[libc++] Optimize ctype::to{lower,upper} #145344
Open
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Contributor
philnik777
commented
Jun 23, 2025
philnik777
commented
|
✅ With the latest revision this PR passed the C/C++ code formatter. |
philnik777
force-pushed
the
optimize_toupperlower
branch
4 times, most recently
from
c2a64ef to
f80600a
Compare
llvmbot
added
the
libc++
|
@llvm/pr-subscribers-libcxx Author: Nikolas Klauser (philnik777) ChangesFull diff: https://github.com/llvm/llvm-project/pull/145344.diff 11 Files Affected:
diff --git a/libcxx/include/__config b/libcxx/include/__config
index af8a297fdf3fd..e5f94d31d8535 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -639,10 +639,6 @@ typedef __char32_t char32_t;
# define _LIBCPP_HAS_C11_ALIGNED_ALLOC 1
# endif
-# if defined(__APPLE__) || defined(__FreeBSD__)
-# define _LIBCPP_HAS_DEFAULTRUNELOCALE
-# endif
-
# if defined(__APPLE__) || defined(__FreeBSD__)
# define _LIBCPP_WCTYPE_IS_MASK
# endif
diff --git a/libcxx/include/__locale b/libcxx/include/__locale
index 92e45e2531c2a..757a53951f66e 100644
--- a/libcxx/include/__locale
+++ b/libcxx/include/__locale
@@ -589,18 +589,6 @@ public:
# endif
_LIBCPP_HIDE_FROM_ABI const mask* table() const _NOEXCEPT { return __tab_; }
static const mask* classic_table() _NOEXCEPT;
-# if defined(__GLIBC__) || defined(__EMSCRIPTEN__)
- static const int* __classic_upper_table() _NOEXCEPT;
- static const int* __classic_lower_table() _NOEXCEPT;
-# endif
-# if defined(__NetBSD__)
- static const short* __classic_upper_table() _NOEXCEPT;
- static const short* __classic_lower_table() _NOEXCEPT;
-# endif
-# if defined(__MVS__)
- static const unsigned short* __classic_upper_table() _NOEXCEPT;
- static const unsigned short* __classic_lower_table() _NOEXCEPT;
-# endif
protected:
~ctype() override;
diff --git a/libcxx/include/__locale_dir/locale_base_api.h b/libcxx/include/__locale_dir/locale_base_api.h
index bbc30b1cfe03f..8dbc28e839839 100644
--- a/libcxx/include/__locale_dir/locale_base_api.h
+++ b/libcxx/include/__locale_dir/locale_base_api.h
@@ -64,8 +64,6 @@
// Character manipulation functions
// --------------------------------
// namespace __locale {
-// int __islower(int, __locale_t);
-// int __isupper(int, __locale_t);
// int __isdigit(int, __locale_t); // required by the headers
// int __isxdigit(int, __locale_t); // required by the headers
// int __toupper(int, __locale_t);
@@ -208,11 +206,6 @@ __strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
//
// Character manipulation functions
//
-# if defined(_LIBCPP_BUILDING_LIBRARY)
-inline _LIBCPP_HIDE_FROM_ABI int __islower(int __ch, __locale_t __loc) { return islower_l(__ch, __loc); }
-inline _LIBCPP_HIDE_FROM_ABI int __isupper(int __ch, __locale_t __loc) { return isupper_l(__ch, __loc); }
-# endif
-
inline _LIBCPP_HIDE_FROM_ABI int __isdigit(int __ch, __locale_t __loc) { return isdigit_l(__ch, __loc); }
inline _LIBCPP_HIDE_FROM_ABI int __isxdigit(int __ch, __locale_t __loc) { return isxdigit_l(__ch, __loc); }
diff --git a/libcxx/include/__locale_dir/support/bsd_like.h b/libcxx/include/__locale_dir/support/bsd_like.h
index 54eb397358d7a..ac402924709e5 100644
--- a/libcxx/include/__locale_dir/support/bsd_like.h
+++ b/libcxx/include/__locale_dir/support/bsd_like.h
@@ -89,12 +89,6 @@ __strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
//
// Character manipulation functions
//
-#if defined(_LIBCPP_BUILDING_LIBRARY)
-inline _LIBCPP_HIDE_FROM_ABI int __islower(int __c, __locale_t __loc) { return ::islower_l(__c, __loc); }
-
-inline _LIBCPP_HIDE_FROM_ABI int __isupper(int __c, __locale_t __loc) { return ::isupper_l(__c, __loc); }
-#endif
-
inline _LIBCPP_HIDE_FROM_ABI int __isdigit(int __c, __locale_t __loc) { return ::isdigit_l(__c, __loc); }
