cgemm3mf.f

SUBROUTINECGEMM3MF(TRA,TRB,M,N,K,ALPHA,A,LDA,B,LDB,BETA,C,LDC)
* .. Scalar Arguments ..
COMPLEX ALPHA,BETA
INTEGER K,LDA,LDB,LDC,M,N
CHARACTER TRA,TRB
* ..
* .. Array Arguments ..
COMPLEX A(LDA,*),B(LDB,*),C(LDC,*)
* ..
*
* Purpose
* =======
*
* CGEMM 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' or op( X ) = conjg( 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.
*
* Arguments
* ==========
*
* TRA - CHARACTER*1.
* On entry, TRA specifies the form of op( A ) to be used in
* the matrix multiplication as follows:
*
* TRA = 'N' or 'n', op( A ) = A.
*
* TRA = 'T' or 't', op( A ) = A'.
*
* TRA = 'C' or 'c', op( A ) = conjg( A' ).
*
* Unchanged on exit.
*
* TRB - CHARACTER*1.
* On entry, TRB specifies the form of op( B ) to be used in
* the matrix multiplication as follows:
*
* TRB = 'N' or 'n', op( B ) = B.
*
* TRB = 'T' or 't', op( B ) = B'.
*
* TRB = 'C' or 'c', op( B ) = conjg( 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 - COMPLEX .
* On entry, ALPHA specifies the scalar alpha.
* Unchanged on exit.
*
* A - COMPLEX array of DIMENSION ( LDA, ka ), where ka is
* k when TRA = 'N' or 'n', and is m otherwise.
* Before entry with TRA = '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 TRA = '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 - COMPLEX array of DIMENSION ( LDB, kb ), where kb is
* n when TRB = 'N' or 'n', and is k otherwise.
* Before entry with TRB = '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 TRB = '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 - COMPLEX .
* 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 - COMPLEX 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 CONJG,MAX
* ..
* .. Local Scalars ..
COMPLEX TEMP
INTEGER I,INFO,J,L,NCOLA,NROWA,NROWB
LOGICAL CONJA,CONJB,NOTA,NOTB
* ..
* .. Parameters ..
COMPLEX ONE
PARAMETER (ONE= (1.0E+0,0.0E+0))
COMPLEX ZERO
PARAMETER (ZERO= (0.0E+0,0.0E+0))
* ..
*
* Set NOTA and NOTB as true if A and B respectively are not
* conjugated or transposed, set CONJA and CONJB as true if A and
* B respectively are to be transposed but not conjugated 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(TRA,'N')
 NOTB = LSAME(TRB,'N')
 CONJA = LSAME(TRA,'C')
 CONJB = LSAME(TRB,'C')
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.CONJA) .AND.
+ (.NOT.LSAME(TRA,'T'))) THEN
 INFO =1
ELSEIF ((.NOT.NOTB) .AND. (.NOT.CONJB) .AND.
+ (.NOT.LSAME(TRB,'T'))) THEN
 INFO =2
ELSEIF (M.LT.0) THEN
 INFO =3
ELSEIF (N.LT.0) THEN
 INFO =4
ELSEIF (K.LT.0) THEN
 INFO =5
ELSEIF (LDA.LT.MAX(1,NROWA)) THEN
 INFO =8
ELSEIF (LDB.LT.MAX(1,NROWB)) THEN
 INFO =10
ELSEIF (LDC.LT.MAX(1,M)) THEN
 INFO =13
END IF
IF (INFO.NE.0) THEN
CALL XERBLA('CGEMM ',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 when alpha.eq.zero.
*
IF (ALPHA.EQ.ZERO) THEN
IF (BETA.EQ.ZERO) THEN
DO20 J =1,N
DO10 I =1,M
 C(I,J) = ZERO
10CONTINUE
20CONTINUE
ELSE
DO40 J =1,N
DO30 I =1,M
 C(I,J) = BETA*C(I,J)
30CONTINUE
40CONTINUE
END IF
RETURN
END IF
*
* Start the operations.
*
IF (NOTB) THEN
IF (NOTA) THEN
*
* Form C := alpha*A*B + beta*C.
*
DO90 J =1,N
IF (BETA.EQ.ZERO) THEN
DO50 I =1,M
 C(I,J) = ZERO
50CONTINUE
ELSEIF (BETA.NE.ONE) THEN
DO60 I =1,M
 C(I,J) = BETA*C(I,J)
60CONTINUE
END IF
DO80 L =1,K
IF (B(L,J).NE.ZERO) THEN
 TEMP = ALPHA*B(L,J)
DO70 I =1,M
 C(I,J) = C(I,J) + TEMP*A(I,L)
70CONTINUE
END IF
80CONTINUE
90CONTINUE
ELSEIF (CONJA) THEN
*
* Form C := alpha*conjg( A' )*B + beta*C.
