[Bug tree-optimization/62167] [4.8 Regression][tail-merge] dead type-unsafe load replaces type-safe load

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62167

--- Comment #5 from vries at gcc dot gnu.org ---
Author: vries
Date: Wed Nov 19 11:08:02 2014
New Revision: 217764

URL: https://gcc.gnu.org/viewcvs?rev=217764&root=gcc&view=rev
Log:
Fix tail-merge pass for dead type-unsafe code

2014-11-19  Tom de Vries  <tom@codesourcery.com>

    Backport from mainline
    PR tree-optimization/62167
    * tree-ssa-tail-merge.c (stmt_local_def): Handle statements with vuse
    conservatively.
    (gimple_equal_p): Don't use vn_valueize to compare for lhs equality of
    assigns.

    * gcc.dg/pr51879-12.c: Add xfails.
    * gcc.dg/pr62167-run.c: New test.
    * gcc.dg/pr62167.c: New test.

Added:
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/pr62167-run.c
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/pr62167.c
Modified:
    branches/gcc-4_8-branch/gcc/ChangeLog
    branches/gcc-4_8-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/pr51879-12.c
    branches/gcc-4_8-branch/gcc/tree-ssa-tail-merge.c