inline _LIBCPP_HIDE_FROM_ABI int __isxdigit(int __c, __locale_t __loc) { return ::isxdigit_l(__c, __loc); }
diff --git a/libcxx/include/__locale_dir/support/linux.h b/libcxx/include/__locale_dir/support/linux.h
index fa0b03c646a2a..23bcf44c31dbf 100644
--- a/libcxx/include/__locale_dir/support/linux.h
+++ b/libcxx/include/__locale_dir/support/linux.h
@@ -116,12 +116,6 @@ __strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
//
// Character manipulation functions
//
-#if defined(_LIBCPP_BUILDING_LIBRARY)
-inline _LIBCPP_HIDE_FROM_ABI int __islower(int __c, __locale_t __loc) { return islower_l(__c, __loc); }
-
-inline _LIBCPP_HIDE_FROM_ABI int __isupper(int __c, __locale_t __loc) { return isupper_l(__c, __loc); }
-#endif
-
inline _LIBCPP_HIDE_FROM_ABI int __isdigit(int __c, __locale_t __loc) { return isdigit_l(__c, __loc); }
inline _LIBCPP_HIDE_FROM_ABI int __isxdigit(int __c, __locale_t __loc) { return isxdigit_l(__c, __loc); }
diff --git a/libcxx/include/__locale_dir/support/no_locale/characters.h b/libcxx/include/__locale_dir/support/no_locale/characters.h
index 4fb48ed9ceac1..1281b8bd13094 100644
--- a/libcxx/include/__locale_dir/support/no_locale/characters.h
+++ b/libcxx/include/__locale_dir/support/no_locale/characters.h
@@ -29,12 +29,6 @@ namespace __locale {
//
// Character manipulation functions
//
-#if defined(_LIBCPP_BUILDING_LIBRARY)
-inline _LIBCPP_HIDE_FROM_ABI int __islower(int __c, __locale_t) { return std::islower(__c); }
-
-inline _LIBCPP_HIDE_FROM_ABI int __isupper(int __c, __locale_t) { return std::isupper(__c); }
-#endif
-
inline _LIBCPP_HIDE_FROM_ABI int __isdigit(int __c, __locale_t) { return std::isdigit(__c); }
inline _LIBCPP_HIDE_FROM_ABI int __isxdigit(int __c, __locale_t) { return std::isxdigit(__c); }
diff --git a/libcxx/include/__locale_dir/support/windows.h b/libcxx/include/__locale_dir/support/windows.h
index 0d3089c150081..0df8709f118d0 100644
--- a/libcxx/include/__locale_dir/support/windows.h
+++ b/libcxx/include/__locale_dir/support/windows.h
@@ -197,12 +197,6 @@ __strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
//
// Character manipulation functions
//
-#if defined(_LIBCPP_BUILDING_LIBRARY)
-inline _LIBCPP_HIDE_FROM_ABI int __islower(int __c, __locale_t __loc) { return _islower_l(__c, __loc); }
-
-inline _LIBCPP_HIDE_FROM_ABI int __isupper(int __c, __locale_t __loc) { return _isupper_l(__c, __loc); }
-#endif
-
inline _LIBCPP_HIDE_FROM_ABI int __isdigit(int __c, __locale_t __loc) { return _isdigit_l(__c, __loc); }
inline _LIBCPP_HIDE_FROM_ABI int __isxdigit(int __c, __locale_t __loc) { return _isxdigit_l(__c, __loc); }
diff --git a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist
index 679a0626d3268..8c55c4385f6f6 100644
--- a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -1318,8 +1318,6 @@
{'is_defined': True, 'name': '_ZNSt3__15alignEmmRPvRm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__15ctypeIcE10table_sizeE', 'size': 8, 'type': 'OBJECT'}
{'is_defined': True, 'name': '_ZNSt3__15ctypeIcE13classic_tableEv', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__15ctypeIcE21__classic_lower_tableEv', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__15ctypeIcE21__classic_upper_tableEv', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__15ctypeIcE2idE', 'size': 16, 'type': 'OBJECT'}
{'is_defined': True, 'name': '_ZNSt3__15ctypeIcEC1EPKtbm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__15ctypeIcEC2EPKtbm', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist
index 02bec0e7cbefb..51caa07a74330 100644
--- a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist
+++ b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist
@@ -1289,8 +1289,6 @@
