mirrors/llvm-project
0
0
Fork 0
mirror of https://github.com/llvm/llvm-project.git synced 2025-04-16 01:16:36 +00:00
Code Issues Projects Releases Wiki Activity

[libc++] Remove one of the std::signbit overloads (#130505)

Browse Source 
We'e specialized `std::signbit` for signed and unsigned integral types
seperately, even though the optimizer can trivially figure out that
`unsigned_value < 0` always false is. This patch removes the
specialization, since there is really not much of a benefit to it.
This commit is contained in:
Nikolas Klauser 2025-03-24 07:30:45 +01:00 committed by GitHub
parent e3bd1f2b3f
commit 66531c998a
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
3 changed files with 7 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
libcxx/include/__math/traits.h
View File

@ -13,7 +13,6 @@
#include <__type_traits/enable_if.h>
#include <__type_traits/is_arithmetic.h>
#include <__type_traits/is_integral.h>
#include <__type_traits/is_signed.h>
#include <__type_traits/promote.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@ -51,16 +50,11 @@ template <class = void>
return __builtin_signbit(__x);
}
template <class _A1, __enable_if_t<is_integral<_A1>::value && is_signed<_A1>::value, int> = 0>
template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
[[__nodiscard__]] inline _LIBCPP_SIGNBIT_CONSTEXPR _LIBCPP_HIDE_FROM_ABI bool signbit(_A1 __x) _NOEXCEPT {
return __x < 0;
}
template <class _A1, __enable_if_t<is_integral<_A1>::value && !is_signed<_A1>::value, int> = 0>
[[__nodiscard__]] inline _LIBCPP_SIGNBIT_CONSTEXPR _LIBCPP_HIDE_FROM_ABI bool signbit(_A1) _NOEXCEPT {
return false;
}
// isfinite
template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>

3
libcxx/test/std/depr/depr.c.headers/math_h.pass.cpp
View File

@ -12,6 +12,9 @@
// <math.h>
// GCC warns about signbit comparing `bool_v < 0`, which we're testing
// ADDITIONAL_COMPILE_FLAGS(gcc): -Wno-bool-compare
#include <math.h>
#include <type_traits>
#include <cassert>

3
libcxx/test/std/numerics/c.math/signbit.pass.cpp
View File

@ -14,6 +14,9 @@
// These compilers don't support constexpr `__builtin_signbit` yet.
// UNSUPPORTED: clang-18, clang-19, apple-clang-15, apple-clang-16, apple-clang-17
// GCC warns about signbit comparing `bool_v < 0`, which we're testing
// ADDITIONAL_COMPILE_FLAGS(gcc): -Wno-bool-compare
// XFAIL: FROZEN-CXX03-HEADERS-FIXME
#include <cassert>