int
sp_dtrsv(char *uplo, char *trans, char *diag, SuperMatrix *L,
SuperMatrix *U, double *x, int *info)
{
/*
* Purpose
* =======
*
* sp_dtrsv() solves one of the systems of equations
* A*x = b, or A'*x = b,
* where b and x are n element vectors and A is a sparse unit , or
* non-unit, upper or lower triangular matrix.
* No test for singularity or near-singularity is included in this
* routine. Such tests must be performed before calling this routine.
*
* Parameters
* ==========
*
* uplo - (input) char*
* On entry, uplo specifies whether the matrix is an upper or
* lower triangular matrix as follows:
* uplo = 'U' or 'u' A is an upper triangular matrix.
* uplo = 'L' or 'l' A is a lower triangular matrix.
*
* trans - (input) char*
* On entry, trans specifies the equations to be solved as
* follows:
* trans = 'N' or 'n' A*x = b.
* trans = 'T' or 't' A'*x = b.
* trans = 'C' or 'c' A'*x = b.
*
* diag - (input) char*
* On entry, diag specifies whether or not A is unit
* triangular as follows:
* diag = 'U' or 'u' A is assumed to be unit triangular.
* diag = 'N' or 'n' A is not assumed to be unit
* triangular.
*
* L - (input) SuperMatrix*
* The factor L from the factorization Pr*A*Pc=L*U. Use
* compressed row subscripts storage for supernodes,
* i.e., L has types: Stype = SC, Dtype = _D, Mtype = TRLU.
*
* U - (input) SuperMatrix*
* The factor U from the factorization Pr*A*Pc=L*U.
* U has types: Stype = NCP, Dtype = _D, Mtype = TRU.
*
* x - (input/output) double*
* Before entry, the incremented array X must contain the n
* element right-hand side vector b. On exit, X is overwritten
* with the solution vector x.
*
* info - (output) int*
* If *info = -i, the i-th argument had an illegal value.
*
*/
#if ( MACH==CRAY_PVP )
_fcd ftcs1, ftcs2, ftcs3;
#endif
SCPformat *Lstore;
NCPformat *Ustore;
double *Lval, *Uval;
int incx = 1, incy = 1;
double alpha = 1.0, beta = 1.0;
register int fsupc, luptr, istart, irow, k, iptr, jcol, nsuper;
int nsupr, nsupc, nrow, i;
double *work;
flops_t solve_ops;
/* Test the input parameters */
*info = 0;
if ( !lsame_(uplo,"L") && !lsame_(uplo, "U") ) *info = -1;
else if ( !lsame_(trans, "N") && !lsame_(trans, "T") ) *info = -2;
else if ( !lsame_(diag, "U") && !lsame_(diag, "N") ) *info = -3;
else if ( L->nrow != L->ncol || L->nrow < 0 ) *info = -4;
else if ( U->nrow != U->ncol || U->nrow < 0 ) *info = -5;
if ( *info ) {
i = -(*info);
xerbla_("sp_dtrsv", &i);
return 0;
}
Lstore = L->Store;
Lval = Lstore->nzval;
Ustore = U->Store;
Uval = Ustore->nzval;
nsuper = Lstore->nsuper;
solve_ops = 0;
if ( !(work = doubleCalloc(L->nrow)) )
SUPERLU_ABORT("Malloc fails for work in sp_dtrsv().");
if ( lsame_(trans, "N") ) { /* Form x := inv(A)*x. */
if ( lsame_(uplo, "L") ) {
/* Form x := inv(L)*x */
if ( L->nrow == 0 ) return 0; /* Quick return */
for (k = 0; k <= nsuper; k++) {
