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1 | // spreadsort double sorting example. |
2 | // | |
3 | // Copyright Steven Ross 2009-2014. | |
4 | // | |
5 | // Distributed under the Boost Software License, Version 1.0. | |
6 | // (See accompanying file LICENSE_1_0.txt or copy at | |
7 | // http://www.boost.org/LICENSE_1_0.txt) | |
8 | ||
9 | // See http://www.boost.org/libs/sort for library home page. | |
10 | ||
11 | #include <boost/sort/spreadsort/spreadsort.hpp> | |
12 | #include <time.h> | |
13 | #include <stdio.h> | |
14 | #include <stdlib.h> | |
15 | #include <algorithm> | |
16 | #include <vector> | |
17 | #include <string> | |
18 | #include <fstream> | |
19 | #include <iostream> | |
20 | using namespace boost::sort::spreadsort; | |
21 | ||
22 | #define DATA_TYPE double | |
23 | #define CAST_TYPE boost::int64_t | |
24 | ||
25 | //Pass in an argument to test std::sort | |
26 | //Note that this converts NaNs and -0.0 to 0.0, so that sorting results are | |
27 | //identical every time | |
28 | int main(int argc, const char ** argv) { | |
29 | size_t uCount,uSize=sizeof(DATA_TYPE); | |
30 | bool stdSort = false; | |
31 | unsigned loopCount = 1; | |
32 | for (int u = 1; u < argc; ++u) { | |
33 | if (std::string(argv[u]) == "-std") | |
34 | stdSort = true; | |
35 | else | |
36 | loopCount = atoi(argv[u]); | |
37 | } | |
38 | std::ifstream input("input.txt", std::ios_base::in | std::ios_base::binary); | |
39 | if (input.fail()) { | |
40 | printf("input.txt could not be opened\n"); | |
41 | return 1; | |
42 | } | |
43 | double total = 0.0; | |
44 | std::vector<DATA_TYPE> array; | |
45 | input.seekg (0, std::ios_base::end); | |
46 | size_t length = input.tellg(); | |
47 | uCount = length/uSize; | |
48 | //Using this to support compilers that don't support 64-bit constants | |
49 | CAST_TYPE exponent_mask = 0x7ff00000; | |
50 | exponent_mask <<= 32; | |
51 | CAST_TYPE top_exponent_bit = 0x40000000; | |
52 | top_exponent_bit <<= 32; | |
53 | //Run multiple loops, if requested | |
54 | for (unsigned u = 0; u < loopCount; ++u) { | |
55 | input.seekg (0, std::ios_base::beg); | |
56 | //Conversion to a vector | |
57 | array.resize(uCount); | |
58 | unsigned v = 0; | |
59 | while (input.good() && v < uCount) { | |
60 | input.read(reinterpret_cast<char *>(&(array[v])), uSize ); | |
61 | //Checking for denormalized numbers | |
62 | if (!(float_mem_cast<DATA_TYPE, CAST_TYPE>(array[v]) & exponent_mask)) { | |
63 | //Make the top exponent bit high | |
64 | CAST_TYPE temp = top_exponent_bit | | |
65 | float_mem_cast<DATA_TYPE, CAST_TYPE>(array[v]); | |
66 | memcpy(&(array[v]), &temp, sizeof(DATA_TYPE)); | |
67 | } | |
68 | //Testcase doesn't sort NaNs; they just cause confusion | |
69 | if (!(array[v] < 0.0) && !(0.0 < array[v])) | |
70 | array[v] = 0.0; | |
71 | ++v; | |
72 | } | |
73 | clock_t start, end; | |
74 | double elapsed; | |
75 | start = clock(); | |
76 | if (stdSort) | |
77 | //std::sort(&(array[0]), &(array[0]) + uCount); | |
78 | std::sort(array.begin(), array.end()); | |
79 | else | |
80 | //float_sort(&(array[0]), &(array[0]) + uCount); | |
81 | float_sort(array.begin(), array.end()); | |
82 | end = clock(); | |
83 | elapsed = static_cast<double>(end - start) ; | |
84 | std::ofstream ofile; | |
85 | if (stdSort) | |
86 | ofile.open("standard_sort_out.txt", std::ios_base::out | | |
87 | std::ios_base::binary | std::ios_base::trunc); | |
88 | else | |
89 | ofile.open("boost_sort_out.txt", std::ios_base::out | | |
90 | std::ios_base::binary | std::ios_base::trunc); | |
91 | if (ofile.good()) { | |
92 | for (unsigned v = 0; v < array.size(); ++v) { | |
93 | ofile.write(reinterpret_cast<char *>(&(array[v])), sizeof(array[v]) ); | |
94 | } | |
95 | ofile.close(); | |
96 | } | |
97 | total += elapsed; | |
98 | array.clear(); | |
99 | } | |
100 | if (stdSort) | |
101 | printf("std::sort elapsed time %f\n", total / CLOCKS_PER_SEC); | |
102 | else | |
103 | printf("spreadsort elapsed time %f\n", total / CLOCKS_PER_SEC); | |
104 | return 0; | |
105 | } |