[Bug tree-optimization/77309] [5/6 Regression] wrong code at -Os and above on x86_64-linux-gnu (in the 64-bit mode)

[bernds at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77309

--- Comment #5 from Bernd Schmidt <bernds at gcc dot gnu.org> ---
Author: bernds
Date: Mon Dec 12 13:00:53 2016
New Revision: 243549

URL: https://gcc.gnu.org/viewcvs?rev=243549&root=gcc&view=rev
Log:
        Backport from mainline
        2016-11-07  Bernd Schmidt  <bschmidt@redhat.com>

        PR rtl-optimization/77309
        * combine.c (make_compound_operation): Allow EQ for IN_CODE, and
        don't assume an equality comparison for plain COMPARE.
        (simplify_comparison): Pass a more accurate code to
        make_compound_operation.

        PR rtl-optimization/77309
        * gcc.dg/torture/pr77309.c: New test.


Added:
    branches/gcc-6-branch/gcc/testsuite/gcc.dg/torture/pr77309.c
Modified:
    branches/gcc-6-branch/gcc/ChangeLog
    branches/gcc-6-branch/gcc/combine.c
    branches/gcc-6-branch/gcc/testsuite/ChangeLog