fsupc = L_FST_SUPC(k);
istart = L_SUB_START(fsupc);
nsupr = L_SUB_END(fsupc) - istart;
nsupc = L_LAST_SUPC(k) - fsupc;
luptr = L_NZ_START(fsupc);
nrow = nsupr - nsupc;
solve_ops += nsupc * (nsupc - 1);
solve_ops += 2 * nrow * nsupc;
if ( nsupc == 1 ) {
for (iptr=istart+1; iptr < L_SUB_END(fsupc); ++iptr) {
irow = L_SUB(iptr);
++luptr;
x[irow] -= x[fsupc] * Lval[luptr];
}
} else {
#ifdef USE_VENDOR_BLAS
#if ( MACH==CRAY_PVP )
ftcs1 = _cptofcd("L", strlen("L"));
ftcs2 = _cptofcd("N", strlen("N"));
ftcs3 = _cptofcd("U", strlen("U"));
STRSV(ftcs1, ftcs2, ftcs3, &nsupc, &Lval[luptr], &nsupr,
&x[fsupc], &incx);
SGEMV(ftcs2, &nrow, &nsupc, &alpha, &Lval[luptr+nsupc],
&nsupr, &x[fsupc], &incx, &beta, &work[0], &incy);
#else
dtrsv_("L", "N", "U", &nsupc, &Lval[luptr], &nsupr,
&x[fsupc], &incx);
dgemv_("N", &nrow, &nsupc, &alpha, &Lval[luptr+nsupc],
&nsupr, &x[fsupc], &incx, &beta, &work[0], &incy);
#endif
#else
dlsolve (nsupr, nsupc, &Lval[luptr], &x[fsupc]);
dmatvec (nsupr, nsupr-nsupc, nsupc, &Lval[luptr+nsupc],
&x[fsupc], &work[0] );
#endif
iptr = istart + nsupc;
for (i = 0; i < nrow; ++i, ++iptr) {
irow = L_SUB(iptr);
x[irow] -= work[i]; /* Scatter */
work[i] = 0.0;
}
}
} /* for k ... */
} else {
/* Form x := inv(U)*x */
if ( U->nrow == 0 ) return 0; /* Quick return */
for (k = nsuper; k >= 0; k--) {
fsupc = L_FST_SUPC(k);
nsupr = L_SUB_END(fsupc) - L_SUB_START(fsupc);
nsupc = L_LAST_SUPC(k) - fsupc;
luptr = L_NZ_START(fsupc);
solve_ops += nsupc * (nsupc + 1);
if ( nsupc == 1 ) {
x[fsupc] /= Lval[luptr];
for (i = U_NZ_START(fsupc); i < U_NZ_END(fsupc); ++i) {
irow = U_SUB(i);
x[irow] -= x[fsupc] * Uval[i];
}
} else {
#ifdef USE_VENDOR_BLAS
#if ( MACH==CRAY_PVP )
ftcs1 = _cptofcd("U", strlen("U"));
ftcs2 = _cptofcd("N", strlen("N"));
ftcs3 = _cptofcd("N", strlen("N"));
STRSV(ftcs1, ftcs2, ftcs3, &nsupc, &Lval[luptr], &nsupr,
&x[fsupc], &incx);
#else
dtrsv_("U", "N", "N", &nsupc, &Lval[luptr], &nsupr,
&x[fsupc], &incx);
#endif
#else
dusolve ( nsupr, nsupc, &Lval[luptr], &x[fsupc] );
#endif
for (jcol = fsupc; jcol < fsupc + nsupc; jcol++) {
solve_ops += 2*(U_NZ_END(jcol) - U_NZ_START(jcol));
for (i = U_NZ_START(jcol); i < U_NZ_END(jcol); i++) {
irow = U_SUB(i);
x[irow] -= x[jcol] * Uval[i];
}
}
}
} /* for k ... */
}
} else { /* Form x := inv(A')*x */
if ( lsame_(uplo, "L") ) {
/* Form x := inv(L')*x */
if ( L->nrow == 0 ) return 0; /* Quick return */
for (k = nsuper; k >= 0; --k) {
fsupc = L_FST_SUPC(k);
istart = L_SUB_START(fsupc);
nsupr = L_SUB_END(fsupc) - istart;
nsupc = L_LAST_SUPC(k) - fsupc;
luptr = L_NZ_START(fsupc);
solve_ops += 2 * (nsupr - nsupc) * nsupc;
for (jcol = fsupc; jcol < L_LAST_SUPC(k); jcol++) {
iptr = istart + nsupc;
for (i = L_NZ_START(jcol) + nsupc;
i < L_NZ_END(jcol); i++) {
irow = L_SUB(iptr);
x[jcol] -= x[irow] * Lval[i];
iptr++;
}
