[Bug tree-optimization/77839] [6/7 Regression] Memory- and compile time hog at -O1 and above

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77839

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Thu Oct  6 08:54:37 2016
New Revision: 240829

URL: https://gcc.gnu.org/viewcvs?rev=240829&root=gcc&view=rev
Log:
2016-10-06  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/77839
        * tree-ssa-sccvn.c (set_ssa_val_to): Forbid value -> constant value
        lattice transition.

        * gcc.dg/torture/pr77839.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr77839.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-sccvn.c