# sgemm.f - Man Page

BLAS/SRC/sgemm.f

## Synopsis

### Functions/Subroutines

subroutine sgemm (transa, transb, m, n, k, alpha, a, lda, b, ldb, beta, c, ldc)
SGEMM

## Function/Subroutine Documentation

### subroutine sgemm (character transa, character transb, integer m, integer n, integer k, real alpha, real, dimension(lda,*) a, integer lda, real, dimension(ldb,*) b, integer ldb, real beta, real, dimension(ldc,*) c, integer ldc)

SGEMM

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**T,

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

```          TRANSA is 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**T.

TRANSA = 'C' or 'c',  op( A ) = A**T.```

TRANSB

```          TRANSB is 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**T.

TRANSB = 'C' or 'c',  op( B ) = B**T.```

M

```          M is 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.```

N

```          N is 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.```

K

```          K is 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.```

ALPHA

```          ALPHA is REAL
On entry, ALPHA specifies the scalar alpha.```

A

```          A is REAL array, 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.```

LDA

```          LDA is 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 ).```

B

```          B is REAL array, 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.```

LDB

```          LDB is 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 ).```

BETA

```          BETA is REAL
On entry,  BETA  specifies the scalar  beta.  When  BETA  is
supplied as zero then C need not be set on input.```

C

```          C is REAL array, 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

```          LDC is 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 ).```
Author

Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Further Details:

```  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.```

Definition at line 186 of file sgemm.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page sgemm(3) is an alias of sgemm.f(3).

Tue Nov 28 2023 12:08:41 Version 3.12.0 LAPACK