/tools/ATLAS/src/blas/reference/level1/ATL_srefaxpy.c
C | 157 lines | 45 code | 8 blank | 104 comment | 8 complexity | df127197fae54954628de7c4d673ebcb MD5 | raw file
Possible License(s): Apache-2.0
- /* ---------------------------------------------------------------------
- *
- * -- Automatically Tuned Linear Algebra Software (ATLAS)
- * (C) Copyright 2000 All Rights Reserved
- *
- * -- ATLAS routine -- Version 3.9.24 -- December 25, 2000
- *
- * Author : Antoine P. Petitet
- * Originally developed at the University of Tennessee,
- * Innovative Computing Laboratory, Knoxville TN, 37996-1301, USA.
- *
- * ---------------------------------------------------------------------
- *
- * -- Copyright notice and Licensing terms:
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions, and the following disclaimer in
- * the documentation and/or other materials provided with the distri-
- * bution.
- * 3. The name of the University, the ATLAS group, or the names of its
- * contributors may not be used to endorse or promote products deri-
- * ved from this software without specific written permission.
- *
- * -- Disclaimer:
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY
- * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
- * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
- * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
- * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEO-
- * RY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (IN-
- * CLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * ---------------------------------------------------------------------
- */
- /*
- * Include files
- */
- #include "atlas_refmisc.h"
- #include "atlas_reflevel1.h"
- void ATL_srefaxpy
- (
- const int N,
- const float ALPHA,
- const float * X,
- const int INCX,
- float * Y,
- const int INCY
- )
- {
- /*
- * Purpose
- * =======
- *
- * ATL_srefaxpy performs the following operation:
- *
- * y := y + alpha * x,
- *
- * where alpha is a scalar and x and y are two n-vectors.
- *
- * Arguments
- * =========
- *
- * N (input) const int
- * On entry, N specifies the length of the vector x. N must be
- * at least zero. Unchanged on exit.
- *
- * ALPHA (input) const float
- * On entry, ALPHA specifies the scalar alpha. When ALPHA is
- * supplied as zero, then the entries of the incremented array X
- * need not be set on input. Unchanged on exit.
- *
- * X (input) const float *
- * On entry, X points to the first entry to be accessed of an
- * incremented array of size equal to or greater than
- * ( 1 + ( n - 1 ) * abs( INCX ) ) * sizeof( float ),
- * that contains the vector x. Unchanged on exit.
- *
- * INCX (input) const int
- * On entry, INCX specifies the increment for the elements of X.
- * INCX must not be zero. Unchanged on exit.
- *
- * Y (input/output) float *
- * On entry, Y points to the first entry to be accessed of an
- * incremented array of size equal to or greater than
- * ( 1 + ( n - 1 ) * abs( INCY ) ) * sizeof( float ),
- * that contains the vector y. On exit, the entries of the in-
- * cremented array Y are updated with the scaled entries of the
- * incremented array X.
- *
- * INCY (input) const int
- * On entry, INCY specifies the increment for the elements of Y.
- * INCY must not be zero. Unchanged on exit.
- *
- * ---------------------------------------------------------------------
- */
- /*
- * .. Local Variables ..
- */
- register const float alpha = ALPHA;
- register float x0, x1, x2, x3, y0, y1, y2, y3;
- float * StX;
- register int i;
- int nu;
- const int incX2 = 2 * INCX, incY2 = 2 * INCY,
- incX3 = 3 * INCX, incY3 = 3 * INCY,
- incX4 = 4 * INCX, incY4 = 4 * INCY;
- /* ..
- * .. Executable Statements ..
- *
- */
- if( ( N > 0 ) && ( alpha != ATL_sZERO ) )
- {
- if( ( nu = ( N >> 2 ) << 2 ) != 0 )
- {
- StX = (float *)X + nu * INCX;
- do
- {
- x0 = (*X); y0 = (*Y); x1 = X[INCX ]; y1 = Y[INCY ];
- x2 = X[incX2]; y2 = Y[incY2]; x3 = X[incX3]; y3 = Y[incY3];
- *Y = y0 + alpha * x0; Y[INCY ] = y1 + alpha * x1;
- Y[incY2] = y2 + alpha * x2; Y[incY3] = y3 + alpha * x3;
- X += incX4;
- Y += incY4;
- } while( X != StX );
- }
- for( i = N - nu; i != 0; i-- )
- {
- x0 = (*X);
- y0 = (*Y);
- *Y = y0 + alpha * x0;
- X += INCX;
- Y += INCY;
- }
- }
- /*
- * End of ATL_srefaxpy
- */
- }