hypre/lapack/dsygst.c

349 lines
11 KiB
C

/*BHEADER**********************************************************************
* Copyright (c) 2006 The Regents of the University of California.
* Produced at the Lawrence Livermore National Laboratory.
* Written by the HYPRE team. UCRL-CODE-222953.
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*
* This file is part of HYPRE (see http://www.llnl.gov/CASC/hypre/).
* Please see the COPYRIGHT_and_LICENSE file for the copyright notice,
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*
* HYPRE is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License (as published by the Free Software
* Foundation) version 2.1 dated February 1999.
*
* HYPRE is distributed in the hope that it will be useful, but WITHOUT ANY
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* FOR A PARTICULAR PURPOSE. See the terms and conditions of the GNU General
* Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
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***********************************************************************EHEADER*/
#include "../blas/hypre_blas.h"
#include "hypre_lapack.h"
#include "f2c.h"
/* Subroutine */ int dsygst_(integer *itype, char *uplo, integer *n,
doublereal *a, integer *lda, doublereal *b, integer *ldb, integer *
info)
{
/* -- LAPACK routine (version 3.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
September 30, 1994
Purpose
=======
DSYGST reduces a real symmetric-definite generalized eigenproblem
to standard form.
If ITYPE = 1, the problem is A*x = lambda*B*x,
and A is overwritten by inv(U**T)*A*inv(U) or inv(L)*A*inv(L**T)
If ITYPE = 2 or 3, the problem is A*B*x = lambda*x or
B*A*x = lambda*x, and A is overwritten by U*A*U**T or L**T*A*L.
B must have been previously factorized as U**T*U or L*L**T by DPOTRF.
Arguments
=========
ITYPE (input) INTEGER
= 1: compute inv(U**T)*A*inv(U) or inv(L)*A*inv(L**T);
= 2 or 3: compute U*A*U**T or L**T*A*L.
UPLO (input) CHARACTER
= 'U': Upper triangle of A is stored and B is factored as
U**T*U;
= 'L': Lower triangle of A is stored and B is factored as
L*L**T.
N (input) INTEGER
The order of the matrices A and B. N >= 0.
A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
On entry, the symmetric matrix A. If UPLO = 'U', the leading
N-by-N upper triangular part of A contains the upper
triangular part of the matrix A, and the strictly lower
triangular part of A is not referenced. If UPLO = 'L', the
leading N-by-N lower triangular part of A contains the lower
triangular part of the matrix A, and the strictly upper
triangular part of A is not referenced.
On exit, if INFO = 0, the transformed matrix, stored in the
same format as A.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
B (input) DOUBLE PRECISION array, dimension (LDB,N)
The triangular factor from the Cholesky factorization of B,
as returned by DPOTRF.
LDB (input) INTEGER
The leading dimension of the array B. LDB >= max(1,N).
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
=====================================================================
Test the input parameters.
Parameter adjustments */
/* Table of constant values */
