcol ) { /* diagonal process */
		    nbrecvmod += brecv[lk];
		    if ( !brecv[lk] && !bmod[lk] ) ++nroot;
#if ( DEBUGlevel>=2 )
		    printf("(%2d) brecv[%4d]  %2d\n", iam, k, brecv[lk]);
		    assert( brecv[lk] < Pc );
#endif
		}
	    }
	}

#else /* old */

	for (k = 0; k < nsupers; ++k) {
	    krow = PROW( k, grid );
	    if ( myrow == krow ) {
		lk = LBi( k, grid );    /* Local block number. */
		kcol = PCOL( k, grid ); /* Root process in this row scope. */
		if ( mycol != kcol && bmod[lk] )
		    i = 1;  /* Contribution from non-diagonal process. */
		else i = 0;
		MPI_Reduce( &i, &brecv[lk], 1, mpi_int_t,
			   MPI_SUM, kcol, scp->comm );
		if ( mycol == kcol ) { /* Diagonal process. */
		    nbrecvmod += brecv[lk];
		    if ( !brecv[lk] && !bmod[lk] ) ++nroot;
#if ( DEBUGlevel>=2 )
		    printf("(%2d) brecv[%4d]  %2d\n", iam, k, brecv[lk]);
		    assert( brecv[lk] < Pc );
#endif
		}
	    }
	}
#endif
    }

    /* Re-initialize lsum to zero. Each block header is already in place. */
    for (k = 0; k < nsupers; ++k) {
	krow = PROW( k, grid );
	if ( myrow == krow ) {
	    knsupc = SuperSize( k );
	    lk = LBi( k, grid );
	    il = LSUM_BLK( lk );
	    dest = &lsum[il];
	    RHS_ITERATE(j) {
		for (i = 0; i < knsupc; ++i) dest[i + j*knsupc] = zero;
	    }
	}
    }
示例#11
0
void
pdgssvx_ABglobal(superlu_options_t_Distributed *options, SuperMatrix *A, 
		 ScalePermstruct_t *ScalePermstruct,
		 double B[], int ldb, int nrhs, gridinfo_t *grid,
		 LUstruct_t *LUstruct, double *berr,
		 SuperLUStat_t *stat, int *info)
{
/* 
 * -- Distributed SuperLU routine (version 1.0) --
 * Lawrence Berkeley National Lab, Univ. of California Berkeley.
 * September 1, 1999
 *
 *
 * Purpose
 * =======
 *
 * pdgssvx_ABglobal solves a system of linear equations A*X=B,
 * by using Gaussian elimination with "static pivoting" to
 * compute the LU factorization of A.
 *
 * Static pivoting is a technique that combines the numerical stability
 * of partial pivoting with the scalability of Cholesky (no pivoting),
 * to run accurately and efficiently on large numbers of processors.
 *
 * See our paper at http://www.nersc.gov/~xiaoye/SuperLU/ for a detailed
 * description of the parallel algorithms.
 *
 * Here are the options for using this code:
 *
 *   1. Independent of all the other options specified below, the
 *      user must supply
 *
 *      -  B, the matrix of right hand sides, and its dimensions ldb and nrhs
 *      -  grid, a structure describing the 2D processor mesh
 *      -  options->IterRefine, which determines whether or not to
 *            improve the accuracy of the computed solution using 
 *            iterative refinement
 *
 *      On output, B is overwritten with the solution X.
 *
 *   2. Depending on options->Fact, the user has several options
 *      for solving A*X=B. The standard option is for factoring
 *      A "from scratch". (The other options, described below,
 *      are used when A is sufficiently similar to a previously 
 *      solved problem to save time by reusing part or all of 
 *      the previous factorization.)
 *
 *      -  options->Fact = DOFACT: A is factored "from scratch"
 *
 *      In this case the user must also supply
 *
 *      -  A, the input matrix
 *
 *      as well as the following options, which are described in more 
 *      detail below:
 *
 *      -  options->Equil,   to specify how to scale the rows and columns
 *                           of A to "equilibrate" it (to try to reduce its
 *                           condition number and so improve the
 *                           accuracy of the computed solution)
 *
 *      -  options->RowPerm, to specify how to permute the rows of A
 *                           (typically to control numerical stability)
 *
 *      -  options->ColPerm, to specify how to permute the columns of A
 *                           (typically to control fill-in and enhance
 *                           parallelism during factorization)
 *
 *      -  options->ReplaceTinyPivot, to specify how to deal with tiny
 *                           pivots encountered during factorization
 *                           (to control numerical stability)
 *
 *      The outputs returned include
 *         
 *      -  ScalePermstruct,  modified to describe how the input matrix A
 *                           was equilibrated and permuted:
 *         -  ScalePermstruct->DiagScale, indicates whether the rows and/or
 *                                        columns of A were scaled
 *         -  ScalePermstruct->R, array of row scale factors
 *         -  ScalePermstruct->C, array of column scale factors
 *         -  ScalePermstruct->perm_r, row permutation vector
 *         -  ScalePermstruct->perm_c, column permutation vector
 *
 *            (part of ScalePermstruct may also need to be supplied on input,
 *             depending on options->RowPerm and options->ColPerm as described 
 *             later).
 *
 *      -  A, the input matrix A overwritten by the scaled and permuted matrix
 *                Pc*Pr*diag(R)*A*diag(C)
 *             where 
 *                Pr and Pc are row and columns permutation matrices determined
 *                  by ScalePermstruct->perm_r and ScalePermstruct->perm_c, 
 *                  respectively, and 
 *                diag(R) and diag(C) are diagonal scaling matrices determined
 *                  by ScalePermstruct->DiagScale, ScalePermstruct->R and 
 *                  ScalePermstruct->C
 *
 *      -  LUstruct, which contains the L and U factorization of A1 where
 *
 *                A1 = Pc*Pr*diag(R)*A*diag(C)*Pc^T = L*U
 *
 *              (Note that A1 = Aout * Pc^T, where Aout is the matrix stored
 *               in A on output.)
 *
 *   3. The second value of options->Fact assumes that a matrix with the same
 *      sparsity pattern as A has already been factored:
 *     
 *      -  options->Fact = SamePattern: A is factored, assuming that it has
 *            the same nonzero pattern as a previously factored matrix. In this
 *            case the algorithm saves time by reusing the previously computed
 *            column permutation vector stored in ScalePermstruct->perm_c
 *            and the "elimination tree" of A stored in LUstruct->etree.
 *
 *      In this case the user must still specify the following options
 *      as before:
 *
 *      -  options->Equil
 *      -  options->RowPerm
 *      -  options->ReplaceTinyPivot
 *
 *      but not options->ColPerm, whose value is ignored. This is because the
 *      previous column permutation from ScalePermstruct->perm_c is used as
 *      input. The user must also supply 
 *
 *      -  A, the input matrix
 *      -  ScalePermstruct->perm_c, the column permutation
 *      -  LUstruct->etree, the elimination tree
 *
 *      The outputs returned include
 *         
 *      -  A, the input matrix A overwritten by the scaled and permuted matrix
 *            as described above
 *      -  ScalePermstruct,  modified to describe how the input matrix A was
 *                           equilibrated and row permuted
 *      -  LUstruct, modified to contain the new L and U factors
 *
 *   4. The third value of options->Fact assumes that a matrix B with the same
 *      sparsity pattern as A has already been factored, and where the
 *      row permutation of B can be reused for A. This is useful when A and B
 *      have similar numerical values, so that the same row permutation
 *      will make both factorizations numerically stable. This lets us reuse
 *      all of the previously computed structure of L and U.
 *
 *      -  options->Fact = SamePattern_SameRowPerm: A is factored,
 *            assuming not only the same nonzero pattern as the previously
 *            factored matrix B, but reusing B's row permutation.
 *
 *      In this case the user must still specify the following options
 *      as before:
 *
 *      -  options->Equil
 *      -  options->ReplaceTinyPivot
 *
 *      but not options->RowPerm or options->ColPerm, whose values are ignored.
 *      This is because the permutations from ScalePermstruct->perm_r and
 *      ScalePermstruct->perm_c are used as input.
 *
 *      The user must also supply 
 *
 *      -  A, the input matrix
 *      -  ScalePermstruct->DiagScale, how the previous matrix was row and/or
 *                                     column scaled
 *      -  ScalePermstruct->R, the row scalings of the previous matrix, if any
 *      -  ScalePermstruct->C, the columns scalings of the previous matrix, 
 *                             if any
 *      -  ScalePermstruct->perm_r, the row permutation of the previous matrix
 *      -  ScalePermstruct->perm_c, the column permutation of the previous 
 *                                  matrix
 *      -  all of LUstruct, the previously computed information about L and U
 *                (the actual numerical values of L and U stored in
 *                 LUstruct->Llu are ignored)
 *
 *      The outputs returned include
 *         
 *      -  A, the input matrix A overwritten by the scaled and permuted matrix
 *            as described above
 *      -  ScalePermstruct,  modified to describe how the input matrix A was
 *                           equilibrated 
 *                  (thus ScalePermstruct->DiagScale, R and C may be modified)
 *      -  LUstruct, modified to contain the new L and U factors
 *
 *   5. The fourth and last value of options->Fact assumes that A is
 *      identical to a matrix that has already been factored on a previous 
 *      call, and reuses its entire LU factorization
 *
 *      -  options->Fact = Factored: A is identical to a previously
 *            factorized matrix, so the entire previous factorization
 *            can be reused.
 *
 *      In this case all the other options mentioned above are ignored
 *      (options->Equil, options->RowPerm, options->ColPerm, 
 *       options->ReplaceTinyPivot)
 *
 *      The user must also supply 
 *
 *      -  A, the unfactored matrix, only in the case that iterative refinment
 *            is to be done (specifically A must be the output A from 
 *            the previous call, so that it has been scaled and permuted)
 *      -  all of ScalePermstruct
 *      -  all of LUstruct, including the actual numerical values of L and U
 *
 *      all of which are unmodified on output.
 *         
 * Arguments
 * =========
 *
 * options (input) superlu_options_t_Distributed*
 *         The structure defines the input parameters to control
 *         how the LU decomposition will be performed.
 *         The following fields should be defined for this structure:
 *         
 *         o Fact (fact_t)
 *           Specifies whether or not the factored form of the matrix
 *           A is supplied on entry, and if not, how the matrix A should
 *           be factorized based on the previous history.
 *
 *           = DOFACT: The matrix A will be factorized from scratch.
 *                 Inputs:  A
 *                          options->Equil, RowPerm, ColPerm, ReplaceTinyPivot
 *                 Outputs: modified A
 *                             (possibly row and/or column scaled and/or 
 *                              permuted)
 *                          all of ScalePermstruct
 *                          all of LUstruct
 *
 *           = SamePattern: the matrix A will be factorized assuming
 *             that a factorization of a matrix with the same sparsity
 *             pattern was performed prior to this one. Therefore, this
 *             factorization will reuse column permutation vector 
 *             ScalePermstruct->perm_c and the elimination tree
 *             LUstruct->etree
 *                 Inputs:  A
 *                          options->Equil, RowPerm, ReplaceTinyPivot
 *                          ScalePermstruct->perm_c
 *                          LUstruct->etree
 *                 Outputs: modified A
 *                             (possibly row and/or column scaled and/or 
 *                              permuted)
 *                          rest of ScalePermstruct (DiagScale, R, C, perm_r)
 *                          rest of LUstruct (GLU_persist, Llu)
 *
 *           = SamePattern_SameRowPerm: the matrix A will be factorized
 *             assuming that a factorization of a matrix with the same
 *             sparsity	pattern and similar numerical values was performed
 *             prior to this one. Therefore, this factorization will reuse
 *             both row and column scaling factors R and C, and the
 *             both row and column permutation vectors perm_r and perm_c,
 *             distributed data structure set up from the previous symbolic
 *             factorization.
 *                 Inputs:  A
 *                          options->Equil, ReplaceTinyPivot
 *                          all of ScalePermstruct
 *                          all of LUstruct
 *                 Outputs: modified A
 *                             (possibly row and/or column scaled and/or 
 *                              permuted)
 *                          modified LUstruct->Llu
 *           = FACTORED: the matrix A is already factored.
 *                 Inputs:  all of ScalePermstruct
 *                          all of LUstruct
 *
 *         o Equil (yes_no_t)
 *           Specifies whether to equilibrate the system.
 *           = NO:  no equilibration.
 *           = YES: scaling factors are computed to equilibrate the system:
 *                      diag(R)*A*diag(C)*inv(diag(C))*X = diag(R)*B.
 *                  Whether or not the system will be equilibrated depends
 *                  on the scaling of the matrix A, but if equilibration is
 *                  used, A is overwritten by diag(R)*A*diag(C) and B by
 *                  diag(R)*B.
 *
 *         o RowPerm (rowperm_t)
 *           Specifies how to permute rows of the matrix A.
 *           = NATURAL:   use the natural ordering.
 *           = LargeDiag: use the Duff/Koster algorithm to permute rows of
 *                        the original matrix to make the diagonal large
 *                        relative to the off-diagonal.
 *           = MY_PERMR:  use the ordering given in ScalePermstruct->perm_r
 *                        input by the user.
 *           
 *         o ColPerm (colperm_t)
 *           Specifies what type of column permutation to use to reduce fill.
 *           = NATURAL:       natural ordering.
 *           = MMD_AT_PLUS_A: minimum degree ordering on structure of A'+A.
 *           = MMD_ATA:       minimum degree ordering on structure of A'*A.
 *           = COLAMD:        approximate minimum degree column ordering.
 *           = MY_PERMC:      the ordering given in ScalePermstruct->perm_c.
 *         
 *         o ReplaceTinyPivot (yes_no_t)
 *           = NO:  do not modify pivots
 *           = YES: replace tiny pivots by sqrt(epsilon)*norm(A) during 
 *                  LU factorization.
 *
 *         o IterRefine (IterRefine_t)
 *           Specifies how to perform iterative refinement.
 *           = NO:     no iterative refinement.
 *           = DOUBLE: accumulate residual in double precision.
 *           = EXTRA:  accumulate residual in extra precision.
 *
 *         NOTE: all options must be indentical on all processes when
 *               calling this routine.
 *
 * A (input/output) SuperMatrix*
 *         On entry, matrix A in A*X=B, of dimension (A->nrow, A->ncol).
 *         The number of linear equations is A->nrow. The type of A must be:
 *         Stype = NC; Dtype = D; Mtype = GE. That is, A is stored in
 *         compressed column format (also known as Harwell-Boeing format).
 *         See supermatrix.h for the definition of 'SuperMatrix'.
 *         This routine only handles square A, however, the LU factorization
 *         routine pdgstrf can factorize rectangular matrices.
 *         On exit, A may be overwtirren by Pc*Pr*diag(R)*A*diag(C),
 *         depending on ScalePermstruct->DiagScale, options->RowPerm and
 *         options->colpem:
 *             if ScalePermstruct->DiagScale != NOEQUIL, A is overwritten by
 *                diag(R)*A*diag(C).
 *             if options->RowPerm != NATURAL, A is further overwritten by
 *                Pr*diag(R)*A*diag(C).
 *             if options->ColPerm != NATURAL, A is further overwritten by
 *                Pc*Pr*diag(R)*A*diag(C).
 *         If all the above condition are true, the LU decomposition is
 *         performed on the matrix Pc*Pr*diag(R)*A*diag(C)*Pc^T.
 *
 *         NOTE: Currently, A must reside in all processes when calling
 *               this routine.
 *
 * ScalePermstruct (input/output) ScalePermstruct_t*
 *         The data structure to store the scaling and permutation vectors
 *         describing the transformations performed to the matrix A.
 *         It contains the following fields:
 *
 *         o DiagScale (DiagScale_t)
 *           Specifies the form of equilibration that was done.
 *           = NOEQUIL: no equilibration.
 *           = ROW:     row equilibration, i.e., A was premultiplied by
 *                      diag(R).
 *           = COL:     Column equilibration, i.e., A was postmultiplied
 *                      by diag(C).
 *           = BOTH:    both row and column equilibration, i.e., A was 
 *                      replaced by diag(R)*A*diag(C).
 *           If options->Fact = FACTORED or SamePattern_SameRowPerm,
 *           DiagScale is an input argument; otherwise it is an output
 *           argument.
 *
 *         o perm_r (int*)
 *           Row permutation vector, which defines the permutation matrix Pr;
 *           perm_r[i] = j means row i of A is in position j in Pr*A.
 *           If options->RowPerm = MY_PERMR, or
 *           options->Fact = SamePattern_SameRowPerm, perm_r is an
 *           input argument; otherwise it is an output argument.
 *
 *         o perm_c (int*)
 *           Column permutation vector, which defines the 
 *           permutation matrix Pc; perm_c[i] = j means column i of A is 
 *           in position j in A*Pc.
 *           If options->ColPerm = MY_PERMC or options->Fact = SamePattern
 *           or options->Fact = SamePattern_SameRowPerm, perm_c is an
 *           input argument; otherwise, it is an output argument.
 *           On exit, perm_c may be overwritten by the product of the input
 *           perm_c and a permutation that postorders the elimination tree
 *           of Pc*A'*A*Pc'; perm_c is not changed if the elimination tree
 *           is already in postorder.
 *
 *         o R (double*) dimension (A->nrow)
 *           The row scale factors for A.
 *           If DiagScale = ROW or BOTH, A is multiplied on the left by 
 *                          diag(R).
 *           If DiagScale = NOEQUIL or COL, R is not defined.
 *           If options->Fact = FACTORED or SamePattern_SameRowPerm, R is
 *           an input argument; otherwise, R is an output argument.
 *
 *         o C (double*) dimension (A->ncol)
 *           The column scale factors for A.
 *           If DiagScale = COL or BOTH, A is multiplied on the right by 
 *                          diag(C).
 *           If DiagScale = NOEQUIL or ROW, C is not defined.
 *           If options->Fact = FACTORED or SamePattern_SameRowPerm, C is
 *           an input argument; otherwise, C is an output argument.
 *         
 * B       (input/output) double*
 *         On entry, the right-hand side matrix of dimension (A->nrow, nrhs).
 *         On exit, the solution matrix if info = 0;
 *
 *         NOTE: Currently, B must reside in all processes when calling
 *               this routine.
 *
 * ldb     (input) int (global)
 *         The leading dimension of matrix B.
 *
 * nrhs    (input) int (global)
 *         The number of right-hand sides.
 *         If nrhs = 0, only LU decomposition is performed, the forward
 *         and back substitutions are skipped.
 *
 * grid    (input) gridinfo_t*
 *         The 2D process mesh. It contains the MPI communicator, the number
 *         of process rows (NPROW), the number of process columns (NPCOL),
 *         and my process rank. It is an input argument to all the
 *         parallel routines.
 *         Grid can be initialized by subroutine SUPERLU_GRIDINIT.
 *         See superlu_ddefs.h for the definition of 'gridinfo_t'.
 *
 * LUstruct (input/output) LUstruct_t*
 *         The data structures to store the distributed L and U factors.
 *         It contains the following fields:
 *
 *         o etree (int*) dimension (A->ncol)
 *           Elimination tree of Pc*(A'+A)*Pc' or Pc*A'*A*Pc', dimension A->ncol.
 *           It is computed in sp_colorder() during the first factorization,
 *           and is reused in the subsequent factorizations of the matrices
 *           with the same nonzero pattern.
 *           On exit of sp_colorder(), the columns of A are permuted so that
 *           the etree is in a certain postorder. This postorder is reflected
 *           in ScalePermstruct->perm_c.
 *           NOTE:
 *           Etree is a vector of parent pointers for a forest whose vertices
 *           are the integers 0 to A->ncol-1; etree[root]==A->ncol.
 *
 *         o Glu_persist (Glu_persist_t*)
 *           Global data structure (xsup, supno) replicated on all processes,
 *           describing the supernode partition in the factored matrices
 *           L and U:
 *	       xsup[s] is the leading column of the s-th supernode,
 *             supno[i] is the supernode number to which column i belongs.
 *
 *         o Llu (LocalLU_t*)
 *           The distributed data structures to store L and U factors.
 *           See superlu_ddefs.h for the definition of 'LocalLU_t'.
 *
 * berr    (output) double*, dimension (nrhs)
 *         The componentwise relative backward error of each solution   
 *         vector X(j) (i.e., the smallest relative change in   
 *         any element of A or B that makes X(j) an exact solution).
 *
 * stat   (output) SuperLUStat_t*
 *        Record the statistics on runtime and floating-point operation count.
 *        See util.h for the definition of 'SuperLUStat_t'.
 *
 * info    (output) int*
 *         = 0: successful exit
 *         > 0: if info = i, and i is
 *             <= A->ncol: U(i,i) is exactly zero. The factorization has
 *                been completed, but the factor U is exactly singular,
 *                so the solution could not be computed.
 *             > A->ncol: number of bytes allocated when memory allocation
 *                failure occurred, plus A->ncol.
 *
 *
 * See superlu_ddefs.h for the definitions of various data types.
 *
 */
    SuperMatrix AC;
    NCformat *Astore;
    NCPformat *ACstore;
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    Glu_freeable_t *Glu_freeable;
            /* The nonzero structures of L and U factors, which are
	       replicated on all processrs.
	           (lsub, xlsub) contains the compressed subscript of
		                 supernodes in L.
          	   (usub, xusub) contains the compressed subscript of
		                 nonzero segments in U.
	      If options->Fact != SamePattern_SameRowPerm, they are 
	      computed by SYMBFACT routine, and then used by DDISTRIBUTE
	      routine. They will be freed after DDISTRIBUTE routine.
	      If options->Fact == SamePattern_SameRowPerm, these
	      structures are not used.                                  */
    fact_t   Fact;
    double   *a;
    int_t    *perm_r; /* row permutations from partial pivoting */
    int_t    *perm_c; /* column permutation vector */
    int_t    *etree;  /* elimination tree */
    int_t    *colptr, *rowind;
    int_t    colequ, Equil, factored, job, notran, rowequ;
    int_t    i, iinfo, j, irow, m, n, nnz, permc_spec, dist_mem_use;
    int      iam;
    int      ldx;  /* LDA for matrix X (global). */
    char     equed[1], norm[1];
    double   *C, *R, *C1, *R1, amax, anorm, colcnd, rowcnd;
    double   *X, *b_col, *b_work, *x_col;
    double   t;
    static mem_usage_t_Distributed num_mem_usage, symb_mem_usage;
#if ( PRNTlevel>= 2 )
    double   dmin, dsum, dprod;
#endif

    /* Test input parameters. */
    *info = 0;
    Fact = options->Fact;
    if ( Fact < 0 || Fact > FACTORED )
	*info = -1;
    else if ( options->RowPerm < 0 || options->RowPerm > MY_PERMR )
	*info = -1;
    else if ( options->ColPerm < 0 || options->ColPerm > MY_PERMC )
	*info = -1;
    else if ( options->IterRefine < 0 || options->IterRefine > EXTRA )
	*info = -1;
    else if ( options->IterRefine == EXTRA ) {
	*info = -1;
	fprintf(stderr, "Extra precise iterative refinement yet to support.");
    } else if ( A->nrow != A->ncol || A->nrow < 0 ||
         A->Stype != SLU_NC || A->Dtype != SLU_D || A->Mtype != SLU_GE )
	*info = -2;
    else if ( ldb < A->nrow )
	*info = -5;
    else if ( nrhs < 0 )
	*info = -6;
    if ( *info ) {
	i = -(*info);
	pxerbla("pdgssvx_ABglobal", grid, -*info);
	return;
    }

