sbsrmm(3P) Sun Performance Library sbsrmm(3P)NAMEsbsrmm - block sparse row format matrix-matrix multiply
SYNOPSIS
SUBROUTINE SBSRMM( TRANSA, MB, N, KB, ALPHA, DESCRA,
* VAL, BINDX, BPNTRB, BPNTRE, LB,
* B, LDB, BETA, C, LDC, WORK, LWORK )
INTEGER TRANSA, MB, N, KB, DESCRA(5), LB,
* LDB, LDC, LWORK
INTEGER BINDX(BNNZ), BPNTRB(MB), BPNTRE(MB)
REAL ALPHA, BETA
REAL VAL(LB*LB*BNNZ), B(LDB,*), C(LDC,*), WORK(LWORK)
SUBROUTINE SBSRMM_64( TRANSA, MB, N, KB, ALPHA, DESCRA,
* VAL, BINDX, BPNTRB, BPNTRE, LB,
* B, LDB, BETA, C, LDC, WORK, LWORK )
INTEGER*8 TRANSA, MB, N, KB, DESCRA(5), LB,
* LDB, LDC, LWORK
INTEGER*8 BINDX(BNNZ), BPNTRB(MB), BPNTRE(MB)
REAL ALPHA, BETA
REAL VAL(LB*LB*BNNZ), B(LDB,*), C(LDC,*), WORK(LWORK)
where: BNNZ = BPNTRE(MB)-BPNTRB(1)
F95 INTERFACE
SUBROUTINE BSRMM( TRANSA, MB, [N], KB, ALPHA, DESCRA, VAL, BINDX,
* BPNTRB, BPNTRE, LB, B, [LDB], BETA, C, [LDC], [WORK], [LWORK])
INTEGER TRANSA, MB, KB, LB
INTEGER, DIMENSION(:) :: DESCRA, BINDX, BPNTRB, BPNTRE
REAL ALPHA, BETA
REAL, DIMENSION(:) :: VAL
REAL, DIMENSION(:, :) :: B, C
SUBROUTINE BSRMM_64( TRANSA, MB, [N], KB, ALPHA, DESCRA, VAL, BINDX,
* BPNTRB, BPNTRE, LB, B, [LDB], BETA, C, [LDC], [WORK], [LWORK])
INTEGER*8 TRANSA, MB, KB, LB
INTEGER*8, DIMENSION(:) :: DESCRA, BINDX, BPNTRB, BPNTRE
REAL ALPHA, BETA
REAL, DIMENSION(:) :: VAL
REAL, DIMENSION(:, :) :: B, C
C INTERFACE
#include <sunperf.h>
void sbsrmm (const int transa, const int mb, const int n, const int kb,
const float alpha, const int* descra, const float* val, const
int* bindx, const int* bpntrb, const int* bpntre, const int
lb, const float* b, const int ldb, const float beta, float*
c, const int ldc);
void sbsrmm_64 (const long transa, const long mb, const long n, const
long kb, const float alpha, const long* descra, const float*
val, const long* bindx, const long* bpntrb, const long* bpn‐
tre, const long lb, const float* b, const long ldb, const
float beta, float* c, const long ldc);
DESCRIPTIONsbsrmm performs one of the matrix-matrix operations
C <- alpha op(A) B + beta C
where alpha and beta are scalars, C and B are dense matrices,
A is an (mb*lb) by (kb*lb) sparse matrix represented in the
block sparse row format and op( A ) is one of
op( A ) = A or op( A ) = A' or op( A ) = conjg( A' ).
( ' indicates matrix transpose)
ARGUMENTSTRANSA(input) 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.
MB(input) On entry, MB specifies the number of block rows
in the matrix A. Unchanged on exit.
N(input) On entry, N specifies the number of columns
in the matrix C. Unchanged on exit.
KB(input) On entry, KB specifies the number of block 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
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 block 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 of length LB*LB*BNNZ
consisting of the non-zero block entries stored
column-major within each dense block where
BNNZ = BPNTRE(MB)-BPNTRB(1). Unchanged on exit.
BINDX(input) On entry, BINDX is an integer array of length BNNZ consisting
of the block column indices of the block entries of A where
BNNZ = BPNTRE(MB)-BPNTRB(1). Unchanged on exit.
BPNTRB(input) On entry,BPNTRB is an integer array of length MB such
that BPNTRB(J)-BPNTRB(1)+1 points to location in BINDX
of the first block entry of the J-th block row
of A. Unchanged on exit.
BPNTRE(input) On entry, BPNTRE is an integer array of length MB such
that BPNTRE(J)-BPNTRB(1) points to location in BINDX
of the last block entry of the J-th block row
of A. Unchanged on exit.
LB (input) On entry, LB specifies the dimension of dense blocks
composing A. Unchanged on exit.
B (input) Array of DIMENSION ( LDB, N ).
Before entry with TRANSA = 0, the leading kb*lb by n
part of the array B must contain the matrix B, otherwise
the leading mb*lb 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 mb*lb by n
part of the array C must contain the matrix C, otherwise
the leading kb*lb 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
The routine is designed so that it provides a possibility to use just
one sparse matrix representation of a general matrix A for computing
matrix-matrix multiply for another sparse matrix composed by block
triangles and/or the main block diagonal of A. The full description of
the feature for block entry formats is given in section NOTES/BUGS for
the sbcomm manpage.
NOTES/BUGS
It is known that there exists another representation of the block
sparse row format (see for example Y.Saad, "Iterative Methods for
Sparse Linear Systems", WPS, 1996). Its data structure consists of
three array instead of the four used in the current implementation.
The main difference is that only one array, IA, containing the pointers
to the beginning of each block row in the arrays VAL and BINDX is used
instead of two arrays BPNTRB and BPNTRE. To use the routine with this
kind of block sparse row format the following calling sequence should
be used
CALL SBSRMM( TRANSA, MB, N, KB, ALPHA, DESCRA,
* VAL, BINDX, IA, IA(2), LB,
* B, LDB, BETA, C, LDC, WORK, LWORK )
3rd Berkeley Distribution 6 Mar 2009 sbsrmm(3P)