src/gromacs/linearalgebra/gmx_lapack/dorm2l.c

   1 #include "../gmx_lapack.h"
   2
   3 void
   4 F77_FUNC(dorm2l,DORM2L)(const char *side,
   5         const char *trans,
   6         int *m,
   7         int *n,
   8         int *k,
   9         double *a,
  10         int *lda,
  11         double *tau,
  12         double *c__,
  13         int *ldc,
  14         double *work,
  15         int *info)
  16 {
  17     int a_dim1, a_offset, c_dim1, c_offset, i__1, i__2;
  18     int c__1 = 1;
  19
  20     int i__, i1, i2, i3, mi, ni, nq;
  21     double aii;
  22     int left;
  23     int notran;
  24
  25     a_dim1 = *lda;
  26     a_offset = 1 + a_dim1;
  27     a -= a_offset;
  28     --tau;
  29     c_dim1 = *ldc;
  30     c_offset = 1 + c_dim1;
  31     c__ -= c_offset;
  32     --work;
  33
  34     /* Function Body */
  35     *info = 0;
  36     left = (*side=='L' || *side=='l');
  37     notran = (*trans=='N' || *trans=='n');
  38
  39     if (left) {
  40         nq = *m;
  41     } else {
  42         nq = *n;
  43     }
  44     if (*info != 0) {
  45         i__1 = -(*info);
  46         return;
  47     }
  48
  49     if (*m == 0 || *n == 0 || *k == 0) {
  50         return;
  51     }
  52
  53     if ((left && notran) || (! left && ! notran)) {
  54         i1 = 1;
  55         i2 = *k;
  56         i3 = 1;
  57     } else {
  58         i1 = *k;
  59         i2 = 1;
  60         i3 = -1;
  61     }
  62
  63     if (left) {
  64         ni = *n;
  65     } else {
  66         mi = *m;
  67     }
  68
  69     i__1 = i2;
  70     i__2 = i3;
  71     for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) {
  72         if (left) {
  73
  74             mi = *m - *k + i__;
  75         } else {
  76
  77             ni = *n - *k + i__;
  78         }
  79
  80         aii = a[nq - *k + i__ + i__ * a_dim1];
  81         a[nq - *k + i__ + i__ * a_dim1] = 1.;
  82         F77_FUNC(dlarf,DLARF)(side, &mi, &ni, &a[i__ * a_dim1 + 1], &c__1, &tau[i__], &c__[
  83                 c_offset], ldc, &work[1]);
  84         a[nq - *k + i__ + i__ * a_dim1] = aii;
  85     }
  86     return;
  87 }