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Diffstat (limited to 'BLAS/SRC/dtrmm.f')
| -rw-r--r-- | BLAS/SRC/dtrmm.f | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/BLAS/SRC/dtrmm.f b/BLAS/SRC/dtrmm.f new file mode 100644 index 00000000..1ae449ab --- /dev/null +++ b/BLAS/SRC/dtrmm.f @@ -0,0 +1,346 @@ + SUBROUTINE DTRMM(SIDE,UPLO,TRANSA,DIAG,M,N,ALPHA,A,LDA,B,LDB) +* .. Scalar Arguments .. + DOUBLE PRECISION ALPHA + INTEGER LDA,LDB,M,N + CHARACTER DIAG,SIDE,TRANSA,UPLO +* .. +* .. 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'. +* +* 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. +* +* +* .. External Functions .. + LOGICAL LSAME + EXTERNAL LSAME +* .. +* .. External Subroutines .. + EXTERNAL XERBLA +* .. +* .. Intrinsic Functions .. + INTRINSIC MAX +* .. +* .. Local Scalars .. + DOUBLE PRECISION TEMP + INTEGER I,INFO,J,K,NROWA + LOGICAL LSIDE,NOUNIT,UPPER +* .. +* .. Parameters .. + DOUBLE PRECISION ONE,ZERO + PARAMETER (ONE=1.0D+0,ZERO=0.0D+0) +* .. +* +* 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 (M.EQ.0 .OR. 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*A'*B. +* + 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 |