[PATCH 1/2] Always set DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT correctly

Andi Kleen andi@firstfloor.org
Fri Sep 12 14:33:00 GMT 2014


From: Andi Kleen <ak@linux.intel.com>

When profiling is disabled force DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT
for each function to one. This information is then preserved
through LTO.

With this patch for LTO builds -pg needs to be set on both the
LTO final link and the original source build, to allow -pg
(or -pg -fentry) to be active for that source file. This allows
to build large projects mostly with -pg, except for a few files,
and still use LTO.

Originally suggested by Richard Biener
Passes bootstrap and testing on x86_64-linux.

gcc/:

2014-09-11  Andi Kleen  <ak@linux.intel.com>

	* function.c (allocate_struct_function): Force
	DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT to zero when
	profiling is disabled.
---
 gcc/function.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gcc/function.c b/gcc/function.c
index c8daf95..f07fdcf 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -4555,6 +4555,9 @@ allocate_struct_function (tree fndecl, bool abstract_p)
          but is this worth the hassle?  */
       cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
       cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
+
+      if (!profile_flag && !flag_instrument_function_entry_exit)
+	DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
     }
 }
 
-- 
2.1.0



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