xref: /llvm-project/pstl/test/std/algorithms/alg.nonmodifying/find.pass.cpp (revision 3dee12e4a57241e4a53687f4a4e463b581dabf46)
1 // -*- C++ -*-
2 //===-- find.pass.cpp -----------------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // Tests for find
11 #include "support/pstl_test_config.h"
12 
13 #ifdef PSTL_STANDALONE_TESTS
14 #include "pstl/execution"
15 #include "pstl/algorithm"
16 #else
17 #include <execution>
18 #include <algorithm>
19 #endif // PSTL_STANDALONE_TESTS
20 
21 #include "support/utils.h"
22 
23 using namespace TestUtils;
24 
25 struct test_find
26 {
27 #if _PSTL_ICC_17_VC141_TEST_SIMD_LAMBDA_DEBUG_32_BROKEN ||                                                            \
28     _PSTL_ICC_16_VC14_TEST_SIMD_LAMBDA_DEBUG_32_BROKEN //dummy specialization by policy type, in case of broken configuration
29     template <typename Iterator, typename Value>
30     void
31     operator()(pstl::execution::unsequenced_policy, Iterator first, Iterator last, Value value)
32     {
33     }
34     template <typename Iterator, typename Value>
35     void
36     operator()(pstl::execution::parallel_unsequenced_policy, Iterator first, Iterator last, Value value)
37     {
38     }
39 #endif
40 
41     template <typename Policy, typename Iterator, typename Value>
42     void
43     operator()(Policy&& exec, Iterator first, Iterator last, Value value)
44     {
45         auto i = std::find(first, last, value);
46         auto j = find(exec, first, last, value);
47         EXPECT_TRUE(i == j, "wrong return value from find");
48     }
49 };
50 
51 template <typename T, typename Value, typename Hit, typename Miss>
52 void
53 test(Value value, Hit hit, Miss miss)
54 {
55     // Try sequences of various lengths.
56     for (size_t n = 0; n <= 100000; n = n <= 16 ? n + 1 : size_t(3.1415 * n))
57     {
58         Sequence<T> in(n, [&](size_t k) -> T { return miss(n ^ k); });
59         // Try different find positions, including not found.
60         // By going backwards, we can add extra matches that are *not* supposed to be found.
61         // The decreasing exponential gives us O(n) total work for the loop since each find takes O(m) time.
62         for (size_t m = n; m > 0; m *= 0.6)
63         {
64             if (m < n)
65                 in[m] = hit(n ^ m);
66             invoke_on_all_policies(test_find(), in.begin(), in.end(), value);
67             invoke_on_all_policies(test_find(), in.cbegin(), in.cend(), value);
68         }
69     }
70 }
71 
72 // Type defined for sake of checking that std::find works with asymmetric ==.
73 class Weird
74 {
75     Number value;
76 
77   public:
78     friend bool
79     operator==(Number x, Weird y)
80     {
81         return x == y.value;
82     }
83     Weird(int32_t val, OddTag) : value(val, OddTag()) {}
84 };
85 
86 int32_t
87 main()
88 {
89     // Note that the "hit" and "miss" functions here avoid overflow issues.
90     test<Number>(Weird(42, OddTag()), [](int32_t j) { return Number(42, OddTag()); }, // hit
91                  [](int32_t j) { return Number(j == 42 ? 0 : j, OddTag()); });        // miss
92 
93     // Test with value that is equal to two different bit patterns (-0.0 and 0.0)
94     test<float32_t>(-0.0, [](int32_t j) { return j & 1 ? 0.0 : -0.0; }, // hit
95                     [](int32_t j) { return j == 0 ? ~j : j; });         // miss
96 
97     std::cout << done() << std::endl;
98     return 0;
99 }
100