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dft_tools/triqs/arrays/impl/flags.hpp
Olivier Parcollet 552c440238 arrays : add ConstView to fix const correctness
- A()(0) = 1
will not work any more if A is const, as it should be.

- Introduced the notion of const_view, simply done by a flag
(flag 0, for easy debug)
- changed the slice of ISP to use it (only on C++11 compliant compiler)
- Move BoundCheck Flags to 5.
2013-07-23 08:13:52 +02:00

119 lines
4.6 KiB
C++

/*******************************************************************************
*
* TRIQS: a Toolbox for Research in Interacting Quantum Systems
*
* Copyright (C) 2011-2013 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_FLAGS_H
#define TRIQS_ARRAYS_FLAGS_H
#include "../indexmaps/permutation.hpp"
namespace triqs { namespace arrays {
typedef unsigned long long ull_t;
// Flags is a 64 bit unsigned int.
// 0 is the default option.
// Meaning of the bits :
// 0 -> Const
// 1,2 -> Predefined order :
// 0 : None, 1 : C, 2 : Fortran
// 3 -> Init the array
// 5 -> Boundcheck
constexpr ull_t ConstView = 1ull << 0;
constexpr ull_t TraversalOrderC = 1ull << 1;
constexpr ull_t TraversalOrderFortran = 1ull << 2;
constexpr ull_t DefaultInit = 1ull << 3;
constexpr ull_t BoundCheck = 1ull << 5;
#define BOUND_CHECK triqs::arrays::BoundCheck
#define TRAVERSAL_ORDER_C triqs::arrays::TraversalOrderC
#define TRAVERSAL_ORDER_FORTRAN triqs::arrays::TraversalOrderFortran
#define DEFAULT_INIT triqs::arrays::DefaultInit
// NB : flags MUST be insensitive to slicing ...
// i.e. when I slice, the flags does not change.
namespace flags {
#ifndef TRIQS_WORKAROUND_INTEL_COMPILER_BUGS
constexpr ull_t get(ull_t f, ull_t a) { return ((f & (1ull<<a)) >> a);}
constexpr ull_t get2(ull_t f, ull_t a) { return ((f & ((1ull<<a) + (1ull<< (a+1ull)))) >> a);}
constexpr bool is_const (ull_t f) { return get (f,0) !=0;}
#ifdef TRIQS_ARRAYS_ENFORCE_BOUNDCHECK
constexpr bool bound_check (ull_t f) { return true;}
#else
constexpr bool bound_check (ull_t f) { return get (f, 5)!=0;}
#endif
constexpr bool traversal_order_c (ull_t f) { return get (f,1ull)!=0ull;}
constexpr bool traversal_order_fortran (ull_t f) { return get (f,2ull)!=0ull;}
template< ull_t F> struct bound_check_trait { static constexpr bool value = bound_check(F); };
constexpr ull_t init_mode (ull_t f) { return get (f,3);}
template<ull_t F> struct init_tag1;
template<> struct init_tag1<0> { typedef Tag::no_init type;};
template<> struct init_tag1<1> { typedef Tag::default_init type;};
// for the init_tag, we pass the *whole* option flag.
template<ull_t F> struct init_tag : init_tag1 < init_mode(F)> {};
template<ull_t F, ull_t To> struct assert_make_sense {
static constexpr bool bc = bound_check(F);
static constexpr bool is_c = traversal_order_c(F);
static constexpr bool is_f = traversal_order_fortran(F);
static_assert ( (!( is_c && is_f)), "You asked C and Fortran traversal order at the same time...");
static_assert ( (!( (is_c || is_f) && To )), "You asked C or Fortran traversal order and gave a traversal order ...");
};
#else
#define TRIQS_FLAGS_GET(f,a) ((f & (1ull<<a)) >> a)
#define TRIQS_FLAGS_GET2(f,a) ((f & ((1ull<<a) + (1ull<< (a+1ull)))) >> a)
constexpr bool is_const (ull_t f) { return false;} // non const view on icc
#ifdef TRIQS_ARRAYS_ENFORCE_BOUNDCHECK
template< ull_t F> struct bound_check_trait { static constexpr bool value = true;};
#else
template< ull_t F> struct bound_check_trait { static constexpr bool value = TRIQS_FLAGS_GET (F, 5)!=0; };
#endif
template< ull_t F> struct traversal_order_c { static constexpr bool value = TRIQS_FLAGS_GET(F,1) !=0; };
template< ull_t F> struct traversal_order_fortran { static constexpr bool value = TRIQS_FLAGS_GET(F,2) !=0; };
template< ull_t F> struct init_mode_tr { static constexpr int value = TRIQS_FLAGS_GET(F,3); };
template<ull_t F> struct init_tag1;
template<> struct init_tag1<0> { typedef Tag::no_init type;};
template<> struct init_tag1<1> { typedef Tag::default_init type;};
template<ull_t F> struct init_tag : init_tag1 < init_mode_tr<F>::value > {};
template<ull_t F, ull_t To> struct assert_make_sense { };// no check on icc
#undef TRIQS_FLAGS_GET
#undef TRIQS_FLAGS_GET2
#endif
}
}}//namespace triqs::arrays
#endif