dskymm(3P) Sun Performance Library dskymm(3P)NAMEdskymm - Skyline format matrix-matrix multiply
SYNOPSIS
SUBROUTINE DSKYMM( TRANSA, M, N, K, ALPHA, DESCRA,
* VAL, PNTR,
* B, LDB, BETA, C, LDC, WORK, LWORK)
INTEGER TRANSA, M, N, K, DESCRA(5),
* LDB, LDC, LWORK
INTEGER PNTR(*),
DOUBLE PRECISION ALPHA, BETA
DOUBLE PRECISION VAL(NNZ), B(LDB,*), C(LDC,*), WORK(LWORK)
SUBROUTINE DSKYMM_64( TRANSA, M, N, K, ALPHA, DESCRA,
* VAL, PNTR,
* B, LDB, BETA, C, LDC, WORK, LWORK)
INTEGER*8 TRANSA, M, N, K, DESCRA(5),
* LDB, LDC, LWORK
INTEGER*8 PNTR(*),
DOUBLE PRECISION ALPHA, BETA
DOUBLE PRECISION VAL(NNZ), B(LDB,*), C(LDC,*), WORK(LWORK)
where NNZ = PNTR(K+1)-PNTR(1) (upper triangular)
NNZ = PNTR(M+1)-PNTR(1) (lower triangular)
PNTR() size = (K+1) (upper triangular)
PNTR() size = (M+1) (lower triangular)
F95 INTERFACE
SUBROUTINE SKYMM( TRANSA, M, [N], K, ALPHA, DESCRA, VAL,
* PNTR, B, [LDB], BETA, C, [LDC], [WORK], [LWORK])
INTEGER TRANSA, M, K
INTEGER, DIMENSION(:) :: DESCRA, PNTR
DOUBLE PRECISION ALPHA, BETA
DOUBLE PRECISION, DIMENSION(:) :: VAL
DOUBLE PRECISION, DIMENSION(:, :) :: B, C
SUBROUTINE SKYMM_64( TRANSA, M, [N], K, ALPHA, DESCRA, VAL,
* PNTR, B, [LDB], BETA, C, [LDC], [WORK], [LWORK])
INTEGER*8 TRANSA, M, K
INTEGER*8, DIMENSION(:) :: DESCRA, PNTR
DOUBLE PRECISION ALPHA, BETA
DOUBLE PRECISION, DIMENSION(:) :: VAL
DOUBLE PRECISION, DIMENSION(:, :) :: B, C
C INTERFACE
#include <sunperf.h>
void dskymm (const int transa, const int m, const int n, const int k,
const double alpha, const int* descra, const double* val,
const int* pntr, const double* b, const int ldb, const double
beta, double* c, const int ldc);
void dskymm_64 (const long transa, const long m, const long n, const
long k, const double alpha, const long* descra, const double*
val, const long* pntr, const double* b, const long ldb, const
double beta, double* c, const long ldc);
DESCRIPTIONdskymm performs one of the matrix-matrix operations
C <- alpha op(A) B + beta C
where op( A ) is one of
op( A ) = A or op( A ) = A' or op( A ) = conjg( A' )
( ' indicates matrix transpose),
A is an M-by-K sparse matrix represented in the skyline format,
alpha and beta are scalars, C and B are dense matrices.
ARGUMENTSTRANSA(input) On entry, integer TRANSA specifies the form
of op( A ) to be used in the matrix
multiplication as follows:
0 : operate with matrix
1 : operate with transpose matrix
2 : operate with the conjugate transpose of matrix.
2 is equivalent to 1 if matrix is real.
Unchanged on exit.
M(input) On entry, integer M specifies the number of rows in
the matrix A. Unchanged on exit.
N(input) On entry, integer N specifies the number of columns in
the matrix C. Unchanged on exit.
K(input) On entry, integer K specifies the number of columns
in the matrix A. Unchanged on exit.
ALPHA(input) On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
DESCRA (input) Descriptor argument. Five element integer array.
DESCRA(1) matrix structure
0 : general (NOT SUPPORTED)
1 : symmetric (A=A')
2 : Hermitian (A= CONJG(A'))
3 : Triangular
4 : Skew(Anti)-Symmetric (A=-A')
5 : Diagonal
6 : Skew-Hermitian (A= -CONJG(A'))
DESCRA(2) upper/lower triangular indicator
1 : lower
2 : upper
DESCRA(3) main diagonal type
0 : non-unit
1 : unit
DESCRA(4) Array base (NOT IMPLEMENTED)
0 : C/C++ compatible
1 : Fortran compatible
DESCRA(5) repeated indices? (NOT IMPLEMENTED)
0 : unknown
1 : no repeated indices
VAL(input) On entry, VAL is a scalar array consisting of
the nonzeros of A in skyline profile form.
Row-oriented if DESCRA(2) = 1 (lower triangular),
column oriented if DESCRA(2) = 2 (upper triangular).
Unchanged on exit.
PNTR (input) On entry, INDX is an integer array of length
M+1 (lower triangular) or K+1 (upper triangular)
such that PNTR(I)-PNTR(1)+1 points to the
location in VAL of the first element of the skyline
profile in row (column) I. Unchanged on exit.
B (input) Array of DIMENSION ( LDB, N ).
Before entry with TRANSA = 0, the leading k by n
part of the array B must contain the matrix B, otherwise
the leading m by n part of the array B must contain the
matrix B. Unchanged on exit.
LDB (input) On entry, LDB specifies the first dimension of B as declared
in the calling (sub) program. Unchanged on exit.
BETA (input) On entry, BETA specifies the scalar beta. Unchanged on exit.
C(input/output) Array of DIMENSION ( LDC, N ).
Before entry with TRANSA = 0, the leading m by n
part of the array C must contain the matrix C, otherwise
the leading k by n part of the array C must contain the
matrix C. On exit, the array C is overwritten by the matrix
( alpha*op( A )* B + beta*C ).
LDC (input) On entry, LDC specifies the first dimension of C as declared
in the calling (sub) program. Unchanged on exit.
WORK (is not referenced in the current version)
LWORK (is not referenced in the current version)
SEE ALSO
Libsunperf SPARSE BLAS is fully parallel and compatible with NIST FOR‐
TRAN Sparse Blas but the sources are different. Libsunperf SPARSE BLAS
is free of bugs found in NIST FORTRAN Sparse Blas. Besides several new
features and routines are implemented.
NIST FORTRAN Sparse Blas User's Guide available at:
http://math.nist.gov/mcsd/Staff/KRemington/fspblas/
Based on the standard proposed in
"Document for the Basic Linear Algebra Subprograms (BLAS) Standard",
University of Tennessee, Knoxville, Tennessee, 1996:
http://www.netlib.org/utk/papers/sparse.ps
NOTES/BUGS
The SKY data structure is not supported for a general matrix structure
(DESCRA(1)=0).
Also not supported:
1. lower triangular matrix A of size m by n where m > n
2. upper triangular matrix A of size m by n where m < n
3rd Berkeley Distribution 6 Mar 2009 dskymm(3P)
