[libc++] Optimize num_get integral functions

Author: philnik777

libcxx/docs/ReleaseNotes/20.rst

@@ -120,6 +120,8 @@ Improvements and New Features
 
 - Added :ref:`hardening mode <hardening>` support for ``forward_list`` and ``bitset``.
 
+- The ``num_get::do_get`` integral overloads have been optimized. resulting in a performance improvement of up to 2.8x.
+
 Deprecations and Removals
 -------------------------
 

libcxx/include/__algorithm/simd_utils.h

@@ -116,11 +116,36 @@ template <class _VecT, class _Iter>
   }(make_index_sequence<__simd_vector_size_v<_VecT>>{});
 }
 
+// Load the first _Np elements, zero the rest
+_LIBCPP_DIAGNOSTIC_PUSH
+_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wpsabi")
+template <class _VecT, size_t _Np, class _Iter>
+[[__nodiscard__]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _VecT __partial_load(_Iter __iter) noexcept {
+  return [=]<size_t... _LoadIndices, size_t... _ZeroIndices>(
+             index_sequence<_LoadIndices...>, index_sequence<_ZeroIndices...>) _LIBCPP_ALWAYS_INLINE noexcept {
+    return _VecT{__iter[_LoadIndices]...};
+  }(make_index_sequence<_Np>{}, make_index_sequence<__simd_vector_size_v<_VecT> - _Np>{});
+}
+
+template <class _VecT>
+[[__nodiscard__]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _VecT
+__broadcast(__simd_vector_underlying_type_t<_VecT> __val) {
+  return [&]<std::size_t... _Indices>(index_sequence<_Indices...>) {
+    return _VecT{((void)_Indices, __val)...};
+  }(make_index_sequence<__simd_vector_size_v<_VecT>>());
+}
+_LIBCPP_DIAGNOSTIC_POP
+
 template <class _Tp, size_t _Np>
 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool __all_of(__simd_vector<_Tp, _Np> __vec) noexcept {
   return __builtin_reduce_and(__builtin_convertvector(__vec, __simd_vector<bool, _Np>));
 }
 
+template <class _Tp, size_t _Np>
+[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool __none_of(__simd_vector<_Tp, _Np> __vec) noexcept {
+  return !__builtin_reduce_or(__vec);
+}
+
 template <class _Tp, size_t _Np>
 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI size_t __find_first_set(__simd_vector<_Tp, _Np> __vec) noexcept {
   using __mask_vec = __simd_vector<bool, _Np>;

libcxx/include/__locale_dir/locale_base_api.h

@@ -51,8 +51,6 @@
 //  float               __strtof(const char*, char**, __locale_t);
 //  double              __strtod(const char*, char**, __locale_t);
 //  long double         __strtold(const char*, char**, __locale_t);
-//  long long           __strtoll(const char*, char**, __locale_t);
-//  unsigned long long  __strtoull(const char*, char**, __locale_t);
 // }
 //
 // Character manipulation functions
@@ -182,15 +180,6 @@ inline _LIBCPP_HIDE_FROM_ABI long double __strtold(const char* __nptr, char** __
   return strtold_l(__nptr, __endptr, __loc);
 }
 
-inline _LIBCPP_HIDE_FROM_ABI long long __strtoll(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
-  return strtoll_l(__nptr, __endptr, __base, __loc);
-}
-
-inline _LIBCPP_HIDE_FROM_ABI unsigned long long
-__strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
-  return strtoull_l(__nptr, __endptr, __base, __loc);
-}
-
 //
 // Character manipulation functions
 //

libcxx/include/__locale_dir/support/bsd_like.h

@@ -75,15 +75,6 @@ inline _LIBCPP_HIDE_FROM_ABI long double __strtold(const char* __nptr, char** __
   return ::strtold_l(__nptr, __endptr, __loc);
 }
 
-inline _LIBCPP_HIDE_FROM_ABI long long __strtoll(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
-  return ::strtoll_l(__nptr, __endptr, __base, __loc);
-}
-
-inline _LIBCPP_HIDE_FROM_ABI unsigned long long
-__strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
-  return ::strtoull_l(__nptr, __endptr, __base, __loc);
-}
-
 //
 // Character manipulation functions
 //

libcxx/include/__locale_dir/support/windows.h

@@ -184,14 +184,6 @@ inline _LIBCPP_HIDE_FROM_ABI double __strtod(const char* __nptr, char** __endptr
   return ::_strtod_l(__nptr, __endptr, __loc);
 }
 
-inline _LIBCPP_HIDE_FROM_ABI long long __strtoll(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
-  return ::_strtoi64_l(__nptr, __endptr, __base, __loc);
-}
-inline _LIBCPP_HIDE_FROM_ABI unsigned long long
-__strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
-  return ::_strtoui64_l(__nptr, __endptr, __base, __loc);
-}
-
 //
 // Character manipulation functions
 //