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6d749c172a
The size_t type means a number of _bytes_, and it was misused as counting e.g. the number of rows/columns in a matrix. Moreover, it is unsigned, which can give strange bugs if a signed/unsigned mismatch occurs.
110 lines
2.7 KiB
C++
110 lines
2.7 KiB
C++
/*
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* Tiny Vector Matrix Library
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* Dense Vector Matrix Libary of Tiny size using Expression Templates
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*
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* Copyright (C) 2001 - 2003 Olaf Petzold <opetzold@users.sourceforge.net>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* $Id: Gemv.h,v 1.3 2004/06/16 09:30:07 opetzold Exp $
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*/
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#ifndef TVMET_LOOP_GEMV_H
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#define TVMET_LOOP_GEMV_H
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namespace tvmet {
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namespace loop {
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/**
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* \class gemv Gemv.h "tvmet/loop/Gemv.h"
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* \brief class for matrix-vector product using loop unrolling.
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* using formula
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* \f[
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* M\,v
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* \f]
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* \par Example:
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* \code
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* template<class T, int Rows, int Cols>
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* inline
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* void
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* prod(const Matrix<T, Rows, Cols>& lhs, const Vector<T, Cols>& rhs,
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* Vector<T, Rows>& dest)
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* {
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* for (int i = 0; i != Rows; ++i) {
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* dest(i) = tvmet::loop::gemv<Rows, Cols>().prod(lhs, rhs, i);
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* }
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* }
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* \endcode
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*/
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template<int Rows, int Cols>
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class gemv
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{
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gemv(const gemv&);
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gemv& operator=(const gemv&);
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private:
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enum {
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count = Cols,
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N = (count+7)/8
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};
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public:
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gemv() { }
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public:
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template<class E1, class E2>
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static inline
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typename PromoteTraits<
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typename E1::value_type,
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typename E2::value_type
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>::value_type
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prod(const E1& lhs, const E2& rhs, int i) {
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typename PromoteTraits<
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typename E1::value_type,
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typename E2::value_type
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>::value_type sum(0);
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int j(0);
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int n(N);
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// Duff's device
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switch(count % 8) {
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case 0: do { sum += lhs(i, j) * rhs(j); ++j;
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case 7: sum += lhs(i, j) * rhs(j); ++j;
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case 6: sum += lhs(i, j) * rhs(j); ++j;
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case 5: sum += lhs(i, j) * rhs(j); ++j;
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case 4: sum += lhs(i, j) * rhs(j); ++j;
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case 3: sum += lhs(i, j) * rhs(j); ++j;
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case 2: sum += lhs(i, j) * rhs(j); ++j;
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case 1: sum += lhs(i, j) * rhs(j); ++j;
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} while(--n != 0);
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}
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return sum;
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}
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};
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} // namespace loop
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} // namespace tvmet
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#endif /* TVMET_LOOP_GEMV_H */
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// Local Variables:
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// mode:C++
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// End:
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