tree-ssa-pre.c (eliminate_dom_walker::before_dom_children): Rewrite to propagate the VN result into all uses where possible and to remove...

2014-06-13  Richard Biener  <rguenther@suse.de>

	* tree-ssa-pre.c (eliminate_dom_walker::before_dom_children):
	Rewrite to propagate the VN result into all uses where
	possible and to remove stmts becoming dead because of that.
	(eliminate): Generalize stmt removal handling, remove in
	reverse dominator order to support proper debug stmt
	generation.  Update stmts before removing stmts.
	* tree-ssa-propagate.c (propagate_tree_value): Remove
	bogus assert.

	* c-c++-common/pr46562-2.c: Adjust.
	* g++.dg/tree-ssa/pr8781.C: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-24.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-25.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-32.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-39.c: Likewise.
	* gcc.dg/tree-ssa/ssa-pre-16.c: Likewise.

From-SVN: r211625