예제 #1
0
파일: ATL_potrfU.c 프로젝트: apollos/atlas
static int ATL_potrf2(const int N, TYPE *A, const int lda)
{
   int j, k;
   static const TYPE one[2] = {ATL_rone, ATL_rzero};
   static const TYPE none[2] = {ATL_rnone, ATL_rzero};
   const size_t lda2 = lda+lda;
   TYPE Ajj, *Ac=A, *An=A+lda2;

   for (k=j=0; j != N; j++, k += 2)
   {
      Ajj = Ac[k] - llt_dot(k, Ac, 1, Ac, 1);
      Ac[k+1] = ATL_rzero;
      if (Ajj > ATL_rzero)
      {
         Ac[k] = Ajj = sqrt(Ajj);
         if (j != N-1)
         {
            llt_scal(j, ATL_rnone, Ac+1, 2);
            cblas_gemv(CblasColMajor, CblasTrans, j, N-j-1, none,
                       An, lda, Ac, 1, one, An+k, lda);
            llt_scal(j, ATL_rnone, Ac+1, 2);
            llt_rscal(N-j-1, ATL_rone/Ajj, An+k, lda);
            Ac = An;
            An += lda2;
         }
      }
      else
      {
         Ac[k] = Ajj;
         return(j+1);
      }
   }
   return(0);
}
예제 #2
0
/*
 *             Automatically Tuned Linear Algebra Software v3.11.28
 *                    (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.
 *
 */
static int ATL_potrf2(const int N, TYPE *A, const int lda)
{
#ifdef TREAL
    TYPE Ajj, *Ac=A;
    const int N_1 = N-1;
    int j;

    for (j=0; j != N_1; j++, Ac += lda)
    {
       Ajj = Ac[j] - cblas_dot(j, A+j, lda, A+j, lda);

       if (Ajj > ATL_rzero)
       {
          Ac[j] = Ajj = sqrt(Ajj);
          cblas_gemv(CblasColMajor, CblasNoTrans, N-j-1, j, ATL_rnone,
                     A+j+1, lda, A+j, lda, ATL_rone, Ac+j+1, 1);
          cblas_scal(N-j-1, ATL_rone/Ajj, Ac+j+1, 1);
       }
       else
       {
          Ac[j] = Ajj;
          return(j+1);
       }
    }
    Ajj = Ac[j] - cblas_dot(j, A+j, lda, A+j, lda);
    if (Ajj > ATL_rzero) Ac[j] = Ajj = sqrt(Ajj);
    else
    {
       Ac[j] = Ajj;
       return(N);
    }
#else
    TYPE Ajj, *Ac=A;
    TYPE one[2] = {ATL_rone, ATL_rzero};
    TYPE none[2] = {ATL_rnone, ATL_rzero};
    const int N_1 = N-1, lda2 = lda<<1;
    int j, j2;

    for (j2=j=0; j != N_1; j++, j2 += 2, Ac += lda2)
    {
       Ajj = Ac[j2];
       cblas_dotc_sub(j, A+j2, lda, A+j2, lda, Ac+j2);
       Ajj -= Ac[j2];

       if (Ajj > ATL_rzero)
       {
          Ac[j2] = Ajj = sqrt(Ajj);
          llt_scal(j, ATL_rnone, A+j2+1, lda2);
          cblas_gemv(CblasColMajor, CblasNoTrans, N-j-1, j, none,
                     A+j2+2, lda, A+j2, lda, one, Ac+j2+2, 1);
          llt_scal(j, ATL_rnone, A+j2+1, lda2);
          llt_scal((N-j-1)<<1, ATL_rone/Ajj, Ac+j2+2, 1);
       }
       else
       {
          Ac[j2] = Ajj;
          return(j+1);
       }
    }
    Ajj = Ac[j2];
    cblas_dotc_sub(j, A+j2, lda, A+j2, lda, Ac+j2);
    Ajj -= Ac[j2];
    if (Ajj > ATL_rzero) Ac[j2] = sqrt(Ajj);
    else
    {
       Ac[j2] = Ajj;
       return(N);
    }
#endif
   return(0);
}