DO NOT MERGE: [libc++] Move __clamp_to_integral to <cmath>, and harden against min()/max() macros am: 7af7a63c2e

am: d190f65c64

Change-Id: If4680e91b42c8d183de0b7e15a9b682f3efa7fb5
This commit is contained in:
Louis Dionne
2019-09-17 12:06:24 -07:00
committed by android-build-merger

View File

@@ -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