[Bug tree-optimization/67975] Failure to optimise equality between two call sequences

["rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67975

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Mon Oct 19 14:00:28 2015
New Revision: 228971

URL: https://gcc.gnu.org/viewcvs?rev=228971&root=gcc&view=rev
Log:
2015-10-19  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/67975
        * tree-cfg.h (extract_true_false_controlled_edges): Declare.
        * tree-cfg.c (extract_true_false_controlled_edges): Split out
        core worker from ...
        * tree-ssa-loop-im.c (extract_true_false_args_from_phi): ... here.
        * tree-ssa-sccvn.c (vn_phi_compute_hash): Hash number of args
        instead of block number for PHIs with two or one args.
        (vn_phi_eq): Compare edge predicates of PHIs that are in different
        blocks.

        * gcc.dg/tree-ssa/ssa-fre-50.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-50.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-cfg.c
    trunk/gcc/tree-cfg.h
    trunk/gcc/tree-ssa-loop-im.c
    trunk/gcc/tree-ssa-sccvn.c