Mercurial > hg > octave-nkf
diff libcruft/blas/sgemm.f @ 4347:024ef171aec3
[project @ 2003-02-20 23:31:46 by jwe]
| author | jwe |
|---|---|
| date | Thu, 20 Feb 2003 23:32:25 +0000 |
| parents | |
| children | 82be108cc558 |
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new file mode 100644 --- /dev/null +++ b/libcruft/blas/sgemm.f @@ -0,0 +1,313 @@ + SUBROUTINE SGEMM ( TRANSA, TRANSB, M, N, K, ALPHA, A, LDA, B, LDB, + $ BETA, C, LDC ) +* .. Scalar Arguments .. + CHARACTER*1 TRANSA, TRANSB + INTEGER M, N, K, LDA, LDB, LDC + REAL ALPHA, BETA +* .. Array Arguments .. + REAL A( LDA, * ), B( LDB, * ), C( LDC, * ) +* .. +* +* Purpose +* ======= +* +* SGEMM performs one of the matrix-matrix operations +* +* C := alpha*op( A )*op( B ) + beta*C, +* +* where op( X ) is one of +* +* op( X ) = X or op( X ) = X', +* +* alpha and beta are scalars, and A, B and C are matrices, with op( A ) +* an m by k matrix, op( B ) a k by n matrix and C an m by n matrix. +* +* Parameters +* ========== +* +* 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. +* +* TRANSB - CHARACTER*1. +* On entry, TRANSB specifies the form of op( B ) to be used in +* the matrix multiplication as follows: +* +* TRANSB = 'N' or 'n', op( B ) = B. +* +* TRANSB = 'T' or 't', op( B ) = B'. +* +* TRANSB = 'C' or 'c', op( B ) = B'. +* +* Unchanged on exit. +* +* M - INTEGER. +* On entry, M specifies the number of rows of the matrix +* op( A ) and of the matrix C. M must be at least zero. +* Unchanged on exit. +* +* N - INTEGER. +* On entry, N specifies the number of columns of the matrix +* op( B ) and the number of columns of the matrix C. N must be +* at least zero. +* Unchanged on exit. +* +* K - INTEGER. +* On entry, K specifies the number of columns of the matrix +* op( A ) and the number of rows of the matrix op( B ). K must +* be at least zero. +* Unchanged on exit. +* +* ALPHA - REAL . +* On entry, ALPHA specifies the scalar alpha. +* Unchanged on exit. +* +* A - REAL array of DIMENSION ( LDA, ka ), where ka is +* k when TRANSA = 'N' or 'n', and is m otherwise. +* Before entry with TRANSA = 'N' or 'n', the leading m by k +* part of the array A must contain the matrix A, otherwise +* the leading k by m part of the array A must contain the +* matrix A. +* Unchanged on exit. +* +* LDA - INTEGER. +* On entry, LDA specifies the first dimension of A as declared +* in the calling (sub) program. When TRANSA = 'N' or 'n' then +* LDA must be at least max( 1, m ), otherwise LDA must be at +* least max( 1, k ). +* Unchanged on exit. +* +* B - REAL array of DIMENSION ( LDB, kb ), where kb is +* n when TRANSB = 'N' or 'n', and is k otherwise. +* Before entry with TRANSB = 'N' or 'n', the leading k by n +* part of the array B must contain the matrix B, otherwise +* the leading n by k part of the array B must contain the +* matrix B. +* Unchanged on exit. +* +* LDB - INTEGER. +* On entry, LDB specifies the first dimension of B as declared +* in the calling (sub) program. When TRANSB = 'N' or 'n' then +* LDB must be at least max( 1, k ), otherwise LDB must be at +* least max( 1, n ). +* Unchanged on exit. +* +* BETA - REAL . +* On entry, BETA specifies the scalar beta. When BETA is +* supplied as zero then C need not be set on input. +* Unchanged on exit. +* +* C - REAL array of DIMENSION ( LDC, n ). +* Before entry, the leading m by n part of the array C must +* contain the matrix C, except when beta is zero, in which +* case C need not be set on entry. +* On exit, the array C is