r255093 - in /trunk/gcc: ChangeLog testsuite/Ch...

[rguenth@gcc.gnu.org]

Author: rguenth
Date: Thu Nov 23 09:05:11 2017
New Revision: 255093

URL: https://gcc.gnu.org/viewcvs?rev=255093&root=gcc&view=rev
Log:
2017-11-23  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/23094
	* tree-ssa-sccvn.c (vuse_ssa_val): Handle VN_TOP when we
	come here from walking over backedges in the first iteration.
	(vn_reference_lookup_3): Skip clobbers that store the same value.

	* gcc.dg/tree-ssa/ssa-fre-61.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-61.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-sccvn.c