> I think the __throw_bad_alloc() and __throw_bad_array_new_length()
> functions should always be rare, so marking them cold seems fine (users who
> define their own allocators that want to throw bad_alloc "often" will
> probably throw it directly, they shouldn't be using our __throw_bad_alloc()
> function anyway). I don't think __throw_bad_exception is ever used, so that
> doesn't matter (we could remove it from the header and just keep its
> definition in the library, but there's no big advantage to doing that).
> Others like __throw_length_error() should also be very very rare, and could
> be marked cold.
> 
> Maybe we should just mark everything in <bits/functexcept.h> as cold. If
> users want to avoid the cost of calls to those functions they can do so by
> checking function preconditions/arguments to avoid the exceptions. There
> are very few places where a throwing libstdc++ API doesn't have a way to
> avoid the exception. The only one that isn't easily avoidable is
> __throw_bad_alloc but OOM should be rare.

Hi,
this marks everything in functexcept.h as cold and I also noticed that
we probably want to mark as such terminate.

With fix to 110436 and -O3 we now inline _M_realloc_insert, yay :)

tested on x86_64-linux, OK?

        * include/bits/c++config (std::__terminate): Mark cold.
        * include/bits/functexcept.h: Mark everything as cold.
        * libsupc++/exception: Mark terminate and unexpected as cold.
diff --git a/libstdc++-v3/include/bits/c++config 
b/libstdc++-v3/include/bits/c++config
index 009a017b048..dd47f274d5f 100644
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -320,7 +320,7 @@ namespace std
   extern "C++" __attribute__ ((__noreturn__, __always_inline__))
   inline void __terminate() _GLIBCXX_USE_NOEXCEPT
   {
-    void terminate() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__noreturn__));
+    void terminate() _GLIBCXX_USE_NOEXCEPT __attribute__ 
((__noreturn__,__cold__));
     terminate();
   }
 #pragma GCC visibility pop
diff --git a/libstdc++-v3/include/bits/functexcept.h 
b/libstdc++-v3/include/bits/functexcept.h
index 2765f7865df..a2e97413661 100644
--- a/libstdc++-v3/include/bits/functexcept.h
+++ b/libstdc++-v3/include/bits/functexcept.h
@@ -57,61 +57,61 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   // Helper for exception objects in <typeinfo>
   void
-  __throw_bad_cast(void) __attribute__((__noreturn__));
+  __throw_bad_cast(void) __attribute__((__noreturn__,__cold__));
 
   void
-  __throw_bad_typeid(void) __attribute__((__noreturn__));
+  __throw_bad_typeid(void) __attribute__((__noreturn__,__cold__));
 
   // Helpers for exception objects in <stdexcept>
   void
-  __throw_logic_error(const char*) __attribute__((__noreturn__));
+  __throw_logic_error(const char*) __attribute__((__noreturn__,__cold__));
 
   void
-  __throw_domain_error(const char*) __attribute__((__noreturn__));
+  __throw_domain_error(const char*) __attribute__((__noreturn__,__cold__));
 
   void
-  __throw_invalid_argument(const char*) __attribute__((__noreturn__));
+  __throw_invalid_argument(const char*) __attribute__((__noreturn__,__cold__));
 
   void
-  __throw_length_error(const char*) __attribute__((__noreturn__));
+  __throw_length_error(const char*) __attribute__((__noreturn__,__cold__));
 
   void
-  __throw_out_of_range(const char*) __attribute__((__noreturn__));
+  __throw_out_of_range(const char*) __attribute__((__noreturn__,__cold__));
 
   void
-  __throw_out_of_range_fmt(const char*, ...) __attribute__((__noreturn__))
+  __throw_out_of_range_fmt(const char*, ...) 
__attribute__((__noreturn__,__cold__))
     __attribute__((__format__(__gnu_printf__, 1, 2)));
 
   void
-  __throw_runtime_error(const char*) __attribute__((__noreturn__));
+  __throw_runtime_error(const char*) __attribute__((__noreturn__,__cold__));
 
   void
-  __throw_range_error(const char*) __attribute__((__noreturn__));
+  __throw_range_error(const char*) __attribute__((__noreturn__,__cold__));
 
   void
-  __throw_overflow_error(const char*) __attribute__((__noreturn__));
+  __throw_overflow_error(const char*) __attribute__((__noreturn__,__cold__));
 
   void
-  __throw_underflow_error(const char*) __attribute__((__noreturn__));
+  __throw_underflow_error(const char*) __attribute__((__noreturn__,__cold__));
 
   // Helpers for exception objects in <ios>
   void
-  __throw_ios_failure(const char*) __attribute__((__noreturn__));
+  __throw_ios_failure(const char*) __attribute__((__noreturn__,__cold__));
 
   void
-  __throw_ios_failure(const char*, int) __attribute__((__noreturn__));
+  __throw_ios_failure(const char*, int) __attribute__((__noreturn__,__cold__));
 
   // Helpers for exception objects in <system_error>
   void
-  __throw_system_error(int) __attribute__((__noreturn__));
+  __throw_system_error(int) __attribute__((__noreturn__,__cold__));
 
   // Helpers for exception objects in <future>
   void
-  __throw_future_error(int) __attribute__((__noreturn__));
+  __throw_future_error(int) __attribute__((__noreturn__,__cold__));
 
   // Helpers for exception objects in <functional>
   void
-  __throw_bad_function_call() __attribute__((__noreturn__));
+  __throw_bad_function_call() __attribute__((__noreturn__,__cold__));
 
 #else // ! HOSTED
 
diff --git a/libstdc++-v3/libsupc++/exception b/libstdc++-v3/libsupc++/exception
index a34386e6026..00a6347ebe5 100644
--- a/libstdc++-v3/libsupc++/exception
+++ b/libstdc++-v3/libsupc++/exception
@@ -75,7 +75,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
 
   /** The runtime will call this function if %exception handling must be
    *  abandoned for any reason.  It can also be called by the user.  */
-  void terminate() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__noreturn__));
+  void terminate() _GLIBCXX_USE_NOEXCEPT __attribute__ 
((__noreturn__,__cold__));
 
 #if __cplusplus < 201703L || (__cplusplus <= 202002L && 
_GLIBCXX_USE_DEPRECATED)
   /// If you write a replacement %unexpected handler, it must be of this type.
@@ -104,7 +104,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
    * @deprecated Removed from the C++ standard in C++17
    */
   _GLIBCXX11_DEPRECATED
-  void unexpected() __attribute__ ((__noreturn__));
+  void unexpected() __attribute__ ((__noreturn__,__cold__));
 #endif
 
   /** [18.6.4]/1:  'Returns true after completing evaluation of a

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