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[libc++] Simplify the implementation of __libcpp_{,de}allocate #147989

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merged 1 commit into from
Jul 15, 2025
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[libc++] Simplify the implementation of __libcpp_{,de}allocate #147989

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71 changes: 20 additions & 51 deletions libcxx/include/__new/allocate.h
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Original file line number Diff line number Diff line change
Expand Up @@ -31,37 +31,16 @@ _LIBCPP_CONSTEXPR inline _LIBCPP_HIDE_FROM_ABI bool __is_overaligned_for_new(siz
#endif
}

template <class... _Args>
_LIBCPP_HIDE_FROM_ABI void* __libcpp_operator_new(_Args... __args) {
#if __has_builtin(__builtin_operator_new) && __has_builtin(__builtin_operator_delete)
return __builtin_operator_new(__args...);
#else
return ::operator new(__args...);
#endif
}

template <class... _Args>
_LIBCPP_HIDE_FROM_ABI void __libcpp_operator_delete(_Args... __args) _NOEXCEPT {
#if __has_builtin(__builtin_operator_new) && __has_builtin(__builtin_operator_delete)
__builtin_operator_delete(__args...);
#else
::operator delete(__args...);
#endif
}

template <class _Tp>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_CFI _Tp*
__libcpp_allocate(__element_count __n, size_t __align = _LIBCPP_ALIGNOF(_Tp)) {
__libcpp_allocate(__element_count __n, [[__maybe_unused__]] size_t __align = _LIBCPP_ALIGNOF(_Tp)) {
size_t __size = static_cast<size_t>(__n) * sizeof(_Tp);
#if _LIBCPP_HAS_ALIGNED_ALLOCATION
if (__is_overaligned_for_new(__align)) {
const align_val_t __align_val = static_cast<align_val_t>(__align);
return static_cast<_Tp*>(std::__libcpp_operator_new(__size, __align_val));
}
if (__is_overaligned_for_new(__align))
return static_cast<_Tp*>(__builtin_operator_new(__size, static_cast<align_val_t>(__align)));
#endif

(void)__align;
return static_cast<_Tp*>(std::__libcpp_operator_new(__size));
return static_cast<_Tp*>(__builtin_operator_new(__size));
}

#if _LIBCPP_HAS_SIZED_DEALLOCATION
Expand All @@ -71,39 +50,29 @@ __libcpp_allocate(__element_count __n, size_t __align = _LIBCPP_ALIGNOF(_Tp)) {
#endif

template <class _Tp>
inline _LIBCPP_HIDE_FROM_ABI void __libcpp_deallocate(
__type_identity_t<_Tp>* __ptr, __element_count __n, size_t __align = _LIBCPP_ALIGNOF(_Tp)) _NOEXCEPT {
size_t __size = static_cast<size_t>(__n) * sizeof(_Tp);
(void)__size;
#if !_LIBCPP_HAS_ALIGNED_ALLOCATION
(void)__align;
return std::__libcpp_operator_delete(__ptr _LIBCPP_ONLY_IF_SIZED_DEALLOCATION(, __size));
#else
if (__is_overaligned_for_new(__align)) {
const align_val_t __align_val = static_cast<align_val_t>(__align);
return std::__libcpp_operator_delete(__ptr _LIBCPP_ONLY_IF_SIZED_DEALLOCATION(, __size), __align_val);
} else {
return std::__libcpp_operator_delete(__ptr _LIBCPP_ONLY_IF_SIZED_DEALLOCATION(, __size));
}
inline _LIBCPP_HIDE_FROM_ABI void
__libcpp_deallocate(__type_identity_t<_Tp>* __ptr,
__element_count __n,
[[__maybe_unused__]] size_t __align = _LIBCPP_ALIGNOF(_Tp)) _NOEXCEPT {
[[__maybe_unused__]] size_t __size = static_cast<size_t>(__n) * sizeof(_Tp);
#if _LIBCPP_HAS_ALIGNED_ALLOCATION
if (__is_overaligned_for_new(__align))
return __builtin_operator_delete(
__ptr _LIBCPP_ONLY_IF_SIZED_DEALLOCATION(, __size), static_cast<align_val_t>(__align));
#endif
return __builtin_operator_delete(__ptr _LIBCPP_ONLY_IF_SIZED_DEALLOCATION(, __size));
}

#undef _LIBCPP_ONLY_IF_SIZED_DEALLOCATION

template <class _Tp>
inline _LIBCPP_HIDE_FROM_ABI void
__libcpp_deallocate_unsized(__type_identity_t<_Tp>* __ptr, size_t __align = _LIBCPP_ALIGNOF(_Tp)) _NOEXCEPT {
#if !_LIBCPP_HAS_ALIGNED_ALLOCATION
(void)__align;
return std::__libcpp_operator_delete(__ptr);
#else
if (__is_overaligned_for_new(__align)) {
const align_val_t __align_val = static_cast<align_val_t>(__align);
return std::__libcpp_operator_delete(__ptr, __align_val);
} else {
return std::__libcpp_operator_delete(__ptr);
}
inline _LIBCPP_HIDE_FROM_ABI void __libcpp_deallocate_unsized(
__type_identity_t<_Tp>* __ptr, [[__maybe_unused__]] size_t __align = _LIBCPP_ALIGNOF(_Tp)) _NOEXCEPT {
#if _LIBCPP_HAS_ALIGNED_ALLOCATION
if (__is_overaligned_for_new(__align))
return __builtin_operator_delete(__ptr, static_cast<align_val_t>(__align));
#endif
return __builtin_operator_delete(__ptr);
}
_LIBCPP_END_NAMESPACE_STD

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