Tested powerpc64le-linux. Pushed to gcc-12.
-- >8 --
The std::try_facet and std::use_facet functions were optimized in
r13-3888-gb3ac43a3c05744 to avoid redundant checking for all facets that
are required to always be present in every locale.
This performs a simpler version of the optimization that only applies to
std::ctype<char>, std::num_get<char>, std::num_put<char>, and the
wchar_t specializations of those facets. Those are the facets that are
cached by std::basic_ios, which means they're used on construction for
every iostream object. This smaller change is suitable for the gcc-12
branch, and mitigates the performance loss for powerpc64le-linux on the
gcc-12 branch caused by r12-9454-g24cf9f4c6f45f7 for PR 103387. It also
greatly improves the performance of constructing iostreams objects, for
all targets.
libstdc++-v3/ChangeLog:
PR libstdc++/103755
* include/bits/locale_classes.tcc (try_facet, use_facet): Do not
check array index or dynamic type when accessing required
specializations of std::ctype, std::num_get, or std::num_put.
* testsuite/22_locale/ctype/is/string/89728_neg.cc: Adjust
expected errors.
---
libstdc++-v3/include/bits/locale_classes.tcc | 23 +++++++++++++++++++
.../22_locale/ctype/is/string/89728_neg.cc | 1 +
2 files changed, 24 insertions(+)
diff --git a/libstdc++-v3/include/bits/locale_classes.tcc
b/libstdc++-v3/include/bits/locale_classes.tcc
index 64cd7534dc6..e6ce07ae8b7 100644
--- a/libstdc++-v3/include/bits/locale_classes.tcc
+++ b/libstdc++-v3/include/bits/locale_classes.tcc
@@ -103,6 +103,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
bool
has_facet(const locale& __loc) throw()
{
+ if _GLIBCXX17_CONSTEXPR (__is_same(_Facet, ctype<char>)
+ || __is_same(_Facet, num_get<char>)
+ || __is_same(_Facet, num_put<char>))
+ return true;
+#ifdef _GLIBCXX_USE_WCHAR_T
+ else if _GLIBCXX17_CONSTEXPR (__is_same(_Facet, ctype<wchar_t>)
+ || __is_same(_Facet, num_get<wchar_t>)
+ || __is_same(_Facet, num_put<wchar_t>))
+ return true;
+#endif
+
const size_t __i = _Facet::id._M_id();
const locale::facet** __facets = __loc._M_impl->_M_facets;
return (__i < __loc._M_impl->_M_facets_size
@@ -133,6 +144,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
const size_t __i = _Facet::id._M_id();
const locale::facet** __facets = __loc._M_impl->_M_facets;
+
+ if _GLIBCXX17_CONSTEXPR (__is_same(_Facet, ctype<char>)
+ || __is_same(_Facet, num_get<char>)
+ || __is_same(_Facet, num_put<char>))
+ return static_cast<const _Facet&>(*__facets[__i]);
+#ifdef _GLIBCXX_USE_WCHAR_T
+ else if _GLIBCXX17_CONSTEXPR (__is_same(_Facet, ctype<wchar_t>)
+ || __is_same(_Facet, num_get<wchar_t>)
+ || __is_same(_Facet, num_put<wchar_t>))
+ return static_cast<const _Facet&>(*__facets[__i]);
+#endif
+
if (__i >= __loc._M_impl->_M_facets_size || !__facets[__i])
__throw_bad_cast();
#if __cpp_rtti
diff --git a/libstdc++-v3/testsuite/22_locale/ctype/is/string/89728_neg.cc
b/libstdc++-v3/testsuite/22_locale/ctype/is/string/89728_neg.cc
index 77bb1a64f45..baed67d64f4 100644
--- a/libstdc++-v3/testsuite/22_locale/ctype/is/string/89728_neg.cc
+++ b/libstdc++-v3/testsuite/22_locale/ctype/is/string/89728_neg.cc
@@ -18,6 +18,7 @@
// <http://www.gnu.org/licenses/>.
// { dg-error "complete" "" { target *-*-* } 0 }
+// { dg-error "invalid .static_cast." "" { target c++14_down } 0 }
#include <locale>
--
2.40.0
