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author | Louis Dionne <ldionne@apple.com> | 2019-09-04 13:35:03 +0000 |
---|---|---|
committer | Dan Albert <danalbert@google.com> | 2019-09-13 18:07:32 -0700 |
commit | 44a8861f2c85a8f46107a541c5d610c1d3b464fe (patch) | |
tree | 9adb575b38fe3f450e91c613c86630b960b84b9b | |
parent | 34d1dd71fa4c096107dde636e5c723c32a20d387 (diff) | |
download | libcxx-44a8861f2c85a8f46107a541c5d610c1d3b464fe.tar.gz |
[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)
-rw-r--r-- | include/cmath | 36 | ||||
-rw-r--r-- | include/math.h | 34 | ||||
-rw-r--r-- | test/libcxx/numerics/c.math/undef_min_max.pass.cpp | 19 |
3 files changed, 55 insertions, 34 deletions
diff --git a/include/cmath b/include/cmath index f5f62adcf..56d17bfdd 100644 --- a/include/cmath +++ b/include/cmath @@ -304,11 +304,15 @@ long double truncl(long double x); #include <__config> #include <math.h> #include <version> +#include <type_traits> #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) #pragma GCC system_header #endif +_LIBCPP_PUSH_MACROS +#include <__undef_macros> + _LIBCPP_BEGIN_NAMESPACE_STD using ::signbit; @@ -607,6 +611,38 @@ __libcpp_isfinite_or_builtin(_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 +_LIBCPP_POP_MACROS + #endif // _LIBCPP_CMATH diff --git a/include/math.h b/include/math.h index 9dfbb0e78..3cc72aa27 100644 --- a/include/math.h +++ b/include/math.h @@ -1510,40 +1510,6 @@ inline _LIBCPP_INLINE_VISIBILITY typename std::enable_if<std::is_integral<_A1>::value, double>::type trunc(_A1 __lcpp_x) _NOEXCEPT {return ::trunc((double)__lcpp_x);} -_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; } |