1
/* ---------------------------------------------------------------------
3
* -- Automatically Tuned Linear Algebra Software (ATLAS)
4
* (C) Copyright 2000 All Rights Reserved
6
* -- ATLAS routine -- Version 3.2 -- December 15, 2000
8
* -- Suggestions, comments, bugs reports should be sent to the follo-
9
* wing e-mail address: atlas@cs.utk.edu
11
* Author : Antoine P. Petitet
12
* University of Tennessee - Innovative Computing Laboratory
13
* Knoxville TN, 37996-1301, USA.
15
* ---------------------------------------------------------------------
17
* -- Copyright notice and Licensing terms:
19
* Redistribution and use in source and binary forms, with or without
20
* modification, are permitted provided that the following conditions
23
* 1. Redistributions of source code must retain the above copyright
24
* notice, this list of conditions and the following disclaimer.
25
* 2. Redistributions in binary form must reproduce the above copyright
26
* notice, this list of conditions, and the following disclaimer in
27
* the documentation and/or other materials provided with the distri-
29
* 3. The name of the University, the ATLAS group, or the names of its
30
* contributors may not be used to endorse or promote products deri-
31
* ved from this software without specific written permission.
35
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
36
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
37
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
38
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY
39
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
40
* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
41
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
42
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEO-
43
* RY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (IN-
44
* CLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
45
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
47
* ---------------------------------------------------------------------
52
#include "atlas_refmisc.h"
53
#include "atlas_reflevel1.h"
68
* ATL_drefswap swaps the entries of two n-vectors x and y.
74
* On entry, N specifies the length of the vector x. N must be
75
* at least zero. Unchanged on exit.
77
* X (input/output) double *
78
* On entry, X points to the first entry to be accessed of an
79
* incremented array of size equal to or greater than
80
* ( 1 + ( n - 1 ) * abs( INCX ) ) * sizeof( double ),
81
* that contains the vector x. On exit, the entries of the in-
82
* cremented array X are swapped with the entries of the incre-
85
* INCX (input) const int
86
* On entry, INCX specifies the increment for the elements of X.
87
* INCX must not be zero. Unchanged on exit.
89
* Y (input/output) double *
90
* On entry, Y points to the first entry to be accessed of an
91
* incremented array of size equal to or greater than
92
* ( 1 + ( n - 1 ) * abs( INCY ) ) * sizeof( double ),
93
* that contains the vector y. On exit, the entries of the in-
94
* cremented array Y are swapped with the entries of the incre-
97
* INCY (input) const int
98
* On entry, INCY specifies the increment for the elements of Y.
99
* INCY must not be zero. Unchanged on exit.
101
* ---------------------------------------------------------------------
104
* .. Local Variables ..
106
register double x0, x1, x2, x3, y0, y1, y2, y3;
110
const int incX2 = 2 * INCX, incY2 = 2 * INCY,
111
incX3 = 3 * INCX, incY3 = 3 * INCY,
112
incX4 = 4 * INCX, incY4 = 4 * INCY;
114
* .. Executable Statements ..
119
if( ( nu = ( N >> 2 ) << 2 ) != 0 )
121
StX = (double *)X + nu * INCX;
125
x0 = (*X); y0 = (*Y);
126
x1 = X[INCX ]; y1 = Y[INCY ];
127
x2 = X[incX2]; y2 = Y[incY2];
128
x3 = X[incX3]; y3 = Y[incY3];
131
Y[INCY ] = x1; X[INCX ] = y1;
132
Y[incY2] = x2; X[incX2] = y2;
133
Y[incY3] = x3; X[incX3] = y3;
141
for( i = N - nu; i != 0; i-- )
154
* End of ATL_drefswap