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author | Louis Dionne <ldionne@apple.com> | 2019-09-04 13:35:03 +0000 |
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committer | Max Spector <mspector@google.com> | 2019-09-18 17:13:27 -0700 |
commit | 228614bbd0171b696c58114a86f242d33b4a8e0f (patch) | |
tree | 13cc95ec9befb5039c558755ff3f9b82cc63deec | |
parent | a45e84a8cff0cc2391e7ac175cd9d90abc9fe1ec (diff) | |
download | external_libcxx-228614bbd0171b696c58114a86f242d33b4a8e0f.tar.gz external_libcxx-228614bbd0171b696c58114a86f242d33b4a8e0f.tar.bz2 external_libcxx-228614bbd0171b696c58114a86f242d33b4a8e0f.zip |
DO NOT MERGE: [libc++] Move __clamp_to_integral to <cmath>, and harden against min()/max() macros
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@370900 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 87e6185621d332d2ef8695b94778663380c83bb9)
Bug: https://bugs.chromium.org/p/chromium/issues/detail?id=994957
Bug: http://b/139690488
Change-Id: Ice92a8ea6f675be069a70c5ad1003cf99b4fc474
(cherry picked from commit 82e0483c4a47233ed2f7bab545b32e5ddd474e59)
(cherry picked from commit 280d459517680a16b34e0bd7843e2ac56ee3ea4d)
-rw-r--r-- | include/cmath | 32 | ||||
-rw-r--r-- | include/math.h | 34 | ||||
-rw-r--r-- | test/libcxx/numerics/c.math/undef_min_max.pass.cpp | 19 |
3 files changed, 51 insertions, 34 deletions
diff --git a/include/cmath b/include/cmath index 74b4ab8a8..6a081b560 100644 --- a/include/cmath +++ b/include/cmath @@ -303,6 +303,8 @@ long double truncl(long double x); #include <__config> #include <math.h> +#include <limits> +#include <type_traits> #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) #pragma GCC system_header @@ -612,6 +614,36 @@ __libcpp_isfinite(_A1 __lcpp_x) _NOEXCEPT return isfinite(__lcpp_x); } +template <class _IntT, class _FloatT, + bool _FloatBigger = (numeric_limits<_FloatT>::digits > numeric_limits<_IntT>::digits), + int _Bits = (numeric_limits<_IntT>::digits - numeric_limits<_FloatT>::digits)> +_LIBCPP_INLINE_VISIBILITY +_LIBCPP_CONSTEXPR _IntT __max_representable_int_for_float() _NOEXCEPT { + static_assert(is_floating_point<_FloatT>::value, "must be a floating point type"); + static_assert(is_integral<_IntT>::value, "must be an integral type"); + static_assert(numeric_limits<_FloatT>::radix == 2, "FloatT has incorrect radix"); + static_assert(is_same<_FloatT, float>::value || is_same<_FloatT, double>::value + || is_same<_FloatT,long double>::value, "unsupported floating point type"); + return _FloatBigger ? numeric_limits<_IntT>::max() : (numeric_limits<_IntT>::max() >> _Bits << _Bits); +} + +// Convert a floating point number to the specified integral type after +// clamping to the integral types representable range. +// +// The behavior is undefined if `__r` is NaN. +template <class _IntT, class _RealT> +_LIBCPP_INLINE_VISIBILITY +_IntT __clamp_to_integral(_RealT __r) _NOEXCEPT { + using _Lim = std::numeric_limits<_IntT>; + const _IntT _MaxVal = std::__max_representable_int_for_float<_IntT, _RealT>(); + if (__r >= ::nextafter(static_cast<_RealT>(_MaxVal), INFINITY)) { + return _Lim::max(); + } else if (__r <= _Lim::lowest()) { + return _Lim::min(); + } + return static_cast<_IntT>(__r); +} + _LIBCPP_END_NAMESPACE_STD #endif // _LIBCPP_CMATH diff --git a/include/math.h b/include/math.h index b61c2253d..b7659267e 100644 --- a/include/math.h +++ b/include/math.h @@ -1426,40 +1426,6 @@ trunc(_A1 __lcpp_x) _NOEXCEPT {return ::trunc((double)__lcpp_x);} #endif // !(defined(_LIBCPP_MSVCRT) && ((_VC_CRT_MAJOR_VERSION-0) < 14)) -_LIBCPP_BEGIN_NAMESPACE_STD - -template <class _IntT, class _FloatT, - bool _FloatBigger = (numeric_limits<_FloatT>::digits > numeric_limits<_IntT>::digits), - int _Bits = (numeric_limits<_IntT>::digits - numeric_limits<_FloatT>::digits)> -_LIBCPP_INLINE_VISIBILITY -_LIBCPP_CONSTEXPR _IntT __max_representable_int_for_float() _NOEXCEPT { - static_assert(is_floating_point<_FloatT>::value, "must be a floating point type"); - static_assert(is_integral<_IntT>::value, "must be an integral type"); - static_assert(numeric_limits<_FloatT>::radix == 2, "FloatT has incorrect radix"); - static_assert(_IsSame<_FloatT, float>::value || _IsSame<_FloatT, double>::value - || _IsSame<_FloatT,long double>::value, "unsupported floating point type"); - return _FloatBigger ? numeric_limits<_IntT>::max() : (numeric_limits<_IntT>::max() >> _Bits << _Bits); -} - -// Convert a floating point number to the specified integral type after -// clamping to the integral types representable range. -// -// The behavior is undefined if `__r` is NaN. -template <class _IntT, class _RealT> -_LIBCPP_INLINE_VISIBILITY -_IntT __clamp_to_integral(_RealT __r) _NOEXCEPT { - using _Lim = std::numeric_limits<_IntT>; - const _IntT _MaxVal = std::__max_representable_int_for_float<_IntT, _RealT>(); - if (__r >= ::nextafter(static_cast<_RealT>(_MaxVal), INFINITY)) { - return _Lim::max(); - } else if (__r <= _Lim::lowest()) { - return _Lim::min(); - } - return static_cast<_IntT>(__r); -} - -_LIBCPP_END_NAMESPACE_STD - } // extern "C++" #endif // __cplusplus diff --git a/test/libcxx/numerics/c.math/undef_min_max.pass.cpp b/test/libcxx/numerics/c.math/undef_min_max.pass.cpp new file mode 100644 index 000000000..ba1696eb2 --- /dev/null +++ b/test/libcxx/numerics/c.math/undef_min_max.pass.cpp @@ -0,0 +1,19 @@ +// +// 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 +// +//===----------------------------------------------------------------------===// + +#if defined(__GNUC__) || defined(__clang__) +#pragma GCC diagnostic ignored "-W#warnings" +#endif + +#define min THIS IS A NASTY MACRO! +#define max THIS IS A NASTY MACRO! + +#include <cmath> + +#include "test_macros.h" + +int main(int, char**) { return 0; } |