[Bug ipa/58862] [4.9 Regression] LTO profiledbootstrap failure: lto1: ICE in edge_badness, at ipa-inline.c:1008

["tejohnson at google dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58862

Teresa Johnson <tejohnson at google dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |tejohnson at gcc dot gnu.org,
                   |                            |tejohnson at google dot com

--- Comment #3 from Teresa Johnson <tejohnson at google dot com> ---
I hit the "verify_flow_info: Wrong probability of edge" error in a
profiledbootstrap. I triaged this down to the following commit, made by me:

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r203823 | tejohnson | 2013-10-18 07:36:53 -0700 (Fri, 18 Oct 2013) | 5 lines
Changed paths:
   M /trunk/gcc/ChangeLog
   M /trunk/gcc/tree-ssa-tail-merge.c

2013-10-18  Teresa Johnson  <tejohnson@google.com>

        * tree-ssa-tail-merge.c (replace_block_by): Update edge
        weights during merging.

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Investigating right now. Looks like there were profile weight insanities going
into this code, that were magnified by the fixes being performed by my change.
To avoid the error, I need to adjust the change I made to ensure that the
profile insanities don't get propagated into the edge probabilities.

In the case I looked at, the edge weight insanities were originally introduced 
during jump threading. I had previously made a fix to the profile updates being
done by that optimization (r203041, committed by law), but there have been a
number of changes to that code since then so this needs to be revisited.

I will get a fix for the failure though hopefully today.

Thanks,
Teresa