{'is_defined': True, 'name': '_ZNSt3__15alignEmmRPvRm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__15ctypeIcE10table_sizeE', 'size': 8, 'type': 'OBJECT'}
{'is_defined': True, 'name': '_ZNSt3__15ctypeIcE13classic_tableEv', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__15ctypeIcE21__classic_lower_tableEv', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__15ctypeIcE21__classic_upper_tableEv', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__15ctypeIcE2idE', 'size': 16, 'type': 'OBJECT'}
{'is_defined': True, 'name': '_ZNSt3__15ctypeIcEC1EPKtbm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__15ctypeIcEC2EPKtbm', 'type': 'FUNC'}
diff --git a/libcxx/src/locale.cpp b/libcxx/src/locale.cpp
index 30a7a54e1c016..da735865c322c 100644
--- a/libcxx/src/locale.cpp
+++ b/libcxx/src/locale.cpp
@@ -697,6 +697,20 @@ const ctype_base::mask ctype_base::graph;
// template <> class ctype<wchar_t>;
+template <class CharT>
+static CharT to_upper_impl(CharT c) {
+ if (c < 'a' || c > 'z')
+ return c;
+ return c & ~0x20;
+}
+
+template <class CharT>
+static CharT to_lower_impl(CharT c) {
+ if (c < 'A' || c > 'Z')
+ return c;
+ return c | 0x20;
+}
+
#if _LIBCPP_HAS_WIDE_CHARACTERS
constinit locale::id ctype<wchar_t>::id;
@@ -726,48 +740,19 @@ const wchar_t* ctype<wchar_t>::do_scan_not(mask m, const char_type* low, const c
return low;
}
-wchar_t ctype<wchar_t>::do_toupper(char_type c) const {
-# ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
- return std::__libcpp_isascii(c) ? _DefaultRuneLocale.__mapupper[c] : c;
-# elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__) || defined(__MVS__)
- return std::__libcpp_isascii(c) ? ctype<char>::__classic_upper_table()[c] : c;
-# else
- return (std::__libcpp_isascii(c) && __locale::__iswlower(c, _LIBCPP_GET_C_LOCALE)) ? c - L'a' + L'A' : c;
-# endif
-}
+wchar_t ctype<wchar_t>::do_toupper(char_type c) const { return to_upper_impl(c); }
const wchar_t* ctype<wchar_t>::do_toupper(char_type* low, const char_type* high) const {
for (; low != high; ++low)
-# ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
- *low = std::__libcpp_isascii(*low) ? _DefaultRuneLocale.__mapupper[*low] : *low;
-# elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__) || defined(__MVS__)
- *low = std::__libcpp_isascii(*low) ? ctype<char>::__classic_upper_table()[*low] : *low;
-# else
- *low =
- (std::__libcpp_isascii(*low) && __locale::__islower(*low, _LIBCPP_GET_C_LOCALE)) ? (*low - L'a' + L'A') : *low;
-# endif
+ *low = to_upper_impl(*low);
return low;
}
-wchar_t ctype<wchar_t>::do_tolower(char_type c) const {
-# ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
- return std::__libcpp_isascii(c) ? _DefaultRuneLocale.__maplower[c] : c;
-# elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__) || defined(__MVS__)
- return std::__libcpp_isascii(c) ? ctype<char>::__classic_lower_table()[c] : c;
-# else
- return (std::__libcpp_isascii(c) && __locale::__isupper(c, _LIBCPP_GET_C_LOCALE)) ? c - L'A' + 'a' : c;
-# endif
-}
+wchar_t ctype<wchar_t>::do_tolower(char_type c) const { return to_lower_impl(c); }
const wchar_t* ctype<wchar_t>::do_tolower(char_type* low, const char_type* high) const {
for (; low != high; ++low)
-# ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
- *low = std::__libcpp_isascii(*low) ? _DefaultRuneLocale.__maplower[*low] : *low;
-# elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__) || defined(__MVS__)
- *low = std::__libcpp_isascii(*low) ? ctype<char>::__classic_lower_table()[*low] : *low;
-# else
- *low = (std::__libcpp_isascii(*low) && __locale::__isupper(*low, _LIBCPP_GET_C_LOCALE)) ? *low - L'A' + L'a' : *low;
-# endif
+ *low = to_lower_impl(*low);
return low;
}
