https://hal.archives-ouvertes.fr/hal-02128878
Tip revision: 4201397494d9af8b687117e8ff4d85a8944f5c5a authored by Software Heritage on 11 June 2019, 10:15:02 UTC
hal: Deposit 298 in collection hal
hal: Deposit 298 in collection hal
Tip revision: 4201397
fflas_ftrsv.inl
/* fflas/fflas_ftrsv.inl
* Copyright (C) 2005 Clement Pernet
*
* Written by Clement Pernet <Clement.Pernet@imag.fr>
*
*
* ========LICENCE========
* This file is part of the library FFLAS-FFPACK.
*
* FFLAS-FFPACK is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
* ========LICENCE========
*.
*/
#ifndef __FFLASFFPACK_ftrsv_INL
#define __FFLASFFPACK_ftrsv_INL
namespace FFLAS {
//---------------------------------------------------------------------
// ftrsv: TRiangular System solve with vector
// Computes X <- op(A^-1).X
// size of X is m
//---------------------------------------------------------------------
template<class Field>
inline void
ftrsv (const Field& F, const FFLAS_UPLO Uplo,
const FFLAS_TRANSPOSE TransA, const FFLAS_DIAG Diag,
const size_t N,typename Field::ConstElement_ptr A, size_t lda,
typename Field::Element_ptr X, int incX)
{
typename Field::Element_ptr Xi;
typename Field::ConstElement_ptr Ai;
if ( Uplo == FflasLower ){
if ( TransA == FflasTrans){
Ai = A+(N-1)*(lda+1); // bottom right entry of A
Xi = X+(int)(N-1)*incX;
for(size_t i=0; i<N; Ai-=(lda+1), Xi-=incX, ++i) {
if (i)
F.subin(*Xi, fdot(F, i, Ai+lda, lda, Xi+incX, incX));
if ( Diag==FflasNonUnit )
F.divin(*Xi,*Ai);
}
} // End FflasTrans
else{
Ai = A;
Xi = X;
for(size_t i=0 ; i<N; Ai+=lda,Xi+=incX, ++i ){
F.subin (*Xi, fdot (F, i, Ai, 1, X, incX));
if ( Diag==FflasNonUnit )
F.divin(*Xi,*(Ai+i));
}
}
} // End EFflasLower
else{
if ( TransA == FflasTrans){
Ai = A;
Xi = X;
for(size_t i=0; i<N; ++Ai,Xi+=incX, ++i) {
F.subin(*Xi, fdot(F, i, Ai, lda, X, incX));
if ( Diag == FflasNonUnit )
F.divin(*Xi, *(Ai+i*lda));
}
} // End FflasTrans
else{
Ai = A+(lda+1)*(N-1);
Xi = X+incX*(int)(N-1);
for(size_t i=0; Xi>=X; Ai-=lda+1,Xi-=incX, ++i ){
if (i)
F.subin (*Xi, fdot (F, i, Ai+1, 1, Xi+incX, incX));
if ( Diag==FflasNonUnit )
F.divin(*Xi,*Ai);
}
}
}
}
}
#endif // __FFLASFFPACK_ftrsv_INL
/* -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
// vim:sts=4:sw=4:ts=4:et:sr:cino=>s,f0,{0,g0,(0,\:0,t0,+0,=s