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Diffstat (limited to '2.3-1/src/fortran/blas/zherk.f')
| -rw-r--r-- | 2.3-1/src/fortran/blas/zherk.f | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/2.3-1/src/fortran/blas/zherk.f b/2.3-1/src/fortran/blas/zherk.f new file mode 100644 index 00000000..cfbf7180 --- /dev/null +++ b/2.3-1/src/fortran/blas/zherk.f @@ -0,0 +1,330 @@ + SUBROUTINE ZHERK( UPLO, TRANS, N, K, ALPHA, A, LDA, BETA, C, LDC ) +* .. Scalar Arguments .. + CHARACTER TRANS, UPLO + INTEGER K, LDA, LDC, N + DOUBLE PRECISION ALPHA, BETA +* .. +* .. Array Arguments .. + COMPLEX*16 A( LDA, * ), C( LDC, * ) +* .. +* +* Purpose +* ======= +* +* ZHERK performs one of the hermitian rank k operations +* +* C := alpha*A*conjg( A' ) + beta*C, +* +* or +* +* C := alpha*conjg( A' )*A + beta*C, +* +* where alpha and beta are real scalars, C is an n by n hermitian +* matrix and A is an n by k matrix in the first case and a k by n +* matrix in the second case. +* +* Parameters +* ========== +* +* UPLO - CHARACTER*1. +* On entry, UPLO specifies whether the upper or lower +* triangular part of the array C is to be referenced as +* follows: +* +* UPLO = 'U' or 'u' Only the upper triangular part of C +* is to be referenced. +* +* UPLO = 'L' or 'l' Only the lower triangular part of C +* is to be referenced. +* +* Unchanged on exit. +* +* TRANS - CHARACTER*1. +* On entry, TRANS specifies the operation to be performed as +* follows: +* +* TRANS = 'N' or 'n' C := alpha*A*conjg( A' ) + beta*C. +* +* TRANS = 'C' or 'c' C := alpha*conjg( A' )*A + beta*C. +* +* Unchanged on exit. +* +* N - INTEGER. +* On entry, N specifies the order of the matrix C. N must be +* at least zero. +* Unchanged on exit. +* +* K - INTEGER. +* On entry with TRANS = 'N' or 'n', K specifies the number +* of columns of the matrix A, and on entry with +* TRANS = 'C' or 'c', K specifies the number of rows of the +* matrix A. K must be at least zero. +* Unchanged on exit. +* +* ALPHA - DOUBLE PRECISION . +* On entry, ALPHA specifies the scalar alpha. +* Unchanged on exit. +* +* A - COMPLEX*16 array of DIMENSION ( LDA, ka ), where ka is +* k when TRANS = 'N' or 'n', and is n otherwise. +* Before entry with TRANS = 'N' or 'n', the leading n by k +* part of the array A must contain the matrix A, otherwise +* the leading k by n 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 TRANS = 'N' or 'n' +* then LDA must be at least max( 1, n ), otherwise LDA must +* be at least max( 1, k ). +* Unchanged on exit. +* +* BETA - DOUBLE PRECISION. +* On entry, BETA specifies the scalar beta. +* Unchanged on exit. +* +* C - COMPLEX*16 array of DIMENSION ( LDC, n ). +* Before entry with UPLO = 'U' or 'u', the leading n by n +* upper triangular part of the array C must contain the upper +* triangular part of the hermitian matrix and the strictly +* lower triangular part of C is not referenced. On exit, the +* upper triangular part of the array C is overwritten by the +* upper triangular part of the updated matrix. +* Before entry with UPLO = 'L' or 'l', the leading n by n +* lower triangular part of the array C must contain the lower +* triangular part of the hermitian matrix and the strictly +* upper triangular part of C is not referenced. On exit, the +* lower triangular part of the array C is overwritten by the +* lower triangular part of the updated matrix. +* Note that the imaginary parts of the diagonal elements need +* not be set, they are assumed to be zero, and on exit they +* are set to zero. +* +* 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, n ). +* 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. +* +* -- Modified 8-Nov-93 to set C(J,J) to DBLE( C(J,J) ) when BETA = 1. +* Ed Anderson, Cray Research Inc. +* +* +* .. External Functions .. + LOGICAL LSAME + EXTERNAL LSAME +* .. +* .. External Subroutines .. + EXTERNAL XERBLA +* .. +* .. Intrinsic