src/gromacs/linearalgebra/gmx_lapack/slasd3.cpp

   1 #include <cmath>
   2 #include "../gmx_blas.h"
   3 #include "../gmx_lapack.h"
   4
   5 void
   6 F77_FUNC(slasd3,SLASD3)(int *nl,
   7         int *nr,
   8         int *sqre,
   9         int *k,
  10         float *d__,
  11         float *q,
  12         int *ldq,
  13         float *dsigma,
  14         float *u,
  15         int *ldu,
  16         float *u2,
  17         int *ldu2,
  18         float *vt,
  19         int *ldvt,
  20         float *vt2,
  21         int *ldvt2,
  22         int *idxc,
  23         int *ctot,
  24         float *z__,
  25         int *info)
  26 {
  27     int q_dim1, q_offset, u_dim1, u_offset, u2_dim1, u2_offset, vt_dim1,
  28             vt_offset, vt2_dim1, vt2_offset, i__1, i__2;
  29     float d__2;
  30
  31     int i__, j, m, n, jc;
  32     float rho;
  33     int nlp1, nlp2, nrp1;
  34     float temp;
  35     int ctemp;
  36     int ktemp;
  37     int c__1 = 1;
  38     int c__0 = 0;
  39     float zero = 0.0;
  40     float one = 1.0;
  41
  42     --d__;
  43     q_dim1 = *ldq;
  44     q_offset = 1 + q_dim1;
  45     q -= q_offset;
  46     --dsigma;
  47     u_dim1 = *ldu;
  48     u_offset = 1 + u_dim1;
  49     u -= u_offset;
  50     u2_dim1 = *ldu2;
  51     u2_offset = 1 + u2_dim1;
  52     u2 -= u2_offset;
  53     vt_dim1 = *ldvt;
  54     vt_offset = 1 + vt_dim1;
  55     vt -= vt_offset;
  56     vt2_dim1 = *ldvt2;
  57     vt2_offset = 1 + vt2_dim1;
  58     vt2 -= vt2_offset;
  59     --idxc;
  60     --ctot;
  61     --z__;
  62
  63     /* Function Body */
  64     *info = 0;
  65
  66     if (*nl < 1) {
  67         *info = -1;
  68     } else if (*nr < 1) {
  69         *info = -2;
  70     } else if (*sqre != 1 && *sqre != 0) {
  71         *info = -3;
  72     }
  73
  74     n = *nl + *nr + 1;
  75     m = n + *sqre;
  76     nlp1 = *nl + 1;
  77     nlp2 = *nl + 2;
  78
  79     if (*k == 1) {
  80         d__[1] = std::abs(z__[1]);
  81         F77_FUNC(scopy,SCOPY)(&m, &vt2[vt2_dim1 + 1], ldvt2, &vt[vt_dim1 + 1], ldvt);
  82         if (z__[1] > 0.) {
  83             F77_FUNC(scopy,SCOPY)(&n, &u2[u2_dim1 + 1], &c__1, &u[u_dim1 + 1], &c__1);
  84         } else {
  85             i__1 = n;
  86             for (i__ = 1; i__ <= i__1; ++i__) {
  87                 u[i__ + u_dim1] = -u2[i__ + u2_dim1];
  88             }
  89         }
  90         return;
  91     }
  92
  93     F77_FUNC(scopy,SCOPY)(k, &z__[1], &c__1, &q[q_offset], &c__1);
  94
  95     rho = F77_FUNC(snrm2,SNRM2)(k, &z__[1], &c__1);
  96     F77_FUNC(slascl,SLASCL)("G", &c__0, &c__0, &rho, &one, k, &c__1, &z__[1], k, info);
  97     rho *= rho;
  98
  99
 100     i__1 = *k;
 101     for (j = 1; j <= i__1; ++j) {
 102         F77_FUNC(slasd4,SLASD4)(k, &j, &dsigma[1], &z__[1], &u[j * u_dim1 + 1], &rho, &d__[j],
 103                  &vt[j * vt_dim1 + 1], info);
 104
 105         if (*info != 0) {
 106             return;
 107         }
 108     }
 109
 110     i__1 = *k;
 111     for (i__ = 1; i__ <= i__1; ++i__) {
 112         z__[i__] = u[i__ + *k * u_dim1] * vt[i__ + *k * vt_dim1];
 113         i__2 = i__ - 1;
 114         for (j = 1; j <= i__2; ++j) {
 115             z__[i__] *= u[i__ + j * u_dim1] * vt[i__ + j * vt_dim1] / (dsigma[
 116                     i__] - dsigma[j]) / (dsigma[i__] + dsigma[j]);
 117         }
 118         i__2 = *k - 1;
 119         for (j = i__; j <= i__2; ++j) {
 120             z__[i__] *= u[i__ + j * u_dim1] * vt[i__ + j * vt_dim1] / (dsigma[
 121                     i__] - dsigma[j + 1]) / (dsigma[i__] + dsigma[j + 1]);
 122         }
 123         d__2 =  std::sqrt(std::abs(z__[i__]));
 124         z__[i__] = (q[i__ + q_dim1] > 0) ? d__2 : -d__2;
 125     }
 126
 127     i__1 = *k;
 128     for (i__ = 1; i__ <= i__1; ++i__) {
 129         vt[i__ * vt_dim1 + 1] = z__[1] / u[i__ * u_dim1 + 1] / vt[i__ *
