mkl_jit_create

Create a GEMM kernel that computes a scalar-matrix-matrix product and adds the result to a scalar-matrix product.

Syntax

status = mkl_jit_create_sgemm(jitter, transa, transb, m, n, k, alpha, lda, ldb, beta, ldc)

status = mkl_jit_create_dgemm(jitter, transa, transb, m, n, k, alpha, lda, ldb, beta, ldc)

status = mkl_jit_create_cgemm(jitter, transa, transb, m, n, k, alpha, lda, ldb, beta, ldc)

status = mkl_jit_create_zgemm(jitter, transa, transb, m, n, k, alpha, lda, ldb, beta, ldc)

Include Files

mkl_blas.f90

Description

The mkl_jit_create_?gemm functions belong to a set of related routines that enable use of just-in-time code generation.

The mkl_jit_create_?gemm functions create a handle to a just-in-time code generator (a jitter) and generate a GEMM kernel that computes a scalar-matrix-matrix product and adds the result to a scalar-matrix product, with general matrices. The operation of the generated GEMM kernel is defined as follows:

C := alpha*op(A)*op(B) + beta*C

Where:

op(X) is either op(X) = X or op(X) = X^T or op(X) = X^H
alpha and beta are scalars
A, B, and C are matrices
op(A) is an m-by-k matrix
op(B) is a k-by-n matrix
C is an m-by-n matrix

Note

Generating a new kernel with mkl_jit_create_?gemm involves moderate runtime overhead. To benefit from JIT code generation, use this feature when you need to call the generated kernel many times (for example, several hundred calls).

Note

The JIT API requires Fortran 90 and the ISO_C_BINDING module.

Input Parameters

transa

CHARACTER*1.

Specifies the form of op(A) used in the generated matrix multiplication:

if transa = 'N', then op(A) = A
if transa = 'T', then op(A) = A^T
if transa = 'C', then op(A) = A^H

transb

CHARACTER*1.

Specifies the form of op(B) used in the generated matrix multiplication:

if transb = 'N', then op(B) = B
if transb = 'T', then op(B) = B^T
if transb = 'C', then op(B) = B^H

m

INTEGER.

Specifies the number of rows of the matrix op(A) and of the matrix C. The value of m must be at least zero.

n

INTEGER.

Specifies the number of columns of the matrix op(B) and of the matrix C. The value of n must be at least zero.

k

INTEGER.

Specifies the number of columns of the matrix op(A) and the number of rows of the matrix op(B). The value of k must be at least zero.

alpha

REAL for mkl_jit_create_sgemm

DOUBLE PRECISION for mkl_jit_create_dgemm.

COMPLEX for mkl_jit_create_cgemm

DOUBLE COMPLEX for mkl_jit_create_zgemm

Specifies the scalar alpha.

lda

INTEGER.

Specifies the leading dimension of a.

If transa = 'N'lda must be at least max(1,m).
If transa = 'T' or transa = 'C', lda must be at least max(1,k).

ldb

INTEGER.

Specifies the leading dimension of b:

If transb = 'N'ldb must be at least max(1,k).
If transb = 'T' or transb = 'C', ldb must be at least max(1,n).

beta

REAL for mkl_jit_create_sgemm

DOUBLE PRECISION for mkl_jit_create_dgemm.

COMPLEX for mkl_jit_create_cgemm

DOUBLE COMPLEX for mkl_jit_create_zgemm

Specifies the scalar beta.

ldc

INTEGER.

Specifies the leading dimension of c which must be at least max(1,m).

Output Parameters

jitter

TYPE(C_PTR). C pointer to a handle to the newly created code generator.

Return Values

status

INTEGER

Returns one of the following:

MKL_JIT_ERROR if the handle cannot be created (no memory)

—or—
MKL_JIT_SUCCESS if the jitter has been created and the GEMM kernel was successfully created

—or—
MKL_NO_JIT if the jitter has been created, but a JIT GEMM kernel was not created because JIT is not beneficial for the given input parameters. The function pointer returned by mkl_jit_get_?gemm_ptr will call standard (non-JIT) GEMM.