Developer Reference

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

cblas_?trmv

Computes a matrix-vector product using a triangular matrix.

Syntax

void
cblas_strmv
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_UPLO
uplo
,
const
CBLAS_TRANSPOSE
trans
,
const
CBLAS_DIAG
diag
,
const
MKL_INT
n
,
const
float
*a
,
const
MKL_INT
lda
,
float
*x
,
const
MKL_INT
incx
);
void
cblas_dtrmv
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_UPLO
uplo
,
const
CBLAS_TRANSPOSE
trans
,
const
CBLAS_DIAG
diag
,
const
MKL_INT
n
,
const
double
*a
,
const
MKL_INT
lda
,
double
*x
,
const
MKL_INT
incx
);
void
cblas_ctrmv
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_UPLO
uplo
,
const
CBLAS_TRANSPOSE
trans
,
const
CBLAS_DIAG
diag
,
const
MKL_INT
n
,
const
void
*a
,
const
MKL_INT
lda
,
void
*x
,
const
MKL_INT
incx
);
void
cblas_ztrmv
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_UPLO
uplo
,
const
CBLAS_TRANSPOSE
trans
,
const
CBLAS_DIAG
diag
,
const
MKL_INT
n
,
const
void
*a
,
const
MKL_INT
lda
,
void
*x
,
const
MKL_INT
incx
);
Include Files
  • mkl.h
Description
The
?trmv
routines perform one of the following matrix-vector operations defined as
x
:=
A
*
x
, or
x
:= A'*
x
, or
x
:= conjg(
A
')*
x
,
where:
x
is an
n
-element vector,
A
is an
n
-by-
n
unit, or non-unit, upper or lower triangular matrix.
Input Parameters
Layout
Specifies whether two-dimensional array storage is row-major (
CblasRowMajor
) or column-major (
CblasColMajor
).
uplo
Specifies whether the matrix
A
is upper or lower triangular:
uplo
=
CblasUpper
if
uplo
=
CblasLower
, then the matrix is low triangular.
trans
Specifies the operation:
if
trans
=
CblasNoTrans
, then
x
:=
A
*
x
;
if
trans
=
CblasTrans
, then
x
:=
A
'*
x
;
if
trans
=
CblasConjTrans
, then
x
:= conjg(
A
')*
x
.
diag
Specifies whether the matrix
A
is unit triangular:
if
diag
=
CblasUnit
then the matrix is unit triangular;
if
diag
=
CblasNonUnit
, then the matrix is not unit triangular.
n
Specifies the order of the matrix
A
. The value of
n
must be at least zero.
a
Array, size
lda
*
n
. Before entry with
uplo
=
CblasUpper
, the leading
n
-by-
n
upper triangular part of the array
a
must contain the upper triangular matrix and the strictly lower triangular part of
a
is not referenced. Before entry with
uplo
=
CblasLower
, the leading
n
-by-
n
lower triangular part of the array
a
must contain the lower triangular matrix and the strictly upper triangular part of
a
is not referenced.
When
diag
=
CblasUnit
, the diagonal elements of
a
are not referenced either, but are assumed to be unity.
lda
Specifies the leading dimension of
a
as declared in the calling (sub)program. The value of
lda
must be at least
max(1,
n
)
.
x
Array, size at least
(1 + (
n
- 1)*abs(
incx
))
. Before entry, the incremented array
x
must contain the
n
-element vector
x
.
incx
Specifies the increment for the elements of
x
.
The value of
incx
must not be zero.
Output Parameters
x
Overwritten with the transformed vector
x
.

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