p?hemm

Developer Reference for Intel® oneAPI Math Kernel Library for C

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ID 766684

Date 11/07/2023

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p?hemm

Performs a scalar-matrix-matrix product (one matrix operand is Hermitian) and adds the result to a scalar-matrix product.

Syntax

void pchemm (const char *side , const char *uplo , const MKL_INT *m , const MKL_INT *n , const MKL_Complex8 *alpha , const MKL_Complex8 *a , const MKL_INT *ia , const MKL_INT *ja , const MKL_INT *desca , const MKL_Complex8 *b , const MKL_INT *ib , const MKL_INT *jb , const MKL_INT *descb , const MKL_Complex8 *beta , MKL_Complex8 *c , const MKL_INT *ic , const MKL_INT *jc , const MKL_INT *descc );

void pzhemm (const char *side , const char *uplo , const MKL_INT *m , const MKL_INT *n , const MKL_Complex16 *alpha , const MKL_Complex16 *a , const MKL_INT *ia , const MKL_INT *ja , const MKL_INT *desca , const MKL_Complex16 *b , const MKL_INT *ib , const MKL_INT *jb , const MKL_INT *descb , const MKL_Complex16 *beta , MKL_Complex16 *c , const MKL_INT *ic , const MKL_INT *jc , const MKL_INT *descc );

Include Files

mkl_pblas.h

Description

The p?hemm routines perform a matrix-matrix operation with distributed matrices. The operation is defined as

sub(C):=alpha*sub(A)*sub(B)+ beta*sub(C),

sub(C):=alpha*sub(B)*sub(A)+ beta*sub(C),

where:

alpha and beta are scalars,

sub(A) is a Hermitian distributed matrix, sub(A)=A(ia:ia+m-1, ja:ja+m-1), if side = 'L', and sub(A)=A(ia:ia+n-1, ja:ja+n-1), if side = 'R'.

sub(B) and sub(C) are m-by-n distributed matrices.

sub(B)=B(ib:ib+m-1, jb:jb+n-1), sub(C)=C(ic:ic+m-1, jc:jc+n-1).

Input Parameters

side

(global) Specifies whether the Hermitian distributed matrix sub(A) appears on the left or right in the operation:

if side = 'L' or 'l', then sub(C) := alpha*sub(A) *sub(B) + beta*sub(C);

if side = 'R' or 'r', then sub(C) := alpha*sub(B) *sub(A) + beta*sub(C).

uplo

(global) Specifies whether the upper or lower triangular part of the Hermitian distributed matrix sub(A) is used:

if uplo = 'U' or 'u', then the upper triangular part is used;

if uplo = 'L' or 'l', then the lower triangular part is used.

m

(global) Specifies the number of rows of the distribute submatrix sub(C), m≥ 0.

n

(global) Specifies the number of columns of the distribute submatrix sub(C), n≥ 0.

alpha

(global)

Specifies the scalar alpha.

a

(local)

Array, size (lld_a, LOCq(ja+na-1)).

Before entry this array must contain the local pieces of the symmetric distributed matrix sub(A), such that when uplo = 'U' or 'u', the na-by-na upper triangular part of the distributed matrix sub(A) must contain the upper triangular part of the Hermitian distributed matrix and the strictly lower triangular part of sub(A) is not referenced, and when uplo = 'L' or 'l', the na-by-na lower triangular part of the distributed matrix sub(A) must contain the lower triangular part of the Hermitian distributed matrix and the strictly upper triangular part of sub(A) is not referenced.

ia, ja

(global) The row and column indices in the distributed matrix A indicating the first row and the first column of the submatrix sub(A), respectively

desca

(global and local) array of dimension 9. The array descriptor of the distributed matrix A.

b

(local)

Array, size (lld_b, LOCq(jb+n-1) ). Before entry this array must contain the local pieces of the distributed matrix sub(B).

ib, jb

(global) The row and column indices in the distributed matrix B indicating the first row and the first column of the submatrix sub(B), respectively.

descb

(global and local) array of dimension 9. The array descriptor of the distributed matrix B.

beta

(global)

Specifies the scalar beta.

When beta is set to zero, then sub(C) need not be set on input.

c

(local)

Array, size (lld_c, LOCq(jc+n-1)). Before entry this array must contain the local pieces of the distributed matrix sub(C).

ic, jc

(global) The row and column indices in the distributed matrix C indicating the first row and the first column of the submatrix sub(C), respectively

descc

(global and local) array of dimension 9. The array descriptor of the distributed matrix C.

Output Parameters

c: Overwritten by the m-by-n updated distributed matrix.

Parent topic: PBLAS Level 3 Routines

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Developer Reference for Intel® oneAPI Math Kernel Library for C

p?hemm

Syntax

Include Files

Description

Input Parameters

Output Parameters