#include "blaswrap.h"
#include "f2c.h"
/* Subroutine */ int dtrmm_(char *side, char *uplo, char *transa, char *diag,
integer *m, integer *n, doublereal *alpha, doublereal *a, integer *
lda, doublereal *b, integer *ldb)
{
/* System generated locals */
integer a_dim1, a_offset, b_dim1, b_offset, i__1, i__2, i__3;
/* Local variables */
static integer i__, j, k, info;
static doublereal temp;
static logical lside;
extern logical lsame_(char *, char *);
static integer nrowa;
static logical upper;
extern /* Subroutine */ int xerbla_(char *, integer *);
static logical nounit;
/* Purpose
=======
DTRMM performs one of the matrix-matrix operations
B := alpha*op( A )*B, or B := alpha*B*op( A ),
where alpha is a scalar, B is an m by n matrix, A is a unit, or
non-unit, upper or lower triangular matrix and op( A ) is one of
op( A ) = A or op( A ) = A'.
Arguments
==========
SIDE - CHARACTER*1.
On entry, SIDE specifies whether op( A ) multiplies B from
the left or right as follows:
SIDE = 'L' or 'l' B := alpha*op( A )*B.
SIDE = 'R' or 'r' B := alpha*B*op( A ).
Unchanged on exit.
UPLO - CHARACTER*1.
On entry, UPLO specifies whether the matrix A is an upper or
lower triangular matrix as follows:
UPLO = 'U' or 'u' A is an upper triangular matrix.
UPLO = 'L' or 'l' A is a lower triangular matrix.
Unchanged on exit.
TRANSA - CHARACTER*1.
On entry, TRANSA specifies the form of op( A ) to be used in
the matrix multiplication as follows:
TRANSA = 'N' or 'n' op( A ) = A.
TRANSA = 'T' or 't' op( A ) = A'.
TRANSA = 'C' or 'c' op( A ) = A'.
Unchanged on exit.
DIAG - CHARACTER*1.
On entry, DIAG specifies whether or not A is unit triangular
as follows:
DIAG = 'U' or 'u' A is assumed to be unit triangular.
DIAG = 'N' or 'n' A is not assumed to be unit
triangular.
Unchanged on exit.
M - INTEGER.
On entry, M specifies the number of rows of B. M must be at
least zero.
Unchanged on exit.
N - INTEGER.
On entry, N specifies the number of columns of B. N must be
at least zero.
Unchanged on exit.
ALPHA - DOUBLE PRECISION.
On entry, ALPHA specifies the scalar alpha. When alpha is
zero then A is not referenced and B need not be set before
entry.
Unchanged on exit.
A - DOUBLE PRECISION array of DIMENSION ( LDA, k ), where k is m
when SIDE = 'L' or 'l' and is n when SIDE = 'R' or 'r'.
Before entry with UPLO = 'U' or 'u', the leading k by k
upper triangular part of the array A must contain the upper
triangular matrix and the strictly lower triangular part of
A is not referenced.
Before entry with UPLO = 'L' or 'l', the leading k by k
lower triangular part of the array A must contain the lower
triangular matrix and the strictly upper triangular part of
A is not referenced.
Note that when DIAG = 'U' or 'u', the diagonal elements of
A are not referenced either, but are assumed to be unity.
Unchanged on exit.
LDA - INTEGER.
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. When SIDE = 'L' or 'l' then
LDA must be at least max( 1, m ), when SIDE = 'R' or 'r'
then LDA must be at least max( 1, n ).
Unchanged on exit.
B - DOUBLE PRECISION array of DIMENSION ( LDB, n ).
Before entry, the leading m by n part of the array B must
contain the matrix B, and on exit is overwritten by the
transformed matrix.
LDB - INTEGER.
On entry, LDB specifies the first dimension of B as declared
in the calling (sub) program. LDB must be at least
max( 1, m ).
Unchanged on exit.
Level 3 Blas routine.
-- Written on 8-February-1989.
Jack Dongarra, Argonne National Laboratory.
Iain Duff, AERE Harwell.
Jeremy Du Croz, Numerical Algorithms Group Ltd.
Sven Hammarling, Numerical Algorithms Group Ltd.
Test the input parameters.
