[Bug middle-end/55481] [4.8 regression] -O2 generates a wrong-code infinite loop in C++Benchmark's simple_types_constant_folding int8 xor test

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55481

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.0                       |4.7.3

--- Comment #21 from Richard Biener <rguenth at gcc dot gnu.org> 2013-03-01 13:55:15 UTC ---
Fixed for 4.7.3 as well.

--- Comment #22 from Richard Biener <rguenth at gcc dot gnu.org> 2013-03-01 13:55:19 UTC ---
Author: rguenth
Date: Fri Mar  1 13:55:11 2013
New Revision: 196379

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=196379
Log:
2013-03-01  Richard Biener  <rguenther@suse.de>

    Backport from mainline
    2012-12-12  Zdenek Dvorak  <ook@ucw.cz>

    PR tree-optimization/55481
    * tree-ssa-loop-ivopts.c (rewrite_use_nonlinear_expr): Fall
    back to general rewriting if we cannot leave an original biv
    definition alone.

    * gcc.dg/torture/pr55481.c: New testcase.
    * gcc.dg/torture/pr56488.c: Likewise.

Added:
    branches/gcc-4_7-branch/gcc/testsuite/gcc.dg/torture/pr55481.c
    branches/gcc-4_7-branch/gcc/testsuite/gcc.dg/torture/pr56488.c
Modified:
    branches/gcc-4_7-branch/gcc/ChangeLog
    branches/gcc-4_7-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_7-branch/gcc/tree-ssa-loop-ivopts.c