    /* Initialization */
    factored = (Fact == FACTORED);
    Equil = (!factored && options->Equil == YES);
    notran = (options->Trans == NOTRANS);
    iam = grid->iam;
    job = 5;
    m = A->nrow;
    n = A->ncol;
    Astore = A->Store;
    nnz = Astore->nnz;
    a = Astore->nzval;
    colptr = Astore->colptr;
    rowind = Astore->rowind;
    if ( factored || (Fact == SamePattern_SameRowPerm && Equil) ) {
	rowequ = (ScalePermstruct->DiagScale == ROW) ||
	         (ScalePermstruct->DiagScale == BOTH);
	colequ = (ScalePermstruct->DiagScale == COL) ||
	         (ScalePermstruct->DiagScale == BOTH);
    } else rowequ = colequ = FALSE;

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter pdgssvx_ABglobal()");
#endif

    perm_r = ScalePermstruct->perm_r;
    perm_c = ScalePermstruct->perm_c;
    etree = LUstruct->etree;
    R = ScalePermstruct->R;
    C = ScalePermstruct->C;
    if ( Equil ) {
	/* Allocate storage if not done so before. */
	switch ( ScalePermstruct->DiagScale ) {
	    case NOEQUIL:
		if ( !(R = (double *) doubleMalloc_dist(m)) )
		    ABORT("Malloc fails for R[].");
	        if ( !(C = (double *) doubleMalloc_dist(n)) )
		    ABORT("Malloc fails for C[].");
		ScalePermstruct->R = R;
		ScalePermstruct->C = C;
		break;
	    case ROW: 
	        if ( !(C = (double *) doubleMalloc_dist(n)) )
		    ABORT("Malloc fails for C[].");
		ScalePermstruct->C = C;
		break;
	    case COL: 
		if ( !(R = (double *) doubleMalloc_dist(m)) )
		    ABORT("Malloc fails for R[].");
		ScalePermstruct->R = R;
		break;
	}
    }

    /* ------------------------------------------------------------
       Diagonal scaling to equilibrate the matrix.
       ------------------------------------------------------------*/
    if ( Equil ) {
#if ( DEBUGlevel>=1 )
	CHECK_MALLOC(iam, "Enter equil");
#endif
	t = SuperLU_timer_();

	if ( Fact == SamePattern_SameRowPerm ) {
	    /* Reuse R and C. */
	    switch ( ScalePermstruct->DiagScale ) {
	      case NOEQUIL:
		break;
	      case ROW:
		for (j = 0; j < n; ++j) {
		    for (i = colptr[j]; i < colptr[j+1]; ++i) {
			irow = rowind[i];
			a[i] *= R[irow];       /* Scale rows. */
		    }
		}
		break;
	      case COL:
		for (j = 0; j < n; ++j)
		    for (i = colptr[j]; i < colptr[j+1]; ++i)
			a[i] *= C[j];          /* Scale columns. */
		break;
	      case BOTH: 
		for (j = 0; j < n; ++j) {
		    for (i = colptr[j]; i < colptr[j+1]; ++i) {
			irow = rowind[i];
			a[i] *= R[irow] * C[j]; /* Scale rows and columns. */
		    }
		}
	        break;
	    }
	} else {
	    if ( !iam ) {
		/* Compute row and column scalings to equilibrate matrix A. */
		dgsequ_dist(A, R, C, &rowcnd, &colcnd, &amax, &iinfo);
	    
		MPI_Bcast( &iinfo, 1, mpi_int_t, 0, grid->comm );
		if ( iinfo == 0 ) {
		    MPI_Bcast( R,       m, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( C,       n, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &rowcnd, 1, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &colcnd, 1, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &amax,   1, MPI_DOUBLE, 0, grid->comm );
		} else {
		    if ( iinfo > 0 ) {
			if ( iinfo <= m )
			    fprintf(stderr, "The %d-th row of A is exactly zero\n", 
				    iinfo);
			else fprintf(stderr, "The %d-th column of A is exactly zero\n", 
				     iinfo-n);
			exit(-1);
		    }
		}
	    } else {
		MPI_Bcast( &iinfo, 1, mpi_int_t, 0, grid->comm );
		if ( iinfo == 0 ) {
		    MPI_Bcast( R,       m, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( C,       n, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &rowcnd, 1, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &colcnd, 1, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &amax,   1, MPI_DOUBLE, 0, grid->comm );
		} else {
		    ABORT("DGSEQU failed\n");
		}
	    }
	
	    /* Equilibrate matrix A. */
	    dlaqgs_dist(A, R, C, rowcnd, colcnd, amax, equed);
	    if ( lsame_(equed, "R") ) {
		ScalePermstruct->DiagScale = rowequ = ROW;
	    } else if ( lsame_(equed, "C") ) {
		ScalePermstruct->DiagScale = colequ = COL;
	    } else if ( lsame_(equed, "B") ) {
		ScalePermstruct->DiagScale = BOTH;
		rowequ = ROW;
		colequ = COL;
	    } else ScalePermstruct->DiagScale = NOEQUIL;

#if ( PRNTlevel>=1 )
	    if ( !iam ) {
		printf(".. equilibrated? *equed = %c\n", *equed);
		/*fflush(stdout);*/
	    }
#endif
	} /* if Fact ... */

	stat->utime[EQUIL] = SuperLU_timer_() - t;
#if ( DEBUGlevel>=1 )
	CHECK_MALLOC(iam, "Exit equil");
#endif
    } /* if Equil ... */
    
    /* ------------------------------------------------------------
       Permute rows of A. 
       ------------------------------------------------------------*/
    if ( options->RowPerm != NO ) {
	t = SuperLU_timer_();

	if ( Fact == SamePattern_SameRowPerm /* Reuse perm_r. */
	    || options->RowPerm == MY_PERMR ) { /* Use my perm_r. */
/*	    for (j = 0; j < n; ++j) {
		for (i = colptr[j]; i < colptr[j+1]; ++i) {*/
	    for (i = 0; i < colptr[n]; ++i) {
		    irow = rowind[i]; 
		    rowind[i] = perm_r[irow];
/*		}*/
	    }
	} else if ( !factored ) {
	    if ( job == 5 ) {
		/* Allocate storage for scaling factors. */
		if ( !(R1 = (double *) SUPERLU_MALLOC(m * sizeof(double))) ) 
		    ABORT("SUPERLU_MALLOC fails for R1[]");
		if ( !(C1 = (double *) SUPERLU_MALLOC(n * sizeof(double))) )
		    ABORT("SUPERLU_MALLOC fails for C1[]");
	    }

	    if ( !iam ) {
		/* Process 0 finds a row permutation for large diagonal. */
		dldperm(job, m, nnz, colptr, rowind, a, perm_r, R1, C1);
		
		MPI_Bcast( perm_r, m, mpi_int_t, 0, grid->comm );
		if ( job == 5 && Equil ) {
		    MPI_Bcast( R1, m, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( C1, n, MPI_DOUBLE, 0, grid->comm );
		}
	    } else {
		MPI_Bcast( perm_r, m, mpi_int_t, 0, grid->comm );
		if ( job == 5 && Equil ) {
		    MPI_Bcast( R1, m, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( C1, n, MPI_DOUBLE, 0, grid->comm );
		}
	    }

#if ( PRNTlevel>=2 )
	    dmin = dlamch_("Overflow");
	    dsum = 0.0;
	    dprod = 1.0;
#endif
	    if ( job == 5 ) {
		if ( Equil ) {
		    for (i = 0; i < n; ++i) {
			R1[i] = exp(R1[i]);
			C1[i] = exp(C1[i]);
		    }
		    for (j = 0; j < n; ++j) {
			for (i = colptr[j]; i < colptr[j+1]; ++i) {
			    irow = rowind[i];
			    a[i] *= R1[irow] * C1[j]; /* Scale the matrix. */
			    rowind[i] = perm_r[irow];
#if ( PRNTlevel>=2 )
			    if ( rowind[i] == j ) /* New diagonal */
				dprod *= fabs(a[i]);
#endif
			}
		    }

		    /* Multiply together the scaling factors. */
		    if ( rowequ ) for (i = 0; i < m; ++i) R[i] *= R1[i];
		    else for (i = 0; i < m; ++i) R[i] = R1[i];
		    if ( colequ ) for (i = 0; i < n; ++i) C[i] *= C1[i];
		    else for (i = 0; i < n; ++i) C[i] = C1[i];
		    
		    ScalePermstruct->DiagScale = BOTH;
		    rowequ = colequ = 1;
		} else { /* No equilibration. */
/*		    for (j = 0; j < n; ++j) {
			for (i = colptr[j]; i < colptr[j+1]; ++i) {*/
		    for (i = colptr[0]; i < colptr[n]; ++i) {
			    irow = rowind[i];
			    rowind[i] = perm_r[irow];
			}
/*		    }*/
		}
		SUPERLU_FREE (R1);
		SUPERLU_FREE (C1);
	    } else { /* job = 2,3,4 */
		for (j = 0; j < n; ++j) {
		    for (i = colptr[j]; i < colptr[j+1]; ++i) {
			irow = rowind[i];
			rowind[i] = perm_r[irow];
#if ( PRNTlevel>=2 )
			if ( rowind[i] == j ) { /* New diagonal */
			    if ( job == 2 || job == 3 )
				dmin = SUPERLU_MIN(dmin, fabs(a[i]));
			    else if ( job == 4 )
				dsum += fabs(a[i]);
			    else if ( job == 5 )
				dprod *= fabs(a[i]);
			}
#endif
		    }
		}
	    }

#if ( PRNTlevel>=2 )
	    if ( job == 2 || job == 3 ) {
		if ( !iam ) printf("\tsmallest diagonal %e\n", dmin);
	    } else if ( job == 4 ) {
		if ( !iam ) printf("\tsum of diagonal %e\n", dsum);
	    } else if ( job == 5 ) {
		if ( !iam ) printf("\t product of diagonal %e\n", dprod);
	    }
#endif
	    
        } /* else !factored */

	t = SuperLU_timer_() - t;
	stat->utime[ROWPERM] = t;
#if ( PRNTlevel>=1 )
	if ( !iam ) printf(".. LDPERM job %d\t time: %.2f\n", job, t);
#endif
    
    } /* if options->RowPerm ... */

    if ( !factored || options->IterRefine ) {
	/* Compute norm(A), which will be used to adjust small diagonal. */
	if ( notran ) *(unsigned char *)norm = '1';
	else *(unsigned char *)norm = 'I';
	anorm = dlangs_dist(norm, A);
#if ( PRNTlevel>=1 )
	if ( !iam ) printf(".. anorm %e\n", anorm);
#endif
    }

    /* ------------------------------------------------------------
       Perform the LU factorization.
       ------------------------------------------------------------*/
    if ( !factored ) {
	t = SuperLU_timer_();
	/*
	 * Get column permutation vector perm_c[], according to permc_spec:
	 *   permc_spec = NATURAL:  natural ordering 
	 *   permc_spec = MMD_AT_PLUS_A: minimum degree on structure of A'+A
	 *   permc_spec = MMD_ATA:  minimum degree on structure of A'*A
	 *   permc_spec = COLAMD:   approximate minimum degree column ordering
	 *   permc_spec = MY_PERMC: the ordering already supplied in perm_c[]
	 */
	permc_spec = options->ColPerm;
	if ( permc_spec != MY_PERMC && Fact == DOFACT )
	    /* Use an ordering provided by SuperLU */
	    get_perm_c_dist(iam, permc_spec, A, perm_c);

	/* Compute the elimination tree of Pc*(A'+A)*Pc' or Pc*A'*A*Pc'
	   (a.k.a. column etree), depending on the choice of ColPerm.
	   Adjust perm_c[] to be consistent with a postorder of etree.
	   Permute columns of A to form A*Pc'. */
	sp_colorder(options, A, perm_c, etree, &AC);

	/* Form Pc*A*Pc' to preserve the diagonal of the matrix Pr*A. */
	ACstore = AC.Store;
	for (j = 0; j < n; ++j) 
	    for (i = ACstore->colbeg[j]; i < ACstore->colend[j]; ++i) {
		irow = ACstore->rowind[i];
		ACstore->rowind[i] = perm_c[irow];
	    }
	stat->utime[COLPERM] = SuperLU_timer_() - t;

	/* Perform a symbolic factorization on matrix A and set up the
	   nonzero data structures which are suitable for supernodal GENP. */
	if ( Fact != SamePattern_SameRowPerm ) {
#if ( PRNTlevel>=1 ) 
	    if ( !iam ) 
		printf(".. symbfact(): relax %4d, maxsuper %4d, fill %4d\n",
		       sp_ienv_dist(2), sp_ienv_dist(3), sp_ienv_dist(6));
#endif
	    t = SuperLU_timer_();
	    if ( !(Glu_freeable = (Glu_freeable_t *)
		   SUPERLU_MALLOC(sizeof(Glu_freeable_t))) )
		ABORT("Malloc fails for Glu_freeable.");

	    iinfo = symbfact(iam, &AC, perm_c, etree, 
			     Glu_persist, Glu_freeable);

	    stat->utime[SYMBFAC] = SuperLU_timer_() - t;

	    if ( iinfo < 0 ) {
		QuerySpace_dist(n, -iinfo, Glu_freeable, &symb_mem_usage);
#if ( PRNTlevel>=1 )
		if ( !iam ) {
		    printf("\tNo of supers %ld\n", Glu_persist->supno[n-1]+1);
		    printf("\tSize of G(L) %ld\n", Glu_freeable->xlsub[n]);
		    printf("\tSize of G(U) %ld\n", Glu_freeable->xusub[n]);
		    printf("\tint %d, short %d, float %d, double %d\n", 
			   sizeof(int_t), sizeof(short), sizeof(float),
			   sizeof(double));
		    printf("\tSYMBfact (MB):\tL\\U %.2f\ttotal %.2f\texpansions %d\n",
			   symb_mem_usage.for_lu*1e-6, 
			   symb_mem_usage.total*1e-6,
			   symb_mem_usage.expansions);
		}
#endif
	    } else {
		if ( !iam ) {
		    fprintf(stderr, "symbfact() error returns %d\n", iinfo);
		    exit(-1);
		}
	    }
	}

	/* Distribute the L and U factors onto the process grid. */
	t = SuperLU_timer_();
	dist_mem_use = ddistribute(Fact, n, &AC, Glu_freeable, LUstruct, grid);
	stat->utime[DIST] = SuperLU_timer_() - t;

	/* Deallocate storage used in symbolic factor. */
	if ( Fact != SamePattern_SameRowPerm ) {
	    iinfo = symbfact_SubFree(Glu_freeable);
	    SUPERLU_FREE(Glu_freeable);
	}

	/* Perform numerical factorization in parallel. */
	t = SuperLU_timer_();
	pdgstrf(options, m, n, anorm, LUstruct, grid, stat, info);
	stat->utime[FACT] = SuperLU_timer_() - t;

#if ( PRNTlevel>=1 )
	{
	    int_t TinyPivots;
	    float for_lu, total, max, avg, temp;
	    dQuerySpace_dist(n, LUstruct, grid, &num_mem_usage);
	    MPI_Reduce( &num_mem_usage.for_lu, &for_lu,
		       1, MPI_FLOAT, MPI_SUM, 0, grid->comm );
	    MPI_Reduce( &num_mem_usage.total, &total,
		       1, MPI_FLOAT, MPI_SUM, 0, grid->comm );
	    temp = SUPERLU_MAX(symb_mem_usage.total,
			       symb_mem_usage.for_lu +
			       (float)dist_mem_use + num_mem_usage.for_lu);
	    temp = SUPERLU_MAX(temp, num_mem_usage.total);
	    MPI_Reduce( &temp, &max,
		       1, MPI_FLOAT, MPI_MAX, 0, grid->comm );
	    MPI_Reduce( &temp, &avg,
		       1, MPI_FLOAT, MPI_SUM, 0, grid->comm );
	    MPI_Allreduce( &stat->TinyPivots, &TinyPivots, 1, mpi_int_t,
			  MPI_SUM, grid->comm );
	    stat->TinyPivots = TinyPivots;
	    if ( !iam ) {
		printf("\tNUMfact (MB) all PEs:\tL\\U\t%.2f\tall\t%.2f\n",
		       for_lu*1e-6, total*1e-6);
		printf("\tAll space (MB):"
		       "\t\ttotal\t%.2f\tAvg\t%.2f\tMax\t%.2f\n",
		       avg*1e-6, avg/grid->nprow/grid->npcol*1e-6, max*1e-6);
		printf("\tNumber of tiny pivots: %10d\n", stat->TinyPivots);
	    }
	}
#endif
    
#if ( PRNTlevel>=2 )
	if ( !iam ) printf(".. pdgstrf INFO = %d\n", *info);
#endif

    } else if ( options->IterRefine ) { /* options->Fact==FACTORED */
	/* Permute columns of A to form A*Pc' using the existing perm_c.
	 * NOTE: rows of A were previously permuted to Pc*A.
	 */
	sp_colorder(options, A, perm_c, NULL, &AC);
    } /* if !factored ... */
	
    /* ------------------------------------------------------------
       Compute the solution matrix X.
       ------------------------------------------------------------*/
    if ( nrhs ) {

	if ( !(b_work = doubleMalloc_dist(n)) )
	    ABORT("Malloc fails for b_work[]");

	/* ------------------------------------------------------------
	   Scale the right-hand side if equilibration was performed. 
	   ------------------------------------------------------------*/
	if ( notran ) {
	    if ( rowequ ) {
		b_col = B;
		for (j = 0; j < nrhs; ++j) {
		    for (i = 0; i < m; ++i) b_col[i] *= R[i];
		    b_col += ldb;
		}
	    }
	} else if ( colequ ) {
	    b_col = B;
	    for (j = 0; j < nrhs; ++j) {
		for (i = 0; i < m; ++i) b_col[i] *= C[i];
		b_col += ldb;
	    }
	}

	/* ------------------------------------------------------------
	   Permute the right-hand side to form Pr*B.
	   ------------------------------------------------------------*/
	if ( options->RowPerm != NO ) {
	    if ( notran ) {
		b_col = B;
		for (j = 0; j < nrhs; ++j) {
		    for (i = 0; i < m; ++i) b_work[perm_r[i]] = b_col[i];
		    for (i = 0; i < m; ++i) b_col[i] = b_work[i];
		    b_col += ldb;
		}
	    }
	}


	/* ------------------------------------------------------------
	   Permute the right-hand side to form Pc*B.
	   ------------------------------------------------------------*/
	if ( notran ) {
	    b_col = B;
	    for (j = 0; j < nrhs; ++j) {
		for (i = 0; i < m; ++i) b_work[perm_c[i]] = b_col[i];
		for (i = 0; i < m; ++i) b_col[i] = b_work[i];
		b_col += ldb;
	    }
	}


	/* Save a copy of the right-hand side. */
	ldx = ldb;
	if ( !(X = doubleMalloc_dist(((size_t)ldx) * nrhs)) )
	    ABORT("Malloc fails for X[]");
	x_col = X;  b_col = B;
	for (j = 0; j < nrhs; ++j) {
	    for (i = 0; i < ldb; ++i) x_col[i] = b_col[i];
	    x_col += ldx;  b_col += ldb;
	}

	/* ------------------------------------------------------------
	   Solve the linear system.
	   ------------------------------------------------------------*/
	pdgstrs_Bglobal(n, LUstruct, grid, X, ldb, nrhs, stat, info);

	/* ------------------------------------------------------------
	   Use iterative refinement to improve the computed solution and
	   compute error bounds and backward error estimates for it.
	   ------------------------------------------------------------*/
	if ( options->IterRefine ) {
	    /* Improve the solution by iterative refinement. */
	    t = SuperLU_timer_();
	    pdgsrfs_ABXglobal(n, &AC, anorm, LUstruct, grid, B, ldb,
			      X, ldx, nrhs, berr, stat, info);
	    stat->utime[REFINE] = SuperLU_timer_() - t;
	}

	/* Permute the solution matrix X <= Pc'*X. */
	for (j = 0; j < nrhs; j++) {
	    b_col = &B[j*ldb];
	    x_col = &X[j*ldx];
	    for (i = 0; i < n; ++i) b_col[i] = x_col[perm_c[i]];
	}
	
	/* Transform the solution matrix X to a solution of the original system
	   before the equilibration. */
	if ( notran ) {
	    if ( colequ ) {
		b_col = B;
		for (j = 0; j < nrhs; ++j) {
		    for (i = 0; i < n; ++i) b_col[i] *= C[i];
		    b_col += ldb;
		}
	    }
	} else if ( rowequ ) {
	    b_col = B;
	    for (j = 0; j < nrhs; ++j) {
		for (i = 0; i < n; ++i) b_col[i] *= R[i];
		b_col += ldb;
	    }
	}

	SUPERLU_FREE(b_work);
	SUPERLU_FREE(X);

    } /* end if nrhs != 0 */

#if ( PRNTlevel>=1 )
    if ( !iam ) printf(".. DiagScale = %d\n", ScalePermstruct->DiagScale);
#endif

    /* Deallocate storage. */
    if ( Equil && Fact != SamePattern_SameRowPerm ) {
	switch ( ScalePermstruct->DiagScale ) {
	    case NOEQUIL:
	        SUPERLU_FREE(R);
		SUPERLU_FREE(C);
		break;
	    case ROW: 
		SUPERLU_FREE(C);
		break;
	    case COL: 
		SUPERLU_FREE(R);
		break;
	}
    }
    if ( !factored || (factored && options->IterRefine) )
	Destroy_CompCol_Permuted_dist(&AC);

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Exit pdgssvx_ABglobal()");
#endif
}
示例#12
0
/*! \brief
 *
 * <pre>
 * Purpose
 * =======
 *   symbfact() performs a symbolic factorization on matrix A and sets up 
 *   the nonzero data structures which are suitable for supernodal Gaussian
 *   elimination with no pivoting (GENP). This routine features:
 *        o depth-first search (DFS)
 *        o supernodes
 *        o symmetric structure pruning
 *
 * Return value
 * ============
 *   < 0, number of bytes needed for LSUB.
 *   = 0, matrix dimension is 1.
 *   > 0, number of bytes allocated when out of memory.
 * </pre>
 */
int_t symbfact
/************************************************************************/
(
 superlu_options_t *options, /* input options */
 int         pnum,     /* process number */
 SuperMatrix *A,       /* original matrix A permuted by columns (input) */
 int_t       *perm_c,  /* column permutation vector (input) */
 int_t       *etree,   /* column elimination tree (input) */
 Glu_persist_t *Glu_persist,  /* output */
 Glu_freeable_t *Glu_freeable /* output */
 )
{

    int_t m, n, min_mn, j, i, k, irep, nseg, pivrow, info;
    int_t *iwork, *perm_r, *segrep, *repfnz;
    int_t *xprune, *marker, *parent, *xplore;
    int_t relax, *desc, *relax_end;
    int_t nnzL, nnzU;

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(pnum, "Enter symbfact()");
#endif

    m = A->nrow;
    n = A->ncol;
    min_mn = SUPERLU_MIN(m, n);

    /* Allocate storage common to the symbolic factor routines */
    info = symbfact_SubInit(DOFACT, NULL, 0, m, n, ((NCPformat*)A->Store)->nnz,
			    Glu_persist, Glu_freeable);

    iwork = (int_t *) intMalloc_dist(6*m+2*n);
    perm_r = iwork;
    segrep = iwork + m;
    repfnz = segrep + m;
    marker = repfnz + m;
    parent = marker + m;
    xplore = parent + m;
    xprune = xplore + m;
    relax_end = xprune + n;
    relax = sp_ienv_dist(2);
    ifill_dist(perm_r, m, EMPTY);
    ifill_dist(repfnz, m, EMPTY);
    ifill_dist(marker, m, EMPTY);
    Glu_persist->supno[0] = -1;
    Glu_persist->xsup[0] = 0;
    Glu_freeable->xlsub[0] = 0;
    Glu_freeable->xusub[0] = 0;

