1 // -*- C++ -*-
2 // { dg-options "-ltbb" }
3 // { dg-do run { target c++17 } }
4 // { dg-timeout-factor 3 }
5 // { dg-require-effective-target tbb-backend }
6
7 //===-- nth_element.pass.cpp ----------------------------------------------===//
8 //
9 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
10 // See https://llvm.org/LICENSE.txt for license information.
11 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "pstl/pstl_test_config.h"
16
17 #ifdef PSTL_STANDALONE_TESTS
18 #include <algorithm>
19 #include <iostream>
20 #include "pstl/execution"
21 #include "pstl/algorithm"
22
23 #else
24 #include <execution>
25 #include <algorithm>
26 #endif // PSTL_STANDALONE_TESTS
27
28 #include "pstl/test_utils.h"
29
30 using namespace TestUtils;
31
32 // User defined type with minimal requirements
33 template <typename T>
34 struct DataType
35 {
DataTypeDataType36 explicit DataType(int32_t k) : my_val(k) {}
DataTypeDataType37 DataType(DataType&& input)
38 {
39 my_val = std::move(input.my_val);
40 input.my_val = T(0);
41 }
42 DataType&
operator =DataType43 operator=(DataType&& input)
44 {
45 my_val = std::move(input.my_val);
46 input.my_val = T(0);
47 return *this;
48 }
49 T
get_valDataType50 get_val() const
51 {
52 return my_val;
53 }
54
55 friend std::ostream&
operator <<(std::ostream & stream,const DataType<T> & input)56 operator<<(std::ostream& stream, const DataType<T>& input)
57 {
58 return stream << input.my_val;
59 }
60
61 private:
62 T my_val;
63 };
64
65 template <typename T>
66 bool
is_equal(const DataType<T> & x,const DataType<T> & y)67 is_equal(const DataType<T>& x, const DataType<T>& y)
68 {
69 return x.get_val() == y.get_val();
70 }
71
72 template <typename T>
73 bool
is_equal(const T & x,const T & y)74 is_equal(const T& x, const T& y)
75 {
76 return x == y;
77 }
78
79 struct test_one_policy
80 {
81 #if _PSTL_ICC_17_VC141_TEST_SIMD_LAMBDA_DEBUG_32_BROKEN || \
82 _PSTL_ICC_16_VC14_TEST_SIMD_LAMBDA_DEBUG_32_BROKEN // dummy specialization by policy type, in case of broken configuration
83 template <typename Iterator1, typename Size, typename Generator1, typename Generator2, typename Compare>
84 typename std::enable_if<is_same_iterator_category<Iterator1, std::random_access_iterator_tag>::value, void>::type
operator ()test_one_policy85 operator()(pstl::execution::unsequenced_policy, Iterator1 first1, Iterator1 last1, Iterator1 first2,
86 Iterator1 last2, Size n, Size m, Generator1 generator1, Generator2 generator2, Compare comp)
87 {
88 }
89 template <typename Iterator1, typename Size, typename Generator1, typename Generator2, typename Compare>
90 typename std::enable_if<is_same_iterator_category<Iterator1, std::random_access_iterator_tag>::value, void>::type
operator ()test_one_policy91 operator()(pstl::execution::parallel_unsequenced_policy, Iterator1 first1, Iterator1 last1, Iterator1 first2,
92 Iterator1 last2, Size n, Size m, Generator1 generator1, Generator2 generator2, Compare comp)
93 {
94 }
95 #endif
96
97 // nth_element works only with random access iterators
98 template <typename Policy, typename Iterator1, typename Size, typename Generator1, typename Generator2,
99 typename Compare>
100 typename std::enable_if<is_same_iterator_category<Iterator1, std::random_access_iterator_tag>::value, void>::type
operator ()test_one_policy101 operator()(Policy&& exec, Iterator1 first1, Iterator1 last1, Iterator1 first2, Iterator1 last2, Size n, Size m,
102 Generator1 generator1, Generator2 generator2, Compare comp)
103 {
104
105 using T = typename std::iterator_traits<Iterator1>::value_type;
