107 lines
3.6 KiB
C++
107 lines
3.6 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 integer c__1 = 1;
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static doublereal c_b13 = 1.;
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static doublereal c_b16 = -1.;
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int dgetrf2_(integer *m, integer *n, doublereal *a, integer *lda, integer *ipiv, integer *info)
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{
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integer a_dim1, a_offset, i__1, i__2;
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doublereal d__1;
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integer i__, n1, n2;
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doublereal temp;
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extern int dscal_(integer *, doublereal *, doublereal *, integer *),
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dgemm_(char *, char *, integer *, integer *, integer *, doublereal *, doublereal *,
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integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, ftnlen,
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ftnlen);
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integer iinfo;
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doublereal sfmin;
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extern int dtrsm_(char *, char *, char *, char *, integer *, integer *, doublereal *,
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doublereal *, integer *, doublereal *, integer *, ftnlen, ftnlen, ftnlen,
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ftnlen);
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extern doublereal dlamch_(char *, ftnlen);
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extern integer idamax_(integer *, doublereal *, integer *);
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extern int xerbla_(char *, integer *, ftnlen),
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dlaswp_(integer *, doublereal *, integer *, integer *, integer *, integer *, integer *);
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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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--ipiv;
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*info = 0;
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if (*m < 0) {
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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, *m)) {
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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 *)"DGETRF2", &i__1, (ftnlen)7);
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return 0;
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}
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if (*m == 0 || *n == 0) {
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return 0;
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}
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if (*m == 1) {
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ipiv[1] = 1;
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if (a[a_dim1 + 1] == 0.) {
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*info = 1;
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}
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} else if (*n == 1) {
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sfmin = dlamch_((char *)"S", (ftnlen)1);
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i__ = idamax_(m, &a[a_dim1 + 1], &c__1);
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ipiv[1] = i__;
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if (a[i__ + a_dim1] != 0.) {
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if (i__ != 1) {
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temp = a[a_dim1 + 1];
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a[a_dim1 + 1] = a[i__ + a_dim1];
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a[i__ + a_dim1] = temp;
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}
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if ((d__1 = a[a_dim1 + 1], abs(d__1)) >= sfmin) {
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i__1 = *m - 1;
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d__1 = 1. / a[a_dim1 + 1];
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dscal_(&i__1, &d__1, &a[a_dim1 + 2], &c__1);
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} else {
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i__1 = *m - 1;
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for (i__ = 1; i__ <= i__1; ++i__) {
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a[i__ + 1 + a_dim1] /= a[a_dim1 + 1];
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}
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}
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} else {
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*info = 1;
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}
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} else {
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n1 = min(*m, *n) / 2;
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n2 = *n - n1;
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dgetrf2_(m, &n1, &a[a_offset], lda, &ipiv[1], &iinfo);
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if (*info == 0 && iinfo > 0) {
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*info = iinfo;
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}
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dlaswp_(&n2, &a[(n1 + 1) * a_dim1 + 1], lda, &c__1, &n1, &ipiv[1], &c__1);
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dtrsm_((char *)"L", (char *)"L", (char *)"N", (char *)"U", &n1, &n2, &c_b13, &a[a_offset], lda, &a[(n1 + 1) * a_dim1 + 1],
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lda, (ftnlen)1, (ftnlen)1, (ftnlen)1, (ftnlen)1);
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i__1 = *m - n1;
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dgemm_((char *)"N", (char *)"N", &i__1, &n2, &n1, &c_b16, &a[n1 + 1 + a_dim1], lda,
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&a[(n1 + 1) * a_dim1 + 1], lda, &c_b13, &a[n1 + 1 + (n1 + 1) * a_dim1], lda,
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(ftnlen)1, (ftnlen)1);
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i__1 = *m - n1;
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dgetrf2_(&i__1, &n2, &a[n1 + 1 + (n1 + 1) * a_dim1], lda, &ipiv[n1 + 1], &iinfo);
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if (*info == 0 && iinfo > 0) {
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*info = iinfo + n1;
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}
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i__1 = min(*m, *n);
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for (i__ = n1 + 1; i__ <= i__1; ++i__) {
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ipiv[i__] += n1;
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}
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i__1 = n1 + 1;
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i__2 = min(*m, *n);
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dlaswp_(&n1, &a[a_dim1 + 1], lda, &i__1, &i__2, &ipiv[1], &c__1);
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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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