    /*for (j = 0; j < n; ++j) iperm_c[perm_c[j]] = j;*/

    /* Identify relaxed supernodes. */
    if ( !(desc = intMalloc_dist(n+1)) )
	ABORT("Malloc fails for desc[]");;
    relax_snode(n, etree, relax, desc, relax_end);
    SUPERLU_FREE(desc);
    
    for (j = 0; j < min_mn; ) {
	if ( relax_end[j] != EMPTY ) { /* beginning of a relaxed snode */
   	    k = relax_end[j];          /* end of the relaxed snode */
	 
	    /* Determine union of the row structure of supernode (j:k). */
	    if ( (info = snode_dfs(A, j, k, xprune, marker,
				   Glu_persist, Glu_freeable)) != 0 )
		return info;

	    for (i = j; i <= k; ++i)
		pivotL(i, perm_r, &pivrow, Glu_persist, Glu_freeable); 

	    j = k+1;
	} else {
	    /* Perform a symbolic factorization on column j, and detects
	       whether column j starts a new supernode. */
	    if ((info = column_dfs(A, j, perm_r, &nseg, segrep, repfnz,
				   xprune, marker, parent, xplore,
				   Glu_persist, Glu_freeable)) != 0)
		return info;
	    
	    /* Copy the U-segments to usub[*]. */
	    if ((info = set_usub(min_mn, j, nseg, segrep, repfnz,
				 Glu_persist, Glu_freeable)) != 0)
		return info;

	    pivotL(j, perm_r, &pivrow, Glu_persist, Glu_freeable); 

	    /* Prune columns [0:j-1] using column j. */
	    pruneL(j, perm_r, pivrow, nseg, segrep, repfnz, xprune,
		   Glu_persist, Glu_freeable);

	    /* Reset repfnz[*] to prepare for the next column. */
	    for (i = 0; i < nseg; i++) {
		irep = segrep[i];
		repfnz[irep] = EMPTY;
	    }

	    ++j;
	} /* else */
    } /* for j ... */

    countnz_dist(min_mn, xprune, &nnzL, &nnzU, Glu_persist, Glu_freeable);

    /* Apply perm_r to L; Compress LSUB array. */
    i = fixupL_dist(min_mn, perm_r, Glu_persist, Glu_freeable);

    if ( !pnum && (options->PrintStat == YES)) {
	printf("\tNonzeros in L       %ld\n", nnzL);
	printf("\tNonzeros in U       %ld\n", nnzU);
	printf("\tnonzeros in L+U     %ld\n", nnzL + nnzU - min_mn);
	printf("\tnonzeros in LSUB    %ld\n", i);
    }
    SUPERLU_FREE(iwork);

#if ( PRNTlevel>=3 )
    PrintInt10("lsub", Glu_freeable->xlsub[n], Glu_freeable->lsub);
    PrintInt10("xlsub", n+1, Glu_freeable->xlsub);
    PrintInt10("xprune", n, xprune);
    PrintInt10("usub", Glu_freeable->xusub[n], Glu_freeable->usub);
    PrintInt10("xusub", n+1, Glu_freeable->xusub);
    PrintInt10("supno", n, Glu_persist->supno);
    PrintInt10("xsup", (Glu_persist->supno[n])+2, Glu_persist->xsup);
#endif

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(pnum, "Exit symbfact()");
#endif

    return (-i);

} /* SYMBFACT */
示例#13
0
/*! \brief
 *
 * <pre>
 * Purpose
 * =======
 *   column_dfs() performs a symbolic factorization on column jcol, and
 *   detects the supernode boundary. This routine uses the row indices of
 *   A[*,jcol] to start the depth-first search (DFS).
 *
 * Output
 * ======
 *   A supernode representative is the last column of a supernode.
 *   The nonzeros in U[*,j] are segments that end at supernodal
 *   representatives. The routine returns a list of such supernodal 
 *   representatives ( segrep[*] ) in topological order of the DFS that 
 *   generates them. The location of the first nonzero in each such 
 *   supernodal segment is also returned ( repfnz[*] ).
 *
 * Data structure
 * ==============
 *   (lsub, xlsub):
 *      lsub[*] contains the compressed subscripts of the supernodes;
 *      xlsub[j] points to the starting location of the j-th column in
 *               lsub[*]; 
 *	Storage: original row subscripts in A.
 *
 *      During the course of symbolic factorization, we also use
 *	(lsub, xlsub, xprune) for the purpose of symmetric pruning.
 *      For each supernode {s,s+1,...,t=s+r} with first column s and last
 *	column t, there are two subscript sets,  the last column
 *      structures (for pruning) will be removed in the end.
 *        o lsub[j], j = xlsub[s], ..., xlsub[s+1]-1
 *          is the structure of column s (i.e. structure of this supernode).
 *          It is used for the storage of numerical values.
 *	  o lsub[j], j = xlsub[t], ..., xlsub[t+1]-1
 *	    is the structure of the last column t of this supernode.
 *	    It is for the purpose of symmetric pruning. Therefore, the
 *	    structural subscripts can be rearranged without making physical
 *	    interchanges among the numerical values.
 *
 *      (1) if t > s, only the subscript sets for column s and column t
 *          are stored. Column t represents pruned adjacency structure.
 *
 *                  --------------------------------------------
 *          lsub[*]    ... |   col s    |   col t   | ...
 *                  --------------------------------------------
 *                          ^            ^           ^
 *                       xlsub[s]    xlsub[s+1]  xlsub[t+1]
 *                                       :           :
 *                                       :         xprune[t]
 *                                   xlsub[t]      
 *                                   xprune[s]    
 *
 *      (2) if t == s, i.e., a singleton supernode, the same subscript set
 *          is used for both G(L) and pruned graph:
 *
 *                  --------------------------------------
 *          lsub[*]    ... |      s     | ...
 *                  --------------------------------------
 *                          ^            ^   
 *                       xlsub[s]   xlsub[s+1]  
 *                                  xprune[s]
 *
 *       DFS will traverse the second subscript list, i.e., the part of the
 *       pruned graph.
 *
 * Local parameters
 * ================
 *   nseg: no of segments in current U[*,j]
 *   jsuper: jsuper=EMPTY if column j does not belong to the same
 *	supernode as j-1. Otherwise, jsuper=nsuper.
 *
 *   marker: A-row --> A-row/col (0/1)
 *   repfnz: SuperA-col --> PA-row
 *   parent: SuperA-col --> SuperA-col
 *   xplore: SuperA-col --> index to L-structure
 *
 * Return value
 * ============
 *     0  success;
 *   > 0  number of bytes allocated when run out of space.
 * </pre>
 */
static int_t column_dfs
/************************************************************************/
(
 SuperMatrix *A,        /* original matrix A permuted by columns (input) */
 const int_t jcol,      /* current column number (input) */
 int_t       *perm_r,   /* row permutation vector (input) */
 int_t       *nseg,     /* number of U-segments in column jcol (output) */
 int_t       *segrep,   /* list of U-segment representatives (output) */
 int_t       *repfnz,   /* list of first nonzeros in the U-segments (output) */
 int_t       *xprune,   /* pruned location in each adjacency list (output) */
 int_t       *marker,   /* working array of size m */
 int_t       *parent,   /* working array of size m */
 int_t       *xplore,   /* working array of size m */
 Glu_persist_t *Glu_persist,   /* global LU data structures (modified) */
 Glu_freeable_t *Glu_freeable
 )
{

    NCPformat *Astore;
    int_t     *asub, *xa_begin, *xa_end;
    int_t     jcolp1, jcolm1, jsuper, nsuper, nextl;
    int_t     k, krep, krow, kmark, kperm;
    int_t     fsupc; /* first column of a supernode */
    int_t     myfnz; /* first nonzero column of a U-segment */
    int_t     chperm, chmark, chrep, kchild;
    int_t     xdfs, maxdfs, kpar, oldrep;
    int_t     jptr, jm1ptr;
    int_t     ito, ifrom, istop;	/* used to compress row subscripts */
    int_t     *xsup, *supno, *lsub, *xlsub;
    int_t     nzlmax;
    static int_t first = 1, maxsuper;
    int_t     mem_error;
    
    /* Initializations */
    Astore   = A->Store;
    asub     = Astore->rowind;
    xa_begin = Astore->colbeg;
    xa_end   = Astore->colend;
    xsup     = Glu_persist->xsup;
    supno    = Glu_persist->supno;
    lsub     = Glu_freeable->lsub;
    xlsub    = Glu_freeable->xlsub;
    nzlmax   = Glu_freeable->nzlmax;
    jcolp1   = jcol + 1;
    jcolm1   = jcol - 1;
    jsuper   = nsuper = supno[jcol];
    nextl    = xlsub[jcol];
    if ( first ) {
	maxsuper = sp_ienv_dist(3);
	first = 0;
    }
    
    *nseg = 0;

    /* For each nonzero in A[*,jcol] perform depth-first search. */
    for (k = xa_begin[jcol]; k < xa_end[jcol]; ++k) {
	krow = asub[k];
	kmark = marker[krow];

	/* krow was visited before, go to the next nonzero. */
	if ( kmark == jcol ) continue; 
	
	/* 
	 * For each unmarked neighber krow of jcol ...
	 */
	marker[krow] = jcol; /* mark as "visited" */
	kperm = perm_r[krow];

	if ( kperm == EMPTY ) {
	    /* ---------------
	     *  krow is in L
	     * ---------------
	     * place it in structure of L[*,jcol].
	     */
	    lsub[nextl++] = krow; 	/* krow is indexed into A */
	    if ( nextl >= nzlmax ) {
		if ( mem_error = symbfact_SubXpand(A->ncol, jcol, nextl, LSUB,
						   &nzlmax, Glu_freeable) )
		    return (mem_error);
		lsub = Glu_freeable->lsub;
	    }
	    if ( kmark != jcolm1 ) jsuper = EMPTY; /* Row index subset test */
	} else {
	    /* ---------------
	     *  krow is in U
	     * ---------------
	     * If its supernode krep has been explored, update repfnz[*].
	     */
	    krep = xsup[supno[kperm]+1] - 1;
	    myfnz = repfnz[krep];
	    
	    if ( myfnz != EMPTY ) { /* krep was visited before */
		if ( kperm < myfnz ) repfnz[krep] = kperm;
		/* continue; */
	    } else {
		/* Otherwise perform DFS, starting at krep */
		oldrep = EMPTY;
		parent[krep] = oldrep;
		repfnz[krep] = kperm;
		xdfs = xlsub[krep];
		maxdfs = xprune[krep];
		
		do {
		    /* 
		     * For each unmarked kchild of krep 
		     */
		    while ( xdfs < maxdfs ) {
			kchild = lsub[xdfs++];
			chmark = marker[kchild];
			
			if ( chmark != jcol ) { /* Not reached yet */
			    marker[kchild] = jcol;
			    chperm = perm_r[kchild];
			    
			    /* Case kchild is in L: place it in L[*,k] */
			    if ( chperm == EMPTY ) {
				lsub[nextl++] = kchild;
				if ( nextl >= nzlmax ) {
				    if ( mem_error =
					symbfact_SubXpand(A->ncol, jcol, nextl,
							  LSUB, &nzlmax,
							  Glu_freeable) )
					return (mem_error);
				    lsub = Glu_freeable->lsub;
				}
				if ( chmark != jcolm1 ) jsuper = EMPTY;
			    } else {
				/* Case kchild is in U: 
				 * chrep = its supernode-rep. If its rep 
				 * has been explored, update its repfnz[*].
				 */
				chrep = xsup[supno[chperm]+1] - 1;
				myfnz = repfnz[chrep];
				if ( myfnz != EMPTY ) {/* Visited before */
				    if (chperm < myfnz) repfnz[chrep] = chperm;
				} else {
				    /* Continue DFS at sup-rep of kchild */
				    xplore[krep] = xdfs;
				    oldrep = krep;
				    krep = chrep; /* Go deeper down G(L') */
				    parent[krep] = oldrep;
				    repfnz[krep] = chperm;
				    xdfs = xlsub[krep];     
				    maxdfs = xprune[krep];
				} /* else */
			    } /* else */
			} /* if chmark != jcol */
			
		    } /* while */
		    
		    /* krow has no more unexplored neighbors:
		     *    place supernode-rep krep in postorder DFS;
		     *    backtrack DFS to its parent.
		     */
		    segrep[*nseg] = krep;
		    ++(*nseg);
		    kpar = parent[krep]; /* Pop from stack; recurse */
		    if ( kpar == EMPTY ) break; /* DFS done */
		    krep = kpar;
		    xdfs = xplore[krep];
		    maxdfs = xprune[krep];
		} while ( kpar != EMPTY ); /* Until empty stack */
	    } /* else */
	} /* else: krow is in U */
    } /* for each nonzero in A[*, jcol] */
    
    /* Check to see if jcol belongs in the same supernode as jcol-1 */
    if ( jcol == 0 ) { /* Do nothing for column 0 */
	nsuper = supno[0] = 0;
    } else {
	fsupc = xsup[nsuper];
	jptr = xlsub[jcol];	/* Not compressed yet */
	jm1ptr = xlsub[jcolm1];
	
#ifdef T2_SUPER
	if ( (nextl-jptr != jptr-jm1ptr-1) ) jsuper = EMPTY;
#endif
	/* Make sure the number of columns in a supernode doesn't
	   exceed threshold. */
	if ( jcol - fsupc >= maxsuper ) jsuper = EMPTY;
	
	/* If jcol starts a new supernode, reclaim storage space in
	 * lsub[*] from the previous supernode. Note we only store
	 * the subscript set of the first and last columns of
	 * a supernode. (first for G(L'), last for pruned graph)
	 */
	if ( jsuper ==EMPTY ) { /* Starts a new supernode */
	    if ( (fsupc < jcolm1-1) ) { /* >= 3 columns in nsuper */
#ifdef CHK_COMPRESS
		printf("  Compress lsub[] at super %d-%d\n",fsupc,jcolm1);
#endif
		ito = xlsub[fsupc+1];
		xlsub[jcolm1] = ito;
		istop = ito + jptr - jm1ptr;
		xprune[jcolm1] = istop; /* Initialize xprune[jcol-1] */
		xlsub[jcol] = istop;
		for (ifrom = jm1ptr; ifrom < nextl; ++ifrom, ++ito)
		    lsub[ito] = lsub[ifrom];
		nextl = ito;            /* = istop + length(jcol) */
	    }
	    ++nsuper;
	    supno[jcol] = nsuper;
	} /* if a new supernode */
	
    } /* else: jcol > 0 */ 
    
    /* Tidy up the pointers before exit */
    xsup[nsuper+1] = jcolp1;
    supno[jcolp1]  = nsuper;
    xprune[jcol]   = nextl; /* Initialize an upper bound for pruning. */
    xlsub[jcolp1]  = nextl;
    return 0;
} /* COLUMN_DFS */
示例#14
0
int_t
pddistribute(fact_t fact, int_t n, SuperMatrix *A,
	     ScalePermstruct_t *ScalePermstruct,
	     Glu_freeable_t *Glu_freeable, LUstruct_t *LUstruct,
	     gridinfo_t *grid)
/*
 * -- Distributed SuperLU routine (version 2.0) --
 * Lawrence Berkeley National Lab, Univ. of California Berkeley.
 * March 15, 2003
 *
 *
 * Purpose
 * =======
 *   Distribute the matrix onto the 2D process mesh.
 * 
 * Arguments
 * =========
 * 
 * fact (input) fact_t
 *        Specifies whether or not the L and U structures will be re-used.
 *        = SamePattern_SameRowPerm: L and U structures are input, and
 *                                   unchanged on exit.
 *        = DOFACT or SamePattern: L and U structures are computed and output.
 *
 * n      (input) int
 *        Dimension of the matrix.
 *
 * A      (input) SuperMatrix*
 *	  The distributed input matrix A of dimension (A->nrow, A->ncol).
 *        A may be overwritten by diag(R)*A*diag(C)*Pc^T.
 *        The type of A can be: Stype = NR; Dtype = SLU_D; Mtype = GE.
 *
 * ScalePermstruct (input) ScalePermstruct_t*
 *        The data structure to store the scaling and permutation vectors
 *        describing the transformations performed to the original matrix A.
 *
 * Glu_freeable (input) *Glu_freeable_t
 *        The global structure describing the graph of L and U.
 * 
 * LUstruct (input) LUstruct_t*
 *        Data structures for L and U factors.
 *
 * grid   (input) gridinfo_t*
 *        The 2D process mesh.
 *
 * Return value
 * ============
 *   > 0, working storage required (in bytes).
 *
 */
{
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    LocalLU_t *Llu = LUstruct->Llu;
    int_t bnnz, fsupc, i, irow, istart, j, jb, jj, k, len, len1, nsupc;
    int_t ljb;  /* local block column number */
    int_t nrbl; /* number of L blocks in current block column */
    int_t nrbu; /* number of U blocks in current block column */
    int_t gb;   /* global block number; 0 < gb <= nsuper */
    int_t lb;   /* local block number; 0 < lb <= ceil(NSUPERS/Pr) */
    int iam, jbrow, kcol, mycol, myrow, pc, pr;
    int_t mybufmax[NBUFFERS];
#if 0
    NCPformat *Astore;
#else /* XSL ==> */
    NRformat_loc *Astore;
#endif
    double *a;
    int_t *asub, *xa;
#if 0
    int_t *xa_begin, *xa_end;
#endif
    int_t *xsup = Glu_persist->xsup;    /* supernode and column mapping */
    int_t *supno = Glu_persist->supno;   
    int_t *lsub, *xlsub, *usub, *xusub;
    int_t nsupers;
    int_t next_lind;      /* next available position in index[*] */
    int_t next_lval;      /* next available position in nzval[*] */
    int_t *index;         /* indices consist of headers and row subscripts */
    double *lusup, *uval; /* nonzero values in L and U */
    double **Lnzval_bc_ptr;  /* size ceil(NSUPERS/Pc) */
    int_t  **Lrowind_bc_ptr; /* size ceil(NSUPERS/Pc) */
    double **Unzval_br_ptr;  /* size ceil(NSUPERS/Pr) */
    int_t  **Ufstnz_br_ptr;  /* size ceil(NSUPERS/Pr) */

    /*-- Counts to be used in factorization. --*/
    int_t  *ToRecv, *ToSendD, **ToSendR;

    /*-- Counts to be used in lower triangular solve. --*/
    int_t  *fmod;          /* Modification count for L-solve.        */
    int_t  **fsendx_plist; /* Column process list to send down Xk.   */
    int_t  nfrecvx = 0;    /* Number of Xk I will receive.           */
    int_t  kseen;

    /*-- Counts to be used in upper triangular solve. --*/
    int_t  *bmod;          /* Modification count for U-solve.        */
    int_t  **bsendx_plist; /* Column process list to send down Xk.   */
    int_t  nbrecvx = 0;    /* Number of Xk I will receive.           */
    int_t  *ilsum;         /* starting position of each supernode in 
			      the full array (local)                 */

    /*-- Auxiliary arrays; freed on return --*/
    int_t *rb_marker;  /* block hit marker; size ceil(NSUPERS/Pr)           */
    int_t *Urb_length; /* U block length; size ceil(NSUPERS/Pr)             */
    int_t *Urb_indptr; /* pointers to U index[]; size ceil(NSUPERS/Pr)      */
    int_t *Urb_fstnz;  /* # of fstnz in a block row; size ceil(NSUPERS/Pr)  */
    int_t *Ucbs;       /* number of column blocks in a block row            */
    int_t *Lrb_length; /* L block length; size ceil(NSUPERS/Pr)             */
    int_t *Lrb_number; /* global block number; size ceil(NSUPERS/Pr)        */
    int_t *Lrb_indptr; /* pointers to L index[]; size ceil(NSUPERS/Pr)      */
    int_t *Lrb_valptr; /* pointers to L nzval[]; size ceil(NSUPERS/Pr)      */
    double *dense, *dense_col; /* SPA */
    double zero = 0.0;
    int_t ldaspa;     /* LDA of SPA */
    int_t mem_use = 0, iword, dword;

#if ( PRNTlevel>=1 )
    int_t nLblocks = 0, nUblocks = 0;
#endif
#if ( PROFlevel>=1 ) 
    double t, t_u, t_l;
    int_t u_blks;
#endif

    /* Initialization. */
    iam = grid->iam;
    myrow = MYROW( iam, grid );
    mycol = MYCOL( iam, grid );
    for (i = 0; i < NBUFFERS; ++i) mybufmax[i] = 0;
    nsupers  = supno[n-1] + 1;
    Astore   = (NRformat_loc *) A->Store;

#if ( PRNTlevel>=1 )
    iword = sizeof(int_t);
    dword = sizeof(double);
#endif

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter pddistribute()");
#endif

    dReDistribute_A(A, ScalePermstruct, Glu_freeable, xsup, supno,
		      grid, &xa, &asub, &a);

    if ( fact == SamePattern_SameRowPerm ) {
#if ( PROFlevel>=1 )
	t_l = t_u = 0; u_blks = 0;
#endif
	/* We can propagate the new values of A into the existing
	   L and U data structures.            */
	ilsum = Llu->ilsum;
	ldaspa = Llu->ldalsum;
	if ( !(dense = doubleCalloc_dist(ldaspa * sp_ienv_dist(3))) )
	    ABORT("Calloc fails for SPA dense[].");
	nrbu = CEILING( nsupers, grid->nprow ); /* Number of local block rows */
	if ( !(Urb_length = intCalloc_dist(nrbu)) )
	    ABORT("Calloc fails for Urb_length[].");
	if ( !(Urb_indptr = intMalloc_dist(nrbu)) )
	    ABORT("Malloc fails for Urb_indptr[].");
	for (lb = 0; lb < nrbu; ++lb) 
	    Urb_indptr[lb] = BR_HEADER; /* Skip header in U index[]. */
	Lrowind_bc_ptr = Llu->Lrowind_bc_ptr;
	Lnzval_bc_ptr = Llu->Lnzval_bc_ptr;
	Ufstnz_br_ptr = Llu->Ufstnz_br_ptr;
	Unzval_br_ptr = Llu->Unzval_br_ptr;
#if ( PRNTlevel>=1 )
	mem_use += 2*nrbu*iword + ldaspa*sp_ienv_dist(3)*dword;
#endif
	for (jb = 0; jb < nsupers; ++jb) { /* Loop through each block column */
	    pc = PCOL( jb, grid );
	    if ( mycol == pc ) { /* Block column jb in my process column */
		fsupc = FstBlockC( jb );
		nsupc = SuperSize( jb );

		/* Scatter A into SPA. */
		for (j = fsupc, dense_col = dense; j < FstBlockC(jb+1); ++j) {
		    for (i = xa[j]; i < xa[j+1]; ++i) {
			irow = asub[i];
			gb = BlockNum( irow );
			if ( myrow == PROW( gb, grid ) ) {
			    lb = LBi( gb, grid );
			    irow = ilsum[lb] + irow - FstBlockC( gb );
			    dense_col[irow] = a[i];
			}
		    }
		    dense_col += ldaspa;
		}

