Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

  • 0.9
  • 09/09/2020
  • Public Content
Contents

cblas_gemm_bf16bf16f32

Computes a matrix-matrix product with general bfloat16 matrices.

Syntax

void
cblas_gemm_bf16bf16f32
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_TRANSPOSE
transa
,
const
CBLAS_TRANSPOSE
transb
,
const
MKL_INT
m
,
const
MKL_INT
n
,
const
MKL_INT
k
,
const
float
alpha
,
const
MKL_BF16
*a
,
const
MKL_INT
lda
,
const
MKL_BF16
*b
,
const
MKL_INT
ldb
,
const
float
beta
,
float
*c
const
MKL_INT
ldc,
);
Include Files
  • mkl.h
Description
The
cblas_gemm_bf16bf16f32
 routines compute a scalar-matrix-matrix product and adds the result to a scalar-matrix product. The operation is defined as:
C := alpha*(op(A) *(op(B) + beta*C
where :

    op(
    X
    )
     is one of
    op(
    X
    ) =
    X
     or
    op(
    X
    ) =
    X
    T
    ,

    alpha
     and
    beta
     are scalars,

    A
    ,
    B
    , and
    C
     are matrices

    op(
    A
    )
     is
    m
    -by-
    k
     matrix,

    op(
    B
    )
     is
    k
    -by-
    n
     matrix,

    C
     is an
    m
    -by-
    n
     matrix.

Input Parameters
Layout
Specifies whether two-dimensional array storage is row-major (
CblasRowMajor
) or column-major (
CblasColMajor
).
transa
Specifies the form of op(
A
) used in the matrix multiplication:
if
transa
=
CblasNoTrans
, then
op(
A
) =
A
;
if
transa
=
CblasTrans
, then
op(
A
) =
A
T
.
transb
Specifies the form of op(
B
) used in the matrix multiplication:
if
transb
=
CblasNoTrans
, then
op(
B
) =
B
;
if
transb
=
CblasTrans
, then
op(
B
) =
B
T
.
m
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
Specifies the number of columns of the matrix
op(
B
)
 and the number of columns of the matrix
C
. The value of
n
 must be at least zero.
k
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
Specifies the scalar
alpha
.
a
transa
=
CblasNoTrans
transa
=
CblasTrans
Layout
 =
CblasColMajor
Array, size
lda
*
k
Before entry, the leading
m
-by-
k
 part of the array
a
 must contain the matrix
A
.
Array, size
lda
*
m
Before entry, the leading
k
-by-
m
 part of the array
a
 must contain the matrix
A
.
Layout
 =
CblasRowMajor
Array, size
lda
*
m
Before entry, the leading
k
-by-
m
 part of the array
a
 must contain the matrix.
Array, size
lda
*
k
Before entry, the leading
m
-by-
k
 part of the array
a
 must contain the matrix.
lda
Specifies the leading dimension of
a
 as declared in the calling (sub)program.
transa
=
CblasNoTrans
transa
=
CblasTrans
Layout
 =
CblasColMajor
lda
 must be at least
max(1,
m
)
.
lda
 must be at least
max(1,
k
)
.
Layout
 =
CblasRowMajor
lda
 must be at least
max(1,
k
)
.
lda
 must be at least
max(1,
m
)
.
b
transb
=
CblasNoTrans
transb
=
CblasTrans
Layout
 =
CblasColMajor
Array, size
ldb
 by
n
Before entry, the leading
k
-by-
n
 part of the array
b
 must contain the matrix
B
.
Array, size
ldb
 by
k
Before entry the leading
n
-by-
k
 part of the array
b
 must contain the matrix
B
.
Layout
 =
CblasRowMajor
Array, size
ldb
 by
k
Before entry the leading
n
-by-
k
 part of the array
b
 must contain the matrix
B
.
Array, size
ldb
 by
n
Before entry, the leading
k
-by-
n
 part of the array
b
 must contain the matrix
B
.
ldb
Specifies the leading dimension of
b
 as declared in the calling (sub)program.
transb
=
CblasNoTrans
transb
=
CblasTrans
Layout
 =
CblasColMajor
ldb
 must be at least
max(1,
k
)
.
ldb
 must be at least
max(1,
n
)
.
Layout
 =
CblasRowMajor
ldb
 must be at least
max(1,
n
)
.
ldb
 must be at least
max(1,
k
)
.
beta
Specifies the scalar
beta
. When
beta
 is equal to zero, then
c
 need not be set on input.
c
Layout
 =
CblasColMajor
Array, size
ldc
 by
n
. Before entry, the leading
m
-by-
n
 part of the array
c
 must contain the matrix
C
, except when
beta
 is equal to zero, in which case
c
 need not be set on entry.
Layout
 =
CblasRowMajor
Array, size
ldc
 by
m
. Before entry, the leading
n
-by-
m
 part of the array
c
 must contain the matrix
C
, except when
beta
 is equal to zero, in which case
c
 need not be set on entry.
ldc
Specifies the leading dimension of
c
 as declared in the calling (sub)program.
Layout
 =
CblasColMajor
ldc
 must be at least
max(1,
m
)
.
Layout
 =
CblasRowMajor
ldc
 must be at least
max(1,
n
)
.
Output Parameters
c
Overwritten by
alpha
* op(
A
) * op(
B
) +
beta
*
C
.

Example

For examples of routine usage, see these code examples in the
Intel® oneAPI Math Kernel Library
 installation directory:
  • cblas_gemm_bf16bf16f32
    :
    examples\cblas\source\cblas_gemm_bf16bf16f32x.c
Application Notes
On architectures without native bfloat16 hardware instructions, matrix
A
 and
B
 are upconverted to single precision and
SGEMM
 is called to compute matrix multiplication operation.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804