diff options
Diffstat (limited to 'src/fortran/blas/dtrmm.f')
| -rw-r--r-- | src/fortran/blas/dtrmm.f | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/src/fortran/blas/dtrmm.f b/src/fortran/blas/dtrmm.f new file mode 100644 index 0000000..f98da46 --- /dev/null +++ b/src/fortran/blas/dtrmm.f @@ -0,0 +1,355 @@ + SUBROUTINE DTRMM ( SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA, + $ B, LDB ) +* .. Scalar Arguments .. + CHARACTER*1 SIDE, UPLO, TRANSA, DIAG + INTEGER M, N, LDA, LDB + DOUBLE PRECISION ALPHA +* .. Array Arguments .. + DOUBLE PRECISION A( LDA, * ), B( LDB, * ) +* .. +* +* 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'. +* +* Parameters +* ========== +* +* 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. +* +* +* .. External Functions .. + LOGICAL LSAME + EXTERNAL LSAME +* .. External Subroutines .. + EXTERNAL XERBLA +* .. Intrinsic Functions .. + INTRINSIC MAX +* .. Local Scalars .. + LOGICAL LSIDE, NOUNIT, UPPER + INTEGER I, INFO, J, K, NROWA + DOUBLE PRECISION TEMP +* .. Parameters .. + DOUBLE PRECISION ONE , ZERO + PARAMETER ( ONE = 1.0D+0, ZERO = 0.0D+0 ) +* .. +* .. Executable Statements .. +* +* Test the input parameters. +* + LSIDE = LSAME( SIDE , 'L' ) + IF( LSIDE )THEN + NROWA = M + ELSE + NROWA = N + END IF + NOUNIT = LSAME( DIAG , 'N' ) + UPPER = LSAME( UPLO , 'U' ) +* + INFO = 0 + IF( ( .NOT.LSIDE ).AND. + $ ( .NOT.LSAME( SIDE , 'R' ) ) )THEN + INFO = 1 + ELSE IF( ( .NOT.UPPER ).AND. + $ ( .NOT.LSAME( UPLO , 'L' ) ) )THEN + INFO = 2 + ELSE IF( ( .NOT.LSAME( TRANSA, 'N' ) ).AND. + $ ( .NOT.LSAME( TRANSA, 'T' ) ).AND. + $ ( .NOT.LSAME( TRANSA, 'C' ) ) )THEN + INFO = 3 + ELSE IF( ( .NOT.LSAME( DIAG , 'U' ) ).AND. + $ ( .NOT.LSAME( DIAG , 'N' ) ) )THEN + INFO = 4 + ELSE IF( M .LT.0 )THEN + INFO = 5 + ELSE IF( N .LT.0 )THEN + INFO = 6 + ELSE IF( LDA.LT.MAX( 1, NROWA ) )THEN + INFO = 9 + ELSE IF( LDB.LT.MAX( 1, M ) )THEN + INFO = 11 + END IF + IF( INFO.NE.0 )THEN + CALL XERBLA( 'DTRMM ', INFO ) + RETURN + END IF +* +* Quick return if possible. +* + IF( N.EQ.0 ) + $ RETURN +* +* And when alpha.eq.zero. +* + IF( ALPHA.EQ.ZERO )THEN + DO 20, J = 1, N + DO 10, I = 1, M + B( I, J ) = ZERO + 10 CONTINUE + 20 CONTINUE + RETURN + END IF +* +* Start the operations. +* + IF( LSIDE )THEN + IF( LSAME( TRANSA, 'N' ) )THEN +* +* Form B := alpha*A*B. +* + IF( UPPER )THEN + DO 50, J = 1, N + DO 40, K = 1, M + IF( B( K, J ).NE.ZERO )THEN + TEMP = ALPHA*B( K, J ) + DO 30, I = 1, K - 1 + B( I, J ) = B( I, J ) + TEMP*A( I, K ) + 30 CONTINUE + IF( NOUNIT ) + $ TEMP = TEMP*A( K, K ) + B( K, J ) = TEMP + END IF + 40 CONTINUE + 50 CONTINUE + ELSE + DO 80, J = 1, N + DO 70 K = M, 1, -1 + IF( B( K, J ).NE.ZERO )THEN + TEMP = ALPHA*B( K, J ) + B( K, J ) = TEMP + IF( NOUNIT ) + $ B( K, J ) = B( K, J )*A( K, K ) + DO 60, I = K + 1, M + B( I, J ) = B( I, J ) + TEMP*A( I, K ) + 60 CONTINUE + END IF + 70 CONTINUE + 80 CONTINUE + END IF + ELSE +* +* Form B := alpha*B*A'. +* + IF( UPPER )THEN + DO 110, J = 1, N + DO 100, I = M, 1, -1 + TEMP = B( I, J ) + IF( NOUNIT ) + $ TEMP = TEMP*A( I, I ) + DO 90, K = 1, I - 1 + TEMP = TEMP + A( K, I )*B( K, J ) + 90 CONTINUE + B( I, J ) = ALPHA*TEMP + 100 CONTINUE + 110 CONTINUE + ELSE + DO 140, J = 1, N + DO 130, I = 1, M + TEMP = B( I, J ) + IF( NOUNIT ) + $ TEMP = TEMP*A( I, I ) + DO 120, K = I + 1, M + TEMP = TEMP + A( K, I )*B( K, J ) + 120 CONTINUE + B( I, J ) = ALPHA*TEMP + 130 CONTINUE + 140 CONTINUE + END IF + END IF + ELSE + IF( LSAME( TRANSA, 'N' ) )THEN +* +* Form B := alpha*B*A. +* + IF( UPPER )THEN + DO 180, J = N, 1, -1 + TEMP = ALPHA + IF( NOUNIT ) + $ TEMP = TEMP*A( J, J ) + DO 150, I = 1, M + B( I, J ) = TEMP*B( I, J ) + 150 CONTINUE + DO 170, K = 1, J - 1 + IF( A( K, J ).NE.ZERO )THEN + TEMP = ALPHA*A( K, J ) + DO 160, I = 1, M + B( I, J ) = B( I, J ) + TEMP*B( I, K ) + 160 CONTINUE + END IF + 170 CONTINUE + 180 CONTINUE + ELSE + DO 220, J = 1, N + TEMP = ALPHA + IF( NOUNIT ) + $ TEMP = TEMP*A( J, J ) + DO 190, I = 1, M + B( I, J ) = TEMP*B( I, J ) + 190 CONTINUE + DO 210, K = J + 1, N + IF( A( K, J ).NE.ZERO )THEN + TEMP = ALPHA*A( K, J ) + DO 200, I = 1, M + B( I, J ) = B( I, J ) + TEMP*B( I, K ) + 200 CONTINUE + END IF + 210 CONTINUE + 220 CONTINUE + END IF + ELSE +* +* Form B := alpha*B*A'. +* + IF( UPPER )THEN + DO 260, K = 1, N + DO 240, J = 1, K - 1 + IF( A( J, K ).NE.ZERO )THEN + TEMP = ALPHA*A( J, K ) + DO 230, I = 1, M + B( I, J ) = B( I, J ) + TEMP*B( I, K ) + 230 CONTINUE + END IF + 240 CONTINUE + TEMP = ALPHA + IF( NOUNIT ) + $ TEMP = TEMP*A( K, K ) + IF( TEMP.NE.ONE )THEN + DO 250, I = 1, M + B( I, K ) = TEMP*B( I, K ) + 250 CONTINUE + END IF + 260 CONTINUE + ELSE + DO 300, K = N, 1, -1 + DO 280, J = K + 1, N + IF( A( J, K ).NE.ZERO )THEN + TEMP = ALPHA*A( J, K ) + DO 270, I = 1, M + B( I, J ) = B( I, J ) + TEMP*B( I, K ) + 270 CONTINUE + END IF + 280 CONTINUE + TEMP = ALPHA + IF( NOUNIT ) + $ TEMP = TEMP*A( K, K ) + IF( TEMP.NE.ONE )THEN + DO 290, I = 1, M + B( I, K ) = TEMP*B( I, K ) + 290 CONTINUE + END IF + 300 CONTINUE + END IF + END IF + END IF +* + RETURN +* +* End of DTRMM . +* + END |