[Bug tree-optimization/78185] Wrong branch optimization with -O1 on x86/x86_64

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78185

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Fri Nov  4 08:54:42 2016
New Revision: 241841

URL: https://gcc.gnu.org/viewcvs?rev=241841&root=gcc&view=rev
Log:
2016-11-04  Richard Biener  <rguent...@suse.de>

        PR middle-end/78185
        * loop-invariant.c (find_exits): Record entering inner
        loops as possibly exiting to handle infinite sub-loops.
        * tree-ssa-loop-im.c: Include tree-ssa-loop-niter.h.
        (fill_always_executed_in_1): Honor infinite child loops.

        * gcc.dg/pr78185.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/pr78185.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/loop-invariant.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-loop-im.c