Functions .. + INTRINSIC DBLE, DCMPLX, DCONJG, MAX +* .. +* .. Local Scalars .. + LOGICAL UPPER + INTEGER I, INFO, J, L, NROWA + DOUBLE PRECISION RTEMP + COMPLEX*16 TEMP +* .. +* .. Parameters .. + DOUBLE PRECISION ONE, ZERO + PARAMETER ( ONE = 1.0D+0, ZERO = 0.0D+0 ) +* .. +* .. Executable Statements .. +* +* Test the input parameters. +* + IF( LSAME( TRANS, 'N' ) ) THEN + NROWA = N + ELSE + NROWA = K + END IF + UPPER = LSAME( UPLO, 'U' ) +* + INFO = 0 + IF( ( .NOT.UPPER ) .AND. ( .NOT.LSAME( UPLO, 'L' ) ) ) THEN + INFO = 1 + ELSE IF( ( .NOT.LSAME( TRANS, 'N' ) ) .AND. + $ ( .NOT.LSAME( TRANS, 'C' ) ) ) THEN + INFO = 2 + ELSE IF( N.LT.0 ) THEN + INFO = 3 + ELSE IF( K.LT.0 ) THEN + INFO = 4 + ELSE IF( LDA.LT.MAX( 1, NROWA ) ) THEN + INFO = 7 + ELSE IF( LDC.LT.MAX( 1, N ) ) THEN + INFO = 10 + END IF + IF( INFO.NE.0 ) THEN + CALL XERBLA( 'ZHERK ', INFO ) + RETURN + END IF +* +* Quick return if possible. +* + IF( ( 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( UPPER ) THEN + IF( BETA.EQ.ZERO ) THEN + DO 20 J = 1, N + DO 10 I = 1, J + C( I, J ) = ZERO + 10 CONTINUE + 20 CONTINUE + ELSE + DO 40 J = 1, N + DO 30 I = 1, J - 1 + C( I, J ) = BETA*C( I, J ) + 30 CONTINUE + C( J, J ) = BETA*DBLE( C( J, J ) ) + 40 CONTINUE + END IF + ELSE + IF( BETA.EQ.ZERO ) THEN + DO 60 J = 1, N + DO 50 I = J, N + C( I, J ) = ZERO + 50 CONTINUE + 60 CONTINUE + ELSE + DO 80 J = 1, N + C( J, J ) = BETA*DBLE( C( J, J ) ) + DO 70 I = J + 1, N + C( I, J ) = BETA*C( I, J ) + 70 CONTINUE + 80 CONTINUE + END IF + END IF + RETURN + END IF +* +* Start the operations. +* + IF( LSAME( TRANS, 'N' ) ) THEN +* +* Form C := alpha*A*conjg( A' ) + beta*C. +* + IF( UPPER ) THEN + DO 130 J = 1, N + IF( BETA.EQ.ZERO ) THEN + DO 90 I = 1, J + C( I, J ) = ZERO + 90 CONTINUE + ELSE IF( BETA.NE.ONE ) THEN + DO 100 I = 1, J - 1 + C( I, J ) = BETA*C( I, J ) + 100 CONTINUE + C( J, J ) = BETA*DBLE( C( J, J ) ) + ELSE + C( J, J ) = DBLE( C( J, J ) ) + END IF + DO 120 L = 1, K + IF( A( J, L ).NE.DCMPLX( ZERO ) ) THEN + TEMP = ALPHA*DCONJG( A( J, L ) ) + DO 110 I = 1, J - 1 + C( I, J ) = C( I, J ) + TEMP*A( I, L ) + 110 CONTINUE + C( J, J ) = DBLE( C( J, J ) ) + + $ DBLE( TEMP*A( I, L ) ) + END IF + 120 CONTINUE + 130 CONTINUE + ELSE + DO 180 J = 1, N + IF( BETA.EQ.ZERO ) THEN + DO 140 I = J, N + C( I, J ) = ZERO + 140 CONTINUE + ELSE IF( BETA.NE.ONE ) THEN + C( J, J ) = BETA*DBLE( C( J, J ) ) + DO 150 I = J + 1, N + C( I, J ) = BETA*C( I, J ) + 150 CONTINUE + ELSE + C( J, J ) = DBLE( C( J, J ) ) + END IF + DO 170 L = 1, K + IF( A( J, L ).NE.DCMPLX( ZERO ) ) THEN + TEMP = ALPHA*DCONJG( A( J, L ) ) + C( J, J ) = DBLE( C( J, J ) ) + + $ DBLE( TEMP*A( J, L ) ) + DO 160 I = J + 1, N + C( I, J ) = C( I, J ) + TEMP*A( I, L ) + 160 CONTINUE + END IF + 170 CONTINUE + 180 CONTINUE + END IF + ELSE +* +* Form C := alpha*conjg( A' )*A + beta*C. +* + IF( UPPER ) THEN + DO 220 J = 1, N + DO 200 I = 1, J - 1 + TEMP = ZERO + DO 190 L = 1, K + TEMP = TEMP + DCONJG( A( L, I ) )*A( L, J ) + 190 CONTINUE + IF( BETA.EQ.ZERO ) THEN + C( I, J ) = ALPHA*TEMP + ELSE + C( I, J ) = ALPHA*TEMP + BETA*C( I, J ) + END IF + 200 CONTINUE + RTEMP = ZERO + DO 210 L = 1, K + RTEMP = RTEMP + DCONJG( A( L, J ) )*A( L, J ) + 210 CONTINUE + IF( BETA.EQ.ZERO ) THEN + C( J, J ) = ALPHA*RTEMP + ELSE + C( J, J ) = ALPHA*RTEMP + BETA*DBLE( C( J, J ) ) + END IF + 220 CONTINUE + ELSE + DO 260 J = 1, N + RTEMP = ZERO + DO 230 L = 1, K + RTEMP = RTEMP + DCONJG( A( L, J ) )*A( L, J ) + 230 CONTINUE + IF( BETA.EQ.ZERO ) THEN + C( J, J ) = ALPHA*RTEMP + ELSE + C( J, J ) = ALPHA*RTEMP + BETA*DBLE( C( J, J ) ) + END IF + DO 250 I = J + 1, N + TEMP = ZERO + DO 240 L = 1, K + TEMP = TEMP + DCONJG( A( L, I ) )*A( L, J ) + 240 CONTINUE + IF( BETA.EQ.ZERO ) THEN + C( I, J ) = ALPHA*TEMP + ELSE + C( I, J ) = ALPHA*TEMP + BETA*C( I, J ) + END IF + 250 CONTINUE + 260 CONTINUE + END IF + END IF +* + RETURN +* +* End of ZHERK . +* + END |