Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

Contents

?lasrt2

Sorts numbers in increasing or decreasing order.

Syntax

void
slasrt2
(
char
*id
,
MKL_INT
*n
,
float
*d
,
MKL_INT
*key
,
MKL_INT
*info
);
void
dlasrt2
(
char
*id
,
MKL_INT
*n
,
double
*d
,
MKL_INT
*key
,
MKL_INT
*info
);
Include Files
  • mkl_scalapack.h
Description
The
?lasrt2
function
is modified LAPACK
function
?lasrt
, which sorts the numbers in
d
 in increasing order (if
id
 =
'I'
) or in decreasing order (if
id
 =
'D'
 ). It uses Quick Sort, reverting to Insertion Sort on arrays of size
≤
 20. The size of
STACK
 limits
n
 to about 2
32
.
Input Parameters
id
=
'I'
: sort
d
 in increasing order;
=
'D'
: sort
d
 in decreasing order.
n
The length of the array
d
.
d
Array of size
n
.
On entry, the array to be sorted.
key
Array of size
n
.
On entry,
key
 contains a key to each of the entries in
d
.
Typically,
key
[
i
]=
i
+1 for all
i
 = 0, ...,
n
-1
.
Output Parameters
d
On exit,
d
 has been sorted into increasing order
(
d
[0]
≤
 ...
≤
d
[
n
 - 1] )
or into decreasing order
(
d
[0]
≥
 ...
≥
d
[
n
 - 1] )
,
depending on
id
.
info
= 0
: successful exit
< 0
: if
info
 = -i
, the
i
-th argument had an illegal value.
key
On exit,
key
 is permuted in exactly the same manner as
d
 was permuted from input to output. Therefore, if
key
[
i
] =
i
+1 for all
i
 =0, ..., n-1
 on input,
d
[
i
] on output equals
d
[
key
[
i
]-1] on input
.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.