diff options
author | Louis Dionne <ldionne@apple.com> | 2018-12-17 16:04:39 +0000 |
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committer | Louis Dionne <ldionne@apple.com> | 2018-12-17 16:04:39 +0000 |
commit | 04695a7539b47f602eca298cc99783a5dd32c63a (patch) | |
tree | 75f303e909b26071c91e5b573387544b0cc91d04 /libcxx/test | |
parent | a6e58888804f4541e1c705be7c989b4ec9096108 (diff) |
[libcxx] Speeding up partition_point/lower_bound/upper_bound
This is a re-application of r345525, which had been reverted by fear of
a regression.
Reviewed as https://reviews.llvm.org/D53994.
Thanks to Denis Yaroshevskiy for the patch.
llvm-svn: 349358
Diffstat (limited to 'libcxx/test')
-rw-r--r-- | libcxx/test/libcxx/algorithms/half_positive.pass.cpp | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/libcxx/test/libcxx/algorithms/half_positive.pass.cpp b/libcxx/test/libcxx/algorithms/half_positive.pass.cpp new file mode 100644 index 000000000000..7dcfc2c92c94 --- /dev/null +++ b/libcxx/test/libcxx/algorithms/half_positive.pass.cpp @@ -0,0 +1,56 @@ +//===----------------------------------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is dual licensed under the MIT and the University of Illinois Open +// Source Licenses. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +// <algorithm> + +// __half_positive divides an integer number by 2 as unsigned number for known types. +// It can be an important optimization for lower bound, for example. + +#include <algorithm> +#include <cassert> +#include <limits> +#include <type_traits> + +#include "test_macros.h" +#include "user_defined_integral.hpp" + +namespace { + +template <class IntType, class UnderlyingType = IntType> +TEST_CONSTEXPR bool test(IntType max_v = IntType(std::numeric_limits<UnderlyingType>::max())) { + return std::__half_positive(max_v) == max_v / 2; +} + +} // namespace + +int main() +{ + { + assert(test<char>()); + assert(test<int>()); + assert(test<long>()); + assert((test<UserDefinedIntegral<int>, int>())); + assert(test<size_t>()); +#if !defined(_LIBCPP_HAS_NO_INT128) + assert(test<__int128_t>()); +#endif // !defined(_LIBCPP_HAS_NO_INT128) + } + +#if TEST_STD_VER >= 11 + { + static_assert(test<char>(), ""); + static_assert(test<int>(), ""); + static_assert(test<long>(), ""); + static_assert(test<size_t>(), ""); +#if !defined(_LIBCPP_HAS_NO_INT128) + static_assert(test<__int128_t>(), ""); +#endif // !defined(_LIBCPP_HAS_NO_INT128) + } +#endif // TEST_STD_VER >= 11 +} |