1 //---------------------------------------------------------------------------//
2 // Copyright (c) 2013 Kyle Lutz <kyle.r.lutz@gmail.com>
3 //
4 // Distributed under the Boost Software License, Version 1.0
5 // See accompanying file LICENSE_1_0.txt or copy at
6 // http://www.boost.org/LICENSE_1_0.txt
7 //
8 // See http://boostorg.github.com/compute for more information.
9 //---------------------------------------------------------------------------//
10
11 #ifndef BOOST_COMPUTE_ALGORITHM_REPLACE_HPP
12 #define BOOST_COMPUTE_ALGORITHM_REPLACE_HPP
13
14 #include <boost/static_assert.hpp>
15
16 #include <boost/compute/system.hpp>
17 #include <boost/compute/command_queue.hpp>
18 #include <boost/compute/detail/meta_kernel.hpp>
19 #include <boost/compute/detail/iterator_range_size.hpp>
20 #include <boost/compute/type_traits/is_device_iterator.hpp>
21
22 namespace boost {
23 namespace compute {
24 namespace detail {
25
26 template<class Iterator, class T>
27 class replace_kernel : public meta_kernel
28 {
29 public:
replace_kernel()30 replace_kernel()
31 : meta_kernel("replace")
32 {
33 m_count = 0;
34 }
35
set_range(Iterator first,Iterator last)36 void set_range(Iterator first, Iterator last)
37 {
38 m_count = detail::iterator_range_size(first, last);
39
40 *this <<
41 "const uint i = get_global_id(0);\n" <<
42 "if(" << first[var<cl_uint>("i")] << " == " << var<T>("old_value") << ")\n" <<
43 " " << first[var<cl_uint>("i")] << '=' << var<T>("new_value") << ";\n";
44 }
45
set_old_value(const T & old_value)46 void set_old_value(const T &old_value)
47 {
48 add_set_arg<T>("old_value", old_value);
49 }
50
set_new_value(const T & new_value)51 void set_new_value(const T &new_value)
52 {
53 add_set_arg<T>("new_value", new_value);
54 }
55
exec(command_queue & queue)56 void exec(command_queue &queue)
57 {
58 if(m_count == 0){
59 // nothing to do
60 return;
61 }
62
63 exec_1d(queue, 0, m_count);
64 }
65
66 private:
67 size_t m_count;
68 };
69
70 } // end detail namespace
71
72 /// Replaces each instance of \p old_value in the range [\p first,
73 /// \p last) with \p new_value.
74 ///
75 /// Space complexity: \Omega(1)
76 template<class Iterator, class T>
replace(Iterator first,Iterator last,const T & old_value,const T & new_value,command_queue & queue=system::default_queue ())77 inline void replace(Iterator first,
78 Iterator last,
79 const T &old_value,
80 const T &new_value,
81 command_queue &queue = system::default_queue())
82 {
83 BOOST_STATIC_ASSERT(is_device_iterator<Iterator>::value);
84 detail::replace_kernel<Iterator, T> kernel;
85
86 kernel.set_range(first, last);
87 kernel.set_old_value(old_value);
88 kernel.set_new_value(new_value);
89
90 kernel.exec(queue);
91 }
92
93 } // end compute namespace
94 } // end boost namespace
95
96 #endif // BOOST_COMPUTE_ALGORITHM_REPLACE_HPP
97