https://gcc.gnu.org/g:17db5742a555d4f8fd5fa324adb6d1e5c55374be
commit r15-5732-g17db5742a555d4f8fd5fa324adb6d1e5c55374be
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Wed Nov 27 11:52:40 2024 +0000
libstdc++: Add cold attribute to assertion failure functions [PR117650]
This helps the compiler to split the cold path into a separate clone, so
that the hot path is a smaller function that uses less icache, and the
cold path is only fetched into the icache if actually executed.
libstdc++-v3/ChangeLog:
PR libstdc++/117650
* include/bits/c++config (__glibcxx_assert_fail): Add cold
attribute.
* include/debug/formatter.h (_Error_formatter::_M_error):
Likewise.
Diff:
---
libstdc++-v3/include/bits/c++config | 2 +-
libstdc++-v3/include/debug/formatter.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/libstdc++-v3/include/bits/c++config
b/libstdc++-v3/include/bits/c++config
index 236906d2f79f..c74b03013fdb 100644
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -610,7 +610,7 @@ namespace std
{
#pragma GCC visibility push(default)
// Don't use <cassert> because this should be unaffected by NDEBUG.
- extern "C++" _GLIBCXX_NORETURN
+ extern "C++" _GLIBCXX_NORETURN __attribute__((__cold__))
void
__glibcxx_assert_fail /* Called when a precondition violation is detected. */
(const char* __file, int __line, const char* __function,
diff --git a/libstdc++-v3/include/debug/formatter.h
b/libstdc++-v3/include/debug/formatter.h
index 4f5a4539bb9f..df7f6965a4c8 100644
--- a/libstdc++-v3/include/debug/formatter.h
+++ b/libstdc++-v3/include/debug/formatter.h
@@ -571,7 +571,7 @@ namespace __gnu_debug
_Error_formatter&
_M_message(_Debug_msg_id __id) const throw ();
- _GLIBCXX_NORETURN void
+ _GLIBCXX_NORETURN __attribute__((__cold__)) void
_M_error() const;
#if !_GLIBCXX_INLINE_VERSION