#if ( PROFlevel>=1 )
		t = SuperLU_timer_();
#endif
		/* Gather the values of A from SPA into Unzval[]. */
		for (lb = 0; lb < nrbu; ++lb) {
		    index = Ufstnz_br_ptr[lb];
		    if ( index && index[Urb_indptr[lb]] == jb ) {
			uval = Unzval_br_ptr[lb];
			len = Urb_indptr[lb] + UB_DESCRIPTOR;
			gb = lb * grid->nprow + myrow;/* Global block number */
			k = FstBlockC( gb+1 );
			irow = ilsum[lb] - FstBlockC( gb );
			for (jj = 0, dense_col = dense; jj < nsupc; ++jj) {
			    j = index[len+jj];
			    for (i = j; i < k; ++i) {
				uval[Urb_length[lb]++] = dense_col[irow+i];
				dense_col[irow+i] = zero;
			    }
			    dense_col += ldaspa;
			}
			Urb_indptr[lb] += UB_DESCRIPTOR + nsupc;
		    } /* if index != NULL */
		} /* for lb ... */
#if ( PROFlevel>=1 )
		t_u += SuperLU_timer_() - t;
		t = SuperLU_timer_();
#endif
		/* Gather the values of A from SPA into Lnzval[]. */
		ljb = LBj( jb, grid ); /* Local block number */
		index = Lrowind_bc_ptr[ljb];
		if ( index ) {
		    nrbl = index[0];   /* Number of row blocks. */
		    len = index[1];    /* LDA of lusup[]. */
		    lusup = Lnzval_bc_ptr[ljb];
		    next_lind = BC_HEADER;
		    next_lval = 0;
		    for (jj = 0; jj < nrbl; ++jj) {
			gb = index[next_lind++];
			len1 = index[next_lind++]; /* Rows in the block. */
			lb = LBi( gb, grid );
			for (bnnz = 0; bnnz < len1; ++bnnz) {
			    irow = index[next_lind++]; /* Global index. */
			    irow = ilsum[lb] + irow - FstBlockC( gb );
			    k = next_lval++;
			    for (j = 0, dense_col = dense; j < nsupc; ++j) {
				lusup[k] = dense_col[irow];
				dense_col[irow] = zero;
				k += len;
				dense_col += ldaspa;
			    }
			} /* for bnnz ... */
		    } /* for jj ... */
		} /* if index ... */
#if ( PROFlevel>=1 )
		t_l += SuperLU_timer_() - t;
#endif
	    } /* if mycol == pc */
	} /* for jb ... */

	SUPERLU_FREE(dense);
	SUPERLU_FREE(Urb_length);
	SUPERLU_FREE(Urb_indptr);
#if ( PROFlevel>=1 )
	if ( !iam ) printf(".. 2nd distribute time: L %.2f\tU %.2f\tu_blks %d\tnrbu %d\n",
			   t_l, t_u, u_blks, nrbu);
#endif

    } else {
        /* ------------------------------------------------------------
	   FIRST TIME CREATING THE L AND U DATA STRUCTURES.
	   ------------------------------------------------------------*/

#if ( PROFlevel>=1 )
	t_l = t_u = 0; u_blks = 0;
#endif
	/* We first need to set up the L and U data structures and then
	 * propagate the values of A into them.
	 */
	lsub = Glu_freeable->lsub;    /* compressed L subscripts */
	xlsub = Glu_freeable->xlsub;
	usub = Glu_freeable->usub;    /* compressed U subscripts */
	xusub = Glu_freeable->xusub;
    
	if ( !(ToRecv = intCalloc_dist(nsupers)) )
	    ABORT("Calloc fails for ToRecv[].");

	k = CEILING( nsupers, grid->npcol );/* Number of local column blocks */
	if ( !(ToSendR = (int_t **) SUPERLU_MALLOC(k*sizeof(int_t*))) )
	    ABORT("Malloc fails for ToSendR[].");
	j = k * grid->npcol;
	if ( !(index = intMalloc_dist(j)) )
	    ABORT("Malloc fails for index[].");
#if ( PRNTlevel>=1 )
	mem_use = k*sizeof(int_t*) + (j + nsupers)*iword;
#endif
	for (i = 0; i < j; ++i) index[i] = EMPTY;
	for (i = 0,j = 0; i < k; ++i, j += grid->npcol) ToSendR[i] = &index[j];
	k = CEILING( nsupers, grid->nprow ); /* Number of local block rows */

	/* Pointers to the beginning of each block row of U. */
	if ( !(Unzval_br_ptr = 
              (double**)SUPERLU_MALLOC(k * sizeof(double*))) )
	    ABORT("Malloc fails for Unzval_br_ptr[].");
	if ( !(Ufstnz_br_ptr = (int_t**)SUPERLU_MALLOC(k * sizeof(int_t*))) )
	    ABORT("Malloc fails for Ufstnz_br_ptr[].");
	
	if ( !(ToSendD = intCalloc_dist(k)) )
	    ABORT("Malloc fails for ToSendD[].");
	if ( !(ilsum = intMalloc_dist(k+1)) )
	    ABORT("Malloc fails for ilsum[].");

	/* Auxiliary arrays used to set up U block data structures.
	   They are freed on return. */
	if ( !(rb_marker = intCalloc_dist(k)) )
	    ABORT("Calloc fails for rb_marker[].");
	if ( !(Urb_length = intCalloc_dist(k)) )
	    ABORT("Calloc fails for Urb_length[].");
	if ( !(Urb_indptr = intMalloc_dist(k)) )
	    ABORT("Malloc fails for Urb_indptr[].");
	if ( !(Urb_fstnz = intCalloc_dist(k)) )
	    ABORT("Calloc fails for Urb_fstnz[].");
	if ( !(Ucbs = intCalloc_dist(k)) )
	    ABORT("Calloc fails for Ucbs[].");
#if ( PRNTlevel>=1 )	
	mem_use = 2*k*sizeof(int_t*) + (7*k+1)*iword;
#endif
	/* Compute ldaspa and ilsum[]. */
	ldaspa = 0;
	ilsum[0] = 0;
	for (gb = 0; gb < nsupers; ++gb) {
	    if ( myrow == PROW( gb, grid ) ) {
		i = SuperSize( gb );
		ldaspa += i;
		lb = LBi( gb, grid );
		ilsum[lb + 1] = ilsum[lb] + i;
	    }
	}
	
            
	/* ------------------------------------------------------------
	   COUNT NUMBER OF ROW BLOCKS AND THE LENGTH OF EACH BLOCK IN U.
	   THIS ACCOUNTS FOR ONE-PASS PROCESSING OF G(U).
	   ------------------------------------------------------------*/
	
	/* Loop through each supernode column. */
	for (jb = 0; jb < nsupers; ++jb) {
	    pc = PCOL( jb, grid );
	    fsupc = FstBlockC( jb );
	    nsupc = SuperSize( jb );
	    /* Loop through each column in the block. */
	    for (j = fsupc; j < fsupc + nsupc; ++j) {
		/* usub[*] contains only "first nonzero" in each segment. */
		for (i = xusub[j]; i < xusub[j+1]; ++i) {
		    irow = usub[i]; /* First nonzero of the segment. */
		    gb = BlockNum( irow );
		    kcol = PCOL( gb, grid );
		    ljb = LBj( gb, grid );
		    if ( mycol == kcol && mycol != pc ) ToSendR[ljb][pc] = YES;
		    pr = PROW( gb, grid );
		    lb = LBi( gb, grid );
		    if ( mycol == pc ) {
			if  ( myrow == pr ) {
			    ToSendD[lb] = YES;
			    /* Count nonzeros in entire block row. */
			    Urb_length[lb] += FstBlockC( gb+1 ) - irow;
			    if (rb_marker[lb] <= jb) {/* First see the block */
				rb_marker[lb] = jb + 1;
				Urb_fstnz[lb] += nsupc;
				++Ucbs[lb]; /* Number of column blocks
					       in block row lb. */
#if ( PRNTlevel>=1 )
				++nUblocks;
#endif
			    }
			    ToRecv[gb] = 1;
			} else ToRecv[gb] = 2; /* Do I need 0, 1, 2 ? */
		    }
		} /* for i ... */
	    } /* for j ... */
	} /* for jb ... */
	
	/* Set up the initial pointers for each block row in U. */
	nrbu = CEILING( nsupers, grid->nprow );/* Number of local block rows */
	for (lb = 0; lb < nrbu; ++lb) {
	    len = Urb_length[lb];
	    rb_marker[lb] = 0; /* Reset block marker. */
	    if ( len ) {
		/* Add room for descriptors */
		len1 = Urb_fstnz[lb] + BR_HEADER + Ucbs[lb] * UB_DESCRIPTOR;
		if ( !(index = intMalloc_dist(len1+1)) )
		    ABORT("Malloc fails for Uindex[].");
		Ufstnz_br_ptr[lb] = index;
		if ( !(Unzval_br_ptr[lb] = doubleMalloc_dist(len)) )
		    ABORT("Malloc fails for Unzval_br_ptr[*][].");
		mybufmax[2] = SUPERLU_MAX( mybufmax[2], len1 );
		mybufmax[3] = SUPERLU_MAX( mybufmax[3], len );
		index[0] = Ucbs[lb]; /* Number of column blocks */
		index[1] = len;      /* Total length of nzval[] */
		index[2] = len1;     /* Total length of index[] */
		index[len1] = -1;    /* End marker */
	    } else {
		Ufstnz_br_ptr[lb] = NULL;
		Unzval_br_ptr[lb] = NULL;
	    }
	    Urb_length[lb] = 0; /* Reset block length. */
	    Urb_indptr[lb] = BR_HEADER; /* Skip header in U index[]. */
	} /* for lb ... */

	SUPERLU_FREE(Urb_fstnz);
	SUPERLU_FREE(Ucbs);
#if ( PRNTlevel>=1 )
        mem_use -= 2*k * iword;
#endif
	/* Auxiliary arrays used to set up L block data structures.
	   They are freed on return.
	   k is the number of local row blocks.   */
	if ( !(Lrb_length = intCalloc_dist(k)) )
	    ABORT("Calloc fails for Lrb_length[].");
	if ( !(Lrb_number = intMalloc_dist(k)) )
	    ABORT("Malloc fails for Lrb_number[].");
	if ( !(Lrb_indptr = intMalloc_dist(k)) )
	    ABORT("Malloc fails for Lrb_indptr[].");
	if ( !(Lrb_valptr = intMalloc_dist(k)) )
	    ABORT("Malloc fails for Lrb_valptr[].");
	if ( !(dense = doubleCalloc_dist(ldaspa * sp_ienv_dist(3))) )
	    ABORT("Calloc fails for SPA dense[].");

	/* These counts will be used for triangular solves. */
	if ( !(fmod = intCalloc_dist(k)) )
	    ABORT("Calloc fails for fmod[].");
	if ( !(bmod = intCalloc_dist(k)) )
	    ABORT("Calloc fails for bmod[].");
	/* ------------------------------------------------ */
#if ( PRNTlevel>=1 )	
	mem_use += 6*k*iword + ldaspa*sp_ienv_dist(3)*dword;
#endif
	k = CEILING( nsupers, grid->npcol );/* Number of local block columns */

	/* Pointers to the beginning of each block column of L. */
	if ( !(Lnzval_bc_ptr = 
              (double**)SUPERLU_MALLOC(k * sizeof(double*))) )
	    ABORT("Malloc fails for Lnzval_bc_ptr[].");
	if ( !(Lrowind_bc_ptr = (int_t**)SUPERLU_MALLOC(k * sizeof(int_t*))) )
	    ABORT("Malloc fails for Lrowind_bc_ptr[].");
	Lrowind_bc_ptr[k-1] = NULL;

	/* These lists of processes will be used for triangular solves. */
	if ( !(fsendx_plist = (int_t **) SUPERLU_MALLOC(k*sizeof(int_t*))) )
	    ABORT("Malloc fails for fsendx_plist[].");
	len = k * grid->nprow;
	if ( !(index = intMalloc_dist(len)) )
	    ABORT("Malloc fails for fsendx_plist[0]");
	for (i = 0; i < len; ++i) index[i] = EMPTY;
	for (i = 0, j = 0; i < k; ++i, j += grid->nprow)
	    fsendx_plist[i] = &index[j];
	if ( !(bsendx_plist = (int_t **) SUPERLU_MALLOC(k*sizeof(int_t*))) )
	    ABORT("Malloc fails for bsendx_plist[].");
	if ( !(index = intMalloc_dist(len)) )
	    ABORT("Malloc fails for bsendx_plist[0]");
	for (i = 0; i < len; ++i) index[i] = EMPTY;
	for (i = 0, j = 0; i < k; ++i, j += grid->nprow)
	    bsendx_plist[i] = &index[j];
	/* -------------------------------------------------------------- */
#if ( PRNTlevel>=1 )
	mem_use += 4*k*sizeof(int_t*) + 2*len*iword;
#endif

	/*------------------------------------------------------------
	  PROPAGATE ROW SUBSCRIPTS AND VALUES OF A INTO L AND U BLOCKS.
	  THIS ACCOUNTS FOR ONE-PASS PROCESSING OF A, L AND U.
	  ------------------------------------------------------------*/

	for (jb = 0; jb < nsupers; ++jb) {
	    pc = PCOL( jb, grid );
	    if ( mycol == pc ) { /* Block column jb in my process column */
		fsupc = FstBlockC( jb );
		nsupc = SuperSize( jb );
		ljb = LBj( jb, grid ); /* Local block number */
		
		/* Scatter A into SPA. */
		for (j = fsupc, dense_col = dense; j < FstBlockC(jb+1); ++j) {
		    for (i = xa[j]; i < xa[j+1]; ++i) {
			irow = asub[i];
			gb = BlockNum( irow );
			if ( myrow == PROW( gb, grid ) ) {
			    lb = LBi( gb, grid );
			    irow = ilsum[lb] + irow - FstBlockC( gb );
			    dense_col[irow] = a[i];
			}
		    }
		    dense_col += ldaspa;
		}

		jbrow = PROW( jb, grid );

#if ( PROFlevel>=1 )
		t = SuperLU_timer_();
#endif
		/*------------------------------------------------
		 * SET UP U BLOCKS.
		 *------------------------------------------------*/
		kseen = 0;
		/* Loop through each column in the block column. */
		for (j = fsupc; j < FstBlockC( jb+1 ); ++j) {
		    istart = xusub[j];
		    for (i = istart; i < xusub[j+1]; ++i) {
			irow = usub[i]; /* First nonzero in the segment. */
			gb = BlockNum( irow );
			pr = PROW( gb, grid );
			if ( pr != jbrow ) 
			    bsendx_plist[ljb][pr] = YES;
			if ( myrow == pr ) {
			    lb = LBi( gb, grid ); /* Local block number */
			    index = Ufstnz_br_ptr[lb];
			    if (rb_marker[lb] <= jb) {/* First see the block */
				rb_marker[lb] = jb + 1;
				index[Urb_indptr[lb]] = jb; /* Descriptor */
				Urb_indptr[lb] += UB_DESCRIPTOR;
				len = Urb_indptr[lb];
				for (k = 0; k < nsupc; ++k)
				    index[len+k] = FstBlockC( gb+1 );
				if ( gb != jb )/* Exclude diagonal block. */
				    ++bmod[lb];/* Mod. count for back solve */
				if ( kseen == 0 && myrow != jbrow ) {
				    ++nbrecvx;
				    kseen = 1;
				}
			    } else {
				len = Urb_indptr[lb];/* Start fstnz in index */
			    }
			    jj = j - fsupc;
			    index[len+jj] = irow;
			} /* if myrow == pr ... */
		    } /* for i ... */
		} /* for j ... */

		/* Figure out how many nonzeros in each block, and gather
		   the initial values of A from SPA into Uval. */
		for (lb = 0; lb < nrbu; ++lb) {
		    if ( rb_marker[lb] == jb + 1 ) { /* Not an empty block. */
			index = Ufstnz_br_ptr[lb];
			uval = Unzval_br_ptr[lb];
			len = Urb_indptr[lb];
			gb = lb * grid->nprow + myrow;/* Global block number */
			k = FstBlockC( gb+1 );
			irow = ilsum[lb] - FstBlockC( gb );
			for (jj=0, bnnz=0, dense_col=dense; jj < nsupc; ++jj) {
			    j = index[len+jj];  /* First nonzero in segment. */
			    bnnz += k - j;
			    for (i = j; i < k; ++i) {
				uval[Urb_length[lb]++] = dense_col[irow + i];
				dense_col[irow + i] = zero;
			    }
			    dense_col += ldaspa;
			}
			index[len-1] = bnnz; /* Set block length in Descriptor */
			Urb_indptr[lb] += nsupc;
		    }
		} /* for lb ... */
#if ( PROFlevel>=1 )
		t_u += SuperLU_timer_() - t;
		t = SuperLU_timer_();
#endif		
		/*------------------------------------------------
		 * SET UP L BLOCKS.
		 *------------------------------------------------*/

		/* Count number of blocks and length of each block. */
		nrbl = 0;
		len = 0; /* Number of row subscripts I own. */
		kseen = 0;
		istart = xlsub[fsupc];
		for (i = istart; i < xlsub[fsupc+1]; ++i) {
		    irow = lsub[i];
		    gb = BlockNum( irow ); /* Global block number */
		    pr = PROW( gb, grid ); /* Process row owning this block */
		    if ( pr != jbrow )
			fsendx_plist[ljb][pr] = YES;
		    if ( myrow == pr ) {
			lb = LBi( gb, grid );  /* Local block number */
			if (rb_marker[lb] <= jb) { /* First see this block */
			    rb_marker[lb] = jb + 1;
			    Lrb_length[lb] = 1;
			    Lrb_number[nrbl++] = gb;
			    if ( gb != jb ) /* Exclude diagonal block. */
				++fmod[lb]; /* Mod. count for forward solve */
			    if ( kseen == 0 && myrow != jbrow ) {
				++nfrecvx;
				kseen = 1;
			    }
#if ( PRNTlevel>=1 )
			    ++nLblocks;
#endif
			} else {
			    ++Lrb_length[lb];
			}
			++len;
		    }
		} /* for i ... */

		if ( nrbl ) { /* Do not ensure the blocks are sorted! */
		    /* Set up the initial pointers for each block in 
		       index[] and nzval[]. */
		    /* Add room for descriptors */
		    len1 = len + BC_HEADER + nrbl * LB_DESCRIPTOR;
		    if ( !(index = intMalloc_dist(len1)) ) 
			ABORT("Malloc fails for index[]");
		    Lrowind_bc_ptr[ljb] = index;
		    if (!(Lnzval_bc_ptr[ljb] = 
                         doubleMalloc_dist(len*nsupc))) {
			fprintf(stderr, "col block %d ", jb);
			ABORT("Malloc fails for Lnzval_bc_ptr[*][]");
		    }
		    mybufmax[0] = SUPERLU_MAX( mybufmax[0], len1 );
		    mybufmax[1] = SUPERLU_MAX( mybufmax[1], len*nsupc );
		    mybufmax[4] = SUPERLU_MAX( mybufmax[4], len );
		    index[0] = nrbl;  /* Number of row blocks */
		    index[1] = len;   /* LDA of the nzval[] */
		    next_lind = BC_HEADER;
		    next_lval = 0;
		    for (k = 0; k < nrbl; ++k) {
			gb = Lrb_number[k];
			lb = LBi( gb, grid );
			len = Lrb_length[lb];
			Lrb_length[lb] = 0;  /* Reset vector of block length */
			index[next_lind++] = gb; /* Descriptor */
			index[next_lind++] = len; 
			Lrb_indptr[lb] = next_lind;
			Lrb_valptr[lb] = next_lval;
			next_lind += len;
			next_lval += len;
		    }
		    /* Propagate the compressed row subscripts to Lindex[],
                       and the initial values of A from SPA into Lnzval[]. */
		    lusup = Lnzval_bc_ptr[ljb];
		    len = index[1];  /* LDA of lusup[] */
		    for (i = istart; i < xlsub[fsupc+1]; ++i) {
			irow = lsub[i];
			gb = BlockNum( irow );
			if ( myrow == PROW( gb, grid ) ) {
			    lb = LBi( gb, grid );
			    k = Lrb_indptr[lb]++; /* Random access a block */
			    index[k] = irow;
			    k = Lrb_valptr[lb]++;
			    irow = ilsum[lb] + irow - FstBlockC( gb );
			    for (j = 0, dense_col = dense; j < nsupc; ++j) {
				lusup[k] = dense_col[irow];
				dense_col[irow] = zero;
				k += len;
				dense_col += ldaspa;
			    }
			}
		    } /* for i ... */
		} else {
		    Lrowind_bc_ptr[ljb] = NULL;
		    Lnzval_bc_ptr[ljb] = NULL;
		} /* if nrbl ... */
#if ( PROFlevel>=1 )
		t_l += SuperLU_timer_() - t;
#endif
	    } /* if mycol == pc */

	} /* for jb ... */

	Llu->Lrowind_bc_ptr = Lrowind_bc_ptr;
	Llu->Lnzval_bc_ptr = Lnzval_bc_ptr;
	Llu->Ufstnz_br_ptr = Ufstnz_br_ptr;
	Llu->Unzval_br_ptr = Unzval_br_ptr;
	Llu->ToRecv = ToRecv;
	Llu->ToSendD = ToSendD;
	Llu->ToSendR = ToSendR;
	Llu->fmod = fmod;
	Llu->fsendx_plist = fsendx_plist;
	Llu->nfrecvx = nfrecvx;
	Llu->bmod = bmod;
	Llu->bsendx_plist = bsendx_plist;
	Llu->nbrecvx = nbrecvx;
	Llu->ilsum = ilsum;
	Llu->ldalsum = ldaspa;
	
#if ( PRNTlevel>=1 )
	if ( !iam ) printf(".. # L blocks %d\t# U blocks %d\n",
			   nLblocks, nUblocks);
#endif

	SUPERLU_FREE(rb_marker);
	SUPERLU_FREE(Urb_length);
	SUPERLU_FREE(Urb_indptr);
	SUPERLU_FREE(Lrb_length);
	SUPERLU_FREE(Lrb_number);
	SUPERLU_FREE(Lrb_indptr);
	SUPERLU_FREE(Lrb_valptr);
	SUPERLU_FREE(dense);

	/* Find the maximum buffer size. */
	MPI_Allreduce(mybufmax, Llu->bufmax, NBUFFERS, mpi_int_t, 
		      MPI_MAX, grid->comm);
#if ( PROFlevel>=1 )
	if ( !iam ) printf(".. 1st distribute time: L %.2f\tU %.2f\tu_blks %d\tnrbu %d\n",
			   t_l, t_u, u_blks, nrbu);
#endif

    } /* else fact != SamePattern_SameRowPerm */

    SUPERLU_FREE(xa);
    SUPERLU_FREE(asub);
    SUPERLU_FREE(a);