}
if ( nsupc > 1 ) {
solve_ops += nsupc * (nsupc - 1);
#ifdef _CRAY
ftcs1 = _cptofcd("L", strlen("L"));
ftcs2 = _cptofcd("T", strlen("T"));
ftcs3 = _cptofcd("U", strlen("U"));
STRSV(ftcs1, ftcs2, ftcs3, &nsupc, &Lval[luptr], &nsupr,
&x[fsupc], &incx);
#else
dtrsv_("L", "T", "U", &nsupc, &Lval[luptr], &nsupr,
&x[fsupc], &incx);
#endif
}
}
} else {
/* Form x := inv(U')*x */
if ( U->nrow == 0 ) return 0; /* Quick return */
for (k = 0; k <= nsuper; k++) {
fsupc = L_FST_SUPC(k);
nsupr = L_SUB_END(fsupc) - L_SUB_START(fsupc);
nsupc = L_LAST_SUPC(k) - fsupc;
luptr = L_NZ_START(fsupc);
for (jcol = fsupc; jcol < fsupc + nsupc; jcol++) {
solve_ops += 2*(U_NZ_END(jcol) - U_NZ_START(jcol));
for (i = U_NZ_START(jcol); i < U_NZ_END(jcol); i++) {
irow = U_SUB(i);
x[jcol] -= x[irow] * Uval[i];
}
}
solve_ops += nsupc * (nsupc + 1);
if ( nsupc == 1 ) {
x[fsupc] /= Lval[luptr];
} else {
#ifdef _CRAY
ftcs1 = _cptofcd("U", strlen("U"));
ftcs2 = _cptofcd("T", strlen("T"));
ftcs3 = _cptofcd("N", strlen("N"));
STRSV( ftcs1, ftcs2, ftcs3, &nsupc, &Lval[luptr], &nsupr,
&x[fsupc], &incx);
#else
dtrsv_("U", "T", "N", &nsupc, &Lval[luptr], &nsupr,
&x[fsupc], &incx);
#endif
}
} /* for k ... */
}
}
SUPERLU_FREE(work);
return 0;
}
void
dgstrs(trans_t trans, SuperMatrix *L, SuperMatrix *U,
int *perm_r, int *perm_c, SuperMatrix *B, Gstat_t *Gstat, int *info)
{
/*
* -- SuperLU MT routine (version 1.0) --
* Univ. of California Berkeley, Xerox Palo Alto Research Center,
* and Lawrence Berkeley National Lab.
* August 15, 1997
*
* Purpose
* =======
*
* dgstrs() solves a system of linear equations A*X=B or A'*X=B
* with A sparse and B dense, using the LU factorization computed by
* pdgstrf().
*
* Arguments
* =========
*
* trans (input) Specifies the form of the system of equations:
* = NOTRANS: A * X = B (No transpose)
* = TRANS: A'* X = B (Transpose)
*
* L (input) SuperMatrix*
* The factor L from the factorization Pr*A*Pc=L*U as computed by
* pdgstrf(). Use compressed row subscripts storage for supernodes,
* i.e., L has types: Stype = SCP, Dtype = _D, Mtype = TRLU.
*
* U (input) SuperMatrix*
* The factor U from the factorization Pr*A*Pc=L*U as computed by
* pdgstrf(). Use column-wise storage scheme, i.e., U has types:
* Stype = NCP, Dtype = _D, Mtype = TRU.
*
* perm_r (input) int*
* Row permutation vector of size L->nrow, which defines the
* permutation matrix Pr; perm_r[i] = j means row i of A is in
* position j in Pr*A.
*
* perm_c (int*) dimension A->ncol
* 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.
*
* B (input/output) SuperMatrix*
* B has types: Stype = DN, Dtype = _D, Mtype = GE.
* On entry, the right hand side matrix.
* On exit, the solution matrix if info = 0;
*
* Gstat (output) Gstat_t*
* Record all the statistics about the triangular solves;
* See Gstat_t structure defined in util.h.
