cblas_ddot.c

来自「基于Blas CLapck的.用过的人知道是干啥的」· C语言 代码 · 共 54 行

/*
 *             Automatically Tuned Linear Algebra Software v3.8.0
 *                    (C) Copyright 1999 R. Clint Whaley
 *
 * 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 distribution.
 *   3. The name of the ATLAS group or the names of its contributers may
 *      not be used to endorse or promote products derived from this
 *      software without specific written permission.
 *
 * 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 ATLAS GROUP OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 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 THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#define DREAL
#include "atlas_misc.h"
#ifdef ATL_USEPTHREADS
   #include "atlas_ptalias1.h"
#endif
#include "atlas_level1.h"
#include "cblas.h"

double cblas_ddot(const int N, const double *X, const int incX,
                     const double *Y, const int incY)
{
   if (N > 0)
   {
      if (incX < 0)
      {
         if (incY < 0) return(ATL_ddot(N, X, -incX, Y, -incY));
         else return(ATL_ddot(N, X+(1-N)*incX, incX, Y, incY));
      }
      else if (incY < 0) return(ATL_ddot(N, X+(N-1)*incX, -incX, Y, -incY));
      else return(ATL_ddot(N, X, incX, Y, incY));
   }
   else return(0.0);
}