Developer Reference

  • 2020.2
  • 07/15/2020
  • Public Content
Contents

p?dbsv

Solves a general band system of linear equations.

Syntax

call psdbsv
(
n
,
bwl
,
bwu
,
nrhs
,
a
,
ja
,
desca
,
b
,
ib
,
descb
,
work
,
lwork
,
info
)
call pddbsv
(
n
,
bwl
,
bwu
,
nrhs
,
a
,
ja
,
desca
,
b
,
ib
,
descb
,
work
,
lwork
,
info
)
call pcdbsv
(
n
,
bwl
,
bwu
,
nrhs
,
a
,
ja
,
desca
,
b
,
ib
,
descb
,
work
,
lwork
,
info
)
call pzdbsv
(
n
,
bwl
,
bwu
,
nrhs
,
a
,
ja
,
desca
,
b
,
ib
,
descb
,
work
,
lwork
,
info
)
Include Files
Description
The
p?dbsv
routine
solves the following system of linear equations:
A
(1:
n
,
ja
:
ja
+
n
-1)*
X
=
B
(
ib
:
ib
+
n
-1, 1:
nrhs
)
,
where
A
(1:
n
,
ja
:
ja
+
n
-1)
is an
n
-by-
n
real/complex banded diagonally dominant-like distributed matrix with bandwidth
bwl
,
bwu
.
Gaussian elimination without pivoting is used to factor a reordering of the matrix into
LU
.
Optimization Notice
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
This notice covers the following instruction sets: SSE2, SSE4.2, AVX2, AVX-512.
Input Parameters
n
(global)
INTEGER
.
The order of the distributed submatrix
A
,
(
n
0)
.
bwl
(global)
INTEGER
.
Number of subdiagonals.
0 ≤
bwl
n
-1
.
bwu
(global)
INTEGER
.
Number of subdiagonals.
0 ≤
bwu
n
-1
.
nrhs
(global)
INTEGER
.
The number of right-hand sides; the number of columns of the distributed submatrix