#if ( DEBUGlevel>=1 )
    /* Memory allocated but not freed:
       ilsum, fmod, fsendx_plist, bmod, bsendx_plist  */
    CHECK_MALLOC(iam, "Exit pddistribute()");
#endif
    
    return (mem_use);
} /* PDDISTRIBUTE */
示例#15
0
/*! \brief
 *
 * <pre>
 * Purpose
 * =======
 *
 * pzgssvx_ABglobal solves a system of linear equations A*X=B,
 * by using Gaussian elimination with "static pivoting" to
 * compute the LU factorization of A.
 *
 * Static pivoting is a technique that combines the numerical stability
 * of partial pivoting with the scalability of Cholesky (no pivoting),
 * to run accurately and efficiently on large numbers of processors.
 *
 * See our paper at http://www.nersc.gov/~xiaoye/SuperLU/ for a detailed
 * description of the parallel algorithms.
 *
 * Here are the options for using this code:
 *
 *   1. Independent of all the other options specified below, the
 *      user must supply
 *
 *      -  B, the matrix of right hand sides, and its dimensions ldb and nrhs
 *      -  grid, a structure describing the 2D processor mesh
 *      -  options->IterRefine, which determines whether or not to
 *            improve the accuracy of the computed solution using 
 *            iterative refinement
 *
 *      On output, B is overwritten with the solution X.
 *
 *   2. Depending on options->Fact, the user has several options
 *      for solving A*X=B. The standard option is for factoring
 *      A "from scratch". (The other options, described below,
 *      are used when A is sufficiently similar to a previously 
 *      solved problem to save time by reusing part or all of 
 *      the previous factorization.)
 *
 *      -  options->Fact = DOFACT: A is factored "from scratch"
 *
 *      In this case the user must also supply
 *
 *      -  A, the input matrix
 *
 *      as well as the following options, which are described in more 
 *      detail below:
 *
 *      -  options->Equil,   to specify how to scale the rows and columns
 *                           of A to "equilibrate" it (to try to reduce its
 *                           condition number and so improve the
 *                           accuracy of the computed solution)
 *
 *      -  options->RowPerm, to specify how to permute the rows of A
 *                           (typically to control numerical stability)
 *
 *      -  options->ColPerm, to specify how to permute the columns of A
 *                           (typically to control fill-in and enhance
 *                           parallelism during factorization)
 *
 *      -  options->ReplaceTinyPivot, to specify how to deal with tiny
 *                           pivots encountered during factorization
 *                           (to control numerical stability)
 *
 *      The outputs returned include
 *         
 *      -  ScalePermstruct,  modified to describe how the input matrix A
 *                           was equilibrated and permuted:
 *         -  ScalePermstruct->DiagScale, indicates whether the rows and/or
 *                                        columns of A were scaled
 *         -  ScalePermstruct->R, array of row scale factors
 *         -  ScalePermstruct->C, array of column scale factors
 *         -  ScalePermstruct->perm_r, row permutation vector
 *         -  ScalePermstruct->perm_c, column permutation vector
 *
 *            (part of ScalePermstruct may also need to be supplied on input,
 *             depending on options->RowPerm and options->ColPerm as described 
 *             later).
 *
 *      -  A, the input matrix A overwritten by the scaled and permuted matrix
 *                Pc*Pr*diag(R)*A*diag(C)
 *             where 
 *                Pr and Pc are row and columns permutation matrices determined
 *                  by ScalePermstruct->perm_r and ScalePermstruct->perm_c, 
 *                  respectively, and 
 *                diag(R) and diag(C) are diagonal scaling matrices determined
 *                  by ScalePermstruct->DiagScale, ScalePermstruct->R and 
 *                  ScalePermstruct->C
 *
 *      -  LUstruct, which contains the L and U factorization of A1 where
 *
 *                A1 = Pc*Pr*diag(R)*A*diag(C)*Pc^T = L*U
 *
 *              (Note that A1 = Aout * Pc^T, where Aout is the matrix stored
 *               in A on output.)
 *
 *   3. The second value of options->Fact assumes that a matrix with the same
 *      sparsity pattern as A has already been factored:
 *     
 *      -  options->Fact = SamePattern: A is factored, assuming that it has
 *            the same nonzero pattern as a previously factored matrix. In this
 *            case the algorithm saves time by reusing the previously computed
 *            column permutation vector stored in ScalePermstruct->perm_c
 *            and the "elimination tree" of A stored in LUstruct->etree.
 *
 *      In this case the user must still specify the following options
 *      as before:
 *
 *      -  options->Equil
 *      -  options->RowPerm
 *      -  options->ReplaceTinyPivot
 *
 *      but not options->ColPerm, whose value is ignored. This is because the
 *      previous column permutation from ScalePermstruct->perm_c is used as
 *      input. The user must also supply 
 *
 *      -  A, the input matrix
 *      -  ScalePermstruct->perm_c, the column permutation
 *      -  LUstruct->etree, the elimination tree
 *
 *      The outputs returned include
 *         
 *      -  A, the input matrix A overwritten by the scaled and permuted matrix
 *            as described above
 *      -  ScalePermstruct,  modified to describe how the input matrix A was
 *                           equilibrated and row permuted
 *      -  LUstruct, modified to contain the new L and U factors
 *
 *   4. The third value of options->Fact assumes that a matrix B with the same
 *      sparsity pattern as A has already been factored, and where the
 *      row permutation of B can be reused for A. This is useful when A and B
 *      have similar numerical values, so that the same row permutation
 *      will make both factorizations numerically stable. This lets us reuse
 *      all of the previously computed structure of L and U.
 *
 *      -  options->Fact = SamePattern_SameRowPerm: A is factored,
 *            assuming not only the same nonzero pattern as the previously
 *            factored matrix B, but reusing B's row permutation.
 *
 *      In this case the user must still specify the following options
 *      as before:
 *
 *      -  options->Equil
 *      -  options->ReplaceTinyPivot
 *
 *      but not options->RowPerm or options->ColPerm, whose values are ignored.
 *      This is because the permutations from ScalePermstruct->perm_r and
 *      ScalePermstruct->perm_c are used as input.
 *
 *      The user must also supply 
 *
 *      -  A, the input matrix
 *      -  ScalePermstruct->DiagScale, how the previous matrix was row and/or
 *                                     column scaled
 *      -  ScalePermstruct->R, the row scalings of the previous matrix, if any
 *      -  ScalePermstruct->C, the columns scalings of the previous matrix, 
 *                             if any
 *      -  ScalePermstruct->perm_r, the row permutation of the previous matrix
 *      -  ScalePermstruct->perm_c, the column permutation of the previous 
 *                                  matrix
 *      -  all of LUstruct, the previously computed information about L and U
 *                (the actual numerical values of L and U stored in
 *                 LUstruct->Llu are ignored)
 *
 *      The outputs returned include
 *         
 *      -  A, the input matrix A overwritten by the scaled and permuted matrix
 *            as described above
 *      -  ScalePermstruct,  modified to describe how the input matrix A was
 *                           equilibrated 
 *                  (thus ScalePermstruct->DiagScale, R and C may be modified)
 *      -  LUstruct, modified to contain the new L and U factors
 *
 *   5. The fourth and last value of options->Fact assumes that A is
 *      identical to a matrix that has already been factored on a previous 
 *      call, and reuses its entire LU factorization
 *
 *      -  options->Fact = Factored: A is identical to a previously
 *            factorized matrix, so the entire previous factorization
 *            can be reused.
 *
 *      In this case all the other options mentioned above are ignored
 *      (options->Equil, options->RowPerm, options->ColPerm, 
 *       options->ReplaceTinyPivot)
 *
 *      The user must also supply 
 *
 *      -  A, the unfactored matrix, only in the case that iterative refinment
 *            is to be done (specifically A must be the output A from 
 *            the previous call, so that it has been scaled and permuted)
 *      -  all of ScalePermstruct
 *      -  all of LUstruct, including the actual numerical values of L and U
 *
 *      all of which are unmodified on output.
 *         
 * Arguments
 * =========
 *
 * options (input) superlu_options_t*
 *         The structure defines the input parameters to control
 *         how the LU decomposition will be performed.
 *         The following fields should be defined for this structure:
 *         
 *         o Fact (fact_t)
 *           Specifies whether or not the factored form of the matrix
 *           A is supplied on entry, and if not, how the matrix A should
 *           be factorized based on the previous history.
 *
 *           = DOFACT: The matrix A will be factorized from scratch.
 *                 Inputs:  A
 *                          options->Equil, RowPerm, ColPerm, ReplaceTinyPivot
 *                 Outputs: modified A
 *                             (possibly row and/or column scaled and/or 
 *                              permuted)
 *                          all of ScalePermstruct
 *                          all of LUstruct
 *
 *           = SamePattern: the matrix A will be factorized assuming
 *             that a factorization of a matrix with the same sparsity
 *             pattern was performed prior to this one. Therefore, this
 *             factorization will reuse column permutation vector 
 *             ScalePermstruct->perm_c and the elimination tree
 *             LUstruct->etree
 *                 Inputs:  A
 *                          options->Equil, RowPerm, ReplaceTinyPivot
 *                          ScalePermstruct->perm_c
 *                          LUstruct->etree
 *                 Outputs: modified A
 *                             (possibly row and/or column scaled and/or 
 *                              permuted)
 *                          rest of ScalePermstruct (DiagScale, R, C, perm_r)
 *                          rest of LUstruct (GLU_persist, Llu)
 *
 *           = SamePattern_SameRowPerm: the matrix A will be factorized
 *             assuming that a factorization of a matrix with the same
 *             sparsity	pattern and similar numerical values was performed
 *             prior to this one. Therefore, this factorization will reuse
 *             both row and column scaling factors R and C, and the
 *             both row and column permutation vectors perm_r and perm_c,
 *             distributed data structure set up from the previous symbolic
 *             factorization.
 *                 Inputs:  A
 *                          options->Equil, ReplaceTinyPivot
 *                          all of ScalePermstruct
 *                          all of LUstruct
 *                 Outputs: modified A
 *                             (possibly row and/or column scaled and/or 
 *                              permuted)
 *                          modified LUstruct->Llu
 *           = FACTORED: the matrix A is already factored.
 *                 Inputs:  all of ScalePermstruct
 *                          all of LUstruct
 *
 *         o Equil (yes_no_t)
 *           Specifies whether to equilibrate the system.
 *           = NO:  no equilibration.
 *           = YES: scaling factors are computed to equilibrate the system:
 *                      diag(R)*A*diag(C)*inv(diag(C))*X = diag(R)*B.
 *                  Whether or not the system will be equilibrated depends
 *                  on the scaling of the matrix A, but if equilibration is
 *                  used, A is overwritten by diag(R)*A*diag(C) and B by
 *                  diag(R)*B.
 *
 *         o RowPerm (rowperm_t)
 *           Specifies how to permute rows of the matrix A.
 *           = NATURAL:   use the natural ordering.
 *           = LargeDiag: use the Duff/Koster algorithm to permute rows of
 *                        the original matrix to make the diagonal large
 *                        relative to the off-diagonal.
 *           = MY_PERMR:  use the ordering given in ScalePermstruct->perm_r
 *                        input by the user.
 *           
 *         o ColPerm (colperm_t)
 *           Specifies what type of column permutation to use to reduce fill.
 *           = NATURAL:       natural ordering.
 *           = MMD_AT_PLUS_A: minimum degree ordering on structure of A'+A.
 *           = MMD_ATA:       minimum degree ordering on structure of A'*A.
 *           = MY_PERMC:      the ordering given in ScalePermstruct->perm_c.
 *         
 *         o ReplaceTinyPivot (yes_no_t)
 *           = NO:  do not modify pivots
 *           = YES: replace tiny pivots by sqrt(epsilon)*norm(A) during 
 *                  LU factorization.
 *
 *         o IterRefine (IterRefine_t)
 *           Specifies how to perform iterative refinement.
 *           = NO:     no iterative refinement.
 *           = SLU_DOUBLE: accumulate residual in double precision.
 *           = SLU_EXTRA:  accumulate residual in extra precision.
 *
 *         NOTE: all options must be indentical on all processes when
 *               calling this routine.
 *
 * A (input/output) SuperMatrix*
 *         On entry, matrix A in A*X=B, of dimension (A->nrow, A->ncol).
 *         The number of linear equations is A->nrow. The type of A must be:
 *         Stype = SLU_NC; Dtype = SLU_Z; Mtype = SLU_GE. That is, A is stored in
 *         compressed column format (also known as Harwell-Boeing format).
 *         See supermatrix.h for the definition of 'SuperMatrix'.
 *         This routine only handles square A, however, the LU factorization
 *         routine pzgstrf can factorize rectangular matrices.
 *         On exit, A may be overwritten by Pc*Pr*diag(R)*A*diag(C),
 *         depending on ScalePermstruct->DiagScale, options->RowPerm and
 *         options->colpem:
 *             if ScalePermstruct->DiagScale != NOEQUIL, A is overwritten by
 *                diag(R)*A*diag(C).
 *             if options->RowPerm != NATURAL, A is further overwritten by
 *                Pr*diag(R)*A*diag(C).
 *             if options->ColPerm != NATURAL, A is further overwritten by
 *                Pc*Pr*diag(R)*A*diag(C).
 *         If all the above condition are true, the LU decomposition is
 *         performed on the matrix Pc*Pr*diag(R)*A*diag(C)*Pc^T.
 *
 *         NOTE: Currently, A must reside in all processes when calling
 *               this routine.
 *
 * ScalePermstruct (input/output) ScalePermstruct_t*
 *         The data structure to store the scaling and permutation vectors
 *         describing the transformations performed to the matrix A.
 *         It contains the following fields:
 *
 *         o DiagScale (DiagScale_t)
 *           Specifies the form of equilibration that was done.
 *           = NOEQUIL: no equilibration.
 *           = ROW:     row equilibration, i.e., A was premultiplied by
 *                      diag(R).
 *           = COL:     Column equilibration, i.e., A was postmultiplied
 *                      by diag(C).
 *           = BOTH:    both row and column equilibration, i.e., A was 
 *                      replaced by diag(R)*A*diag(C).
 *           If options->Fact = FACTORED or SamePattern_SameRowPerm,
 *           DiagScale is an input argument; otherwise it is an output
 *           argument.
 *
 *         o perm_r (int*)
 *           Row permutation vector, which defines the permutation matrix Pr;
 *           perm_r[i] = j means row i of A is in position j in Pr*A.
 *           If options->RowPerm = MY_PERMR, or
 *           options->Fact = SamePattern_SameRowPerm, perm_r is an
 *           input argument; otherwise it is an output argument.
 *
 *         o perm_c (int*)
 *           Column permutation vector, which defines the 
 *           permutation matrix Pc; perm_c[i] = j means column i of A is 
 *           in position j in A*Pc.
 *           If options->ColPerm = MY_PERMC or options->Fact = SamePattern
 *           or options->Fact = SamePattern_SameRowPerm, perm_c is an
 *           input argument; otherwise, it is an output argument.
 *           On exit, perm_c may be overwritten by the product of the input
 *           perm_c and a permutation that postorders the elimination tree
 *           of Pc*A'*A*Pc'; perm_c is not changed if the elimination tree
 *           is already in postorder.
 *
 *         o R (double*) dimension (A->nrow)
 *           The row scale factors for A.
 *           If DiagScale = ROW or BOTH, A is multiplied on the left by 
 *                          diag(R).
 *           If DiagScale = NOEQUIL or COL, R is not defined.
 *           If options->Fact = FACTORED or SamePattern_SameRowPerm, R is
 *           an input argument; otherwise, R is an output argument.
 *
 *         o C (double*) dimension (A->ncol)
 *           The column scale factors for A.
 *           If DiagScale = COL or BOTH, A is multiplied on the right by 
 *                          diag(C).
 *           If DiagScale = NOEQUIL or ROW, C is not defined.
 *           If options->Fact = FACTORED or SamePattern_SameRowPerm, C is
 *           an input argument; otherwise, C is an output argument.
 *         
 * B       (input/output) doublecomplex*
 *         On entry, the right-hand side matrix of dimension (A->nrow, nrhs).
 *         On exit, the solution matrix if info = 0;
 *
 *         NOTE: Currently, B must reside in all processes when calling
 *               this routine.
 *
 * ldb     (input) int (global)
 *         The leading dimension of matrix B.
 *
 * nrhs    (input) int (global)
 *         The number of right-hand sides.
 *         If nrhs = 0, only LU decomposition is performed, the forward
 *         and back substitutions are skipped.
 *
 * grid    (input) gridinfo_t*
 *         The 2D process mesh. It contains the MPI communicator, the number
 *         of process rows (NPROW), the number of process columns (NPCOL),
 *         and my process rank. It is an input argument to all the
 *         parallel routines.
 *         Grid can be initialized by subroutine SUPERLU_GRIDINIT.
 *         See superlu_zdefs.h for the definition of 'gridinfo_t'.
 *
 * LUstruct (input/output) LUstruct_t*
 *         The data structures to store the distributed L and U factors.
 *         It contains the following fields:
 *
 *         o etree (int*) dimension (A->ncol)
 *           Elimination tree of Pc*(A'+A)*Pc' or Pc*A'*A*Pc', dimension A->ncol.
 *           It is computed in sp_colorder() during the first factorization,
 *           and is reused in the subsequent factorizations of the matrices
 *           with the same nonzero pattern.
 *           On exit of sp_colorder(), the columns of A are permuted so that
 *           the etree is in a certain postorder. This postorder is reflected
 *           in ScalePermstruct->perm_c.
 *           NOTE:
 *           Etree is a vector of parent pointers for a forest whose vertices
 *           are the integers 0 to A->ncol-1; etree[root]==A->ncol.
 *
 *         o Glu_persist (Glu_persist_t*)
 *           Global data structure (xsup, supno) replicated on all processes,
 *           describing the supernode partition in the factored matrices
 *           L and U:
 *	       xsup[s] is the leading column of the s-th supernode,
 *             supno[i] is the supernode number to which column i belongs.
 *
 *         o Llu (LocalLU_t*)
 *           The distributed data structures to store L and U factors.
 *           See superlu_ddefs.h for the definition of 'LocalLU_t'.
 *
 * berr    (output) double*, dimension (nrhs)
 *         The componentwise relative backward error of each solution   
 *         vector X(j) (i.e., the smallest relative change in   
 *         any element of A or B that makes X(j) an exact solution).
 *
 * stat   (output) SuperLUStat_t*
 *        Record the statistics on runtime and floating-point operation count.
 *        See util.h for the definition of 'SuperLUStat_t'.
 *
 * info    (output) int*
 *         = 0: successful exit
 *         > 0: if info = i, and i is
 *             <= A->ncol: U(i,i) is exactly zero. The factorization has
 *                been completed, but the factor U is exactly singular,
 *                so the solution could not be computed.
 *             > A->ncol: number of bytes allocated when memory allocation
 *                failure occurred, plus A->ncol.
 *
 *
 * See superlu_zdefs.h for the definitions of various data types.
 * </pre>
 */
void
pzgssvx_ABglobal(superlu_options_t *options, SuperMatrix *A, 
		 ScalePermstruct_t *ScalePermstruct,
		 doublecomplex B[], int ldb, int nrhs, gridinfo_t *grid,
		 LUstruct_t *LUstruct, double *berr,
		 SuperLUStat_t *stat, int *info)
{
    SuperMatrix AC;
    NCformat *Astore;
    NCPformat *ACstore;
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    Glu_freeable_t *Glu_freeable;
            /* The nonzero structures of L and U factors, which are
	       replicated on all processrs.
	           (lsub, xlsub) contains the compressed subscript of
		                 supernodes in L.
          	   (usub, xusub) contains the compressed subscript of
		                 nonzero segments in U.
	      If options->Fact != SamePattern_SameRowPerm, they are 
	      computed by SYMBFACT routine, and then used by DDISTRIBUTE
	      routine. They will be freed after DDISTRIBUTE routine.
	      If options->Fact == SamePattern_SameRowPerm, these
	      structures are not used.                                  */
    fact_t   Fact;
    doublecomplex   *a;
    int_t    *perm_r; /* row permutations from partial pivoting */
    int_t    *perm_c; /* column permutation vector */
    int_t    *etree;  /* elimination tree */
    int_t    *colptr, *rowind;
    int_t    colequ, Equil, factored, job, notran, rowequ;
    int_t    i, iinfo, j, irow, m, n, nnz, permc_spec, dist_mem_use;
    int      iam;
    int      ldx;  /* LDA for matrix X (global). */
    char     equed[1], norm[1];
    double   *C, *R, *C1, *R1, amax, anorm, colcnd, rowcnd;
    doublecomplex   *X, *b_col, *b_work, *x_col;
    double   t;
    static mem_usage_t num_mem_usage, symb_mem_usage;
#if ( PRNTlevel>= 2 )
    double   dmin, dsum, dprod;
#endif

    /* Test input parameters. */
    *info = 0;
    Fact = options->Fact;
    if ( Fact < 0 || Fact > FACTORED )
	*info = -1;
    else if ( options->RowPerm < 0 || options->RowPerm > MY_PERMR )
	*info = -1;
    else if ( options->ColPerm < 0 || options->ColPerm > MY_PERMC )
	*info = -1;
    else if ( options->IterRefine < 0 || options->IterRefine > SLU_EXTRA )
	*info = -1;
    else if ( options->IterRefine == SLU_EXTRA ) {
	*info = -1;
	fprintf(stderr, "Extra precise iterative refinement yet to support.");
    } else if ( A->nrow != A->ncol || A->nrow < 0 ||
         A->Stype != SLU_NC || A->Dtype != SLU_Z || A->Mtype != SLU_GE )
	*info = -2;
    else if ( ldb < A->nrow )
	*info = -5;
    else if ( nrhs < 0 )
	*info = -6;
    if ( *info ) {
	i = -(*info);
	pxerbla("pzgssvx_ABglobal", grid, -*info);
	return;
    }

    /* Initialization */
    factored = (Fact == FACTORED);
    Equil = (!factored && options->Equil == YES);
    notran = (options->Trans == NOTRANS);
    iam = grid->iam;
    job = 5;
    m = A->nrow;
    n = A->ncol;
    Astore = A->Store;
    nnz = Astore->nnz;
    a = Astore->nzval;
    colptr = Astore->colptr;
    rowind = Astore->rowind;
    if ( factored || (Fact == SamePattern_SameRowPerm && Equil) ) {
	rowequ = (ScalePermstruct->DiagScale == ROW) ||
	         (ScalePermstruct->DiagScale == BOTH);
	colequ = (ScalePermstruct->DiagScale == COL) ||
	         (ScalePermstruct->DiagScale == BOTH);
    } else rowequ = colequ = FALSE;

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter pzgssvx_ABglobal()");
#endif

    perm_r = ScalePermstruct->perm_r;
    perm_c = ScalePermstruct->perm_c;
    etree = LUstruct->etree;
    R = ScalePermstruct->R;
    C = ScalePermstruct->C;
    if ( Equil && Fact != SamePattern_SameRowPerm ) {
	/* Allocate storage if not done so before. */
	switch ( ScalePermstruct->DiagScale ) {
	    case NOEQUIL:
		if ( !(R = (double *) doubleMalloc_dist(m)) )
		    ABORT("Malloc fails for R[].");
	        if ( !(C = (double *) doubleMalloc_dist(n)) )
		    ABORT("Malloc fails for C[].");
		ScalePermstruct->R = R;
		ScalePermstruct->C = C;
		break;
	    case ROW: 
	        if ( !(C = (double *) doubleMalloc_dist(n)) )
		    ABORT("Malloc fails for C[].");
		ScalePermstruct->C = C;
		break;
	    case COL: 
		if ( !(R = (double *) doubleMalloc_dist(m)) )
		    ABORT("Malloc fails for R[].");
		ScalePermstruct->R = R;
		break;
	}
    }

    /* ------------------------------------------------------------
       Diagonal scaling to equilibrate the matrix.
       ------------------------------------------------------------*/
    if ( Equil ) {
#if ( DEBUGlevel>=1 )
	CHECK_MALLOC(iam, "Enter equil");
#endif
	t = SuperLU_timer_();

	if ( Fact == SamePattern_SameRowPerm ) {
	    /* Reuse R and C. */
	    switch ( ScalePermstruct->DiagScale ) {
	      case NOEQUIL:
		break;
	      case ROW:
		for (j = 0; j < n; ++j) {
		    for (i = colptr[j]; i < colptr[j+1]; ++i) {
			irow = rowind[i];
			zd_mult(&a[i], &a[i], R[i]); /* Scale rows. */
		    }
		}
		break;
	      case COL:
		for (j = 0; j < n; ++j)
		    for (i = colptr[j]; i < colptr[j+1]; ++i)
			zd_mult(&a[i], &a[i], C[j]); /* Scale columns. */
		break;
	      case BOTH: 
		for (j = 0; j < n; ++j) {
		    for (i = colptr[j]; i < colptr[j+1]; ++i) {
			irow = rowind[i];
			zd_mult(&a[i], &a[i], R[irow]); /* Scale rows. */
			zd_mult(&a[i], &a[i], C[j]); /* Scale columns. */
		    }
		}
	        break;
	    }
	} else {
	    if ( !iam ) {
		/* Compute row and column scalings to equilibrate matrix A. */
		zgsequ_dist(A, R, C, &rowcnd, &colcnd, &amax, &iinfo);
	    
