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lammps-gran-kokkos/lib/linalg/zgetrf2.cpp
2024-11-09 04:14:11 -05:00

118 lines
4.2 KiB
C++

#ifdef __cplusplus
extern "C" {
#endif
#include "lmp_f2c.h"
static doublecomplex c_b1 = {1., 0.};
static integer c__1 = 1;
int zgetrf2_(integer *m, integer *n, doublecomplex *a, integer *lda, integer *ipiv, integer *info)
{
integer a_dim1, a_offset, i__1, i__2;
doublecomplex z__1;
double z_lmp_abs(doublecomplex *);
void z_lmp_div(doublecomplex *, doublecomplex *, doublecomplex *);
integer i__, n1, n2;
doublecomplex temp;
integer iinfo;
doublereal sfmin;
extern int zscal_(integer *, doublecomplex *, doublecomplex *, integer *),
zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *,
integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *,
ftnlen, ftnlen),
ztrsm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *,
doublecomplex *, integer *, doublecomplex *, integer *, ftnlen, ftnlen, ftnlen,
ftnlen);
extern doublereal dlamch_(char *, ftnlen);
extern int xerbla_(char *, integer *, ftnlen);
extern integer izamax_(integer *, doublecomplex *, integer *);
extern int zlaswp_(integer *, doublecomplex *, integer *, integer *, integer *, integer *,
integer *);
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
--ipiv;
*info = 0;
if (*m < 0) {
*info = -1;
} else if (*n < 0) {
*info = -2;
} else if (*lda < max(1, *m)) {
*info = -4;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_((char *)"ZGETRF2", &i__1, (ftnlen)7);
return 0;
}
if (*m == 0 || *n == 0) {
return 0;
}
if (*m == 1) {
ipiv[1] = 1;
i__1 = a_dim1 + 1;
if (a[i__1].r == 0. && a[i__1].i == 0.) {
*info = 1;
}
} else if (*n == 1) {
sfmin = dlamch_((char *)"S", (ftnlen)1);
i__ = izamax_(m, &a[a_dim1 + 1], &c__1);
ipiv[1] = i__;
i__1 = i__ + a_dim1;
if (a[i__1].r != 0. || a[i__1].i != 0.) {
if (i__ != 1) {
i__1 = a_dim1 + 1;
temp.r = a[i__1].r, temp.i = a[i__1].i;
i__1 = a_dim1 + 1;
i__2 = i__ + a_dim1;
a[i__1].r = a[i__2].r, a[i__1].i = a[i__2].i;
i__1 = i__ + a_dim1;
a[i__1].r = temp.r, a[i__1].i = temp.i;
}
if (z_lmp_abs(&a[a_dim1 + 1]) >= sfmin) {
i__1 = *m - 1;
z_lmp_div(&z__1, &c_b1, &a[a_dim1 + 1]);
zscal_(&i__1, &z__1, &a[a_dim1 + 2], &c__1);
} else {
i__1 = *m - 1;
for (i__ = 1; i__ <= i__1; ++i__) {
i__2 = i__ + 1 + a_dim1;
z_lmp_div(&z__1, &a[i__ + 1 + a_dim1], &a[a_dim1 + 1]);
a[i__2].r = z__1.r, a[i__2].i = z__1.i;
}
}
} else {
*info = 1;
}
} else {
n1 = min(*m, *n) / 2;
n2 = *n - n1;
zgetrf2_(m, &n1, &a[a_offset], lda, &ipiv[1], &iinfo);
if (*info == 0 && iinfo > 0) {
*info = iinfo;
}
zlaswp_(&n2, &a[(n1 + 1) * a_dim1 + 1], lda, &c__1, &n1, &ipiv[1], &c__1);
ztrsm_((char *)"L", (char *)"L", (char *)"N", (char *)"U", &n1, &n2, &c_b1, &a[a_offset], lda, &a[(n1 + 1) * a_dim1 + 1],
lda, (ftnlen)1, (ftnlen)1, (ftnlen)1, (ftnlen)1);
i__1 = *m - n1;
z__1.r = -1., z__1.i = -0.;
zgemm_((char *)"N", (char *)"N", &i__1, &n2, &n1, &z__1, &a[n1 + 1 + a_dim1], lda,
&a[(n1 + 1) * a_dim1 + 1], lda, &c_b1, &a[n1 + 1 + (n1 + 1) * a_dim1], lda,
(ftnlen)1, (ftnlen)1);
i__1 = *m - n1;
zgetrf2_(&i__1, &n2, &a[n1 + 1 + (n1 + 1) * a_dim1], lda, &ipiv[n1 + 1], &iinfo);
if (*info == 0 && iinfo > 0) {
*info = iinfo + n1;
}
i__1 = min(*m, *n);
for (i__ = n1 + 1; i__ <= i__1; ++i__) {
ipiv[i__] += n1;
}
i__1 = n1 + 1;
i__2 = min(*m, *n);
zlaswp_(&n1, &a[a_dim1 + 1], lda, &i__1, &i__2, &ipiv[1], &c__1);
}
return 0;
}
#ifdef __cplusplus
}
#endif