test/std/algorithms/alg.nonmodifying/find_if.pass.cpp

// -*- C++ -*-
//===-- find_if.pass.cpp --------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: c++03, c++11, c++14

// Tests for find_if and find_if_not
#include "support/pstl_test_config.h"

#include <execution>
#include <algorithm>

#include "support/utils.h"

using namespace TestUtils;

struct test_find_if
{
#if defined(_PSTL_ICC_17_VC141_TEST_SIMD_LAMBDA_DEBUG_32_BROKEN) ||                                                             \
    defined(_PSTL_ICC_16_VC14_TEST_SIMD_LAMBDA_DEBUG_32_BROKEN) //dummy specialization by policy type, in case of broken configuration
    template <typename Iterator, typename Predicate, typename NotPredicate>
    void
    operator()(pstl::execution::unsequenced_policy, Iterator first, Iterator last, Predicate pred,
               NotPredicate not_pred)
    {
    }
    template <typename Iterator, typename Predicate, typename NotPredicate>
    void
    operator()(pstl::execution::parallel_unsequenced_policy, Iterator first, Iterator last, Predicate pred,
               NotPredicate not_pred)
    {
    }
#endif

    template <typename Policy, typename Iterator, typename Predicate, typename NotPredicate>
    void
    operator()(Policy&& exec, Iterator first, Iterator last, Predicate pred, NotPredicate not_pred)
    {
        auto i = std::find_if(first, last, pred);
        auto j = find_if(exec, first, last, pred);
        EXPECT_TRUE(i == j, "wrong return value from find_if");
        auto i_not = find_if_not(exec, first, last, not_pred);
        EXPECT_TRUE(i_not == i, "wrong return value from find_if_not");
    }
};

template <typename T, typename Predicate, typename Hit, typename Miss>
void
test(Predicate pred, Hit hit, Miss miss)
{
    auto not_pred = [pred](T x) { return !pred(x); };
    // Try sequences of various lengths.
    for (size_t n = 0; n <= 100000; n = n <= 16 ? n + 1 : size_t(3.1415 * n))
    {
        Sequence<T> in(n, [&](size_t k) -> T { return miss(n ^ k); });
        // Try different find positions, including not found.
        // By going backwards, we can add extra matches that are *not* supposed to be found.
        // The decreasing exponential gives us O(n) total work for the loop since each find takes O(m) time.
        for (size_t m = n; m > 0; m *= 0.6)
        {
            if (m < n)
                in[m] = hit(n ^ m);
            invoke_on_all_policies(test_find_if(), in.begin(), in.end(), pred, not_pred);
            invoke_on_all_policies(test_find_if(), in.cbegin(), in.cend(), pred, not_pred);
        }
    }
}

struct test_non_const
{
    template <typename Policy, typename Iterator>
    void
    operator()(Policy&& exec, Iterator iter)
    {
        auto is_even = [&](float64_t v) {
            uint32_t i = (uint32_t)v;
            return i % 2 == 0;
        };

        invoke_if(exec, [&]() {
            find_if(exec, iter, iter, non_const(is_even));
            find_if_not(exec, iter, iter, non_const(is_even));
        });
    }
};

int
main()
{
#if !defined(_PSTL_ICC_17_TEST_MAC_RELEASE_32_BROKEN)
    // Note that the "hit" and "miss" functions here avoid overflow issues.
    test<Number>(IsMultiple(5, OddTag()), [](int32_t j) { return Number(j - j % 5, OddTag()); }, // hit
                 [](int32_t j) { return Number(j % 5 == 0 ? j ^ 1 : j, OddTag()); });            // miss
#endif

    // Try type for which algorithm can really be vectorized.
    test<float32_t>([](float32_t x) { return x >= 0; }, [](float32_t j) { return j * j; },
                    [](float32_t j) { return -1 - j * j; });

    test_algo_basic_single<int32_t>(run_for_rnd_fw<test_non_const>());

    std::cout << done() << std::endl;
    return 0;
}