*
DO120 J =1,N
DO110 I =1,M
 TEMP = ZERO
DO100 L =1,K
 TEMP = TEMP +CONJG(A(L,I))*B(L,J)
100CONTINUE
IF (BETA.EQ.ZERO) THEN
 C(I,J) = ALPHA*TEMP
ELSE
 C(I,J) = ALPHA*TEMP + BETA*C(I,J)
END IF
110CONTINUE
120CONTINUE
ELSE
*
* Form C := alpha*A'*B + beta*C
*
DO150 J =1,N
DO140 I =1,M
 TEMP = ZERO
DO130 L =1,K
 TEMP = TEMP + A(L,I)*B(L,J)
130CONTINUE
IF (BETA.EQ.ZERO) THEN
 C(I,J) = ALPHA*TEMP
ELSE
 C(I,J) = ALPHA*TEMP + BETA*C(I,J)
END IF
140CONTINUE
150CONTINUE
END IF
ELSEIF (NOTA) THEN
IF (CONJB) THEN
*
* Form C := alpha*A*conjg( B' ) + beta*C.
*
DO200 J =1,N
IF (BETA.EQ.ZERO) THEN
DO160 I =1,M
 C(I,J) = ZERO
160CONTINUE
ELSEIF (BETA.NE.ONE) THEN
DO170 I =1,M
 C(I,J) = BETA*C(I,J)
170CONTINUE
END IF
DO190 L =1,K
IF (B(J,L).NE.ZERO) THEN
 TEMP = ALPHA*CONJG(B(J,L))
DO180 I =1,M
 C(I,J) = C(I,J) + TEMP*A(I,L)
180CONTINUE
END IF
190CONTINUE
200CONTINUE
ELSE
*
* Form C := alpha*A*B' + beta*C
*
DO250 J =1,N
IF (BETA.EQ.ZERO) THEN
DO210 I =1,M
 C(I,J) = ZERO
210CONTINUE
ELSEIF (BETA.NE.ONE) THEN
DO220 I =1,M
 C(I,J) = BETA*C(I,J)
220CONTINUE
END IF
DO240 L =1,K
IF (B(J,L).NE.ZERO) THEN
 TEMP = ALPHA*B(J,L)
DO230 I =1,M
 C(I,J) = C(I,J) + TEMP*A(I,L)
230CONTINUE
END IF
240CONTINUE
250CONTINUE
END IF
ELSEIF (CONJA) THEN
IF (CONJB) THEN
*
* Form C := alpha*conjg( A' )*conjg( B' ) + beta*C.
*
DO280 J =1,N
DO270 I =1,M
 TEMP = ZERO
DO260 L =1,K
 TEMP = TEMP +CONJG(A(L,I))*CONJG(B(J,L))
260CONTINUE
IF (BETA.EQ.ZERO) THEN
 C(I,J) = ALPHA*TEMP
ELSE
 C(I,J) = ALPHA*TEMP + BETA*C(I,J)
END IF
270CONTINUE
280CONTINUE
ELSE
*
* Form C := alpha*conjg( A' )*B' + beta*C
*
DO310 J =1,N
DO300 I =1,M
 TEMP = ZERO
DO290 L =1,K
 TEMP = TEMP +CONJG(A(L,I))*B(J,L)
290CONTINUE
IF (BETA.EQ.ZERO) THEN
 C(I,J) = ALPHA*TEMP
ELSE
 C(I,J) = ALPHA*TEMP + BETA*C(I,J)
END IF
300CONTINUE
310CONTINUE
END IF
ELSE
IF (CONJB) THEN
*
* Form C := alpha*A'*conjg( B' ) + beta*C
*
DO340 J =1,N
DO330 I =1,M
 TEMP = ZERO
DO320 L =1,K
 TEMP = TEMP + A(L,I)*CONJG(B(J,L))
320CONTINUE
IF (BETA.EQ.ZERO) THEN
 C(I,J) = ALPHA*TEMP
ELSE
 C(I,J) = ALPHA*TEMP + BETA*C(I,J)
END IF
330CONTINUE
340CONTINUE
ELSE
*
* Form C := alpha*A'*B' + beta*C
*
DO370 J =1,N
DO360 I =1,M
 TEMP = ZERO
DO350 L =1,K
 TEMP = TEMP + A(L,I)*B(J,L)
350CONTINUE
IF (BETA.EQ.ZERO) THEN
 C(I,J) = ALPHA*TEMP
ELSE
 C(I,J) = ALPHA*TEMP + BETA*C(I,J)
END IF
360CONTINUE
370CONTINUE
END IF
END IF
*
RETURN
*
* End of CGEMM .
*
END