Parameter adjustments */
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
b_dim1 = *ldb;
b_offset = 1 + b_dim1;
b -= b_offset;
/* Function Body */
lside = lsame_(side, "L");
if (lside) {
nrowa = *m;
} else {
nrowa = *n;
}
nounit = lsame_(diag, "N");
upper = lsame_(uplo, "U");
info = 0;
if (! lside && ! lsame_(side, "R")) {
info = 1;
} else if (! upper && ! lsame_(uplo, "L")) {
info = 2;
} else if (! lsame_(transa, "N") && ! lsame_(transa,
"T") && ! lsame_(transa, "C")) {
info = 3;
} else if (! lsame_(diag, "U") && ! lsame_(diag,
"N")) {
info = 4;
} else if (*m < 0) {
info = 5;
} else if (*n < 0) {
info = 6;
} else if (*lda < max(1,nrowa)) {
info = 9;
} else if (*ldb < max(1,*m)) {
info = 11;
}
if (info != 0) {
xerbla_("DTRMM ", &info);
return 0;
}
/* Quick return if possible. */
if (*n == 0) {
return 0;
}
/* And when alpha.eq.zero. */
if (*alpha == 0.) {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
b[i__ + j * b_dim1] = 0.;
/* L10: */
}
/* L20: */
}
return 0;
}
/* Start the operations. */
if (lside) {
if (lsame_(transa, "N")) {
/* Form B := alpha*A*B. */
if (upper) {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (k = 1; k <= i__2; ++k) {
if (b[k + j * b_dim1] != 0.) {
temp = *alpha * b[k + j * b_dim1];
i__3 = k - 1;
for (i__ = 1; i__ <= i__3; ++i__) {
b[i__ + j * b_dim1] += temp * a[i__ + k *
a_dim1];
/* L30: */
}
if (nounit) {
temp *= a[k + k * a_dim1];
}
b[k + j * b_dim1] = temp;
}
/* L40: */
}
/* L50: */
}
} else {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
for (k = *m; k >= 1; --k) {
if (b[k + j * b_dim1] != 0.) {
temp = *alpha * b[k + j * b_dim1];
b[k + j * b_dim1] = temp;
if (nounit) {
b[k + j * b_dim1] *= a[k + k * a_dim1];
}
i__2 = *m;
for (i__ = k + 1; i__ <= i__2; ++i__) {
b[i__ + j * b_dim1] += temp * a[i__ + k *
a_dim1];
/* L60: */
}
}
/* L70: */
}
/* L80: */
}
}
} else {
/* Form B := alpha*A'*B. */
if (upper) {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
for (i__ = *m; i__ >= 1; --i__) {
temp = b[i__ + j * b_dim1];
if (nounit) {
temp *= a[i__ + i__ * a_dim1];
}
i__2 = i__ - 1;
for (k = 1; k <= i__2; ++k) {
temp += a[k + i__ * a_dim1] * b[k + j * b_dim1];
/* L90: */
}
b[i__ + j * b_dim1] = *alpha * temp;
/* L100: */
}
/* L110: */
}
} else {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
temp = b[i__ + j * b_dim1];
if (nounit) {
temp *= a[i__ + i__ * a_dim1];
}
i__3 = *m;
for (k = i__ + 1; k <= i__3; ++k) {
temp += a[k + i__ * a_dim1] * b[k + j * b_dim1];
/* L120: */
}
b[i__ + j * b_dim1] = *alpha * temp;
/* L130: */
}
/* L140: */
}
}
}
} else {
if (lsame_(transa, "N")) {
/* Form B := alpha*B*A. */
if (upper) {
for (j = *n; j >= 1; --j) {
temp = *alpha;
if (nounit) {
temp *= a[j + j * a_dim1];
}
i__1 = *m;
for (i__ = 1; i__ <= i__1; ++i__) {
b[i__ + j * b_dim1] = temp * b[i__ + j * b_dim1];
/* L150: */
}
i__1 = j - 1;
for (k = 1; k <= i__1; ++k) {
if (a[k + j * a_dim1] != 0.) {
temp = *alpha * a[k + j * a_dim1];
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
b[i__ + j * b_dim1] += temp * b[i__ + k *
b_dim1];
/* L160: */
}
}
/* L170: */
}
/* L180: */
}
} else {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
temp = *alpha;
if (nounit) {
temp *= a[j + j * a_dim1];
}
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
b[i__ + j * b_dim1] = temp * b[i__ + j * b_dim1];
/* L190: */
}
i__2 = *n;
for (k = j + 1; k <= i__2; ++k) {
if (a[k + j * a_dim1] != 0.) {
temp = *alpha * a[k + j * a_dim1];
i__3 = *m;
for (i__ = 1; i__ <= i__3; ++i__) {
b[i__ + j * b_dim1] += temp * b[i__ + k *
b_dim1];
/* L200: */
}
}
/* L210: */
}
/* L220: */
}
}
} else {
/* Form B := alpha*B*A'. */
if (upper) {
i__1 = *n;
for (k = 1; k <= i__1; ++k) {
i__2 = k - 1;
for (j = 1; j <= i__2; ++j) {
if (a[j + k * a_dim1] != 0.) {
temp = *alpha * a[j + k * a_dim1];
i__3 = *m;
for (i__ = 1; i__ <= i__3; ++i__) {
b[i__ + j * b_dim1] += temp * b[i__ + k *
b_dim1];
/* L230: */
}
}
/* L240: */
}
temp = *alpha;
if (nounit) {
temp *= a[k + k * a_dim1];
}
if (temp != 1.) {
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
b[i__ + k * b_dim1] = temp * b[i__ + k * b_dim1];
/* L250: */
}
}
/* L260: */
}
} else {
for (k = *n; k >= 1; --k) {
i__1 = *n;
for (j = k + 1; j <= i__1; ++j) {
if (a[j + k * a_dim1] != 0.) {
temp = *alpha * a[j + k * a_dim1];
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
b[i__ + j * b_dim1] += temp * b[i__ + k *
b_dim1];
/* L270: */
}
}
/* L280: */
}
temp = *alpha;
if (nounit) {
temp *= a[k + k * a_dim1];
}
if (temp != 1.) {
i__1 = *m;
for (i__ = 1; i__ <= i__1; ++i__) {
b[i__ + k * b_dim1] = temp * b[i__ + k * b_dim1];
/* L290: */
}
}
/* L300: */
}
}
}
}
return 0;
/* End of DTRMM . */
} /* dtrmm_ */