		MPI_Bcast( &iinfo, 1, mpi_int_t, 0, grid->comm );
		if ( iinfo == 0 ) {
		    MPI_Bcast( R,       m, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( C,       n, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &rowcnd, 1, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &colcnd, 1, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &amax,   1, MPI_DOUBLE, 0, grid->comm );
		} else {
		    if ( iinfo > 0 ) {
			if ( iinfo <= m )
			    fprintf(stderr, "The %d-th row of A is exactly zero\n", 
				    iinfo);
			else fprintf(stderr, "The %d-th column of A is exactly zero\n", 
				     iinfo-n);
			exit(-1);
		    }
		}
	    } else {
		MPI_Bcast( &iinfo, 1, mpi_int_t, 0, grid->comm );
		if ( iinfo == 0 ) {
		    MPI_Bcast( R,       m, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( C,       n, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &rowcnd, 1, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &colcnd, 1, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( &amax,   1, MPI_DOUBLE, 0, grid->comm );
		} else {
		    ABORT("ZGSEQU failed\n");
		}
	    }
	
	    /* Equilibrate matrix A. */
	    zlaqgs_dist(A, R, C, rowcnd, colcnd, amax, equed);
	    if ( lsame_(equed, "R") ) {
		ScalePermstruct->DiagScale = rowequ = ROW;
	    } else if ( lsame_(equed, "C") ) {
		ScalePermstruct->DiagScale = colequ = COL;
	    } else if ( lsame_(equed, "B") ) {
		ScalePermstruct->DiagScale = BOTH;
		rowequ = ROW;
		colequ = COL;
	    } else ScalePermstruct->DiagScale = NOEQUIL;

#if ( PRNTlevel>=1 )
	    if ( !iam ) {
		printf(".. equilibrated? *equed = %c\n", *equed);
		/*fflush(stdout);*/
	    }
#endif
	} /* if Fact ... */

	stat->utime[EQUIL] = SuperLU_timer_() - t;
#if ( DEBUGlevel>=1 )
	CHECK_MALLOC(iam, "Exit equil");
#endif
    } /* end if Equil ... */
    
    /* ------------------------------------------------------------
       Permute rows of A. 
       ------------------------------------------------------------*/
    if ( options->RowPerm != NO ) {
	t = SuperLU_timer_();

	if ( Fact == SamePattern_SameRowPerm /* Reuse perm_r. */
	    || options->RowPerm == MY_PERMR ) { /* Use my perm_r. */
	    for (j = 0; j < n; ++j) {
		for (i = colptr[j]; i < colptr[j+1]; ++i) {
		    irow = rowind[i];
		    rowind[i] = perm_r[irow];
		}
	    }
	} else if ( !factored ) {
	    if ( job == 5 ) {
		/* Allocate storage for scaling factors. */
		if ( !(R1 = (double *) SUPERLU_MALLOC(m * sizeof(double))) ) 
		    ABORT("SUPERLU_MALLOC fails for R1[]");
		if ( !(C1 = (double *) SUPERLU_MALLOC(n * sizeof(double))) )
		    ABORT("SUPERLU_MALLOC fails for C1[]");
	    }

	    if ( !iam ) {
		/* Process 0 finds a row permutation for large diagonal. */
		zldperm(job, m, nnz, colptr, rowind, a, perm_r, R1, C1);
		
		MPI_Bcast( perm_r, m, mpi_int_t, 0, grid->comm );
		if ( job == 5 && Equil ) {
		    MPI_Bcast( R1, m, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( C1, n, MPI_DOUBLE, 0, grid->comm );
		}
	    } else {
		MPI_Bcast( perm_r, m, mpi_int_t, 0, grid->comm );
		if ( job == 5 && Equil ) {
		    MPI_Bcast( R1, m, MPI_DOUBLE, 0, grid->comm );
		    MPI_Bcast( C1, n, MPI_DOUBLE, 0, grid->comm );
		}
	    }

#if ( PRNTlevel>=2 )
	    dmin = dlamch_("Overflow");
	    dsum = 0.0;
	    dprod = 1.0;
#endif
	    if ( job == 5 ) {
		if ( Equil ) {
		    for (i = 0; i < n; ++i) {
			R1[i] = exp(R1[i]);
			C1[i] = exp(C1[i]);
		    }
		    for (j = 0; j < n; ++j) {
			for (i = colptr[j]; i < colptr[j+1]; ++i) {
			    irow = rowind[i];
			    zd_mult(&a[i], &a[i], R1[irow]); /* Scale rows. */
			    zd_mult(&a[i], &a[i], C1[j]); /* Scale columns. */
			    rowind[i] = perm_r[irow];
#if ( PRNTlevel>=2 )
			    if ( rowind[i] == j ) /* New diagonal */
				dprod *= slud_z_abs1(&a[i]);
#endif
			}
		    }

		    /* Multiply together the scaling factors. */
		    if ( rowequ ) for (i = 0; i < m; ++i) R[i] *= R1[i];
		    else for (i = 0; i < m; ++i) R[i] = R1[i];
		    if ( colequ ) for (i = 0; i < n; ++i) C[i] *= C1[i];
		    else for (i = 0; i < n; ++i) C[i] = C1[i];
		    
		    ScalePermstruct->DiagScale = BOTH;
		    rowequ = colequ = 1;
		} else { /* No equilibration. */
		    for (j = 0; j < n; ++j) {
			for (i = colptr[j]; i < colptr[j+1]; ++i) {
			    irow = rowind[i];
			    rowind[i] = perm_r[irow];
			}
		    }
		}
		SUPERLU_FREE (R1);
		SUPERLU_FREE (C1);
	    } else { /* job = 2,3,4 */
		for (j = 0; j < n; ++j) {
		    for (i = colptr[j]; i < colptr[j+1]; ++i) {
			irow = rowind[i];
			rowind[i] = perm_r[irow];
#if ( PRNTlevel>=2 )
			if ( rowind[i] == j ) { /* New diagonal */
			    if ( job == 2 || job == 3 )
				dmin = SUPERLU_MIN(dmin, slud_z_abs1(&a[i]));
			    else if ( job == 4 )
				dsum += slud_z_abs1(&a[i]);
			    else if ( job == 5 )
				dprod *= slud_z_abs1(&a[i]);
			}
#endif
		    }
		}
	    }

#if ( PRNTlevel>=2 )
	    if ( job == 2 || job == 3 ) {
		if ( !iam ) printf("\tsmallest diagonal %e\n", dmin);
	    } else if ( job == 4 ) {
		if ( !iam ) printf("\tsum of diagonal %e\n", dsum);
	    } else if ( job == 5 ) {
		if ( !iam ) printf("\t product of diagonal %e\n", dprod);
	    }
#endif
	    
        } /* else !factored */

	t = SuperLU_timer_() - t;
	stat->utime[ROWPERM] = t;
    
    } else { /* options->RowPerm == NOROWPERM */
        for (i = 0; i < m; ++i) perm_r[i] = i;
    }

    if ( !factored || options->IterRefine ) {
	/* Compute norm(A), which will be used to adjust small diagonal. */
	if ( notran ) *(unsigned char *)norm = '1';
	else *(unsigned char *)norm = 'I';
	anorm = zlangs_dist(norm, A);
    }

    /* ------------------------------------------------------------
       Perform the LU factorization.
       ------------------------------------------------------------*/
    if ( !factored ) {
	t = SuperLU_timer_();
	/*
	 * Get column permutation vector perm_c[], according to permc_spec:
	 *   permc_spec = NATURAL:  natural ordering 
	 *   permc_spec = MMD_AT_PLUS_A: minimum degree on structure of A'+A
	 *   permc_spec = MMD_ATA:  minimum degree on structure of A'*A
	 *   permc_spec = MY_PERMC: the ordering already supplied in perm_c[]
	 */
	permc_spec = options->ColPerm;
	if ( permc_spec != MY_PERMC && Fact == DOFACT )
	    /* Use an ordering provided by SuperLU */
	    get_perm_c_dist(iam, permc_spec, A, perm_c);

	/* Compute the elimination tree of Pc*(A'+A)*Pc' or Pc*A'*A*Pc'
	   (a.k.a. column etree), depending on the choice of ColPerm.
	   Adjust perm_c[] to be consistent with a postorder of etree.
	   Permute columns of A to form A*Pc'. */
	sp_colorder(options, A, perm_c, etree, &AC);

	/* Form Pc*A*Pc' to preserve the diagonal of the matrix Pr*A. */
	ACstore = AC.Store;
	for (j = 0; j < n; ++j) 
	    for (i = ACstore->colbeg[j]; i < ACstore->colend[j]; ++i) {
		irow = ACstore->rowind[i];
		ACstore->rowind[i] = perm_c[irow];
	    }
	stat->utime[COLPERM] = SuperLU_timer_() - t;

	/* Perform a symbolic factorization on matrix A and set up the
	   nonzero data structures which are suitable for supernodal GENP. */
	if ( Fact != SamePattern_SameRowPerm ) {
#if ( PRNTlevel>=1 ) 
	    if ( !iam ) 
		printf(".. symbfact(): relax %4d, maxsuper %4d, fill %4d\n",
		       sp_ienv_dist(2), sp_ienv_dist(3), sp_ienv_dist(6));
#endif
	    t = SuperLU_timer_();
	    if ( !(Glu_freeable = (Glu_freeable_t *)
		   SUPERLU_MALLOC(sizeof(Glu_freeable_t))) )
		ABORT("Malloc fails for Glu_freeable.");

	    iinfo = symbfact(options, iam, &AC, perm_c, etree, 
			     Glu_persist, Glu_freeable);

	    stat->utime[SYMBFAC] = SuperLU_timer_() - t;

	    if ( iinfo < 0 ) {
		QuerySpace_dist(n, -iinfo, Glu_freeable, &symb_mem_usage);
#if ( PRNTlevel>=1 ) 
		if ( !iam ) {
		    printf("\tNo of supers %ld\n", Glu_persist->supno[n-1]+1);
		    printf("\tSize of G(L) %ld\n", Glu_freeable->xlsub[n]);
		    printf("\tSize of G(U) %ld\n", Glu_freeable->xusub[n]);
		    printf("\tint %d, short %d, float %d, double %d\n", 
			   sizeof(int_t), sizeof(short), sizeof(float),
			   sizeof(double));
		    printf("\tSYMBfact (MB):\tL\\U %.2f\ttotal %.2f\texpansions %d\n",
			   symb_mem_usage.for_lu*1e-6, 
			   symb_mem_usage.total*1e-6,
			   symb_mem_usage.expansions);
		}
#endif
	    } else {
		if ( !iam ) {
		    fprintf(stderr, "symbfact() error returns %d\n", iinfo);
		    exit(-1);
		}
	    }
	}

	/* Distribute the L and U factors onto the process grid. */
	t = SuperLU_timer_();
	dist_mem_use = zdistribute(Fact, n, &AC, Glu_freeable, LUstruct, grid);
	stat->utime[DIST] = SuperLU_timer_() - t;

	/* Deallocate storage used in symbolic factor. */
	if ( Fact != SamePattern_SameRowPerm ) {
	    iinfo = symbfact_SubFree(Glu_freeable);
	    SUPERLU_FREE(Glu_freeable);
	}

	/* Perform numerical factorization in parallel. */
	t = SuperLU_timer_();
	pzgstrf(options, m, n, anorm, LUstruct, grid, stat, info);
	stat->utime[FACT] = SuperLU_timer_() - t;

#if ( PRNTlevel>=1 )
	{
	    int_t TinyPivots;
	    float for_lu, total, max, avg, temp;
	    zQuerySpace_dist(n, LUstruct, grid, &num_mem_usage);
	    MPI_Reduce( &num_mem_usage.for_lu, &for_lu,
		       1, MPI_FLOAT, MPI_SUM, 0, grid->comm );
	    MPI_Reduce( &num_mem_usage.total, &total,
		       1, MPI_FLOAT, MPI_SUM, 0, grid->comm );
	    temp = SUPERLU_MAX(symb_mem_usage.total,
			       symb_mem_usage.for_lu +
			       (float)dist_mem_use + num_mem_usage.for_lu);
	    temp = SUPERLU_MAX(temp, num_mem_usage.total);
	    MPI_Reduce( &temp, &max,
		       1, MPI_FLOAT, MPI_MAX, 0, grid->comm );
	    MPI_Reduce( &temp, &avg,
		       1, MPI_FLOAT, MPI_SUM, 0, grid->comm );
	    MPI_Allreduce( &stat->TinyPivots, &TinyPivots, 1, mpi_int_t,
			  MPI_SUM, grid->comm );
	    stat->TinyPivots = TinyPivots;
	    if ( !iam ) {
		printf("\tNUMfact (MB) all PEs:\tL\\U\t%.2f\tall\t%.2f\n",
		       for_lu*1e-6, total*1e-6);
		printf("\tAll space (MB):"
		       "\t\ttotal\t%.2f\tAvg\t%.2f\tMax\t%.2f\n",
		       avg*1e-6, avg/grid->nprow/grid->npcol*1e-6, max*1e-6);
		printf("\tNumber of tiny pivots: %10d\n", stat->TinyPivots);
	    }
	}
#endif
    
#if ( PRNTlevel>=2 )
	if ( !iam ) printf(".. pzgstrf INFO = %d\n", *info);
#endif

    } else if ( options->IterRefine ) { /* options->Fact==FACTORED */
	/* Permute columns of A to form A*Pc' using the existing perm_c.
	 * NOTE: rows of A were previously permuted to Pc*A.
	 */
	sp_colorder(options, A, perm_c, NULL, &AC);
    } /* if !factored ... */
	
    /* ------------------------------------------------------------
       Compute the solution matrix X.
       ------------------------------------------------------------*/
    if ( nrhs ) {

	if ( !(b_work = doublecomplexMalloc_dist(n)) )
	    ABORT("Malloc fails for b_work[]");

	/* ------------------------------------------------------------
	   Scale the right-hand side if equilibration was performed. 
	   ------------------------------------------------------------*/
	if ( notran ) {
	    if ( rowequ ) {
		b_col = B;
		for (j = 0; j < nrhs; ++j) {
		    for (i = 0; i < m; ++i) zd_mult(&b_col[i], &b_col[i], R[i]);
		    b_col += ldb;
		}
	    }
	} else if ( colequ ) {
	    b_col = B;
	    for (j = 0; j < nrhs; ++j) {
		for (i = 0; i < m; ++i) zd_mult(&b_col[i], &b_col[i], C[i]);
		b_col += ldb;
	    }
	}

	/* ------------------------------------------------------------
	   Permute the right-hand side to form Pr*B.
	   ------------------------------------------------------------*/
	if ( options->RowPerm != NO ) {
	    if ( notran ) {
		b_col = B;
		for (j = 0; j < nrhs; ++j) {
		    for (i = 0; i < m; ++i) b_work[perm_r[i]] = b_col[i];
		    for (i = 0; i < m; ++i) b_col[i] = b_work[i];
		    b_col += ldb;
		}
	    }
	}


	/* ------------------------------------------------------------
	   Permute the right-hand side to form Pc*B.
	   ------------------------------------------------------------*/
	if ( notran ) {
	    b_col = B;
	    for (j = 0; j < nrhs; ++j) {
		for (i = 0; i < m; ++i) b_work[perm_c[i]] = b_col[i];
		for (i = 0; i < m; ++i) b_col[i] = b_work[i];
		b_col += ldb;
	    }
	}

	/* Save a copy of the right-hand side. */
	ldx = ldb;
	if ( !(X = doublecomplexMalloc_dist(((size_t)ldx) * nrhs)) )
	    ABORT("Malloc fails for X[]");
	x_col = X;  b_col = B;
	for (j = 0; j < nrhs; ++j) {
	    for (i = 0; i < ldb; ++i) x_col[i] = b_col[i];
	    x_col += ldx;  b_col += ldb;
	}

	/* ------------------------------------------------------------
	   Solve the linear system.
	   ------------------------------------------------------------*/
	pzgstrs_Bglobal(n, LUstruct, grid, X, ldb, nrhs, stat, info);

	/* ------------------------------------------------------------
	   Use iterative refinement to improve the computed solution and
	   compute error bounds and backward error estimates for it.
	   ------------------------------------------------------------*/
	if ( options->IterRefine ) {
	    /* Improve the solution by iterative refinement. */
	    t = SuperLU_timer_();
	    pzgsrfs_ABXglobal(n, &AC, anorm, LUstruct, grid, B, ldb,
			      X, ldx, nrhs, berr, stat, info);
	    stat->utime[REFINE] = SuperLU_timer_() - t;
	}

	/* Permute the solution matrix X <= Pc'*X. */
	for (j = 0; j < nrhs; j++) {
	    b_col = &B[j*ldb];
	    x_col = &X[j*ldx];
	    for (i = 0; i < n; ++i) b_col[i] = x_col[perm_c[i]];
	}
	
	/* Transform the solution matrix X to a solution of the original system
	   before the equilibration. */
	if ( notran ) {
	    if ( colequ ) {
		b_col = B;
		for (j = 0; j < nrhs; ++j) {
		    for (i = 0; i < n; ++i) zd_mult(&b_col[i], &b_col[i], C[i]);
		    b_col += ldb;
		}
	    }
	} else if ( rowequ ) {
	    b_col = B;
	    for (j = 0; j < nrhs; ++j) {
		for (i = 0; i < n; ++i) zd_mult(&b_col[i], &b_col[i], R[i]);
		b_col += ldb;
	    }
	}

	SUPERLU_FREE(b_work);
	SUPERLU_FREE(X);

    } /* end if nrhs != 0 */

#if ( PRNTlevel>=1 )
    if ( !iam ) printf(".. DiagScale = %d\n", ScalePermstruct->DiagScale);
#endif

    /* Deallocate R and/or C if it is not used. */
    if ( Equil && Fact != SamePattern_SameRowPerm ) {
	switch ( ScalePermstruct->DiagScale ) {
	    case NOEQUIL:
	        SUPERLU_FREE(R);
		SUPERLU_FREE(C);
		break;
	    case ROW: 
		SUPERLU_FREE(C);
		break;
	    case COL: 
		SUPERLU_FREE(R);
		break;
	}
    }
    if ( !factored || (factored && options->IterRefine) )
	Destroy_CompCol_Permuted_dist(&AC);

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Exit pzgssvx_ABglobal()");
#endif
}
示例#16
0
int_t pdgstrf
/************************************************************************/
(
 superlu_options_t *options, int m, int n, double anorm,
 LUstruct_t *LUstruct, gridinfo_t *grid, SuperLUStat_t *stat, int *info
 )
/* 
 * Purpose
 * =======
 *
 *  PDGSTRF performs the LU factorization in parallel.
 *
 * Arguments
 * =========
 * 
 * options (input) superlu_options_t*
 *         The structure defines the input parameters to control
 *         how the LU decomposition will be performed.
 *         The following field should be defined:
 *         o ReplaceTinyPivot (yes_no_t)
 *           Specifies whether to replace the tiny diagonals by
 *           sqrt(epsilon)*norm(A) during LU factorization.
 *
 * m      (input) int
 *        Number of rows in the matrix.
 *
 * n      (input) int
 *        Number of columns in the matrix.
 *
 * anorm  (input) double
 *        The norm of the original matrix A, or the scaled A if
 *        equilibration was done.
 *
 * LUstruct (input/output) LUstruct_t*
 *         The data structures to store the distributed L and U factors.
 *         The following fields should be defined:
 *
 *         o Glu_persist (input) Glu_persist_t*
 *           Global data structure (xsup, supno) replicated on all processes,
 *           describing the supernode partition in the factored matrices
 *           L and U:
 *	       xsup[s] is the leading column of the s-th supernode,
 *             supno[i] is the supernode number to which column i belongs.
 *
 *         o Llu (input/output) LocalLU_t*
 *           The distributed data structures to store L and U factors.
 *           See superlu_ddefs.h for the definition of 'LocalLU_t'.
 *
 * grid   (input) gridinfo_t*
 *        The 2D process mesh. It contains the MPI communicator, the number
 *        of process rows (NPROW), the number of process columns (NPCOL),
 *        and my process rank. It is an input argument to all the
 *        parallel routines.
 *        Grid can be initialized by subroutine SUPERLU_GRIDINIT.
 *        See superlu_ddefs.h for the definition of 'gridinfo_t'.
 *
 * stat   (output) SuperLUStat_t*
 *        Record the statistics on runtime and floating-point operation count.
 *        See util.h for the definition of 'SuperLUStat_t'.
 *
 * info   (output) int*
 *        = 0: successful exit
 *        < 0: if info = -i, the i-th argument had an illegal value
 *        > 0: if info = i, U(i,i) is exactly zero. The factorization has
 *             been completed, but the factor U is exactly singular,
 *             and division by zero will occur if it is used to solve a
 *             system of equations.
 *
 */
{
#ifdef _CRAY
    _fcd ftcs = _cptofcd("N", strlen("N"));
    _fcd ftcs1 = _cptofcd("L", strlen("L"));
    _fcd ftcs2 = _cptofcd("N", strlen("N"));
    _fcd ftcs3 = _cptofcd("U", strlen("U"));
#endif
    double alpha = 1.0, beta = 0.0;
    int_t *xsup;
    int_t *lsub, *lsub1, *usub, *Usub_buf,
          *Lsub_buf_2[2];  /* Need 2 buffers to implement Irecv. */
    double *lusup, *lusup1, *uval, *Uval_buf,
           *Lval_buf_2[2]; /* Need 2 buffers to implement Irecv. */
    int_t fnz, i, ib, ijb, ilst, it, iukp, jb, jj, klst, knsupc,
          lb, lib, ldv, ljb, lptr, lptr0, lptrj, luptr, luptr0, luptrj,
          nlb, nub, nsupc, rel, rukp;
    int_t Pc, Pr;
    int   iam, kcol, krow, mycol, myrow, pi, pj;
    int   j, k, lk, nsupers;
    int   nsupr, nbrow, segsize;
    int   msgcnt[4]; /* Count the size of the message xfer'd in each buffer:
		      *     0 : transferred in Lsub_buf[]
		      *     1 : transferred in Lval_buf[]
		      *     2 : transferred in Usub_buf[] 
		      *     3 : transferred in Uval_buf[]
		      */
    int_t  msg0, msg2;
    int_t  **Ufstnz_br_ptr, **Lrowind_bc_ptr;
    double **Unzval_br_ptr, **Lnzval_bc_ptr;
    int_t  *index;
    double *nzval;
    int_t  *iuip, *ruip;/* Pointers to U index/nzval; size ceil(NSUPERS/Pr). */
    double *ucol;
    int_t  *indirect;
    double *tempv, *tempv2d;
    int_t iinfo;
    int_t *ToRecv, *ToSendD, **ToSendR;
    Glu_persist_t *Glu_persist = LUstruct->Glu_persist;
    LocalLU_t *Llu = LUstruct->Llu;
    superlu_scope_t *scp;
    float s_eps;
    double thresh;
    double *tempU2d, *tempu;
    int    full, ldt, ldu, lead_zero, ncols;
    MPI_Request recv_req[4], *send_req, *U_diag_blk_send_req = NULL;
    MPI_Status status;
#if ( DEBUGlevel>=2 ) 
    int_t num_copy=0, num_update=0;
#endif
#if ( PRNTlevel==3 )
    int_t  zero_msg = 0, total_msg = 0;
#endif
#if ( PROFlevel>=1 )
    double t1, t2;
    float msg_vol = 0, msg_cnt = 0;
    int_t iword = sizeof(int_t), dword = sizeof(double);
#endif

