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[SVN r9444]
This commit is contained in:
Ralf W. Grosse-Kunstleve
@ -1,424 +0,0 @@
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/*
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*
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* Copyright (c) 1999
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* Dr John Maddock
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*
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* Permission to use, copy, modify, distribute and sell this software
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* and its documentation for any purpose is hereby granted without fee,
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* provided that the above copyright notice appear in all copies and
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* that both that copyright notice and this permission notice appear
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* in supporting documentation. Dr John Maddock makes no representations
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* about the suitability of this software for any purpose.
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* It is provided "as is" without express or implied warranty.
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*
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* This file provides some example of type_traits usage -
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* by "optimising" various algorithms:
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*
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* opt::copy - optimised for trivial copy (cf std::copy)
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* opt::fill - optimised for trivial copy/small types (cf std::fill)
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* opt::destroy_array - an example of optimisation based upon omitted destructor calls
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* opt::iter_swap - uses type_traits to determine whether the iterator is a proxy
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* in which case it uses a "safe" approach, otherwise calls swap
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* on the assumption that swap may be specialised for the pointed-to type.
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*
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*/
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/* Release notes:
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23rd July 2000:
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Added explicit failure for broken compilers that don't support these examples.
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Fixed broken gcc support (broken using directive).
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Reordered tests slightly.
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*/
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#include <iostream>
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#include <typeinfo>
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#include <algorithm>
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#include <iterator>
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#include <vector>
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#include <memory>
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#include <boost/timer.hpp>
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#include <boost/type_traits.hpp>
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#include <boost/call_traits.hpp>
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using std::cout;
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using std::endl;
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using std::cin;
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#ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
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#error "Sorry, without template partial specialisation support there isn't anything to test here..."
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#endif
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namespace opt{
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//
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// algorithm destroy_array:
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// The reverse of std::unitialized_copy, takes a block of
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// unitialized memory and calls destructors on all objects therein.
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//
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namespace detail{
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template <bool>
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struct array_destroyer
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{
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template <class T>
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static void destroy_array(T* i, T* j){ do_destroy_array(i, j); }
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};
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template <>
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struct array_destroyer<true>
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{
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template <class T>
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static void destroy_array(T*, T*){}
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};
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template <class T>
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void do_destroy_array(T* first, T* last)
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{
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while(first != last)
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{
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first->~T();
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++first;
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}
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}
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}; // namespace detail
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template <class T>
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inline void destroy_array(T* p1, T* p2)
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{
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detail::array_destroyer<boost::has_trivial_destructor<T>::value>::destroy_array(p1, p2);
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}
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//
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// unoptimised versions of destroy_array:
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//
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template <class T>
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void destroy_array1(T* first, T* last)
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{
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while(first != last)
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{
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first->~T();
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++first;
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}
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}
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template <class T>
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void destroy_array2(T* first, T* last)
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{
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for(; first != last; ++first) first->~T();
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}
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//
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// opt::copy
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// same semantics as std::copy
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// calls memcpy where appropiate.
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//
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namespace detail{
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template <bool b>
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struct copier
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{
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template<typename I1, typename I2>
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static I2 do_copy(I1 first, I1 last, I2 out);
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};
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template <bool b>
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template<typename I1, typename I2>
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I2 copier<b>::do_copy(I1 first, I1 last, I2 out)
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{
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while(first != last)
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{
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*out = *first;
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++out;
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++first;
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}
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return out;
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}
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template <>
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struct copier<true>
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{
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template<typename I1, typename I2>
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static I2* do_copy(I1* first, I1* last, I2* out)
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{
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memcpy(out, first, (last-first)*sizeof(I2));
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return out+(last-first);
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}
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};
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}
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template<typename I1, typename I2>
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inline I2 copy(I1 first, I1 last, I2 out)
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{
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typedef typename boost::remove_cv<typename std::iterator_traits<I1>::value_type>::type v1_t;
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typedef typename boost::remove_cv<typename std::iterator_traits<I2>::value_type>::type v2_t;
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enum{ can_opt = boost::is_same<v1_t, v2_t>::value
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&& boost::is_pointer<I1>::value
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&& boost::is_pointer<I2>::value
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&& boost::has_trivial_assign<v1_t>::value };
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return detail::copier<can_opt>::do_copy(first, last, out);
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}
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//
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// fill
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// same as std::fill, uses memset where appropriate, along with call_traits
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// to "optimise" parameter passing.