*
* info (output) Diagnostics
* = 0: successful exit
* < 0: if info = -i, the i-th argument had an illegal value
*
*/
#if ( MACH==CRAY_PVP )
_fcd ftcs1, ftcs2, ftcs3, ftcs4;
#endif
#ifdef USE_VENDOR_BLAS
int incx = 1, incy = 1;
double alpha = 1.0, beta = 1.0;
#endif
register int j, k, jcol, iptr, luptr, ksupno, istart, irow, bptr;
register int fsupc, nsuper;
int i, n, nsupc, nsupr, nrow, nrhs, ldb;
int *supno;
DNformat *Bstore;
SCPformat *Lstore;
NCPformat *Ustore;
double *Lval, *Uval, *Bmat;
double *work, *work_col, *rhs_work, *soln;
flops_t solve_ops;
void dprint_soln();
/* Test input parameters ... */
*info = 0;
Bstore = B->Store;
ldb = Bstore->lda;
nrhs = B->ncol;
if ( trans != NOTRANS && trans != TRANS ) *info = -1;
else if ( L->nrow != L->ncol || L->nrow < 0 ) *info = -3;
else if ( U->nrow != U->ncol || U->nrow < 0 ) *info = -4;
else if ( ldb < MAX(0, L->nrow) ) *info = -6;
if ( *info ) {
i = -(*info);
xerbla_("dgstrs", &i);
return;
}
n = L->nrow;
work = doubleCalloc(n * nrhs);
if ( !work ) ABORT("Malloc fails for local work[].");
soln = doubleMalloc(n);
if ( !soln ) ABORT("Malloc fails for local soln[].");
Bmat = Bstore->nzval;
Lstore = L->Store;
Lval = Lstore->nzval;
Ustore = U->Store;
Uval = Ustore->nzval;
supno = Lstore->col_to_sup;
nsuper = Lstore->nsuper;
solve_ops = 0;
if ( trans == NOTRANS ) {
/* Permute right hand sides to form Pr*B */
for (i = 0, bptr = 0; i < nrhs; i++, bptr += ldb) {
rhs_work = &Bmat[bptr];
for (k = 0; k < n; k++) soln[perm_r[k]] = rhs_work[k];
for (k = 0; k < n; k++) rhs_work[k] = soln[k];
}
/* Forward solve PLy=Pb. */
/*>> for (k = 0; k < n; k += nsupc) {
ksupno = supno[k];
*/
for (ksupno = 0; ksupno <= nsuper; ++ksupno) {
fsupc = L_FST_SUPC(ksupno);
istart = L_SUB_START(fsupc);
nsupr = L_SUB_END(fsupc) - istart;
nsupc = L_LAST_SUPC(ksupno) - fsupc;
nrow = nsupr - nsupc;
solve_ops += nsupc * (nsupc - 1) * nrhs;
solve_ops += 2 * nrow * nsupc * nrhs;
if ( nsupc == 1 ) {
for (j = 0, bptr = 0; j < nrhs; j++, bptr += ldb) {
rhs_work = &Bmat[bptr];
luptr = L_NZ_START(fsupc);
for (iptr=istart+1; iptr < L_SUB_END(fsupc); iptr++){
irow = L_SUB(iptr);
++luptr;
rhs_work[irow] -= rhs_work[fsupc] * Lval[luptr];
}
}
} else {
luptr = L_NZ_START(fsupc);
#ifdef USE_VENDOR_BLAS
#if ( MACH==CRAY_PVP )
ftcs1 = _cptofcd("L", strlen("L"));
ftcs2 = _cptofcd("N", strlen("N"));
ftcs3 = _cptofcd("U", strlen("U"));
STRSM(ftcs1, ftcs1, ftcs2, ftcs3, &nsupc, &nrhs, &alpha,
&Lval[luptr], &nsupr, &Bmat[fsupc], &ldb);
SGEMM(ftcs2, ftcs2, &nrow, &nrhs, &nsupc, &alpha,
&Lval[luptr+nsupc], &nsupr, &Bmat[fsupc], &ldb,
&beta, &work[0], &n );
#else
dtrsm_("L", "L", "N", "U", &nsupc, &nrhs, &alpha,
&Lval[luptr], &nsupr, &Bmat[fsupc], &ldb);
dgemm_( "N", "N", &nrow, &nrhs, &nsupc, &alpha,
&Lval[luptr+nsupc], &nsupr, &Bmat[fsupc], &ldb,
&beta, &work[0], &n );
#endif
for (j = 0, bptr = 0; j < nrhs; j++, bptr += ldb) {
rhs_work = &Bmat[bptr];
work_col = &work[j*n];
iptr = istart + nsupc;
for (i = 0; i < nrow; i++) {
irow = L_SUB(iptr);
rhs_work[irow] -= work_col[i]; /* Scatter */
work_col[i] = 0.0;
iptr++;
}
}
#else
for (j = 0, bptr = 0; j < nrhs; j++, bptr += ldb) {
rhs_work = &Bmat[bptr];
dlsolve (nsupr, nsupc, &Lval[luptr], &rhs_work[fsupc]);
dmatvec (nsupr, nrow, nsupc, &Lval[luptr+nsupc],
&rhs_work[fsupc], &work[0] );
iptr = istart + nsupc;
for (i = 0; i < nrow; i++) {
irow = L_SUB(iptr);
rhs_work[irow] -= work[i];
work[i] = 0.0;
iptr++;
}
}
#endif
} /* if-else: nsupc == 1 ... */
} /* for L-solve */
#if ( DEBUGlevel>=2 )
printf("After L-solve: y=\n");
dprint_soln(n, nrhs, Bmat);
#endif
/*
* Back solve Ux=y.
