/*
* Processes all the tasks put in the work queue.
*/
static
void *empty_workQ(void *argin)
{
int tid;
proc_t *procinfo;
val_t *Wstruct;
vec_t *Zstruct;
tol_t *tolstruct;
workQ_t *workQ;
counter_t *num_left;
retrieve_auxarg3
((auxarg3_t*)argin, &tid, &procinfo, &Wstruct,
&Zstruct, &tolstruct, &workQ, &num_left);
int n = Wstruct->n;
/* max. needed double precision work space: odr1v */
double *work = (double*)malloc(4*n*sizeof(double));
assert(work != NULL);
/* max. needed double precision work space: odrrb */
int *iwork = (int*)malloc(2*n*sizeof(int));
assert(iwork != NULL);
/* while loop to empty the work queue */
while (PMR_get_counter_value(num_left) > 0) {
/* empty r-queue before processing other tasks */
PMR_process_r_queue
(tid, procinfo, Wstruct, Zstruct, tolstruct, workQ, num_left, work, iwork);
task_t *task = PMR_remove_task_at_front(workQ->s_queue);
if ( task != NULL ) {
assert(task->flag == SINGLETON_TASK_FLAG);
PMR_process_s_task
((singleton_t*)task->data, tid, procinfo,
Wstruct, Zstruct, tolstruct, num_left, work, iwork);
free(task);
continue;
}
task = PMR_remove_task_at_front(workQ->c_queue);
if ( task != NULL ) {
assert(task->flag == CLUSTER_TASK_FLAG);
PMR_process_c_task
((cluster_t*)task->data, tid, procinfo,
Wstruct, Zstruct, tolstruct, workQ, num_left, work, iwork);
free(task);
continue;
}
} /* end while */
free(work);
free(iwork);
return NULL;
}
int PMR_process_s_task(singleton_t *sng, int tid, counter_t *num_left,
workQ_t *workQ, val_t *Wstruct, vec_t *Zstruct,
tol_t *tolstruct, double *work, int *iwork)
{
/* Inputs */
int begin = sng->begin;
int end = sng->end;
int size = end - begin + 1;
int bl_begin = sng->bl_begin;
int bl_end = sng->bl_end;
int bl_size = bl_end - bl_begin + 1;
double bl_spdiam = sng->bl_spdiam;
rrr_t *RRR = sng->RRR;
double *restrict D = RRR->D;
double *restrict L = RRR->L;
double *restrict DL = RRR->DL;
double *restrict DLL = RRR->DLL;
int n = Wstruct->n;
double *restrict W = Wstruct->W;
double *restrict Werr = Wstruct->Werr;
double *restrict Wgap = Wstruct->Wgap;
int *restrict Windex = Wstruct->Windex;
double *restrict Wshifted = Wstruct->Wshifted;
int ldz = Zstruct->ldz;
double *restrict Z = Zstruct->Z;
int *restrict isuppZ = Zstruct->Zsupp;;
int *restrict Zindex = Zstruct->Zindex;
double pivmin = tolstruct->pivmin;
/* others */
int info, i, k, itmp;
int IONE = 1;
double DZERO = 0.0;
double tol, lambda, left, right;
int i_local;
size_t zind;
double gap, lgap, rgap, gaptol, savedgap, tmp;
bool usedBS, usedRQ, needBS, wantNC, step2II;
int r, offset;
double twoeps = 2*DBL_EPSILON, RQtol = 2*DBL_EPSILON;
double residual, bstres, bstw;
int i_supmn, i_supmx;
double RQcorr;
int negcount;
int sgndef, suppsize;
double sigma;
int i_Zfrom, i_Zto;
double ztz, norminv, mingma;
int count=1;
/* set tolerance parameter */
tol = 4.0 * log( (double) bl_size ) * DBL_EPSILON;
/* decrement counter */
PMR_decrement_counter(num_left, size);
/* loop over all singletons in the task */
for (i=begin; i<=end; i++) {
if (bl_size == 1) {
/* set eigenvector to column of identity matrix */
zind = Zindex[i];
memset(&Z[zind*ldz], 0.0, n*sizeof(double) );
Z[zind*ldz + bl_begin] = 1.0;
isuppZ[2*zind ] = bl_begin + 1;
isuppZ[2*zind + 1] = bl_begin + 1;
continue;
}
lambda = Wshifted[i];
left = Wshifted[i] - Werr[i];
right = Wshifted[i] + Werr[i];
i_local = Windex[i];
r = 0;
/* compute left and right gap */
if (i == bl_begin)
lgap = DBL_EPSILON * fmax(fabs(left), fabs(right));
else if (i == begin)
lgap = sng->lgap;
else
lgap = Wgap[i-1];
if (i == bl_end) {
rgap = DBL_EPSILON * fmax(fabs(left), fabs(right));
} else {
rgap = Wgap[i];
}
gap = fmin(lgap, rgap);
if ( i == bl_begin || i == bl_end ) {
gaptol = 0.0;
} else {
gaptol = gap * DBL_EPSILON;