    /* Test the input parameters. */
    *info = 0;
    if ( m < 0 ) *info = -2;
    else if ( n < 0 ) *info = -3;
    if ( *info ) {
	pxerbla("pdgstrf", grid, -*info);
	return (-1);
    }

    /* Quick return if possible. */
    if ( m == 0 || n == 0 ) return 0;

    /*
     * Initialization.
     */
    iam = grid->iam;
    Pc = grid->npcol;
    Pr = grid->nprow;
    myrow = MYROW( iam, grid );
    mycol = MYCOL( iam, grid );
    nsupers = Glu_persist->supno[n-1] + 1;
    xsup = Glu_persist->xsup;
    s_eps = slamch_("Epsilon");
    thresh = s_eps * anorm;

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter pdgstrf()");
#endif

    stat->ops[FACT] = 0.0;

    if ( Pr*Pc > 1 ) {
	i = Llu->bufmax[0];
	if ( !(Llu->Lsub_buf_2[0] = intMalloc_dist(2 * ((size_t)i))) )
	    ABORT("Malloc fails for Lsub_buf.");
	Llu->Lsub_buf_2[1] = Llu->Lsub_buf_2[0] + i;
	i = Llu->bufmax[1];
	if ( !(Llu->Lval_buf_2[0] = doubleMalloc_dist(2 * ((size_t)i))) )
	    ABORT("Malloc fails for Lval_buf[].");
	Llu->Lval_buf_2[1] = Llu->Lval_buf_2[0] + i;
	if ( Llu->bufmax[2] != 0 ) 
	    if ( !(Llu->Usub_buf = intMalloc_dist(Llu->bufmax[2])) )
		ABORT("Malloc fails for Usub_buf[].");
	if ( Llu->bufmax[3] != 0 ) 
	    if ( !(Llu->Uval_buf = doubleMalloc_dist(Llu->bufmax[3])) )
		ABORT("Malloc fails for Uval_buf[].");
	if ( !(U_diag_blk_send_req =
	       (MPI_Request *) SUPERLU_MALLOC(Pr*sizeof(MPI_Request))))
	    ABORT("Malloc fails for U_diag_blk_send_req[].");
        U_diag_blk_send_req[myrow] = 0; /* flag no outstanding Isend */
	if ( !(send_req =
	       (MPI_Request *) SUPERLU_MALLOC(2*Pc*sizeof(MPI_Request))))
	    ABORT("Malloc fails for send_req[].");
    }
    k = sp_ienv_dist(3); /* max supernode size */
    if ( !(Llu->ujrow = doubleMalloc_dist(k*(k+1)/2)) )
	ABORT("Malloc fails for ujrow[].");

#if ( PRNTlevel>=1 )
    if ( !iam ) {
	printf(".. thresh = s_eps %e * anorm %e = %e\n", s_eps, anorm, thresh);
	printf(".. Buffer size: Lsub %d\tLval %d\tUsub %d\tUval %d\tLDA %d\n",
	       Llu->bufmax[0], Llu->bufmax[1], 
	       Llu->bufmax[2], Llu->bufmax[3], Llu->bufmax[4]);
    }
#endif

    Lsub_buf_2[0] = Llu->Lsub_buf_2[0];
    Lsub_buf_2[1] = Llu->Lsub_buf_2[1];
    Lval_buf_2[0] = Llu->Lval_buf_2[0];
    Lval_buf_2[1] = Llu->Lval_buf_2[1];
    Usub_buf = Llu->Usub_buf;
    Uval_buf = Llu->Uval_buf;
    Lrowind_bc_ptr = Llu->Lrowind_bc_ptr;
    Lnzval_bc_ptr = Llu->Lnzval_bc_ptr;
    Ufstnz_br_ptr = Llu->Ufstnz_br_ptr;
    Unzval_br_ptr = Llu->Unzval_br_ptr;
    ToRecv = Llu->ToRecv;
    ToSendD = Llu->ToSendD;
    ToSendR = Llu->ToSendR;

    ldt = sp_ienv_dist(3); /* Size of maximum supernode */
    if ( !(tempv2d = doubleCalloc_dist(2*((size_t)ldt)*ldt)) )
	ABORT("Calloc fails for tempv2d[].");
    tempU2d = tempv2d + ldt*ldt;
    if ( !(indirect = intMalloc_dist(ldt)) )
	ABORT("Malloc fails for indirect[].");
    k = CEILING( nsupers, Pr ); /* Number of local block rows */
    if ( !(iuip = intMalloc_dist(k)) )
	ABORT("Malloc fails for iuip[].");
    if ( !(ruip = intMalloc_dist(k)) )
	ABORT("Malloc fails for ruip[].");

#if ( VAMPIR>=1 )
    VT_symdef(1, "Send-L", "Comm");
    VT_symdef(2, "Recv-L", "Comm");
    VT_symdef(3, "Send-U", "Comm");
    VT_symdef(4, "Recv-U", "Comm");
    VT_symdef(5, "TRF2", "Factor");
    VT_symdef(100, "Factor", "Factor");
    VT_begin(100);
    VT_traceon();
#endif

    /* ---------------------------------------------------------------
       Handle the first block column separately to start the pipeline.
       --------------------------------------------------------------- */
    if ( mycol == 0 ) {

#if ( VAMPIR>=1 )
	VT_begin(5);
#endif
	pdgstrf2(options, 0, thresh, Glu_persist, grid, Llu, 
		 U_diag_blk_send_req, stat, info);

#if ( VAMPIR>=1 )
	VT_end(5);
#endif

	scp = &grid->rscp; /* The scope of process row. */

	/* Process column *kcol* multicasts numeric values of L(:,k) 
	   to process rows. */
	lsub = Lrowind_bc_ptr[0];
	lusup = Lnzval_bc_ptr[0];
	if ( lsub ) {
	    msgcnt[0] = lsub[1] + BC_HEADER + lsub[0]*LB_DESCRIPTOR;
	    msgcnt[1] = lsub[1] * SuperSize( 0 );
	} else {
	    msgcnt[0] = msgcnt[1] = 0;
	}
	
	for (pj = 0; pj < Pc; ++pj) {
	    if ( ToSendR[0][pj] != EMPTY ) {
#if ( PROFlevel>=1 )
		TIC(t1);
#endif
#if ( VAMPIR>=1 )
		VT_begin(1);
#endif
		MPI_Isend( lsub, msgcnt[0], mpi_int_t, pj, 0, scp->comm,
			  &send_req[pj] );
		MPI_Isend( lusup, msgcnt[1], MPI_DOUBLE, pj, 1, scp->comm,
			  &send_req[pj+Pc] );
#if ( DEBUGlevel>=2 )
		printf("(%d) Send L(:,%4d): lsub %4d, lusup %4d to Pc %2d\n",
		       iam, 0, msgcnt[0], msgcnt[1], pj);
#endif
#if ( VAMPIR>=1 )
		VT_end(1);
#endif
#if ( PROFlevel>=1 )
		TOC(t2, t1);
		stat->utime[COMM] += t2;
		msg_cnt += 2;
		msg_vol += msgcnt[0]*iword + msgcnt[1]*dword;
#endif
	    }
	} /* for pj ... */
    } else { /* Post immediate receives. */
	if ( ToRecv[0] >= 1 ) { /* Recv block column L(:,0). */
	    scp = &grid->rscp; /* The scope of process row. */
	    MPI_Irecv( Lsub_buf_2[0], Llu->bufmax[0], mpi_int_t, 0,
		      0, scp->comm, &recv_req[0] );
	    MPI_Irecv( Lval_buf_2[0], Llu->bufmax[1], MPI_DOUBLE, 0,
		      1, scp->comm, &recv_req[1] );
#if ( DEBUGlevel>=2 )
	    printf("(%d) Post Irecv L(:,%4d)\n", iam, 0);
#endif
	}
    } /* if mycol == 0 */

    /* ------------------------------------------
       MAIN LOOP: Loop through all block columns.
       ------------------------------------------ */
    for (k = 0; k < nsupers; ++k) {

	knsupc = SuperSize( k );
	krow = PROW( k, grid );
	kcol = PCOL( k, grid );

	if ( mycol == kcol ) {
	    lk = LBj( k, grid ); /* Local block number. */

	    for (pj = 0; pj < Pc; ++pj) {
                /* Wait for Isend to complete before using lsub/lusup. */
		if ( ToSendR[lk][pj] != EMPTY ) {
		    MPI_Wait( &send_req[pj], &status );
		    MPI_Wait( &send_req[pj+Pc], &status );
		}
	    }
	    lsub = Lrowind_bc_ptr[lk];
	    lusup = Lnzval_bc_ptr[lk];
	} else {
	    if ( ToRecv[k] >= 1 ) { /* Recv block column L(:,k). */
		scp = &grid->rscp; /* The scope of process row. */
#if ( PROFlevel>=1 )
		TIC(t1);
#endif
#if ( VAMPIR>=1 )
		VT_begin(2);
#endif
		/*probe_recv(iam, kcol, (4*k)%NTAGS, mpi_int_t, scp->comm, 
		  Llu->bufmax[0]);*/
		/*MPI_Recv( Lsub_buf, Llu->bufmax[0], mpi_int_t, kcol, 
			 (4*k)%NTAGS, scp->comm, &status );*/
		MPI_Wait( &recv_req[0], &status );
		MPI_Get_count( &status, mpi_int_t, &msgcnt[0] );
		/*probe_recv(iam, kcol, (4*k+1)%NTAGS, MPI_DOUBLE, scp->comm, 
		  Llu->bufmax[1]);*/
		/*MPI_Recv( Lval_buf, Llu->bufmax[1], MPI_DOUBLE, kcol, 
			 (4*k+1)%NTAGS, scp->comm, &status );*/
		MPI_Wait( &recv_req[1], &status );
		MPI_Get_count( &status, MPI_DOUBLE, &msgcnt[1] );
#if ( VAMPIR>=1 )
		VT_end(2);
#endif
#if ( PROFlevel>=1 )
		TOC(t2, t1);
		stat->utime[COMM] += t2;
#endif
#if ( DEBUGlevel>=2 )
		printf("(%d) Recv L(:,%4d): lsub %4d, lusup %4d from Pc %2d\n",
		       iam, k, msgcnt[0], msgcnt[1], kcol);
		fflush(stdout);
#endif
		lsub = Lsub_buf_2[k%2];
		lusup = Lval_buf_2[k%2];
#if ( PRNTlevel==3 )
		++total_msg;
		if ( !msgcnt[0] ) ++zero_msg;
#endif
	    } else msgcnt[0] = 0;
	} /* if mycol = Pc(k) */

	scp = &grid->cscp; /* The scope of process column. */

	if ( myrow == krow ) {
	    /* Parallel triangular solve across process row *krow* --
	       U(k,j) = L(k,k) \ A(k,j).  */
#ifdef _CRAY
	    pdgstrs2(n, k, Glu_persist, grid, Llu, stat, ftcs1, ftcs2, ftcs3);
#else
	    pdgstrs2(n, k, Glu_persist, grid, Llu, stat);
#endif

	    /* Multicasts U(k,:) to process columns. */
	    lk = LBi( k, grid );
	    usub = Ufstnz_br_ptr[lk];
	    uval = Unzval_br_ptr[lk];
	    if ( usub )	{
		msgcnt[2] = usub[2];
		msgcnt[3] = usub[1];
	    } else {
		msgcnt[2] = msgcnt[3] = 0;
	    }

	    if ( ToSendD[lk] == YES ) {
		for (pi = 0; pi < Pr; ++pi) {
		    if ( pi != myrow ) {
#if ( PROFlevel>=1 )
			TIC(t1);
#endif
#if ( VAMPIR>=1 )
			VT_begin(3);
#endif
			MPI_Send( usub, msgcnt[2], mpi_int_t, pi,
				 (4*k+2)%NTAGS, scp->comm);
			MPI_Send( uval, msgcnt[3], MPI_DOUBLE, pi,
				 (4*k+3)%NTAGS, scp->comm);
#if ( VAMPIR>=1 )
			VT_end(3);
#endif
#if ( PROFlevel>=1 )
			TOC(t2, t1);
			stat->utime[COMM] += t2;
			msg_cnt += 2;
			msg_vol += msgcnt[2]*iword + msgcnt[3]*dword;
#endif
#if ( DEBUGlevel>=2 )
			printf("(%d) Send U(%4d,:) to Pr %2d\n", iam, k, pi);
#endif
		    } /* if pi ... */
		} /* for pi ... */
	    } /* if ToSendD ... */
	} else { /* myrow != krow */
	    if ( ToRecv[k] == 2 ) { /* Recv block row U(k,:). */
#if ( PROFlevel>=1 )
		TIC(t1);
#endif
#if ( VAMPIR>=1 )
		VT_begin(4);
#endif
		/*probe_recv(iam, krow, (4*k+2)%NTAGS, mpi_int_t, scp->comm, 
		  Llu->bufmax[2]);*/
		MPI_Recv( Usub_buf, Llu->bufmax[2], mpi_int_t, krow,
			 (4*k+2)%NTAGS, scp->comm, &status );
		MPI_Get_count( &status, mpi_int_t, &msgcnt[2] );
		/*probe_recv(iam, krow, (4*k+3)%NTAGS, MPI_DOUBLE, scp->comm, 
		  Llu->bufmax[3]);*/
		MPI_Recv( Uval_buf, Llu->bufmax[3], MPI_DOUBLE, krow, 
			 (4*k+3)%NTAGS, scp->comm, &status );
		MPI_Get_count( &status, MPI_DOUBLE, &msgcnt[3] );
#if ( VAMPIR>=1 )
		VT_end(4);
#endif
#if ( PROFlevel>=1 )
		TOC(t2, t1);
		stat->utime[COMM] += t2;
#endif
		usub = Usub_buf;
		uval = Uval_buf;
#if ( DEBUGlevel>=2 )
		printf("(%d) Recv U(%4d,:) from Pr %2d\n", iam, k, krow);
#endif
#if ( PRNTlevel==3 )
		++total_msg;
		if ( !msgcnt[2] ) ++zero_msg;
#endif
	    } else msgcnt[2] = 0;
	} /* if myrow == Pr(k) */
	  
	/* 
	 * Parallel rank-k update; pair up blocks L(i,k) and U(k,j).
	 *  for (j = k+1; k < N; ++k) {
	 *     for (i = k+1; i < N; ++i) 
	 *         if ( myrow == PROW( i, grid ) && mycol == PCOL( j, grid )
	 *              && L(i,k) != 0 && U(k,j) != 0 )
	 *             A(i,j) = A(i,j) - L(i,k) * U(k,j);
	 */
	msg0 = msgcnt[0];
	msg2 = msgcnt[2];
	if ( msg0 && msg2 ) { /* L(:,k) and U(k,:) are not empty. */
	    nsupr = lsub[1]; /* LDA of lusup. */
	    if ( myrow == krow ) { /* Skip diagonal block L(k,k). */
		lptr0 = BC_HEADER + LB_DESCRIPTOR + lsub[BC_HEADER+1];
		luptr0 = knsupc;
		nlb = lsub[0] - 1;
	    } else {
		lptr0 = BC_HEADER;
		luptr0 = 0;
		nlb = lsub[0];
	    }
	    lptr = lptr0;
	    for (lb = 0; lb < nlb; ++lb) { /* Initialize block row pointers. */
		ib = lsub[lptr];
		lib = LBi( ib, grid );
		iuip[lib] = BR_HEADER;
		ruip[lib] = 0;
		lptr += LB_DESCRIPTOR + lsub[lptr+1];
	    }
	    nub = usub[0];    /* Number of blocks in the block row U(k,:) */
	    iukp = BR_HEADER; /* Skip header; Pointer to index[] of U(k,:) */
	    rukp = 0;         /* Pointer to nzval[] of U(k,:) */
	    klst = FstBlockC( k+1 );
	    
	    /* ---------------------------------------------------
	       Update the first block column A(:,k+1).
	       --------------------------------------------------- */
	    jb = usub[iukp];   /* Global block number of block U(k,j). */
	    if ( jb == k+1 ) { /* First update (k+1)-th block. */
		--nub;
		lptr = lptr0;
		luptr = luptr0;
		ljb = LBj( jb, grid ); /* Local block number of U(k,j). */
		nsupc = SuperSize( jb );
		iukp += UB_DESCRIPTOR; /* Start fstnz of block U(k,j). */

		/* Prepare to call DGEMM. */
		jj = iukp;
		while ( usub[jj] == klst ) ++jj;
		ldu = klst - usub[jj++];
		ncols = 1;
		full = 1;
		for (; jj < iukp+nsupc; ++jj) {
		    segsize = klst - usub[jj];
		    if ( segsize ) {
		        ++ncols;
			if ( segsize != ldu ) full = 0;
		        if ( segsize > ldu ) ldu = segsize;
		    }
		}
#if ( DEBUGlevel>=3 )
		++num_update;
#endif
		if ( full ) {
		    tempu = &uval[rukp];
		} else { /* Copy block U(k,j) into tempU2d. */
#if ( DEBUGlevel>=3 )
		  printf("(%d) full=%d,k=%d,jb=%d,ldu=%d,ncols=%d,nsupc=%d\n",
			 iam, full, k, jb, ldu, ncols, nsupc);
		  ++num_copy;
#endif
		    tempu = tempU2d;
		    for (jj = iukp; jj < iukp+nsupc; ++jj) {
		        segsize = klst - usub[jj];
			if ( segsize ) {
			    lead_zero = ldu - segsize;
			    for (i = 0; i < lead_zero; ++i) tempu[i] = 0.0;
			    tempu += lead_zero;
			    for (i = 0; i < segsize; ++i)
				tempu[i] = uval[rukp+i];
			    rukp += segsize;
			    tempu += segsize;
			}
		    }
		    tempu = tempU2d;
		    rukp -= usub[iukp - 1]; /* Return to start of U(k,j). */
		} /* if full ... */

		for (lb = 0; lb < nlb; ++lb) { 
		    ib = lsub[lptr]; /* Row block L(i,k). */
		    nbrow = lsub[lptr+1];  /* Number of full rows. */
		    lptr += LB_DESCRIPTOR; /* Skip descriptor. */
		    tempv = tempv2d;
#ifdef _CRAY
		    SGEMM(ftcs, ftcs, &nbrow, &ncols, &ldu, &alpha, 
			  &lusup[luptr+(knsupc-ldu)*nsupr], &nsupr, 
			  tempu, &ldu, &beta, tempv, &ldt);
#elif defined (USE_VENDOR_BLAS)
		    dgemm_("N", "N", &nbrow, &ncols, &ldu, &alpha, 
			   &lusup[luptr+(knsupc-ldu)*nsupr], &nsupr, 
			   tempu, &ldu, &beta, tempv, &ldt, 1, 1);
#else
		    dgemm_("N", "N", &nbrow, &ncols, &ldu, &alpha, 
			   &lusup[luptr+(knsupc-ldu)*nsupr], &nsupr, 
			   tempu, &ldu, &beta, tempv, &ldt);
#endif
		    stat->ops[FACT] += 2 * nbrow * ldu * ncols;

		    /* Now gather the result into the destination block. */
		    if ( ib < jb ) { /* A(i,j) is in U. */
			ilst = FstBlockC( ib+1 );
			lib = LBi( ib, grid );
			index = Ufstnz_br_ptr[lib];
			ijb = index[iuip[lib]];
			while ( ijb < jb ) { /* Search for dest block. */
			    ruip[lib] += index[iuip[lib]+1];
			    iuip[lib] += UB_DESCRIPTOR + SuperSize( ijb );
			    ijb = index[iuip[lib]];
			}
			iuip[lib] += UB_DESCRIPTOR; /* Skip descriptor. */

			tempv = tempv2d;
			for (jj = 0; jj < nsupc; ++jj) {
			    segsize = klst - usub[iukp + jj];
			    fnz = index[iuip[lib]++];
			    if ( segsize ) { /* Nonzero segment in U(k.j). */
				ucol = &Unzval_br_ptr[lib][ruip[lib]];
				for (i = 0, it = 0; i < nbrow; ++i) {
				    rel = lsub[lptr + i] - fnz;
				    ucol[rel] -= tempv[it++];
				}
				tempv += ldt;
			    }
			    ruip[lib] += ilst - fnz;
			}
		    } else { /* A(i,j) is in L. */
			index = Lrowind_bc_ptr[ljb];
			ldv = index[1];   /* LDA of the dest lusup. */
			lptrj = BC_HEADER;
			luptrj = 0;
			ijb = index[lptrj];
			while ( ijb != ib ) { /* Search for dest block -- 
						 blocks are not ordered! */
			    luptrj += index[lptrj+1];
			    lptrj += LB_DESCRIPTOR + index[lptrj+1];
			    ijb = index[lptrj];
			}
			/*
			 * Build indirect table. This is needed because the
			 * indices are not sorted.
			 */
			fnz = FstBlockC( ib );
			lptrj += LB_DESCRIPTOR;
			for (i = 0; i < index[lptrj-1]; ++i) {
			    rel = index[lptrj + i] - fnz;
			    indirect[rel] = i;
			}
			nzval = Lnzval_bc_ptr[ljb] + luptrj;
			tempv = tempv2d;
			for (jj = 0; jj < nsupc; ++jj) {
			    segsize = klst - usub[iukp + jj];
			    if ( segsize ) {
/*#pragma _CRI cache_bypass nzval,tempv*/
				for (it = 0, i = 0; i < nbrow; ++i) {
				    rel = lsub[lptr + i] - fnz;
				    nzval[indirect[rel]] -= tempv[it++];
				}
				tempv += ldt;
			    }
			    nzval += ldv;
			}
		    } /* if ib < jb ... */
		    lptr += nbrow;
		    luptr += nbrow;
		} /* for lb ... */
		rukp += usub[iukp - 1]; /* Move to block U(k,j+1) */
		iukp += nsupc;
	    }  /* if jb == k+1 */
	} /* if L(:,k) and U(k,:) not empty */


	if ( k+1 < nsupers ) {
	  kcol = PCOL( k+1, grid );
	  if ( mycol == kcol ) {
#if ( VAMPIR>=1 )
	    VT_begin(5);
#endif
	    /* Factor diagonal and subdiagonal blocks and test for exact
	       singularity.  */
	    pdgstrf2(options, k+1, thresh, Glu_persist, grid, Llu,
		     U_diag_blk_send_req, stat, info);

