90 lines
3.1 KiB
C++
90 lines
3.1 KiB
C++
#ifdef __cplusplus
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extern "C" {
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#endif
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#include "lmp_f2c.h"
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static doublecomplex c_b1 = {1., 0.};
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static doublereal c_b11 = -1.;
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static doublereal c_b12 = 1.;
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int zpotrf2_(char *uplo, integer *n, doublecomplex *a, integer *lda, integer *info, ftnlen uplo_len)
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{
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integer a_dim1, a_offset, i__1;
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doublereal d__1;
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double sqrt(doublereal);
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integer n1, n2;
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doublereal ajj;
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extern logical lsame_(char *, char *, ftnlen, ftnlen);
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integer iinfo;
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extern int zherk_(char *, char *, integer *, integer *, doublereal *, doublecomplex *,
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integer *, doublereal *, doublecomplex *, integer *, ftnlen, ftnlen);
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logical upper;
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extern int ztrsm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *,
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doublecomplex *, integer *, doublecomplex *, integer *, ftnlen, ftnlen,
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ftnlen, ftnlen);
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extern logical disnan_(doublereal *);
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extern int xerbla_(char *, integer *, ftnlen);
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a_dim1 = *lda;
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a_offset = 1 + a_dim1;
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a -= a_offset;
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*info = 0;
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upper = lsame_(uplo, (char *)"U", (ftnlen)1, (ftnlen)1);
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if (!upper && !lsame_(uplo, (char *)"L", (ftnlen)1, (ftnlen)1)) {
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*info = -1;
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} else if (*n < 0) {
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*info = -2;
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} else if (*lda < max(1, *n)) {
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*info = -4;
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}
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if (*info != 0) {
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i__1 = -(*info);
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xerbla_((char *)"ZPOTRF2", &i__1, (ftnlen)7);
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return 0;
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}
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if (*n == 0) {
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return 0;
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}
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if (*n == 1) {
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i__1 = a_dim1 + 1;
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ajj = a[i__1].r;
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if (ajj <= 0. || disnan_(&ajj)) {
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*info = 1;
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return 0;
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}
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i__1 = a_dim1 + 1;
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d__1 = sqrt(ajj);
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a[i__1].r = d__1, a[i__1].i = 0.;
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} else {
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n1 = *n / 2;
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n2 = *n - n1;
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zpotrf2_(uplo, &n1, &a[a_dim1 + 1], lda, &iinfo, (ftnlen)1);
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if (iinfo != 0) {
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*info = iinfo;
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return 0;
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}
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if (upper) {
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ztrsm_((char *)"L", (char *)"U", (char *)"C", (char *)"N", &n1, &n2, &c_b1, &a[a_dim1 + 1], lda,
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&a[(n1 + 1) * a_dim1 + 1], lda, (ftnlen)1, (ftnlen)1, (ftnlen)1, (ftnlen)1);
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zherk_(uplo, (char *)"C", &n2, &n1, &c_b11, &a[(n1 + 1) * a_dim1 + 1], lda, &c_b12,
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&a[n1 + 1 + (n1 + 1) * a_dim1], lda, (ftnlen)1, (ftnlen)1);
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zpotrf2_(uplo, &n2, &a[n1 + 1 + (n1 + 1) * a_dim1], lda, &iinfo, (ftnlen)1);
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if (iinfo != 0) {
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*info = iinfo + n1;
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return 0;
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}
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} else {
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ztrsm_((char *)"R", (char *)"L", (char *)"C", (char *)"N", &n2, &n1, &c_b1, &a[a_dim1 + 1], lda, &a[n1 + 1 + a_dim1],
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lda, (ftnlen)1, (ftnlen)1, (ftnlen)1, (ftnlen)1);
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zherk_(uplo, (char *)"N", &n2, &n1, &c_b11, &a[n1 + 1 + a_dim1], lda, &c_b12,
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&a[n1 + 1 + (n1 + 1) * a_dim1], lda, (ftnlen)1, (ftnlen)1);
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zpotrf2_(uplo, &n2, &a[n1 + 1 + (n1 + 1) * a_dim1], lda, &iinfo, (ftnlen)1);
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if (iinfo != 0) {
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*info = iinfo + n1;
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return 0;
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}
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}
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}
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return 0;
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}
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#ifdef __cplusplus
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}
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#endif
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