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//
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namespace detail{
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template <bool opt>
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struct filler
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{
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template <typename I, typename T>
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static void do_fill(I first, I last, typename boost::call_traits<T>::param_type val);
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};
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template <bool b>
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template <typename I, typename T>
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void filler<b>::do_fill(I first, I last, typename boost::call_traits<T>::param_type val)
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{
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while(first != last)
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{
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*first = val;
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++first;
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}
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}
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template <>
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struct filler<true>
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{
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template <typename I, typename T>
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static void do_fill(I first, I last, T val)
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{
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std::memset(first, val, last-first);
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}
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};
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}
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template <class I, class T>
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inline void fill(I first, I last, const T& val)
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{
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enum{ can_opt = boost::is_pointer<I>::value
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&& boost::is_arithmetic<T>::value
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&& (sizeof(T) == 1) };
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typedef detail::filler<can_opt> filler_t;
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filler_t::template do_fill<I,T>(first, last, val);
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}
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//
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// iter_swap:
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// tests whether iterator is a proxying iterator or not, and
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// uses optimal form accordingly:
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//
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namespace detail{
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template <bool b>
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struct swapper
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{
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template <typename I>
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static void do_swap(I one, I two)
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{
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typedef typename std::iterator_traits<I>::value_type v_t;
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v_t v = *one;
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*one = *two;
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*two = v;
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}
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};
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#ifdef __GNUC__
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using std::swap;
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#endif
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template <>
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struct swapper<true>
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{
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template <typename I>
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static void do_swap(I one, I two)
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{
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using std::swap;
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swap(*one, *two);
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}
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};
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}
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template <typename I1, typename I2>
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inline void iter_swap(I1 one, I2 two)
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{
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typedef typename std::iterator_traits<I1>::reference r1_t;
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typedef typename std::iterator_traits<I2>::reference r2_t;
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enum{ can_opt = boost::is_reference<r1_t>::value && boost::is_reference<r2_t>::value && boost::is_same<r1_t, r2_t>::value };
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detail::swapper<can_opt>::do_swap(one, two);
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}
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}; // namespace opt
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//
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// define some global data:
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//
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const int array_size = 1000;
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int i_array[array_size] = {0,};
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const int ci_array[array_size] = {0,};
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char c_array[array_size] = {0,};
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const char cc_array[array_size] = { 0,};
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const int iter_count = 1000000;
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int main()
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{
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//
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// test destroy_array,
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// compare destruction time of an array of ints
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// with unoptimised form.
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//
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cout << "Measuring times in micro-seconds per 1000 elements processed" << endl << endl;
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cout << "testing destroy_array...\n"
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"[Some compilers may be able to optimise the \"unoptimised\"\n versions as well as type_traits does.]" << endl;
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/*cache load*/ opt::destroy_array(i_array, i_array + array_size);
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boost::timer t;
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double result;
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int i;
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for(i = 0; i < iter_count; ++i)
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{
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opt::destroy_array(i_array, i_array + array_size);
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}
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result = t.elapsed();
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cout << "destroy_array<int>: " << result << endl;
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/*cache load*/ opt::destroy_array1(i_array, i_array + array_size);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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opt::destroy_array1(i_array, i_array + array_size);
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}
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result = t.elapsed();
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cout << "destroy_array<int>(unoptimised#1): " << result << endl;
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/*cache load*/ opt::destroy_array2(i_array, i_array + array_size);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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opt::destroy_array2(i_array, i_array + array_size);
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}
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result = t.elapsed();
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cout << "destroy_array<int>(unoptimised#2): " << result << endl << endl;
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cout << "testing fill(char)...\n"
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"[Some standard library versions may already perform this optimisation.]" << endl;