static integer c__1 = 1;
static integer c_n1 = -1;
static doublereal c_b14 = 1.;
static doublereal c_b16 = -.5;
static doublereal c_b19 = -1.;
static doublereal c_b52 = .5;
/* System generated locals */
integer a_dim1, a_offset, b_dim1, b_offset, i__1, i__2, i__3;
/* Local variables */
static integer k;
extern logical lsame_(char *, char *);
extern /* Subroutine */ int dtrmm_(char *, char *, char *, char *,
integer *, integer *, doublereal *, doublereal *, integer *,
doublereal *, integer *), dsymm_(
char *, char *, integer *, integer *, doublereal *, doublereal *,
integer *, doublereal *, integer *, doublereal *, doublereal *,
integer *);
static logical upper;
extern /* Subroutine */ int dtrsm_(char *, char *, char *, char *,
integer *, integer *, doublereal *, doublereal *, integer *,
doublereal *, integer *), dsygs2_(
integer *, char *, integer *, doublereal *, integer *, doublereal
*, integer *, integer *);
static integer kb;
extern /* Subroutine */ int dsyr2k_(char *, char *, integer *, integer *,
doublereal *, doublereal *, integer *, doublereal *, integer *,
doublereal *, doublereal *, integer *);
static integer nb;
extern /* Subroutine */ int xerbla_(char *, integer *);
extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
integer *, integer *, ftnlen, ftnlen);
#define a_ref(a_1,a_2) a[(a_2)*a_dim1 + a_1]
#define b_ref(a_1,a_2) b[(a_2)*b_dim1 + a_1]
a_dim1 = *lda;
a_offset = 1 + a_dim1 * 1;
a -= a_offset;
b_dim1 = *ldb;
b_offset = 1 + b_dim1 * 1;
b -= b_offset;
/* Function Body */
*info = 0;
upper = lsame_(uplo, "U");
if (*itype < 1 || *itype > 3) {
*info = -1;
} else if (! upper && ! lsame_(uplo, "L")) {
*info = -2;
} else if (*n < 0) {
*info = -3;
} else if (*lda < max(1,*n)) {
*info = -5;
} else if (*ldb < max(1,*n)) {
*info = -7;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("DSYGST", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0) {
return 0;
}
/* Determine the block size for this environment. */
nb = ilaenv_(&c__1, "DSYGST", uplo, n, &c_n1, &c_n1, &c_n1, (ftnlen)6, (
ftnlen)1);
if (nb <= 1 || nb >= *n) {
/* Use unblocked code */
dsygs2_(itype, uplo, n, &a[a_offset], lda, &b[b_offset], ldb, info);
} else {
/* Use blocked code */
if (*itype == 1) {
if (upper) {
/* Compute inv(U')*A*inv(U) */
i__1 = *n;
i__2 = nb;
for (k = 1; i__2 < 0 ? k >= i__1 : k <= i__1; k += i__2) {
/* Computing MIN */
i__3 = *n - k + 1;
kb = min(i__3,nb);
/* Update the upper triangle of A(k:n,k:n) */
dsygs2_(itype, uplo, &kb, &a_ref(k, k), lda, &b_ref(k, k),
ldb, info);
if (k + kb <= *n) {
i__3 = *n - k - kb + 1;
dtrsm_("Left", uplo, "Transpose", "Non-unit", &kb, &
i__3, &c_b14, &b_ref(k, k), ldb, &a_ref(k, k
+ kb), lda);
i__3 = *n - k - kb + 1;
dsymm_("Left", uplo, &kb, &i__3, &c_b16, &a_ref(k, k),
lda, &b_ref(k, k + kb), ldb, &c_b14, &a_ref(
k, k + kb), lda);
i__3 = *n - k - kb + 1;
dsyr2k_(uplo, "Transpose", &i__3, &kb, &c_b19, &a_ref(
k, k + kb), lda, &b_ref(k, k + kb), ldb, &
c_b14, &a_ref(k + kb, k + kb), lda);
i__3 = *n - k - kb + 1;
dsymm_("Left", uplo, &kb, &i__3, &c_b16, &a_ref(k, k),
lda, &b_ref(k, k + kb), ldb, &c_b14, &a_ref(
k, k + kb), lda);
i__3 = *n - k - kb + 1;