overwritten by the m by n matrix +* ( alpha*op( A )*op( B ) + beta*C ). +* +* LDC - INTEGER. +* On entry, LDC specifies the first dimension of C as declared +* in the calling (sub) program. LDC 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 NOTA, NOTB + INTEGER I, INFO, J, L, NCOLA, NROWA, NROWB + REAL TEMP +* .. Parameters .. + REAL ONE , ZERO + PARAMETER ( ONE = 1.0E+0, ZERO = 0.0E+0 ) +* .. +* .. Executable Statements .. +* +* Set NOTA and NOTB as true if A and B respectively are not +* transposed and set NROWA, NCOLA and NROWB as the number of rows +* and columns of A and the number of rows of B respectively. +* + NOTA = LSAME( TRANSA, 'N' ) + NOTB = LSAME( TRANSB, 'N' ) + IF( NOTA )THEN + NROWA = M + NCOLA = K + ELSE + NROWA = K + NCOLA = M + END IF + IF( NOTB )THEN + NROWB = K + ELSE + NROWB = N + END IF +* +* Test the input parameters. +* + INFO = 0 + IF( ( .NOT.NOTA ).AND. + $ ( .NOT.LSAME( TRANSA, 'C' ) ).AND. + $ ( .NOT.LSAME( TRANSA, 'T' ) ) )THEN + INFO = 1 + ELSE IF( ( .NOT.NOTB ).AND. + $ ( .NOT.LSAME( TRANSB, 'C' ) ).AND. + $ ( .NOT.LSAME( TRANSB, 'T' ) ) )THEN + INFO = 2 + ELSE IF( M .LT.0 )THEN + INFO = 3 + ELSE IF( N .LT.0 )THEN + INFO = 4 + ELSE IF( K .LT.0 )THEN + INFO = 5 + ELSE IF( LDA.LT.MAX( 1, NROWA ) )THEN + INFO = 8 + ELSE IF( LDB.LT.MAX( 1, NROWB ) )THEN + INFO = 10 + ELSE IF( LDC.LT.MAX( 1, M ) )THEN + INFO = 13 + END IF + IF( INFO.NE.0 )THEN + CALL XERBLA( 'SGEMM ', INFO ) + RETURN + END IF +* +* Quick return if possible. +* + IF( ( M.EQ.0 ).OR.( N.EQ.0 ).OR. + $ ( ( ( ALPHA.EQ.ZERO ).OR.( K.EQ.0 ) ).AND.( BETA.EQ.ONE ) ) ) + $ RETURN +* +* And if alpha.eq.zero. +* + IF( ALPHA.EQ.ZERO )THEN + IF( BETA.EQ.ZERO )THEN + DO 20, J = 1, N + DO 10, I = 1, M + C( I, J ) = ZERO + 10 CONTINUE + 20 CONTINUE + ELSE + DO 40, J = 1, N + DO 30, I = 1, M + C( I, J ) = BETA*C( I, J ) + 30 CONTINUE + 40 CONTINUE + END IF + RETURN + END IF +* +* Start the operations. +* + IF( NOTB )THEN + IF( NOTA )THEN +* +* Form C := alpha*A*B + beta*C. +* + DO 90, J = 1, N + IF( BETA.EQ.ZERO )THEN + DO 50, I = 1, M + C( I, J ) = ZERO + 50 CONTINUE + ELSE IF( BETA.NE.ONE )THEN + DO 60, I = 1, M + C( I, J ) = BETA*C( I, J ) + 60 CONTINUE + END IF + DO 80, L = 1, K + IF( B( L, J ).NE.ZERO )THEN + TEMP = ALPHA*B( L, J ) + DO 70, I = 1, M + C( I, J ) = C( I, J ) + TEMP*A( I, L ) + 70 CONTINUE + END IF + 80 CONTINUE + 90 CONTINUE + ELSE +* +* Form C := alpha*A'*B + beta*C +* + DO 120, J = 1, N + DO 110, I = 1, M + TEMP = ZERO + DO 100, L = 1, K + TEMP = TEMP + A( L, I )*B( L, J ) + 100 CONTINUE + IF( BETA.EQ.ZERO )THEN + C( I, J ) = ALPHA*TEMP + ELSE + C( I, J ) = ALPHA*TEMP + BETA*C( I, J ) + END IF + 110 CONTINUE + 120 CONTINUE + END IF + ELSE + IF( NOTA )THEN +* +* Form C := alpha*A*B' + beta*C +* + DO 170, J = 1, N + IF( BETA.EQ.ZERO )THEN + DO 130, I = 1, M + C( I, J ) = ZERO + 130 CONTINUE + ELSE IF( BETA.NE.ONE )THEN + DO 140, I = 1, M + C( I, J ) = BETA*C( I, J ) + 140 CONTINUE + END IF + DO 160, L = 1, K + IF( B( J, L ).NE.ZERO )THEN + TEMP = ALPHA*B( J, L ) + DO 150, I = 1, M + C( I, J ) = C( I, J ) + TEMP*A( I, L ) + 150 CONTINUE + END IF + 160 CONTINUE + 170 CONTINUE + ELSE +* +* Form C := alpha*A'*B' + beta*C +* + DO 200, J = 1, N + DO 190, I = 1, M + TEMP = ZERO + DO 180, L = 1, K + TEMP = TEMP + A( L, I )*B( J, L ) + 180 CONTINUE + IF( BETA.EQ.ZERO )THEN + C( I, J ) = ALPHA*TEMP + ELSE + C( I, J ) = ALPHA*TEMP + BETA*C( I, J ) + END IF + 190 CONTINUE + 200 CONTINUE + END IF + END IF +* + RETURN +* +* End of SGEMM . +* + END