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dft_tools/triqs/arrays/linalg/matmul.hpp
Olivier Parcollet fc2a620eae arrays: new ref counting and weak views
- improve the mem_block and shared_block.
- the reference counting is now done in the mem_block and shared_block, removing the need of shared_ptr.

- speed tests shows that shared_ptr is very slow (due to thread safety?)
the new version is much better, though not perfect.

- Hence introducing weak views.

- also :
-- clean the guard mechanism for python (to allow returning from python without any python ref left).
-- clean code, add documentation for mem_block
-- remove nan init, which was not working, and corresponding test
-- serialisation of view still unchanged (need to forbid serialization of view ??).

- tests ok, incl. valgrind tests.
2013-07-23 08:13:44 +02:00

100 lines
4.5 KiB
C++

/*******************************************************************************
*
* TRIQS: a Toolbox for Research in Interacting Quantum Systems
*
* Copyright (C) 2011-2012 by O. Parcollet
*
* TRIQS is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* TRIQS 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 General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* TRIQS. If not, see <http://www.gnu.org/licenses/>.
*
******************************************************************************/
#ifndef TRIQS_ARRAYS_EXPRESSION_MATMUL_H
#define TRIQS_ARRAYS_EXPRESSION_MATMUL_H
#include <boost/type_traits/is_same.hpp>
#include <boost/typeof/typeof.hpp>
#include "../blas_lapack/gemm.hpp"
namespace triqs { namespace arrays {
///
template<typename A, typename B> class matmul_lazy;
///
template<typename A, typename B> matmul_lazy<A,B> matmul (A const & a, B const & b) { return matmul_lazy<A,B>(a,b); }
// ----------------- implementation -----------------------------------------
template<typename A, typename B> class matmul_lazy : TRIQS_MODEL_CONCEPT(ImmutableMatrix) {
typedef typename boost::remove_const<typename A::value_type>::type V1;
typedef typename boost::remove_const<typename B::value_type>::type V2;
//static_assert((boost::is_same<V1,V2>::value),"Different values : not implemented");
public:
typedef BOOST_TYPEOF_TPL( V1() * V2()) value_type; // what is the result of multiplying a V1 by a V2 ?
typedef typename A::domain_type domain_type;
typedef typename const_view_type_if_exists_else_type<A>::type A_type;
typedef typename const_view_type_if_exists_else_type<B>::type B_type;
const A_type a; const B_type b;
private:
typedef matrix<value_type> matrix_type;
struct internal_data { // implementing the pattern LazyPreCompute
matrix_type R;
internal_data(matmul_lazy const & P): R( P.a.dim0(), P.b.dim1()) { blas::gemm(1.0,P.a, P.b, 0.0, R); }
};
friend struct internal_data;
mutable std::shared_ptr<internal_data> _id;
void activate() const { if (!_id) _id= std::make_shared<internal_data>(*this);}
public:
matmul_lazy( A const & a_, B const & b_):a(a_),b(b_){
if (a.dim1() != b.dim0()) TRIQS_RUNTIME_ERROR<< "Matrix product : dimension mismatch in A*B "<< a<<" "<< b;
}
domain_type domain() const { return mini_vector<size_t,2>(a.dim0(), b.dim1());}
//domain_type domain() const { return indexmaps::cuboid::domain_t<2>(mini_vector<size_t,2>(a.dim0(), b.dim1()));}
size_t dim0() const { return a.dim0();}
size_t dim1() const { return b.dim1();}
template<typename K0, typename K1> value_type operator() (K0 const & k0, K1 const & k1) const { activate(); return _id->R(k0,k1); }
// TO BE REMOVED because of the aliasing question
// Optimized implementation of =, +=, -=
template<typename LHS>
friend void triqs_arrays_assign_delegation (LHS & lhs, matmul_lazy const & rhs) {
static_assert((is_matrix_or_view<LHS>::value), "LHS is not a matrix");
resize_or_check_if_view(lhs,make_shape(rhs.dim0(),rhs.dim1()));
blas::gemm(1.0,rhs.a, rhs.b, 0.0, lhs);
}
template<typename LHS>
friend void triqs_arrays_compound_assign_delegation (LHS & lhs, matmul_lazy const & rhs, mpl::char_<'A'>) { rhs.assign_comp_impl(lhs,1.0);}
template<typename LHS>
friend void triqs_arrays_compound_assign_delegation (LHS & lhs, matmul_lazy const & rhs, mpl::char_<'S'>) { rhs.assign_comp_impl(lhs,-1.0);}
private:
template<typename LHS> void assign_comp_impl (LHS & lhs, double S) const {
static_assert((is_matrix_or_view<LHS>::value), "LHS is not a matrix");
if (lhs.dim0() != dim0())
TRIQS_RUNTIME_ERROR<< "Matmul : +=/-= operator : first dimension mismatch in A*B "<< lhs.dim0()<<" vs "<< dim0();
if (lhs.dim1() != dim1())
TRIQS_RUNTIME_ERROR<< "Matmul : +=/-= operator : first dimension mismatch in A*B "<< lhs.dim1()<<" vs "<< dim1();
blas::gemm(S,a, b, 1.0, lhs);
}
friend std::ostream & operator<<(std::ostream & out, matmul_lazy<A,B> const & x){return out<<x.a<<" * "<<x.b;}
};// class matmul_lazy
}}//namespace triqs::arrays
#endif