sla_geamv - vector product using a general matrix to calculate error bounds
SUBROUTINE SLA_GEAMV (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL ALPHA, BETA INTEGER INCX, INCY, LDA, M, N, TRANS REAL A(LDA,*), X(*), Y(*) SUBROUTINE SLA_GEAMV_64 (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL ALPHA, BETA INTEGER*8 INCX, INCY, LDA, M, N, TRANS REAL A(LDA,*), X(*), Y(*) F95 INTERFACE SUBROUTINE LA_GEAMV (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL, DIMENSION(:,:) :: A INTEGER :: TRANS, M, N, LDA, INCX, INCY REAL, DIMENSION(:) :: X, Y REAL :: ALPHA, BETA SUBROUTINE LA_GEAMV_64 (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL, DIMENSION(:,:) :: A INTEGER(8) :: TRANS, M, N, LDA, INCX, INCY REAL, DIMENSION(:) :: X, Y REAL :: ALPHA, BETA C INTERFACE #include <sunperf.h> void sla_geamv (int trans, int m, int n, float alpha, float *a, int lda, float *x, int incx, float beta, float *y, int incy); void sla_geamv_64 (long trans, long m, long n, float alpha, float *a, long lda, float *x, long incx, float beta, float *y, long incy);
Oracle Solaris Studio Performance Library sla_geamv(3P) NAME sla_geamv - compute a matrix-vector product using a general matrix to calculate error bounds SYNOPSIS SUBROUTINE SLA_GEAMV (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL ALPHA, BETA INTEGER INCX, INCY, LDA, M, N, TRANS REAL A(LDA,*), X(*), Y(*) SUBROUTINE SLA_GEAMV_64 (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL ALPHA, BETA INTEGER*8 INCX, INCY, LDA, M, N, TRANS REAL A(LDA,*), X(*), Y(*) F95 INTERFACE SUBROUTINE LA_GEAMV (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL, DIMENSION(:,:) :: A INTEGER :: TRANS, M, N, LDA, INCX, INCY REAL, DIMENSION(:) :: X, Y REAL :: ALPHA, BETA SUBROUTINE LA_GEAMV_64 (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL, DIMENSION(:,:) :: A INTEGER(8) :: TRANS, M, N, LDA, INCX, INCY REAL, DIMENSION(:) :: X, Y REAL :: ALPHA, BETA C INTERFACE #include <sunperf.h> void sla_geamv (int trans, int m, int n, float alpha, float *a, int lda, float *x, int incx, float beta, float *y, int incy); void sla_geamv_64 (long trans, long m, long n, float alpha, float *a, long lda, float *x, long incx, float beta, float *y, long incy); PURPOSE sla_geamv performs one of the matrix-vector operations y := alpha*abs(A)*abs(x) + beta*abs(y), or y := alpha*abs(A)**T*abs(x) + beta*abs(y), where alpha and beta are scalars, x and y are vectors and A is an m by n matrix. This function is primarily used in calculating error bounds. To pro- tect against underflow during evaluation, components in the resulting vector are perturbed away from zero by (N+1) times the underflow threshold. To prevent unnecessarily large errors for block-structure embedded in general matrices, "symbolically" zero components are not perturbed. A zero entry is considered "symbolic" if all multiplications involved in computing that entry have at least one zero multiplicand. ARGUMENTS TRANS (input) TRANS is INTEGER On entry, TRANS specifies the operation to be performed as follows: BLAS_NO_TRANS y := alpha*abs(A)*abs(x) + beta*abs(y) BLAS_TRANS y := alpha*abs(A**T)*abs(x) + beta*abs(y) BLAS_CONJ_TRANS y := alpha*abs(A**T)*abs(x) + beta*abs(y) Unchanged on exit. M (input) M is INTEGER On entry, M specifies the number of rows of the matrix A. M must be at least zero. Unchanged on exit. N (input) N is INTEGER On entry, N specifies the number of columns of the matrix A. N must be at least zero. Unchanged on exit. ALPHA (input) ALPHA is REAL On entry, ALPHA specifies the scalar alpha. Unchanged on exit. A (input) A is REAL array of DIMENSION ( LDA, n ) Before entry, the leading m by n part of the array A must contain the matrix of coefficients. Unchanged on exit. LDA (input) LDA is INTEGER On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. LDA must be at least max( 1, m ). Unchanged on exit. X (input) X is REAL array, dimension (1 + ( n - 1 )*abs( INCX )) when TRANS = 'N' or 'n' and at least (1 + ( m - 1 )*abs( INCX )) otherwise. Before entry, the incremented array X must contain the vector x. Unchanged on exit. INCX (input) INCX is INTEGER On entry, INCX specifies the increment for the elements of X. INCX must not be zero. Unchanged on exit. BETA (input) BETA is REAL On entry, BETA specifies the scalar beta. When BETA is sup- plied as zero then Y need not be set on input. Unchanged on exit. Y (input/output) Y is REAL Array of DIMENSION at least (1 + ( m - 1 )*abs( INCY )) when TRANS = 'N' or 'n' and at least (1 + ( n - 1 )*abs( INCY )) otherwise. Before entry with BETA non-zero, the incremented array Y must contain the vector y. On exit, Y is overwritten by the updated vector y. INCY (input) INCY is INTEGER On entry, INCY specifies the increment for the elements of Y. INCY must not be zero. Unchanged on exit. Level 2 Blas routine. 7 Nov 2015 sla_geamv(3P)