[Bug rtl-optimization/64682] [5 Regression] wrong code at -O2 and -O3 on x86_64-linux-gnu

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64682

--- Comment #8 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Author: segher
Date: Thu Feb  4 23:16:44 2016
New Revision: 233160

URL: https://gcc.gnu.org/viewcvs?rev=233160&root=gcc&view=rev
Log:
combine: distribute_notes again (PR69567, PR64682)

As it happens the patch I did over a year ago for PR64682 isn't quite
correct.  This is PR69567.  This fixes it.


        Backport from mainline
        2016-02-04  Segher Boessenkool  <segher@kernel.crashing.org>

        PR rtl-optimization/64682
        PR rtl-optimization/69567
        * combine.c (distribute_notes) <REG_DEAD>: Place the death note
        before I2 only if the register is both used and set in I2.

Modified:
    branches/gcc-5-branch/gcc/ChangeLog
    branches/gcc-5-branch/gcc/combine.c