sgemm.f
SUBROUTINE SGEMM (TRANSA, TRANSB, M, N, K, ALPHA, A, LDA, B, LDB,
$ BETA, C, LDC)
C***BEGIN PROLOGUE SGEMM
C***PURPOSE Multiply a real general matrix by a real general matrix.
C***LIBRARY SLATEC (BLAS)
C***CATEGORY D1B6
C***TYPE SINGLE PRECISION (SGEMM-S, DGEMM-D, CGEMM-C)
C***KEYWORDS LEVEL 3 BLAS, LINEAR ALGEBRA
C***AUTHOR Dongarra, J., (ANL)
C Duff, I., (AERE)
C Du Croz, J., (NAG)
C Hammarling, S. (NAG)
C***DESCRIPTION
C
C SGEMM performs one of the matrix-matrix operations
C
C C := alpha*op( A )*op( B ) + beta*C,
C
C where op( X ) is one of
C
C op( X ) = X or op( X ) = X',
C
C alpha and beta are scalars, and A, B and C are matrices, with op( A )
C an m by k matrix, op( B ) a k by n matrix and C an m by n matrix.
C
C Parameters
C ==========
C
C TRANSA - CHARACTER*1.
C On entry, TRANSA specifies the form of op( A ) to be used in
C the matrix multiplication as follows:
C
C TRANSA = 'N' or 'n', op( A ) = A.
C
C TRANSA = 'T' or 't', op( A ) = A'.
C
C TRANSA = 'C' or 'c', op( A ) = A'.
C
C Unchanged on exit.
C
C TRANSB - CHARACTER*1.
C On entry, TRANSB specifies the form of op( B ) to be used in
C the matrix multiplication as follows:
C
C TRANSB = 'N' or 'n', op( B ) = B.
C
C TRANSB = 'T' or 't', op( B ) = B'.
C
C TRANSB = 'C' or 'c', op( B ) = B'.
C
C Unchanged on exit.
C
C M - INTEGER.
C On entry, M specifies the number of rows of the matrix
C op( A ) and of the matrix C. M must be at least zero.
C Unchanged on exit.
C
C N - INTEGER.
C On entry, N specifies the number of columns of the matrix
C op( B ) and the number of columns of the matrix C. N must be
C at least zero.
C Unchanged on exit.
C
C K - INTEGER.
C On entry, K specifies the number of columns of the matrix
C op( A ) and the number of rows of the matrix op( B ). K must
C be at least zero.
C Unchanged on exit.
C
C ALPHA - REAL .
C On entry, ALPHA specifies the scalar alpha.
C Unchanged on exit.
C
C A - REAL array of DIMENSION ( LDA, ka ), where ka is
C k when TRANSA = 'N' or 'n', and is m otherwise.
C Before entry with TRANSA = 'N' or 'n', the leading m by k
C part of the array A must contain the matrix A, otherwise
C the leading k by m part of the array A must contain the
C matrix A.
C Unchanged on exit.
C
C LDA - INTEGER.
C On entry, LDA specifies the first dimension of A as declared
C in the calling (sub) program. When TRANSA = 'N' or 'n' then
C LDA must be at least max( 1, m ), otherwise LDA must be at
C least max( 1, k ).
C Unchanged on exit.
C
C B - REAL array of DIMENSION ( LDB, kb ), where kb is
C n when TRANSB = 'N' or 'n', and is k otherwise.
C Before entry with TRANSB = 'N' or 'n', the leading k by n
C part of the array B must contain the matrix B, otherwise
C the leading n by k part of the array B must contain the
C matrix B.
C Unchanged on exit.
C
C LDB - INTEGER.
C On entry, LDB specifies the first dimension of B as declared
C in the calling (sub) program. When TRANSB = 'N' or 'n' then
C LDB must be at least max( 1, k ), otherwise LDB must be at
C least max( 1, n ).
C Unchanged on exit.
C
C BETA - REAL .
C On entry, BETA specifies the scalar beta. When BETA is
C supplied as zero then C need not be set on input.
C Unchanged on exit.
C
C C - REAL array of DIMENSION ( LDC, n ).
C Before entry, the leading m by n part of the array C must
C contain the matrix C, except when beta is zero, in which
C case C need not be set on entry.
C On exit, the array C is overwritten by the m by n matrix
C ( alpha*op( A )*op( B ) + beta*C ).
C
C LDC - INTEGER.
C On entry, LDC specifies the first dimension of C as declared
C in the calling (sub) program. LDC must be at least
C max( 1, m ).
C Unchanged on exit.
C
C***REFERENCES Dongarra, J., Du Croz, J., Duff, I., and Hammarling, S.
C A set of level 3 basic linear algebra subprograms.
C ACM TOMS, Vol. 16, No. 1, pp. 1-17, March 1990.
C***ROUTINES CALLED LSAME, XERBLA
C***REVISION HISTORY (YYMMDD)
C 890208 DATE WRITTEN
C 910605 Modified to meet SLATEC prologue standards. Only comment
C lines were modified. (BKS)
C***END PROLOGUE SGEMM