@@ -811,59 +796,19 @@ ctype<char>::~ctype() {
delete[] __tab_;
}
-char ctype<char>::do_toupper(char_type c) const {
-#ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
- return std::__libcpp_isascii(c) ? static_cast<char>(_DefaultRuneLocale.__mapupper[static_cast<ptrdiff_t>(c)]) : c;
-#elif defined(__NetBSD__)
- return static_cast<char>(__classic_upper_table()[static_cast<unsigned char>(c)]);
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__MVS__)
- return std::__libcpp_isascii(c) ? static_cast<char>(__classic_upper_table()[static_cast<unsigned char>(c)]) : c;
-#else
- return (std::__libcpp_isascii(c) && __locale::__islower(c, _LIBCPP_GET_C_LOCALE)) ? c - 'a' + 'A' : c;
-#endif
-}
+char ctype<char>::do_toupper(char_type c) const { return to_upper_impl(c); }
const char* ctype<char>::do_toupper(char_type* low, const char_type* high) const {
for (; low != high; ++low)
-#ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
- *low = std::__libcpp_isascii(*low)
- ? static_cast<char>(_DefaultRuneLocale.__mapupper[static_cast<ptrdiff_t>(*low)])
- : *low;
-#elif defined(__NetBSD__)
- *low = static_cast<char>(__classic_upper_table()[static_cast<unsigned char>(*low)]);
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__MVS__)
- *low = std::__libcpp_isascii(*low) ? static_cast<char>(__classic_upper_table()[static_cast<size_t>(*low)]) : *low;
-#else
- *low = (std::__libcpp_isascii(*low) && __locale::__islower(*low, _LIBCPP_GET_C_LOCALE)) ? *low - 'a' + 'A' : *low;
-#endif
+ *low = to_upper_impl(*low);
return low;
}
-char ctype<char>::do_tolower(char_type c) const {
-#ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
- return std::__libcpp_isascii(c) ? static_cast<char>(_DefaultRuneLocale.__maplower[static_cast<ptrdiff_t>(c)]) : c;
-#elif defined(__NetBSD__)
- return static_cast<char>(__classic_lower_table()[static_cast<unsigned char>(c)]);
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__MVS__)
- return std::__libcpp_isascii(c) ? static_cast<char>(__classic_lower_table()[static_cast<size_t>(c)]) : c;
-#else
- return (std::__libcpp_isascii(c) && __locale::__isupper(c, _LIBCPP_GET_C_LOCALE)) ? c - 'A' + 'a' : c;
-#endif
-}
+char ctype<char>::do_tolower(char_type c) const { return to_lower_impl(c); }
const char* ctype<char>::do_tolower(char_type* low, const char_type* high) const {
for (; low != high; ++low)
-#ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
- *low = std::__libcpp_isascii(*low)
- ? static_cast<char>(_DefaultRuneLocale.__maplower[static_cast<ptrdiff_t>(*low)])
- : *low;
-#elif defined(__NetBSD__)
- *low = static_cast<char>(__classic_lower_table()[static_cast<unsigned char>(*low)]);
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__MVS__)
- *low = std::__libcpp_isascii(*low) ? static_cast<char>(__classic_lower_table()[static_cast<size_t>(*low)]) : *low;
-#else
- *low = (std::__libcpp_isascii(*low) && __locale::__isupper(*low, _LIBCPP_GET_C_LOCALE)) ? *low - 'A' + 'a' : *low;
-#endif
+ *low = to_lower_impl(*low);
return low;
}
@@ -1010,36 +955,6 @@ const ctype<char>::mask* ctype<char>::classic_table() noexcept {
}
#endif
-#if defined(__GLIBC__)
-const int* ctype<char>::__classic_lower_table() noexcept { return _LIBCPP_GET_C_LOCALE->__ctype_tolower; }
-
-const int* ctype<char>::__classic_upper_table() noexcept { return _LIBCPP_GET_C_LOCALE->__ctype_toupper; }
-#elif defined(__NetBSD__)
-const short* ctype<char>::__classic_lower_table() noexcept { return _C_tolower_tab_ + 1; }
-
-const short* ctype<char>::__classic_upper_table() noexcept { return _C_toupper_tab_ + 1; }
-
-#elif defined(__EMSCRIPTEN__)
-const int* ctype<char>::__classic_lower_table() noexcept { return *__ctype_tolower_loc(); }
-