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/*cache load*/ opt::fill<char*, char>(c_array, c_array + array_size, (char)3);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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opt::fill<char*, char>(c_array, c_array + array_size, (char)3);
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}
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result = t.elapsed();
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cout << "opt::fill<char*, char>: " << result << endl;
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/*cache load*/ std::fill(c_array, c_array + array_size, (char)3);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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std::fill(c_array, c_array + array_size, (char)3);
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}
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result = t.elapsed();
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cout << "std::fill<char*, char>: " << result << endl << endl;
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cout << "testing fill(int)...\n"
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"[Tests the effect of call_traits pass-by-value optimisation -\nthe value of this optimisation may depend upon hardware characteristics.]" << endl;
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/*cache load*/ opt::fill<int*, int>(i_array, i_array + array_size, 3);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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opt::fill<int*, int>(i_array, i_array + array_size, 3);
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}
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result = t.elapsed();
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cout << "opt::fill<int*, int>: " << result << endl;
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/*cache load*/ std::fill(i_array, i_array + array_size, 3);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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std::fill(i_array, i_array + array_size, 3);
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}
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result = t.elapsed();
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cout << "std::fill<int*, int>: " << result << endl << endl;
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cout << "testing copy...\n"
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"[Some standard library versions may already perform this optimisation.]" << endl;
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/*cache load*/ opt::copy<const int*, int*>(ci_array, ci_array + array_size, i_array);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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opt::copy<const int*, int*>(ci_array, ci_array + array_size, i_array);
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}
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result = t.elapsed();
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cout << "opt::copy<const int*, int*>: " << result << endl;
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/*cache load*/ std::copy<const int*, int*>(ci_array, ci_array + array_size, i_array);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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std::copy<const int*, int*>(ci_array, ci_array + array_size, i_array);
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}
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result = t.elapsed();
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cout << "std::copy<const int*, int*>: " << result << endl;
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/*cache load*/ opt::detail::copier<false>::template do_copy<const int*, int*>(ci_array, ci_array + array_size, i_array);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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opt::detail::copier<false>::template do_copy<const int*, int*>(ci_array, ci_array + array_size, i_array);
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}
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result = t.elapsed();
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cout << "standard \"unoptimised\" copy: " << result << endl << endl;
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/*cache load*/ opt::copy<const char*, char*>(cc_array, cc_array + array_size, c_array);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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opt::copy<const char*, char*>(cc_array, cc_array + array_size, c_array);
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}
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result = t.elapsed();
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cout << "opt::copy<const char*, char*>: " << result << endl;
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/*cache load*/ std::copy<const char*, char*>(cc_array, cc_array + array_size, c_array);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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std::copy<const char*, char*>(cc_array, cc_array + array_size, c_array);
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}
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result = t.elapsed();
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cout << "std::copy<const char*, char*>: " << result << endl;
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/*cache load*/ opt::detail::copier<false>::template do_copy<const char*, char*>(cc_array, cc_array + array_size, c_array);
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t.restart();
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for(i = 0; i < iter_count; ++i)
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{
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opt::detail::copier<false>::template do_copy<const char*, char*>(cc_array, cc_array + array_size, c_array);
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}
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result = t.elapsed();
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cout << "standard \"unoptimised\" copy: " << result << endl << endl;
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//
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// testing iter_swap
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// really just a check that it does in fact compile...
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std::vector<int> v1;
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v1.push_back(0);
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v1.push_back(1);
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std::vector<bool> v2;
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v2.push_back(0);
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v2.push_back(1);
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opt::iter_swap(v1.begin(), v1.begin()+1);
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opt::iter_swap(v2.begin(), v2.begin()+1);
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cout << "Press any key to exit...";
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cin.get();
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}
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@ -7,6 +7,7 @@
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// See http://www.boost.org for most recent version including documentation.
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// Revision History
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// 11 Feb 2001 Fixes for Borland (David Abrahams)
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// 23 Jan 2001 Added test for wchar_t (David Abrahams)
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// 23 Jan 2001 Now statically selecting a test for signed numbers to avoid
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// warnings with fancy compilers. Added commentary and
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@ -349,8 +350,15 @@ void test(Number* = 0)
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<< "digits: " << std::numeric_limits<Number>::digits << "\n"
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#endif
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<< "..." << std::flush;
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typedef typename boost::detail::numeric_traits<Number>::difference_type difference_type;
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BOOST_STATIC_ASSERT(boost::detail::is_signed<difference_type>::value);
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// factoring out difference_type for the assert below confused Borland :(
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typedef boost::detail::is_signed<
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#ifndef BOOST_MSVC
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typename
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#endif
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boost::detail::numeric_traits<Number>::difference_type
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> is_signed;
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BOOST_STATIC_ASSERT(is_signed::value);
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typedef typename boost::detail::if_true<
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boost::detail::is_signed<Number>::value
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||||
|
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