*/
/*>> for (k = n-1; k >= 0; k -= nsupc) {
ksupno = supno[k];
*/
for (ksupno = nsuper; ksupno >= 0; --ksupno) {
fsupc = L_FST_SUPC(ksupno);
istart = L_SUB_START(fsupc);
nsupr = L_SUB_END(fsupc) - istart;
nsupc = L_LAST_SUPC(ksupno) - fsupc;
luptr = L_NZ_START(fsupc);
solve_ops += nsupc * (nsupc + 1) * nrhs;
/* dense triangular matrix */
if ( nsupc == 1 ) {
rhs_work = &Bmat[0];
for (j = 0; j < nrhs; j++) {
rhs_work[fsupc] /= Lval[luptr];
rhs_work += ldb;
}
} else {
#ifdef USE_VENDOR_BLAS
#if ( MACH==CRAY_PVP )
ftcs1 = _cptofcd("L", strlen("L"));
ftcs2 = _cptofcd("U", strlen("U"));
ftcs3 = _cptofcd("N", strlen("N"));
STRSM(ftcs1, ftcs2, ftcs3, ftcs3, &nsupc, &nrhs, &alpha,
&Lval[luptr], &nsupr, &Bmat[fsupc], &ldb);
#else
dtrsm_("L", "U", "N", "N", &nsupc, &nrhs, &alpha,
&Lval[luptr], &nsupr, &Bmat[fsupc], &ldb);
#endif
#else
for (j = 0, bptr = fsupc; j < nrhs; j++, bptr += ldb) {
dusolve (nsupr, nsupc, &Lval[luptr], &Bmat[bptr]);
}
#endif
}
/* matrix-vector update */
for (j = 0, bptr = 0; j < nrhs; ++j, bptr += ldb) {
rhs_work = &Bmat[bptr];
for (jcol = fsupc; jcol < fsupc + nsupc; jcol++) {
solve_ops += 2*(U_NZ_END(jcol) - U_NZ_START(jcol));
for (i = U_NZ_START(jcol); i < U_NZ_END(jcol); i++ ){
irow = U_SUB(i);
rhs_work[irow] -= rhs_work[jcol] * Uval[i];
}
}
}
} /* for U-solve */
#if ( DEBUGlevel>=2 )
printf("After U-solve: x=\n");
dprint_soln(n, nrhs, Bmat);
#endif
/* Compute the final solution X <= Pc*X. */
for (i = 0, bptr = 0; i < nrhs; i++, bptr += ldb) {
rhs_work = &Bmat[bptr];
for (k = 0; k < n; k++) soln[k] = rhs_work[perm_c[k]];
for (k = 0; k < n; k++) rhs_work[k] = soln[k];
}
} else { /* Solve A'*X=B */
/* Permute right hand sides to form Pc'*B. */
for (i = 0, bptr = 0; i < nrhs; i++, bptr += ldb) {
rhs_work = &Bmat[bptr];
for (k = 0; k < n; k++) soln[perm_c[k]] = rhs_work[k];
for (k = 0; k < n; k++) rhs_work[k] = soln[k];
}
for (k = 0; k < nrhs; ++k) {
/* Multiply by inv(U'). */
sp_dtrsv("U", "T", "N", L, U, &Bmat[k*ldb], info);
/* Multiply by inv(L'). */
sp_dtrsv("L", "T", "U", L, U, &Bmat[k*ldb], info);
}
/* Compute the final solution X <= Pr'*X (=inv(Pr)*X) */
for (i = 0, bptr = 0; i < nrhs; i++, bptr += ldb) {
rhs_work = &Bmat[bptr];
for (k = 0; k < n; k++) soln[k] = rhs_work[perm_r[k]];
for (k = 0; k < n; k++) rhs_work[k] = soln[k];
}
} /* if-else trans */
Gstat->ops[TRISOLVE] = solve_ops;
SUPERLU_FREE(work);
SUPERLU_FREE(soln);
}
