[Bug gcov-profile/59542] [4.9 Regression] ICE: verify_flow_info failed during Firefox build with 'gold'

[tejohnson at google dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59542

--- Comment #3 from Teresa Johnson <tejohnson at google dot com> ---
On Wed, Dec 18, 2013 at 6:15 AM, Teresa Johnson <tejohnson@google.com> wrote:
> Thanks, I am able to reproduce now with the gold linker option. Investigating...
> Teresa
>
> On Wed, Dec 18, 2013 at 12:52 AM, trippels at gcc dot gnu.org
> <gcc-bugzilla@gcc.gnu.org> wrote:
>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59542
>>
>> Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:
>>
>>            What    |Removed                     |Added
>> ----------------------------------------------------------------------------
>>                  CC|                            |tejohnson at google dot com
>>
>> --
>> You are receiving this mail because:
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Here is the patch that fixes it, and I am currently regression testing:

Teresa

2013-12-18  Teresa Johnson  <tejohnson@google.com>

        * bb-reorder.c (duplicate_computed_gotos): Invoke fixup_partitions
        if we have made any changes.

Index: bb-reorder.c
===================================================================
--- bb-reorder.c        (revision 206100)
+++ bb-reorder.c        (working copy)
@@ -2390,6 +2390,7 @@ duplicate_computed_gotos (void)
   basic_block bb, new_bb;
   bitmap candidates;
   int max_size;
+  bool changed = false;

   if (n_basic_blocks_for_fn (cfun) <= NUM_FIXED_BLOCKS + 1)
     return 0;
@@ -2486,9 +2487,17 @@ duplicate_computed_gotos (void)
       new_bb->aux = bb->aux;
       bb->aux = new_bb;
       new_bb->flags |= BB_VISITED;
+      changed = true;
     }

 done:
+  /* Duplicating blocks above will redirect edges and may cause hot blocks
+     previously reached by both hot and cold blocks to become dominated only
+     by cold blocks. This will cause the verification when leaving cfg layout
+     mode to fail, and lead to now cold code in the hot section. Invoke
+     fixup_partitions to address these problems.  */
+  if (changed)
+    fixup_partitions ();
   cfg_layout_finalize ();

   BITMAP_FREE (candidates);


>
>
>
> --
> Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413