int
congrad_w(int niter, Real rsqmin, Real *final_rsq_ptr)
{
int i;
int iteration; /* counter for iterations */
double source_norm;
double rsqstop;
QLA_Real a, b;
double rsq,oldrsq,pkp; /* Sugar's a,b,resid**2,previous resid*2 */
/* pkp = cg_p.K.cg_p */
QLA_Real mkappa;
QLA_Real sum;
#ifdef CGTIME
double dtime;
#endif
#ifdef LU
mkappa = -kappa*kappa;
#else
mkappa = -kappa;
#endif
setup_cg();
for(i=0; i<4; i++) {
set_M_from_site(gaugelink[i], F_OFFSET(link[i]),EVENANDODD);
}
set_D_from_site(psi, F_OFFSET(psi),EVENANDODD);
set_D_from_site(chi, F_OFFSET(chi),EVENANDODD);
#ifdef PRESHIFT_LINKS
{
QDP_ColorMatrix *tcm;
tcm = QDP_create_M();
for(i=0; i<4; i++) {
QDP_M_eq_sM(tcm, gaugelink[i], QDP_neighbor[i], QDP_backward, QDP_all);
QDP_M_eq_Ma(gaugelink[i+4], tcm, QDP_all);
}
QDP_destroy_M(tcm);
}
#endif
#ifdef CGTIME
dtime = -dclock();
#endif
iteration=0;
start:
/* mp <- M_adjoint*M*psi
r,p <- chi - mp
rsq = |r|^2
source_norm = |chi|^2
*/
rsq = source_norm = 0.0;
#ifdef LU
QDP_D_eq_D(cgp, psi, QDP_even);
dslash_special_qdp(tt1, cgp, 1, QDP_odd, temp1);
dslash_special_qdp(ttt, tt1, 1, QDP_even, temp2);
QDP_D_eq_r_times_D_plus_D(ttt, &mkappa, ttt, cgp, QDP_even);
dslash_special_qdp(tt2, ttt, -1, QDP_odd, temp3);
dslash_special_qdp(mp, tt2, -1, QDP_even, temp4);
QDP_D_eq_r_times_D_plus_D(mp, &mkappa, mp, ttt, QDP_even);
QDP_D_eq_D_minus_D(cgr, chi, mp, QDP_even);
QDP_D_eq_D(cgp, cgr, QDP_even);
QDP_r_eq_norm2_D(&sum, chi, QDP_even);
source_norm = sum;
QDP_r_eq_norm2_D(&sum, cgr, QDP_even);
rsq = sum;
#else
QDP_D_eq_D(cgp, psi, QDP_even);
dslash_special_qdp(ttt, cgp, 1, QDP_all, temp1);
QDP_D_eq_r_times_D_plus_D(ttt, &mkappa, ttt, cgp, QDP_all);
dslash_special_qdp(mp, ttt, -1, QDP_all, temp1);
QDP_D_eq_r_times_D_plus_D(mp, &mkappa, mp, ttt, QDP_all);
QDP_D_eq_D_minus_D(cgr, chi, mp, QDP_all);
QDP_D_eq_D(cgp, cgr, QDP_all);
QDP_r_eq_norm2_D(&sum, chi, QDP_all);
source_norm = sum;
QDP_r_eq_norm2_D(&sum, cgr, QDP_all);
rsq = sum;
#endif
iteration++ ; /* iteration counts number of multiplications
by M_adjoint*M */
total_iters++;
/**if(this_node==0)printf("congrad2: source_norm = %e\n",source_norm);
if(this_node==0)printf("congrad2: iter %d, rsq %e, pkp %e, a %e\n",
iteration,(double)rsq,(double)pkp,(double)a );**/
rsqstop = rsqmin * source_norm;
if( rsq <= rsqstop ){
*final_rsq_ptr= (Real)rsq;
return (iteration);
}
/* main loop - do until convergence or time to restart */
/*
oldrsq <- rsq
mp <- M_adjoint*M*p
pkp <- p.M_adjoint*M.p
a <- rsq/pkp
psi <- psi + a*p
r <- r - a*mp
rsq <- |r|^2
b <- rsq/oldrsq
p <- r + b*p
*/
do {
oldrsq = rsq;
#ifdef LU
dslash_special_qdp(tt1, cgp, 1, QDP_odd, temp1);
dslash_special_qdp(ttt, tt1, 1, QDP_even, temp2);
QDP_D_eq_r_times_D_plus_D(ttt, &mkappa, ttt, cgp, QDP_even);
dslash_special_qdp(tt2, ttt, -1, QDP_odd, temp3);
dslash_special_qdp(mp, tt2, -1, QDP_even, temp4);
QDP_D_eq_r_times_D_plus_D(mp, &mkappa, mp, ttt, QDP_even);
QDP_r_eq_re_D_dot_D(&sum, cgp, mp, QDP_even);
pkp = sum;
#else
dslash_special_qdp(ttt, cgp, 1, QDP_all, temp1);
QDP_D_eq_r_times_D_plus_D(ttt, &mkappa, ttt, cgp, QDP_all);
dslash_special_qdp(mp, ttt, -1, QDP_all, temp1);
QDP_D_eq_r_times_D_plus_D(mp, &mkappa, mp, ttt, QDP_all);
QDP_r_eq_re_D_dot_D(&sum, cgp, mp, QDP_all);
pkp = sum;
#endif
iteration++;
total_iters++;
a = rsq / pkp;
QDP_D_peq_r_times_D(psi, &a, cgp, MYSUBSET);
QDP_D_meq_r_times_D(cgr, &a, mp, MYSUBSET);
QDP_r_eq_norm2_D(&sum, cgr, MYSUBSET);
rsq = sum;
/**if(this_node==0)printf("congrad2: iter %d, rsq %e, pkp %e, a %e\n",
iteration,(double)rsq,(double)pkp,(double)a );**/
if( rsq <= rsqstop ){
*final_rsq_ptr= (Real)rsq;
#ifdef CGTIME
dtime += dclock();
if(this_node==0)
printf("CONGRAD2: time = %.2e size_r= %.2e iters= %d MF = %.1f\n",
dtime,rsq,iteration,
(double)6480*iteration*even_sites_on_node/(dtime*1e6));
//(double)5616*iteration*even_sites_on_node/(dtime*1e6));
#endif
set_site_from_D(F_OFFSET(psi), psi,EVENANDODD);
return (iteration);
}
b = rsq / oldrsq;
QDP_D_eq_r_times_D_plus_D(cgp, &b, cgp, cgr, MYSUBSET);
} while( iteration%niter != 0);
set_site_from_D(F_OFFSET(psi), psi,EVENANDODD);
if( iteration < 3*niter ) goto start;
*final_rsq_ptr= (Real)rsq;
return(iteration);
}
void MultivariateFNormalSufficient::set_use_cg(bool use, double tol)
{
use_cg_=use;
cg_tol_ = std::abs(tol);
if (use) setup_cg();
}