r260253 - in /trunk/gcc: ChangeLog testsuite/Ch...

[rguenth@gcc.gnu.org]

Author: rguenth
Date: Tue May 15 11:30:29 2018
New Revision: 260253

URL: https://gcc.gnu.org/viewcvs?rev=260253&root=gcc&view=rev
Log:
2018-05-15  Richard Biener  <rguenther@suse.de>

	* tree-ssa-dse.c (dse_classify_store): Remove use_stmt parameter,
	add by_clobber_p one.  Change algorithm to collect all defs
	representing uses we need to walk and try reducing them to
	a single one before failing.
	(dse_dom_walker::dse_optimize_stmt): Adjust.

	* gcc.dg/tree-ssa/ssa-dse-31.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-31.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-dse.c