Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 3/22/2024
Public

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p?swap

Swaps two distributed vectors.

Syntax

call psswap(n, x, ix, jx, descx, incx, y, iy, jy, descy, incy)

call pdswap(n, x, ix, jx, descx, incx, y, iy, jy, descy, incy)

call pcswap(n, x, ix, jx, descx, incx, y, iy, jy, descy, incy)

call pzswap(n, x, ix, jx, descx, incx, y, iy, jy, descy, incy)

Include Files

  • mkl_pblas.h

Description

Given two distributed vectors sub(x) and sub(y), the p?swap routines return vectors sub(y) and sub(x) swapped, each replacing the other.

Here sub(x) denotes X(ix, jx:jx+n-1) if incx=m_x, and X(ix: ix+n-1, jx) if incx= 1;

sub(y) denotes Y(iy, jy:jy+n-1) if incy=m_y, and Y(iy: iy+n-1, jy) if incy= 1.

Input Parameters

n

(global) INTEGER. The length of distributed vectors, n0.

x

(local) REAL for psswap

DOUBLE PRECISION for pdswap

COMPLEX for pcswap

DOUBLE COMPLEX for pzswap

Array, size (jx-1)*m_x + ix+(n-1)*abs(incx)).

This array contains the entries of the distributed vector sub(x).

ix, jx

(global) INTEGER. The row and column indices in the distributed matrix X indicating the first row and the first column of the submatrix sub(X), respectively.

descx

(global and local) INTEGER array of dimension 9. The array descriptor of the distributed matrix X.

incx

(global) INTEGER. Specifies the increment for the elements of sub(x). Only two values are supported, namely 1 and m_x. incx must not be zero.

y

(local) REAL for psswap

DOUBLE PRECISION for pdswap

COMPLEX for pcswap

DOUBLE COMPLEX for pzswap

Array, size (jy-1)*m_y + iy+(n-1)*abs(incy)).

This array contains the entries of the distributed vector sub(y).

iy, jy

(global) INTEGER. The row and column indices in the distributed matrix Y indicating the first row and the first column of the submatrix sub(Y), respectively.

descy

(global and local) INTEGER array of dimension 9. The array descriptor of the distributed matrix Y.

incy

(global) INTEGER. Specifies the increment for the elements of sub(y). Only two values are supported, namely 1 and m_y. incy must not be zero.

Output Parameters

x

Overwritten by distributed vector sub(y).

y

Overwritten by distributed vector sub(x).