 130                 vt_dim1 + 1];
 131         u[i__ * u_dim1 + 1] = -1.;
 132         i__2 = *k;
 133         for (j = 2; j <= i__2; ++j) {
 134             vt[j + i__ * vt_dim1] = z__[j] / u[j + i__ * u_dim1] / vt[j + i__
 135                     * vt_dim1];
 136             u[j + i__ * u_dim1] = dsigma[j] * vt[j + i__ * vt_dim1];
 137         }
 138         temp = F77_FUNC(snrm2,SNRM2)(k, &u[i__ * u_dim1 + 1], &c__1);
 139         q[i__ * q_dim1 + 1] = u[i__ * u_dim1 + 1] / temp;
 140         i__2 = *k;
 141         for (j = 2; j <= i__2; ++j) {
 142             jc = idxc[j];
 143             q[j + i__ * q_dim1] = u[jc + i__ * u_dim1] / temp;
 144         }
 145     }
 146
 147     if (*k == 2) {
 148         F77_FUNC(sgemm,SGEMM)("N", "N", &n, k, k, &one, &u2[u2_offset], ldu2, &q[q_offset],
 149                  ldq, &zero, &u[u_offset], ldu);
 150         goto L100;
 151     }
 152     if (ctot[1] > 0) {
 153         F77_FUNC(sgemm,SGEMM)("N", "N", nl, k, &ctot[1], &one, &u2[(u2_dim1 << 1) + 1],
 154                 ldu2, &q[q_dim1 + 2], ldq, &zero, &u[u_dim1 + 1], ldu);
 155         if (ctot[3] > 0) {
 156             ktemp = ctot[1] + 2 + ctot[2];
 157             F77_FUNC(sgemm,SGEMM)("N", "N", nl, k, &ctot[3], &one, &u2[ktemp * u2_dim1 + 1]
 158                     , ldu2, &q[ktemp + q_dim1], ldq, &one, &u[u_dim1 + 1],
 159                     ldu);
 160         }
 161     } else if (ctot[3] > 0) {
 162         ktemp = ctot[1] + 2 + ctot[2];
 163         F77_FUNC(sgemm,SGEMM)("N", "N", nl, k, &ctot[3], &one, &u2[ktemp * u2_dim1 + 1],
 164                 ldu2, &q[ktemp + q_dim1], ldq, &zero, &u[u_dim1 + 1], ldu);
 165     } else {
 166         F77_FUNC(slacpy,SLACPY)("F", nl, k, &u2[u2_offset], ldu2, &u[u_offset], ldu);
 167     }
 168     F77_FUNC(scopy,SCOPY)(k, &q[q_dim1 + 1], ldq, &u[nlp1 + u_dim1], ldu);
 169     ktemp = ctot[1] + 2;
 170     ctemp = ctot[2] + ctot[3];
 171     F77_FUNC(sgemm,SGEMM)("N", "N", nr, k, &ctemp, &one, &u2[nlp2 + ktemp * u2_dim1], ldu2,
 172              &q[ktemp + q_dim1], ldq, &zero, &u[nlp2 + u_dim1], ldu);
 173
 174 L100:
 175     i__1 = *k;
 176     for (i__ = 1; i__ <= i__1; ++i__) {
 177         temp = F77_FUNC(snrm2,SNRM2)(k, &vt[i__ * vt_dim1 + 1], &c__1);
 178         q[i__ + q_dim1] = vt[i__ * vt_dim1 + 1] / temp;
 179         i__2 = *k;
 180         for (j = 2; j <= i__2; ++j) {
 181             jc = idxc[j];
 182             q[i__ + j * q_dim1] = vt[jc + i__ * vt_dim1] / temp;
 183         }
 184     }
 185
 186     if (*k == 2) {
 187         F77_FUNC(sgemm,SGEMM)("N", "N", k, &m, k, &one, &q[q_offset], ldq, &vt2[vt2_offset]
 188                 , ldvt2, &zero, &vt[vt_offset], ldvt);
 189         return;
 190     }
 191     ktemp = ctot[1] + 1;
 192     F77_FUNC(sgemm,SGEMM)("N", "N", k, &nlp1, &ktemp, &one, &q[q_dim1 + 1], ldq, &vt2[
 193             vt2_dim1 + 1], ldvt2, &zero, &vt[vt_dim1 + 1], ldvt);
 194     ktemp = ctot[1] + 2 + ctot[2];
 195     if (ktemp <= *ldvt2) {
 196         F77_FUNC(sgemm,SGEMM)("N", "N", k, &nlp1, &ctot[3], &one, &q[ktemp * q_dim1 + 1],
 197                 ldq, &vt2[ktemp + vt2_dim1], ldvt2, &one, &vt[vt_dim1 + 1],
 198                 ldvt);
 199     }
 200
 201     ktemp = ctot[1] + 1;
 202     nrp1 = *nr + *sqre;
 203     if (ktemp > 1) {
 204         i__1 = *k;
 205         for (i__ = 1; i__ <= i__1; ++i__) {
 206             q[i__ + ktemp * q_dim1] = q[i__ + q_dim1];
 207         }
 208         i__1 = m;
 209         for (i__ = nlp2; i__ <= i__1; ++i__) {
 210             vt2[ktemp + i__ * vt2_dim1] = vt2[i__ * vt2_dim1 + 1];
 211         }
 212     }
 213     ctemp = ctot[2] + 1 + ctot[3];
 214     F77_FUNC(sgemm,SGEMM)("N", "N", k, &nrp1, &ctemp, &one, &q[ktemp * q_dim1 + 1], ldq, &
 215             vt2[ktemp + nlp2 * vt2_dim1], ldvt2, &zero, &vt[nlp2 * vt_dim1 +
 216             1], ldvt);
 217
 218     return;
 219
 220
 221 }
 222
 223