#if ( VAMPIR>=1 )
	    VT_end(5);
#endif

	    /* Process column *kcol+1* multicasts numeric values of L(:,k+1) 
	       to process rows. */
	    lk = LBj( k+1, grid ); /* Local block number. */
	    lsub1 = Lrowind_bc_ptr[lk];
 	    if ( lsub1 ) {
		msgcnt[0] = lsub1[1] + BC_HEADER + lsub1[0]*LB_DESCRIPTOR;
		msgcnt[1] = lsub1[1] * SuperSize( k+1 );
	    } else {
		msgcnt[0] = 0;
		msgcnt[1] = 0;
	    }
	    scp = &grid->rscp; /* The scope of process row. */
	    for (pj = 0; pj < Pc; ++pj) {
		if ( ToSendR[lk][pj] != EMPTY ) {
		    lusup1 = Lnzval_bc_ptr[lk];
#if ( PROFlevel>=1 )
		    TIC(t1);
#endif
#if ( VAMPIR>=1 )
		    VT_begin(1);
#endif
		    MPI_Isend( lsub1, msgcnt[0], mpi_int_t, pj,
			      (4*(k+1))%NTAGS, scp->comm, &send_req[pj] );
		    MPI_Isend( lusup1, msgcnt[1], MPI_DOUBLE, pj,
			     (4*(k+1)+1)%NTAGS, scp->comm, &send_req[pj+Pc] );
#if ( VAMPIR>=1 )
		    VT_end(1);
#endif
#if ( PROFlevel>=1 )
		    TOC(t2, t1);
		    stat->utime[COMM] += t2;
		    msg_cnt += 2;
		    msg_vol += msgcnt[0]*iword + msgcnt[1]*dword;
#endif
#if ( DEBUGlevel>=2 )
		    printf("(%d) Send L(:,%4d): lsub %4d, lusup %4d to Pc %2d\n",
			   iam, k+1, msgcnt[0], msgcnt[1], pj);
#endif
		}
	    } /* for pj ... */
	  } else { /* Post Recv of block column L(:,k+1). */
	    if ( ToRecv[k+1] >= 1 ) {
		scp = &grid->rscp; /* The scope of process row. */
		MPI_Irecv(Lsub_buf_2[(k+1)%2], Llu->bufmax[0], mpi_int_t, kcol,
			  (4*(k+1))%NTAGS, scp->comm, &recv_req[0]);
		MPI_Irecv(Lval_buf_2[(k+1)%2], Llu->bufmax[1], MPI_DOUBLE, kcol, 
			  (4*(k+1)+1)%NTAGS, scp->comm, &recv_req[1]);
#if ( DEBUGlevel>=2 )
		printf("(%d) Post Irecv L(:,%4d)\n", iam, k+1);
#endif
	    }
	  } /* if mycol == Pc(k+1) */
        } /* if k+1 < nsupers */

	if ( msg0 && msg2 ) { /* L(:,k) and U(k,:) are not empty. */
	    /* ---------------------------------------------------
	       Update all other blocks using block row U(k,:)
	       --------------------------------------------------- */
	    for (j = 0; j < nub; ++j) { 
		lptr = lptr0;
		luptr = luptr0;
		jb = usub[iukp];  /* Global block number of block U(k,j). */
		ljb = LBj( jb, grid ); /* Local block number of U(k,j). */
		nsupc = SuperSize( jb );
		iukp += UB_DESCRIPTOR; /* Start fstnz of block U(k,j). */

		/* Prepare to call DGEMM. */
		jj = iukp;
		while ( usub[jj] == klst ) ++jj;
		ldu = klst - usub[jj++];
		ncols = 1;
		full = 1;
		for (; jj < iukp+nsupc; ++jj) {
		    segsize = klst - usub[jj];
		    if ( segsize ) {
		        ++ncols;
			if ( segsize != ldu ) full = 0;
		        if ( segsize > ldu ) ldu = segsize;
		    }
		}
#if ( DEBUGlevel>=3 )
		printf("(%d) full=%d,k=%d,jb=%d,ldu=%d,ncols=%d,nsupc=%d\n",
		       iam, full, k, jb, ldu, ncols, nsupc);
		++num_update;
#endif
		if ( full ) {
		    tempu = &uval[rukp];
		} else { /* Copy block U(k,j) into tempU2d. */
#if ( DEBUGlevel>=3 )
		    ++num_copy;
#endif
		    tempu = tempU2d;
		    for (jj = iukp; jj < iukp+nsupc; ++jj) {
		        segsize = klst - usub[jj];
			if ( segsize ) {
			    lead_zero = ldu - segsize;
			    for (i = 0; i < lead_zero; ++i) tempu[i] = 0.0;
			    tempu += lead_zero;
			    for (i = 0; i < segsize; ++i)
			        tempu[i] = uval[rukp+i];
			    rukp += segsize;
			    tempu += segsize;
			}
		    }
		    tempu = tempU2d;
		    rukp -= usub[iukp - 1]; /* Return to start of U(k,j). */
		} /* if full ... */

		for (lb = 0; lb < nlb; ++lb) { 
		    ib = lsub[lptr];       /* Row block L(i,k). */
		    nbrow = lsub[lptr+1];  /* Number of full rows. */
		    lptr += LB_DESCRIPTOR; /* Skip descriptor. */
		    tempv = tempv2d;
#ifdef _CRAY
		    SGEMM(ftcs, ftcs, &nbrow, &ncols, &ldu, &alpha, 
			  &lusup[luptr+(knsupc-ldu)*nsupr], &nsupr, 
			  tempu, &ldu, &beta, tempv, &ldt);
#elif defined (USE_VENDOR_BLAS)
		    dgemm_("N", "N", &nbrow, &ncols, &ldu, &alpha, 
			   &lusup[luptr+(knsupc-ldu)*nsupr], &nsupr, 
			   tempu, &ldu, &beta, tempv, &ldt, 1, 1);
#else
		    dgemm_("N", "N", &nbrow, &ncols, &ldu, &alpha, 
			   &lusup[luptr+(knsupc-ldu)*nsupr], &nsupr, 
			   tempu, &ldu, &beta, tempv, &ldt);
#endif
		    stat->ops[FACT] += 2 * nbrow * ldu * ncols;

		    /* Now gather the result into the destination block. */
		    if ( ib < jb ) { /* A(i,j) is in U. */
			ilst = FstBlockC( ib+1 );
			lib = LBi( ib, grid );
			index = Ufstnz_br_ptr[lib];
			ijb = index[iuip[lib]];
			while ( ijb < jb ) { /* Search for dest block. */
			    ruip[lib] += index[iuip[lib]+1];
			    iuip[lib] += UB_DESCRIPTOR + SuperSize( ijb );
			    ijb = index[iuip[lib]];
			}
			/* Skip descriptor.  Now point to fstnz index of 
			   block U(i,j). */
			iuip[lib] += UB_DESCRIPTOR;

			tempv = tempv2d;
			for (jj = 0; jj < nsupc; ++jj) {
			    segsize = klst - usub[iukp + jj];
			    fnz = index[iuip[lib]++];
			    if ( segsize ) { /* Nonzero segment in U(k.j). */
				ucol = &Unzval_br_ptr[lib][ruip[lib]];
				for (i = 0 ; i < nbrow; ++i) {
				    rel = lsub[lptr + i] - fnz;
				    ucol[rel] -= tempv[i];
				}
				tempv += ldt;
			    }
			    ruip[lib] += ilst - fnz;
			}
		    } else { /* A(i,j) is in L. */
			index = Lrowind_bc_ptr[ljb];
			ldv = index[1];   /* LDA of the dest lusup. */
			lptrj = BC_HEADER;
			luptrj = 0;
			ijb = index[lptrj];
			while ( ijb != ib ) { /* Search for dest block -- 
						 blocks are not ordered! */
			    luptrj += index[lptrj+1];
			    lptrj += LB_DESCRIPTOR + index[lptrj+1];
			    ijb = index[lptrj];
			}
			/*
			 * Build indirect table. This is needed because the
			 * indices are not sorted for the L blocks.
			 */
			fnz = FstBlockC( ib );
			lptrj += LB_DESCRIPTOR;
			for (i = 0; i < index[lptrj-1]; ++i) {
			    rel = index[lptrj + i] - fnz;
			    indirect[rel] = i;
			}
			nzval = Lnzval_bc_ptr[ljb] + luptrj;
			tempv = tempv2d;
			for (jj = 0; jj < nsupc; ++jj) {
			    segsize = klst - usub[iukp + jj];
			    if ( segsize ) {
/*#pragma _CRI cache_bypass nzval,tempv*/
				for (i = 0; i < nbrow; ++i) {
				    rel = lsub[lptr + i] - fnz;
				    nzval[indirect[rel]] -= tempv[i];
				}
				tempv += ldt;
			    }
			    nzval += ldv;
			}
		    } /* if ib < jb ... */
		    lptr += nbrow;
		    luptr += nbrow;
		} /* for lb ... */
		rukp += usub[iukp - 1]; /* Move to block U(k,j+1) */
		iukp += nsupc;
	    } /* for j ... */
	} /* if  k L(:,k) and U(k,:) are not empty */

    } 
    /* ------------------------------------------
       END MAIN LOOP: for k = ...
       ------------------------------------------ */

#if ( VAMPIR>=1 )
    VT_end(100);
    VT_traceoff();
#endif

    if ( Pr*Pc > 1 ) {
	SUPERLU_FREE(Lsub_buf_2[0]); /* also free Lsub_buf_2[1] */
	SUPERLU_FREE(Lval_buf_2[0]); /* also free Lval_buf_2[1] */
	if ( Llu->bufmax[2] != 0 ) SUPERLU_FREE(Usub_buf);
	if ( Llu->bufmax[3] != 0 ) SUPERLU_FREE(Uval_buf);
	SUPERLU_FREE(send_req);
	if ( U_diag_blk_send_req[myrow] ) {
	    /* wait for last Isend requests to complete, deallocate objects */ 
	    for (krow = 0; krow < Pr; ++krow)
		if ( krow != myrow )
                    MPI_Wait(U_diag_blk_send_req + krow, &status);
	}
	SUPERLU_FREE(U_diag_blk_send_req);
    }

    SUPERLU_FREE(Llu->ujrow);
    SUPERLU_FREE(tempv2d);
    SUPERLU_FREE(indirect);
    SUPERLU_FREE(iuip);
    SUPERLU_FREE(ruip);

    /* Prepare error message. */
    if ( *info == 0 ) *info = n + 1;
#if ( PROFlevel>=1 )
    TIC(t1);
#endif
    MPI_Allreduce( info, &iinfo, 1, mpi_int_t, MPI_MIN, grid->comm );
#if ( PROFlevel>=1 )
    TOC(t2, t1);
    stat->utime[COMM] += t2;
    {
	float msg_vol_max, msg_vol_sum, msg_cnt_max, msg_cnt_sum;
	
	MPI_Reduce( &msg_cnt, &msg_cnt_sum,
		   1, MPI_FLOAT, MPI_SUM, 0, grid->comm );
	MPI_Reduce( &msg_cnt, &msg_cnt_max,
		   1, MPI_FLOAT, MPI_MAX, 0, grid->comm );
	MPI_Reduce( &msg_vol, &msg_vol_sum,
		   1, MPI_FLOAT, MPI_SUM, 0, grid->comm );
	MPI_Reduce( &msg_vol, &msg_vol_max,
		   1, MPI_FLOAT, MPI_MAX, 0, grid->comm );
	if ( !iam ) {
	    printf("\tPDGSTRF comm stat:"
		   "\tAvg\tMax\t\tAvg\tMax\n"
		   "\t\t\tCount:\t%.0f\t%.0f\tVol(MB)\t%.2f\t%.2f\n",
		   msg_cnt_sum/Pr/Pc, msg_cnt_max,
		   msg_vol_sum/Pr/Pc*1e-6, msg_vol_max*1e-6);
	}
    }
#endif
    if ( iinfo == n + 1 ) *info = 0;
    else *info = iinfo;


#if ( PRNTlevel==3 )
    MPI_Allreduce( &zero_msg, &iinfo, 1, mpi_int_t, MPI_SUM, grid->comm );
    if ( !iam ) printf(".. # msg of zero size\t%d\n", iinfo);
    MPI_Allreduce( &total_msg, &iinfo, 1, mpi_int_t, MPI_SUM, grid->comm );
    if ( !iam ) printf(".. # total msg\t%d\n", iinfo);
#endif

#if ( DEBUGlevel>=2 )
    for (i = 0; i < Pr * Pc; ++i) {
	if ( iam == i ) {
	    dPrintLblocks(iam, nsupers, grid, Glu_persist, Llu);
	    dPrintUblocks(iam, nsupers, grid, Glu_persist, Llu);
	    printf("(%d)\n", iam);
	    PrintInt10("Recv", nsupers, Llu->ToRecv);
	}
	MPI_Barrier( grid->comm );
    }
#endif

#if ( DEBUGlevel>=3 )
    printf("(%d) num_copy=%d, num_update=%d\n", iam, num_copy, num_update);
#endif
#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Exit pdgstrf()");
#endif
} /* PDGSTRF */
示例#17
0
static int_t column_dfs
/************************************************************************/
(
 SuperMatrix *A,        /* original matrix A permuted by columns (input) */
 const int_t jcol,      /* current column number (input) */
 int_t       *perm_r,   /* row permutation vector (input) */
 int_t       *nseg,     /* number of U-segments in column jcol (output) */
 int_t       *segrep,   /* list of U-segment representatives (output) */
 int_t       *repfnz,   /* list of first nonzeros in the U-segments (output) */
 int_t       *xprune,   /* pruned location in each adjacency list (output) */
 int_t       *marker,   /* working array of size m */
 int_t       *parent,   /* working array of size m */
 int_t       *xplore,   /* working array of size m */
 Glu_persist_t *Glu_persist,   /* global LU data structures (modified) */
 Glu_freeable_t *Glu_freeable
 )
{
/* 
 * Purpose
 * =======
 *   column_dfs() performs a symbolic factorization on column jcol, and
 *   detects the supernode boundary. This routine uses the row indices of
 *   A[*,jcol] to start the depth-first search (DFS).
 *
 * Output
 * ======
 *   A supernode representative is the last column of a supernode.
 *   The nonzeros in U[*,j] are segments that end at supernodal
 *   representatives. The routine returns a list of such supernodal 
 *   representatives ( segrep[*] ) in topological order of the DFS that 
 *   generates them. The location of the first nonzero in each such 
 *   supernodal segment is also returned ( repfnz[*] ).
 *
 * Data structure
 * ==============
 *   (lsub, xlsub):
 *      lsub[*] contains the compressed subscripts of the supernodes;
 *      xlsub[j] points to the starting location of the j-th column in
 *               lsub[*]; 
 *	Storage: original row subscripts in A.
 *
 *      During the course of symbolic factorization, we also use
 *	(lsub, xlsub, xprune) for the purpose of symmetric pruning.
 *      For each supernode {s,s+1,...,t=s+r} with first column s and last
 *	column t, there are two subscript sets,  the last column
 *      structures (for pruning) will be removed in the end.
 *        o lsub[j], j = xlsub[s], ..., xlsub[s+1]-1
 *          is the structure of column s (i.e. structure of this supernode).
 *          It is used for the storage of numerical values.
 *	  o lsub[j], j = xlsub[t], ..., xlsub[t+1]-1
 *	    is the structure of the last column t of this supernode.
 *	    It is for the purpose of symmetric pruning. Therefore, the
 *	    structural subscripts can be rearranged without making physical
 *	    interchanges among the numerical values.
 *
 *      (1) if t > s, only the subscript sets for column s and column t
 *          are stored. Column t represents pruned adjacency structure.
 *
 *                  --------------------------------------------
 *          lsub[*]    ... |   col s    |   col t   | ...
 *                  --------------------------------------------
 *                          ^            ^           ^
 *                       xlsub[s]    xlsub[s+1]  xlsub[t+1]
 *                                       :           :
 *                                       :         xprune[t]
 *                                   xlsub[t]      
 *                                   xprune[s]    
 *
 *      (2) if t == s, i.e., a singleton supernode, the same subscript set
 *          is used for both G(L) and pruned graph:
 *
 *                  --------------------------------------
 *          lsub[*]    ... |      s     | ...
 *                  --------------------------------------
 *                          ^            ^   
 *                       xlsub[s]   xlsub[s+1]  
 *                                  xprune[s]
 *
 *       DFS will traverse the second subscript list, i.e., the part of the
 *       pruned graph.
 *
 * Local parameters
 * ================
 *   nseg: no of segments in current U[*,j]
 *   jsuper: jsuper=EMPTY if column j does not belong to the same
 *	supernode as j-1. Otherwise, jsuper=nsuper.
 *
 *   marker: A-row --> A-row/col (0/1)
 *   repfnz: SuperA-col --> PA-row
 *   parent: SuperA-col --> SuperA-col
 *   xplore: SuperA-col --> index to L-structure
 *
 * Return value
 * ============
 *     0  success;
 *   > 0  number of bytes allocated when run out of space.
 *
 */
    NCPformat *Astore;
    int_t     *asub, *xa_begin, *xa_end;
    int_t     jcolp1, jcolm1, jsuper, nsuper, nextl;
    int_t     k, krep, krow, kmark, kperm;
    int_t     fsupc; /* first column of a supernode */
    int_t     myfnz; /* first nonzero column of a U-segment */
    int_t     chperm, chmark, chrep, kchild;
    int_t     xdfs, maxdfs, kpar, oldrep;
    int_t     jptr, jm1ptr;
    int_t     ito, ifrom, istop;	/* used to compress row subscripts */
    int_t     *xsup, *supno, *lsub, *xlsub;
    int_t     nzlmax;
    static int_t first = 1, maxsuper;
    int_t     mem_error;
    
    /* Initializations */
    Astore   = A->Store;
    asub     = Astore->rowind;
    xa_begin = Astore->colbeg;
    xa_end   = Astore->colend;
    xsup     = Glu_persist->xsup;
    supno    = Glu_persist->supno;
    lsub     = Glu_freeable->lsub;
    xlsub    = Glu_freeable->xlsub;
    nzlmax   = Glu_freeable->nzlmax;
    jcolp1   = jcol + 1;
    jcolm1   = jcol - 1;
    jsuper   = nsuper = supno[jcol];
    nextl    = xlsub[jcol];
    if ( first ) {
	maxsuper = sp_ienv_dist(3);
	first = 0;
    }
    
    *nseg = 0;

    /* For each nonzero in A[*,jcol] perform depth-first search. */
    for (k = xa_begin[jcol]; k < xa_end[jcol]; ++k) {
	krow = asub[k];
	kmark = marker[krow];

	/* krow was visited before, go to the next nonzero. */
	if ( kmark == jcol ) continue; 
	
	/* 
	 * For each unmarked neighber krow of jcol ...
	 */
	marker[krow] = jcol;
	kperm = perm_r[krow];

	if ( kperm == EMPTY ) {
	    /* krow is in L:
	     * place it in structure of L[*,jcol].
	     */
	    lsub[nextl++] = krow; 	/* krow is indexed into A */
	    if ( nextl >= nzlmax ) {
		if ( mem_error = symbfact_SubXpand(A->ncol, jcol, nextl, LSUB,
						   &nzlmax, Glu_freeable) )
		    return (mem_error);
		lsub = Glu_freeable->lsub;
	    }
	    if ( kmark != jcolm1 ) jsuper = EMPTY; /* Row index subset test */
	} else {
	    /* krow is in U:
	     * If its supernode krep has been explored, update repfnz[*].
	     */
	    krep = xsup[supno[kperm]+1] - 1;
	    myfnz = repfnz[krep];
	    
	    if ( myfnz != EMPTY ) { /* krep was visited before */
		if ( kperm < myfnz ) repfnz[krep] = kperm;
		/* continue; */
	    } else {
		/* Otherwise perform DFS, starting at krep */
		oldrep = EMPTY;
		parent[krep] = oldrep;
		repfnz[krep] = kperm;
		xdfs = xlsub[krep];
		maxdfs = xprune[krep];
		
		do {
		    /* 
		     * For each unmarked kchild of krep 
		     */
		    while ( xdfs < maxdfs ) {
			kchild = lsub[xdfs++];
			chmark = marker[kchild];
			
			if ( chmark != jcol ) { /* Not reached yet */
			    marker[kchild] = jcol;
			    chperm = perm_r[kchild];
			    
			    /* Case kchild is in L: place it in L[*,k] */
			    if ( chperm == EMPTY ) {
				lsub[nextl++] = kchild;
				if ( nextl >= nzlmax ) {
				    if ( mem_error =
					symbfact_SubXpand(A->ncol, jcol, nextl,
							  LSUB, &nzlmax,
							  Glu_freeable) )
					return (mem_error);
				    lsub = Glu_freeable->lsub;
				}
				if ( chmark != jcolm1 ) jsuper = EMPTY;
			    } else {
				/* Case kchild is in U: 
				 * chrep = its supernode-rep. If its rep 
				 * has been explored, update its repfnz[*].
				 */
				chrep = xsup[supno[chperm]+1] - 1;
				myfnz = repfnz[chrep];
				if ( myfnz != EMPTY ) {/* Visited before */
				    if (chperm < myfnz) repfnz[chrep] = chperm;
				} else {
				    /* Continue DFS at sup-rep of kchild */
				    xplore[krep] = xdfs;
				    oldrep = krep;
				    krep = chrep; /* Go deeper down G(L') */
				    parent[krep] = oldrep;
				    repfnz[krep] = chperm;
				    xdfs = xlsub[krep];     
				    maxdfs = xprune[krep];
				} /* else */
			    } /* else */
			} /* if */
			
		    } /* while */
		    
		    /* krow has no more unexplored neighbors:
		     *    place supernode-rep krep in postorder DFS;
		     *    backtrack DFS to its parent.
		     */
		    segrep[*nseg] = krep;
		    ++(*nseg);
		    kpar = parent[krep]; /* Pop from stack; recurse */
		    if ( kpar == EMPTY ) break; /* DFS done */
		    krep = kpar;
		    xdfs = xplore[krep];
		    maxdfs = xprune[krep];
		} while ( kpar != EMPTY ); /* Until empty stack */
	    } /* else */
	} /* else */
    } /* for each nonzero ... */
    
    /* Check to see if jcol belongs in the same supernode as jcol-1 */
    if ( jcol == 0 ) { /* Do nothing for column 0 */
	nsuper = supno[0] = 0;
    } else {
	fsupc = xsup[nsuper];
	jptr = xlsub[jcol];	/* Not compressed yet */
	jm1ptr = xlsub[jcolm1];
	
#ifdef T2_SUPER
	if ( (nextl-jptr != jptr-jm1ptr-1) ) jsuper = EMPTY;
#endif
	/* Make sure the number of columns in a supernode doesn't
	   exceed threshold. */
	if ( jcol - fsupc >= maxsuper ) jsuper = EMPTY;
	
	/* If jcol starts a new supernode, reclaim storage space in
	 * lsub[*] from the previous supernode. Note we only store
	 * the subscript set of the first and last columns of
	 * a supernode. (first for G(L'), last for pruned graph)
	 */
	if ( jsuper ==EMPTY ) { /* Starts a new supernode */
	    if ( (fsupc < jcolm1-1) ) { /* >= 3 columns in nsuper */
#ifdef CHK_COMPRESS
		printf("  Compress lsub[] at super %d-%d\n",fsupc,jcolm1);
#endif
		ito = xlsub[fsupc+1];
		xlsub[jcolm1] = ito;
		istop = ito + jptr - jm1ptr;
		xprune[jcolm1] = istop; /* Initialize xprune[jcol-1] */
		xlsub[jcol] = istop;
		for (ifrom = jm1ptr; ifrom < nextl; ++ifrom, ++ito)
		    lsub[ito] = lsub[ifrom];
		nextl = ito;            /* = istop + length(jcol) */
	    }
	    ++nsuper;
	    supno[jcol] = nsuper;
	} /* if a new supernode */
	
    } /* else: jcol > 0 */ 
    
    /* Tidy up the pointers before exit */
    xsup[nsuper+1] = jcolp1;
    supno[jcolp1]  = nsuper;
    xprune[jcol]   = nextl; /* Initialize an upper bound for pruning. */
    xlsub[jcolp1]  = nextl;
    return 0;
} /* COLUMN_DFS */