Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

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

cblas_?trsv

Solves a system of linear equations whose coefficients are in a triangular matrix.

Syntax

void
cblas_strsv
(
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_dtrsv
(
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_ctrsv
(
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_ztrsv
(
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
?trsv
 routines solve one of the systems of equations:
A
*
x
 =
b
, or
A
'*
x
 =
b
, or
conjg(
A
')*
x
 =
b
,
where:
b
 and
x
 are
n
-element vectors,
A
 is an
n
-by-
n
 unit, or non-unit, upper or lower triangular matrix.
The routine does not test for singularity or near-singularity.
Such tests must be performed before calling this routine.
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 systems of equations:
if
trans
=
CblasNoTrans
, then
A
*
x
 =
b
;
if
trans
=
CblasTrans
, then
A
'*
x
 =
b
;
if
trans
=
CblasConjTrans
, then
oconjg(
A
')*
x
 =
b
.
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 right-hand side vector
b
.
incx
Specifies the increment for the elements of
x
.
The value of
incx
 must not be zero.
Output Parameters
x
Overwritten with the solution 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