2018-01-26  Richard Biener  <rguenther@suse.de>

	PR rtl-optimization/84003
	* dse.c (record_store): Only record redundant stores when
	the earlier store aliases at least all accesses the later one does.

	* g++.dg/torture/pr77745.C: Mark foo noinline to trigger
	latent bug in DSE if NOINLINE is appropriately defined.
	* g++.dg/torture/pr77745-2.C: New testcase including pr77745.C
	and defining NOINLINE.

From-SVN: r257091