1ZGEMM(1) BLAS routine ZGEMM(1)
2
6 ZGEMM - one of the matrix-matrix operations C := alpha*op( A )*op( B
7 ) + beta*C,
8
10 SUBROUTINE ZGEMM(TRANSA,TRANSB,M,N,K,ALPHA,A,LDA,B,LDB,BETA,C,LDC)
11 DOUBLE COM‐
13 PLEX
14 ALPHA,BETA
15 INTEGER K,LDA,LDB,LDC,M,N
17 CHARACTER TRANSA,TRANSB
19 DOUBLE COM‐
21 PLEX
22 A(LDA,*),B(LDB,*),C(LDC,*)
23
25 ZGEMM performs one of the matrix-matrix operations
26 where op( X ) is one of
28 op( X ) = X or op( X ) = X' or op( X ) = conjg( X' ),
30 alpha and beta are scalars, and A, B and C are matrices, with op( A )
32 an m by k matrix, op( B ) a k by n matrix and C an m by n matrix.
33
36 TRANSA - CHARACTER*1. On entry, TRANSA specifies the form of op( A )
37 to be used in the matrix multiplication as follows:
38 TRANSA = 'N' or 'n', op( A ) = A.
40 TRANSA = 'T' or 't', op( A ) = A'.
42 TRANSA = 'C' or 'c', op( A ) = conjg( A' ).
44 Unchanged on exit.
46 TRANSB - CHARACTER*1. On entry, TRANSB specifies the form of op( B )
48 to be used in the matrix multiplication as follows:
49 TRANSB = 'N' or 'n', op( B ) = B.
51 TRANSB = 'T' or 't', op( B ) = B'.
53 TRANSB = 'C' or 'c', op( B ) = conjg( B' ).
55 Unchanged on exit.
57 M - INTEGER.
59 On entry, M specifies the number of rows of the matrix op(
60 A ) and of the matrix C. M must be at least zero.
61 Unchanged on exit.
62 N - INTEGER.
64 On entry, N specifies the number of columns of the matrix op(
65 B ) and the number of columns of the matrix C. N must be at
66 least zero. Unchanged on exit.
67 K - INTEGER.
69 On entry, K specifies the number of columns of the matrix op(
70 A ) and the number of rows of the matrix op( B ). K must be at
71 least zero. Unchanged on exit.
72 ALPHA - COMPLEX*16 .
74 On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
75 A - COMPLEX*16 array of DIMENSION ( LDA, ka ), where ka is
77 k when TRANSA = 'N' or 'n', and is m otherwise. Before
78 entry with TRANSA = 'N' or 'n', the leading m by k part of
79 the array A must contain the matrix A, otherwise the leading
80 k by m part of the array A must contain the matrix A.
81 Unchanged on exit.
82 LDA - INTEGER.
84 On entry, LDA specifies the first dimension of A as declared in
85 the calling (sub) program. When TRANSA = 'N' or 'n' then LDA
86 must be at least max( 1, m ), otherwise LDA must be at least
87 max( 1, k ). Unchanged on exit.
88 B - COMPLEX*16 array of DIMENSION ( LDB, kb ), where kb is
90 n when TRANSB = 'N' or 'n', and is k otherwise. Before
91 entry with TRANSB = 'N' or 'n', the leading k by n part of
92 the array B must contain the matrix B, otherwise the leading
93 n by k part of the array B must contain the matrix B.
94 Unchanged on exit.
95 LDB - INTEGER.
97 On entry, LDB specifies the first dimension of B as declared in
98 the calling (sub) program. When TRANSB = 'N' or 'n' then LDB
99 must be at least max( 1, k ), otherwise LDB must be at least
100 max( 1, n ). Unchanged on exit.
101 BETA - COMPLEX*16 .
103 On entry, BETA specifies the scalar beta. When BETA is
104 supplied as zero then C need not be set on input. Unchanged on
105 exit.
106 C - COMPLEX*16 array of DIMENSION ( LDC, n ).
108 Before entry, the leading m by n part of the array C must
109 contain the matrix C, except when beta is zero, in which
110 case C need not be set on entry. On exit, the array C is
111 overwritten by the m by n matrix ( alpha*op( A )*op( B ) +
112 beta*C ).
113 LDC - INTEGER.
115 On entry, LDC specifies the first dimension of C as declared in
116 the calling (sub) program. LDC must be at least max( 1,
117 m ). Unchanged on exit.
118 Level 3 Blas routine.
120 -- Written on 8-February-1989. Jack Dongarra, Argonne National
122 Laboratory. Iain Duff, AERE Harwell. Jeremy Du Croz, Numerical
123 Algorithms Group Ltd. Sven Hammarling, Numerical Algorithms
124 Group Ltd.
125BLAS routine November 2006 ZGEMM(1)