}
/* initialize lower and upper value of support */
i_supmn = bl_size;
i_supmx = 1;
/* update Wgap so that it holds minimum gap and save the
* old value */
savedgap = Wgap[i];
Wgap[i] = gap;
/* initialize flags indicating if bisection or Rayleigh-Quotient
* correction was used */
usedBS = false;
usedRQ = false;
/* the need for bisection is initially turned off */
needBS = !TRY_RQC;
/* IEEE floating point is assumed, so that all 0 bits are 0.0 */
zind = Zindex[i];
memset(&Z[zind*ldz], 0.0, n*sizeof(double));
/* inverse iteration with twisted factorization */
for (k=1; k<=MAXITER; k++) {
if (needBS == true) {
usedBS = true;
itmp = r;
offset = Windex[i] - 1;
tmp = Wgap[i];
Wgap[i] = 0.0;
dlarrb_(&bl_size, D, DLL, &i_local, &i_local, &DZERO,
&twoeps, &offset, &Wshifted[i], &Wgap[i],
&Werr[i], work, iwork, &pivmin, &bl_spdiam,
&itmp, &info);
assert(info == 0);
Wgap[i] = tmp;
lambda = Wshifted[i];
r = 0;
}
wantNC = (usedBS == true) ? false : true;
/* compute the eigenvector corresponding to lambda */
dlar1v_(&bl_size, &IONE, &bl_size, &lambda, D, L, DL, DLL,
&pivmin, &gaptol, &Z[zind*ldz+bl_begin], &wantNC,
&negcount, &ztz, &mingma, &r, &isuppZ[2*zind],
&norminv, &residual, &RQcorr, work);
if (k == 1) {
bstres = residual;
bstw = lambda;
} else if (residual < bstres) {
bstres = residual;
bstw = lambda;
}
/* update support held */
i_supmn = imin(i_supmn, isuppZ[2*zind ]);
i_supmx = imax(i_supmx, isuppZ[2*zind + 1]);
/* Convergence test for Rayleigh Quotient Iteration
* not done if bisection was used */
if ( !usedBS && residual > tol*gap
&& fabs(RQcorr) > RQtol*fabs(lambda) ) {
if (i_local <= negcount) {
sgndef = -1; /* wanted eigenvalue lies to the left */
} else {
sgndef = 1; /* wanted eigenvalue lies to the right */
}
if ( RQcorr*sgndef >= 0.0
&& lambda+RQcorr <= right
&& lambda+RQcorr >= left ) {
usedRQ = true;
if ( sgndef == 1 )
left = lambda;
else
right = lambda;
Wshifted[i] = 0.5*(left + right);
lambda += RQcorr;
} else { /* bisection is needed */
needBS = true;
}
if ( right-left < RQtol*fabs(lambda) ) {
/* eigenvalue computed to bisection accuracy
* => compute eigenvector */
usedBS = true;
} else if ( k == MAXITER-1 ) {
/* for last iteration use bisection */
needBS = true;
}
} else {
/* go to next iteration */
break;
}
} /* end k */
/* if necessary call dlar1v to improve error angle by 2nd step */
step2II = false;
if ( usedRQ && usedBS && (bstres <= residual) ) {
lambda = bstw;
step2II = true;
}
if ( step2II == true ) {
dlar1v_(&bl_size, &IONE, &bl_size, &lambda, D, L, DL, DLL,
&pivmin, &gaptol, &Z[zind*ldz+bl_begin], &wantNC,
&negcount, &ztz, &mingma, &r, &isuppZ[2*zind],
&norminv, &residual, &RQcorr, work);
}
Wshifted[i] = lambda;
/* compute support w.r.t. whole matrix
* block beginning is offset for each support */
isuppZ[2*zind ] += bl_begin;
isuppZ[2*zind + 1] += bl_begin;
/* ensure vector is okay if support changed in RQI
* minus ones because of indices starting from zero */
i_Zfrom = isuppZ[2*zind ] - 1;
i_Zto = isuppZ[2*zind + 1] - 1;
i_supmn += bl_begin - 1;
i_supmx += bl_begin - 1;
if ( i_supmn < i_Zfrom ) {
for ( k=i_supmn; k < i_Zfrom; k++ ) {
Z[k + zind*ldz] = 0.0;
}
}
if ( i_supmx > i_Zto ) {
for ( k=i_Zto+1; k <= i_supmx; k++ ) {
Z[k + zind*ldz] = 0.0;
}
}
/* normalize eigenvector */
suppsize = i_Zto - i_Zfrom + 1;
mrrr_dscal(&suppsize, &norminv, &Z[i_Zfrom + zind*ldz], &IONE);
sigma = L[bl_size-1];
W[i] = lambda + sigma;
if (i < end)
Wgap[i] = fmax(savedgap, W[i+1]-Werr[i+1] - W[i]-Werr[i]);
/* Every x iterations process all pendinf r-tasks */
count++;
if (count % EMPTY_RQ_ITER == 0)
PMR_process_r_queue(tid, workQ, Wstruct, tolstruct, work,
iwork);
} /* end i */
/* clean up */
PMR_try_destroy_rrr(RRR);
free(sng);
return(0);
}
