pstl/test/std/algorithms/alg.nonmodifying/find.pass.cpp

   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 // UNSUPPORTED: c++03, c++11, c++14
  11
  12 // Tests for find
  13 #include "support/pstl_test_config.h"
  14
  15 #include <execution>
  16 #include <algorithm>
  17
  18 #include "support/utils.h"
  19
  20 using namespace TestUtils;
  21
  22 struct test_find
  23 {
  24 #if defined(_PSTL_ICC_17_VC141_TEST_SIMD_LAMBDA_DEBUG_32_BROKEN) ||                                                             \
  25     defined(_PSTL_ICC_16_VC14_TEST_SIMD_LAMBDA_DEBUG_32_BROKEN) //dummy specialization by policy type, in case of broken configuration
  26     template <typename Iterator, typename Value>
  27     void
  28     operator()(pstl::execution::unsequenced_policy, Iterator first, Iterator last, Value value)
  29     {
  30     }
  31     template <typename Iterator, typename Value>
  32     void
  33     operator()(pstl::execution::parallel_unsequenced_policy, Iterator first, Iterator last, Value value)
  34     {
  35     }
  36 #endif
  37
  38     template <typename Policy, typename Iterator, typename Value>
  39     void
  40     operator()(Policy&& exec, Iterator first, Iterator last, Value value)
  41     {
  42         auto i = std::find(first, last, value);
  43         auto j = find(exec, first, last, value);
  44         EXPECT_TRUE(i == j, "wrong return value from find");
  45     }
  46 };
  47
  48 template <typename T, typename Value, typename Hit, typename Miss>
  49 void
  50 test(Value value, Hit hit, Miss miss)
  51 {
  52     // Try sequences of various lengths.
  53     for (size_t n = 0; n <= 100000; n = n <= 16 ? n + 1 : size_t(3.1415 * n))
  54     {
  55         Sequence<T> in(n, [&](size_t k) -> T { return miss(n ^ k); });
  56         // Try different find positions, including not found.
  57         // By going backwards, we can add extra matches that are *not* supposed to be found.
  58         // The decreasing exponential gives us O(n) total work for the loop since each find takes O(m) time.
  59         for (size_t m = n; m > 0; m *= 0.6)
  60         {
  61             if (m < n)
  62                 in[m] = hit(n ^ m);
  63             invoke_on_all_policies(test_find(), in.begin(), in.end(), value);
  64             invoke_on_all_policies(test_find(), in.cbegin(), in.cend(), value);
  65         }
  66     }
  67 }
  68
  69 // Type defined for sake of checking that std::find works with asymmetric ==.
  70 class Weird
  71 {
  72     Number value;
  73
  74   public:
  75     friend bool
  76     operator==(Number x, Weird y)
  77     {
  78         return x == y.value;
  79     }
  80     Weird(int32_t val, OddTag) : value(val, OddTag()) {}
  81 };
  82
  83 int
  84 main()
  85 {
  86     // Note that the "hit" and "miss" functions here avoid overflow issues.
  87     test<Number>(Weird(42, OddTag()), [](int32_t) { return Number(42, OddTag()); }, // hit
  88                  [](int32_t j) { return Number(j == 42 ? 0 : j, OddTag()); });      // miss
  89
  90     // Test with value that is equal to two different bit patterns (-0.0 and 0.0)
  91     test<float32_t>(-0.0, [](int32_t j) { return j & 1 ? 0.0 : -0.0; }, // hit
  92                     [](int32_t j) { return j == 0 ? ~j : j; });         // miss
  93
  94     std::cout << done() << std::endl;
  95     return 0;
  96 }