106 const Iterator1 mid1 = std::next(first1, m);
107 const Iterator1 mid2 = std::next(first2, m);
108
109 fill_data(first1, mid1, generator1);
110 fill_data(mid1, last1, generator2);
111 fill_data(first2, mid2, generator1);
112 fill_data(mid2, last2, generator2);
113 std::nth_element(first1, mid1, last1, comp);
114 std::nth_element(exec, first2, mid2, last2, comp);
115 if (m > 0 && m < n)
116 {
117 EXPECT_TRUE(is_equal(*mid1, *mid2), "wrong result from nth_element with predicate");
118 }
119 EXPECT_TRUE(std::find_first_of(first2, mid2, mid2, last2, [comp](T& x, T& y) { return comp(y, x); }) == mid2,
120 "wrong effect from nth_element with predicate");
121 }
122
123 template <typename Policy, typename Iterator1, typename Size, typename Generator1, typename Generator2,
124 typename Compare>
125 typename std::enable_if<!is_same_iterator_category<Iterator1, std::random_access_iterator_tag>::value, void>::type
operator ()test_one_policy126 operator()(Policy&& exec, Iterator1 first1, Iterator1 last1, Iterator1 first2, Iterator1 last2, Size n, Size m,
127 Generator1 generator1, Generator2 generator2, Compare comp)
128 {
129 }
130 };
131
132 template <typename T, typename Generator1, typename Generator2, typename Compare>
133 void
test_by_type(Generator1 generator1,Generator2 generator2,Compare comp)134 test_by_type(Generator1 generator1, Generator2 generator2, Compare comp)
135 {
136 using namespace std;
137 size_t max_size = 10000;
138 Sequence<T> in1(max_size, [](size_t v) { return T(v); });
139 Sequence<T> exp(max_size, [](size_t v) { return T(v); });
140 size_t m;
141
142 for (size_t n = 0; n <= max_size; n = n <= 16 ? n + 1 : size_t(3.1415 * n))
143 {
144 m = 0;
145 invoke_on_all_policies(test_one_policy(), exp.begin(), exp.begin() + n, in1.begin(), in1.begin() + n, n, m,
146 generator1, generator2, comp);
147 m = n / 7;
148 invoke_on_all_policies(test_one_policy(), exp.begin(), exp.begin() + n, in1.begin(), in1.begin() + n, n, m,
149 generator1, generator2, comp);
150 m = 3 * n / 5;
151 invoke_on_all_policies(test_one_policy(), exp.begin(), exp.begin() + n, in1.begin(), in1.begin() + n, n, m,
152 generator1, generator2, comp);
153 }
154 invoke_on_all_policies(test_one_policy(), exp.begin(), exp.begin() + max_size, in1.begin(), in1.begin() + max_size,
155 max_size, max_size, generator1, generator2, comp);
156 }
157
158 template <typename T>
159 struct test_non_const
160 {
161 template <typename Policy, typename Iterator>
162 void
operator ()test_non_const163 operator()(Policy&& exec, Iterator iter)
164 {
165 invoke_if(exec, [&]() { nth_element(exec, iter, iter, iter, non_const(std::less<T>())); });
166 }
167 };
168
169 int32_t
main()170 main()
171 {
172 test_by_type<int32_t>([](int32_t i) { return 10 * i; }, [](int32_t i) { return i + 1; }, std::less<int32_t>());
173 test_by_type<int32_t>([](int32_t) { return 0; }, [](int32_t) { return 0; }, std::less<int32_t>());
174
175 test_by_type<float64_t>([](int32_t i) { return -2 * i; }, [](int32_t i) { return -(2 * i + 1); },
176 [](const float64_t x, const float64_t y) { return x > y; });
177
178 test_by_type<DataType<float32_t>>(
179 [](int32_t i) { return DataType<float32_t>(2 * i + 1); }, [](int32_t i) { return DataType<float32_t>(2 * i); },
180 [](const DataType<float32_t>& x, const DataType<float32_t>& y) { return x.get_val() < y.get_val(); });
181
182 test_algo_basic_single<int32_t>(run_for_rnd<test_non_const<int32_t>>());
183
184 std::cout << done() << std::endl;
185 return 0;
186 }
187