dtrsm_("Right", uplo, "No transpose", "Non-unit", &kb,
&i__3, &c_b14, &b_ref(k + kb, k + kb), ldb, &
a_ref(k, k + kb), lda);
}
/* L10: */
}
} else {
/* Compute inv(L)*A*inv(L') */
i__2 = *n;
i__1 = nb;
for (k = 1; i__1 < 0 ? k >= i__2 : k <= i__2; k += i__1) {
/* Computing MIN */
i__3 = *n - k + 1;
kb = min(i__3,nb);
/* Update the lower triangle of A(k:n,k:n) */
dsygs2_(itype, uplo, &kb, &a_ref(k, k), lda, &b_ref(k, k),
ldb, info);
if (k + kb <= *n) {
i__3 = *n - k - kb + 1;
dtrsm_("Right", uplo, "Transpose", "Non-unit", &i__3,
&kb, &c_b14, &b_ref(k, k), ldb, &a_ref(k + kb,
k), lda);
i__3 = *n - k - kb + 1;
dsymm_("Right", uplo, &i__3, &kb, &c_b16, &a_ref(k, k)
, lda, &b_ref(k + kb, k), ldb, &c_b14, &a_ref(
k + kb, k), lda);
i__3 = *n - k - kb + 1;
dsyr2k_(uplo, "No transpose", &i__3, &kb, &c_b19, &
a_ref(k + kb, k), lda, &b_ref(k + kb, k), ldb,
&c_b14, &a_ref(k + kb, k + kb), lda);
i__3 = *n - k - kb + 1;
dsymm_("Right", uplo, &i__3, &kb, &c_b16, &a_ref(k, k)
, lda, &b_ref(k + kb, k), ldb, &c_b14, &a_ref(
k + kb, k), lda);
i__3 = *n - k - kb + 1;
dtrsm_("Left", uplo, "No transpose", "Non-unit", &
i__3, &kb, &c_b14, &b_ref(k + kb, k + kb),
ldb, &a_ref(k + kb, k), lda);
}
/* L20: */
}
}
} else {
if (upper) {
/* Compute U*A*U' */
i__1 = *n;
i__2 = nb;
for (k = 1; i__2 < 0 ? k >= i__1 : k <= i__1; k += i__2) {
/* Computing MIN */
i__3 = *n - k + 1;
kb = min(i__3,nb);
/* Update the upper triangle of A(1:k+kb-1,1:k+kb-1) */
i__3 = k - 1;
dtrmm_("Left", uplo, "No transpose", "Non-unit", &i__3, &
kb, &c_b14, &b[b_offset], ldb, &a_ref(1, k), lda);
i__3 = k - 1;
dsymm_("Right", uplo, &i__3, &kb, &c_b52, &a_ref(k, k),
lda, &b_ref(1, k), ldb, &c_b14, &a_ref(1, k), lda);
i__3 = k - 1;
dsyr2k_(uplo, "No transpose", &i__3, &kb, &c_b14, &a_ref(
1, k), lda, &b_ref(1, k), ldb, &c_b14, &a[
a_offset], lda);
i__3 = k - 1;
dsymm_("Right", uplo, &i__3, &kb, &c_b52, &a_ref(k, k),
lda, &b_ref(1, k), ldb, &c_b14, &a_ref(1, k), lda);
i__3 = k - 1;
dtrmm_("Right", uplo, "Transpose", "Non-unit", &i__3, &kb,
&c_b14, &b_ref(k, k), ldb, &a_ref(1, k), lda);
dsygs2_(itype, uplo, &kb, &a_ref(k, k), lda, &b_ref(k, k),
ldb, info);
/* L30: */
}
} else {
/* Compute L'*A*L */
i__2 = *n;
i__1 = nb;
for (k = 1; i__1 < 0 ? k >= i__2 : k <= i__2; k += i__1) {
/* Computing MIN */
i__3 = *n - k + 1;
kb = min(i__3,nb);
/* Update the lower triangle of A(1:k+kb-1,1:k+kb-1) */
i__3 = k - 1;
dtrmm_("Right", uplo, "No transpose", "Non-unit", &kb, &
i__3, &c_b14, &b[b_offset], ldb, &a_ref(k, 1),
lda);
i__3 = k - 1;
dsymm_("Left", uplo, &kb, &i__3, &c_b52, &a_ref(k, k),
lda, &b_ref(k, 1), ldb, &c_b14, &a_ref(k, 1), lda);
i__3 = k - 1;
dsyr2k_(uplo, "Transpose", &i__3, &kb, &c_b14, &a_ref(k,
1), lda, &b_ref(k, 1), ldb, &c_b14, &a[a_offset],
lda);
i__3 = k - 1;
dsymm_("Left", uplo, &kb, &i__3, &c_b52, &a_ref(k, k),
lda, &b_ref(k, 1), ldb, &c_b14, &a_ref(k, 1), lda);
i__3 = k - 1;
dtrmm_("Left", uplo, "Transpose", "Non-unit", &kb, &i__3,
&c_b14, &b_ref(k, k), ldb, &a_ref(k, 1), lda);
dsygs2_(itype, uplo, &kb, &a_ref(k, k), lda, &b_ref(k, k),
ldb, info);
/* L40: */
}
}
}
}
return 0;
/* End of DSYGST */
} /* dsygst_ */
#undef b_ref
#undef a_ref