-const int* ctype<char>::__classic_upper_table() noexcept { return *__ctype_toupper_loc(); }
-#elif defined(__MVS__)
-const unsigned short* ctype<char>::__classic_lower_table() _NOEXCEPT {
-# if defined(__NATIVE_ASCII_F)
- return const_cast<const unsigned short*>(__OBJ_DATA(__lc_ctype_a)->lower);
-# else
- return const_cast<const unsigned short*>(__ctype + __TOLOWER_INDEX);
-# endif
-}
-const unsigned short* ctype<char>::__classic_upper_table() _NOEXCEPT {
-# if defined(__NATIVE_ASCII_F)
- return const_cast<const unsigned short*>(__OBJ_DATA(__lc_ctype_a)->upper);
-# else
- return const_cast<const unsigned short*>(__ctype + __TOUPPER_INDEX);
-# endif
-}
-#endif // __GLIBC__ || __NETBSD__ || __EMSCRIPTEN__ || __MVS__
-
// template <> class ctype_byname<char>
ctype_byname<char>::ctype_byname(const char* name, size_t refs)
diff --git a/libcxx/test/benchmarks/locale/ctype.bench.cpp b/libcxx/test/benchmarks/locale/ctype.bench.cpp
new file mode 100644
index 0000000000000..92afeb2ca35f3
--- /dev/null
+++ b/libcxx/test/benchmarks/locale/ctype.bench.cpp
@@ -0,0 +1,69 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+#include <locale>
+
+#include <benchmark/benchmark.h>
+
+#include "make_string.h"
+
+template <class CharT>
+static void BM_tolower_char(benchmark::State& state) {
+ const auto& ct = std::use_facet<std::ctype<CharT>>(std::locale::classic());
+
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(ct.tolower(CharT('c')));
+ }
+}
+
+BENCHMARK(BM_tolower_char<char>);
+BENCHMARK(BM_tolower_char<wchar_t>);
+
+template <class CharT>
+static void BM_tolower_string(benchmark::State& state) {
+ const auto& ct = std::use_facet<std::ctype<CharT>>(std::locale::classic());
+ std::basic_string<CharT> str;
+
+ for (auto _ : state) {
+ str = MAKE_STRING_VIEW(CharT, "THIS IS A LONG STRING TO MAKE TO LOWER");
+ benchmark::DoNotOptimize(ct.tolower(str.data(), str.data() + str.size()));
+ }
+}
+
+BENCHMARK(BM_tolower_string<char>);
+BENCHMARK(BM_tolower_string<wchar_t>);
+
+template <class CharT>
+static void BM_toupper_char(benchmark::State& state) {
+ const auto& ct = std::use_facet<std::ctype<CharT>>(std::locale::classic());
+
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(ct.toupper(CharT('c')));
+ }
+}
+
+BENCHMARK(BM_toupper_char<char>);
+BENCHMARK(BM_toupper_char<wchar_t>);
+
+template <class CharT>
+static void BM_toupper_string(benchmark::State& state) {
+ const auto& ct = std::use_facet<std::ctype<CharT>>(std::locale::classic());
+ std::basic_string<CharT> str;
+
+ for (auto _ : state) {
+ str = MAKE_STRING_VIEW(CharT, "THIS IS A LONG STRING TO MAKE TO LOWER");
+ benchmark::DoNotOptimize(ct.toupper(str.data(), str.data() + str.size()));
+ }
+}
+
+BENCHMARK(BM_toupper_string<char>);
+BENCHMARK(BM_toupper_string<wchar_t>);
+
+BENCHMARK_MAIN();
|
ldionne
approved these changes
Jun 25, 2025
There was a problem hiding this comment.
This needs an entry in abi/CHANGELOG.txt (and it should explain why this removal is fine).
There was a problem hiding this comment.
Not attached to this file: we need a release note!
| const auto& ct = std::use_facet<std::ctype<CharT>>(std::locale::classic()); | ||
|
|
||
| for (auto _ : state) { | ||
| benchmark::DoNotOptimize(ct.tolower(CharT('c'))); |
There was a problem hiding this comment.
Minor nit: let's make it so that the compiler can't optimize based on the known value of CharT('c'). That way the benchmark will make sense even if the implementation of tolower were in the headers.
| std::basic_string<CharT> str; | ||
|
|
||
| for (auto _ : state) { | ||
| str = MAKE_STRING_VIEW(CharT, "THIS IS A LONG STRING TO MAKE TO LOWER"); |
philnik777
force-pushed
the
optimize_toupperlower
branch
from
f80600a to
c2f9e66
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.