Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

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

cblas_?rotm

Performs modified Givens rotation of points in the plane.

Syntax

void
cblas_srotm
(
const
MKL_INT
n
,
float
*x
,
const
MKL_INT
incx
,
float
*y
,
const
MKL_INT
incy
,
const
float
*param
);
void
cblas_drotm
(
const
MKL_INT
n
,
double
*x
,
const
MKL_INT
incx
,
double
*y
,
const
MKL_INT
incy
,
const
double
*param
);
Include Files
  • mkl.h
Description
Given two vectors
x
 and
y
, each vector element of these vectors is replaced as follows:
for
i
=1 to
n
, where
H
 is a modified Givens transformation matrix whose values are stored in the
param
[1]
 through
param
[4]
 array. See discussion on the
param
 argument.
Input Parameters
n
Specifies the number of elements in vectors
x
 and
y
.
x
Array, size at least
(1 + (
n
 -1)*abs(
incx
))
.
incx
Specifies the increment for the elements of
x
.
y
Array, size at least
(1 + (
n
 -1)*abs(
incy
))
.
incy
Specifies the increment for the elements of
y
.
param
Array, size 5.
The elements of the
param
 array are:
param
[0]
 contains a switch,
flag
.
param
[1-4]
 contain
h
11
,
h
21
,
h
12
, and
h
22
, respectively, the components of the array
H
.
Depending on the values of
flag
, the components of
H
 are set as follows:
flag
 =
-1.0
:
flag
 =
0.0
:
flag
 =
1.0
:
flag
 =
-2.0
:
In the last three cases, the matrix entries of 1.0, -1.0, and 0.0 are assumed based on the value of
flag
 and are not required to be set in the
param
 vector.
Output Parameters
x
Each element
x[i]
 is replaced by
h
11
*
x[i]
 +
h
12
*
y[i]
.
y
Each element
y[i]
 is replaced by
h
21
*
x[i]
 +
h
22
*
y[i]
.

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