1 //---------------------------------------------------------------------------//
2 // Copyright (c) 2014 Benoit
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 #include <algorithm>
12 #include <iostream>
13 #include <numeric>
14 #include <vector>
15
16 #include <boost/compute/system.hpp>
17 #include <boost/compute/algorithm/exclusive_scan.hpp>
18 #include <boost/compute/container/vector.hpp>
19
20 #include "perf.hpp"
21
rand_int()22 int rand_int()
23 {
24 return static_cast<int>((rand() / double(RAND_MAX)) * 25.0);
25 }
26
main(int argc,char * argv[])27 int main(int argc, char *argv[])
28 {
29 perf_parse_args(argc, argv);
30
31 std::cout << "size: " << PERF_N << std::endl;
32
33 // setup context and queue for the default device
34 boost::compute::device device = boost::compute::system::default_device();
35 boost::compute::context context(device);
36 boost::compute::command_queue queue(context, device);
37 std::cout << "device: " << device.name() << std::endl;
38
39 // create vector of random numbers on the host
40 std::vector<int> host_vector(PERF_N);
41 std::generate(host_vector.begin(), host_vector.end(), rand_int);
42
43 // create vector on the device and copy the data
44 boost::compute::vector<int> device_vector(PERF_N, context);
45 boost::compute::vector<int> device_res(PERF_N,context);
46 boost::compute::copy(
47 host_vector.begin(),
48 host_vector.end(),
49 device_vector.begin(),
50 queue
51 );
52
53 // sum vector
54 perf_timer t;
55 for(size_t trial = 0; trial < PERF_TRIALS; trial++){
56 boost::compute::copy(
57 host_vector.begin(),
58 host_vector.end(),
59 device_vector.begin(),
60 queue
61 );
62
63 t.start();
64 boost::compute::exclusive_scan(
65 device_vector.begin(),
66 device_vector.end(),
67 device_res.begin(),
68 queue
69 );
70 queue.finish();
71 t.stop();
72 }
73 std::cout << "time: " << t.min_time() / 1e6 << " ms" << std::endl;
74
75 // verify sum is correct
76 std::partial_sum(
77 host_vector.begin(),
78 host_vector.end(),
79 host_vector.begin()
80 );
81
82 int device_sum = device_res.back();
83 // when scan is exclusive values are shifted by one on the left
84 // compared to a inclusive scan
85 int host_sum = host_vector[host_vector.size()-2];
86
87 if(device_sum != host_sum){
88 std::cout << "ERROR: "
89 << "device_sum (" << device_sum << ") "
90 << "!= "
91 << "host_sum (" << host_sum << ")"
92 << std::endl;
93 return -1;
94 }
95
96 return 0;
97 }
98