1CGEMM(1) BLAS routine CGEMM(1)
2
6 CGEMM - one of the matrix-matrix operations C := alpha*op( A )*op( B
7 ) + beta*C,
8
10 SUBROUTINE CGEMM(TRANSA,TRANSB,M,N,K,ALPHA,A,LDA,B,LDB,BETA,C,LDC)
11 COMPLEX ALPHA,BETA
13 INTEGER K,LDA,LDB,LDC,M,N
15 CHARACTER TRANSA,TRANSB
17 COMPLEX A(LDA,*),B(LDB,*),C(LDC,*)
19
21 CGEMM performs one of the matrix-matrix operations
22 where op( X ) is one of
24 op( X ) = X or op( X ) = X' or op( X ) = conjg( X' ),
26 alpha and beta are scalars, and A, B and C are matrices, with op( A )
28 an m by k matrix, op( B ) a k by n matrix and C an m by n matrix.
29
32 TRANSA - CHARACTER*1. On entry, TRANSA specifies the form of op( A )
33 to be used in the matrix multiplication as follows:
34 TRANSA = 'N' or 'n', op( A ) = A.
36 TRANSA = 'T' or 't', op( A ) = A'.
38 TRANSA = 'C' or 'c', op( A ) = conjg( A' ).
40 Unchanged on exit.
42 TRANSB - CHARACTER*1. On entry, TRANSB specifies the form of op( B )
44 to be used in the matrix multiplication as follows:
45 TRANSB = 'N' or 'n', op( B ) = B.
47 TRANSB = 'T' or 't', op( B ) = B'.
49 TRANSB = 'C' or 'c', op( B ) = conjg( B' ).
51 Unchanged on exit.
53 M - INTEGER.
55 On entry, M specifies the number of rows of the matrix op(
56 A ) and of the matrix C. M must be at least zero.
57 Unchanged on exit.
58 N - INTEGER.
60 On entry, N specifies the number of columns of the matrix op(
61 B ) and the number of columns of the matrix C. N must be at
62 least zero. Unchanged on exit.
63 K - INTEGER.
65 On entry, K specifies the number of columns of the matrix op(
66 A ) and the number of rows of the matrix op( B ). K must be at
67 least zero. Unchanged on exit.
68 ALPHA - COMPLEX .
70 On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
71 A - COMPLEX array of DIMENSION ( LDA, ka ), where ka is
73 k when TRANSA = 'N' or 'n', and is m otherwise. Before
74 entry with TRANSA = 'N' or 'n', the leading m by k part of
75 the array A must contain the matrix A, otherwise the leading
76 k by m part of the array A must contain the matrix A.
77 Unchanged on exit.
78 LDA - INTEGER.
80 On entry, LDA specifies the first dimension of A as declared in
81 the calling (sub) program. When TRANSA = 'N' or 'n' then LDA
82 must be at least max( 1, m ), otherwise LDA must be at least
83 max( 1, k ). Unchanged on exit.
84 B - COMPLEX array of DIMENSION ( LDB, kb ), where kb is
86 n when TRANSB = 'N' or 'n', and is k otherwise. Before
87 entry with TRANSB = 'N' or 'n', the leading k by n part of
88 the array B must contain the matrix B, otherwise the leading
89 n by k part of the array B must contain the matrix B.
90 Unchanged on exit.
91 LDB - INTEGER.
93 On entry, LDB specifies the first dimension of B as declared in
94 the calling (sub) program. When TRANSB = 'N' or 'n' then LDB
95 must be at least max( 1, k ), otherwise LDB must be at least
96 max( 1, n ). Unchanged on exit.
97 BETA - COMPLEX .
99 On entry, BETA specifies the scalar beta. When BETA is
100 supplied as zero then C need not be set on input. Unchanged on
101 exit.
102 C - COMPLEX array of DIMENSION ( LDC, n ).
104 Before entry, the leading m by n part of the array C must
105 contain the matrix C, except when beta is zero, in which
106 case C need not be set on entry. On exit, the array C is
107 overwritten by the m by n matrix ( alpha*op( A )*op( B ) +
108 beta*C ).
109 LDC - INTEGER.
111 On entry, LDC specifies the first dimension of C as declared in
112 the calling (sub) program. LDC must be at least max( 1,
113 m ). Unchanged on exit.
114 Level 3 Blas routine.
116 -- Written on 8-February-1989. Jack Dongarra, Argonne National
118 Laboratory. Iain Duff, AERE Harwell. Jeremy Du Croz, Numerical
119 Algorithms Group Ltd. Sven Hammarling, Numerical Algorithms
120 Group Ltd.
121BLAS routine November 2006 CGEMM(1)