2014-11-20 Richard Biener <rguenther@suse.de>

2014-11-20   Richard Biener  <rguenther@suse.de>

	PR tree-optimization/63677
	* tree-ssa-dom.c: Include gimplify.h for unshare_expr.
	(avail_exprs_stack): Make a vector of pairs.
	(struct hash_expr_elt): Replace stmt member with vop member.
	(expr_elt_hasher::equal): Simplify.
	(initialize_hash_element): Adjust.
	(initialize_hash_element_from_expr): Likewise.
	(dom_opt_dom_walker::thread_across_edge): Likewise.
	(record_cond): Likewise.
	(dom_opt_dom_walker::before_dom_children): Likewise.
	(print_expr_hash_elt): Likewise.
	(remove_local_expressions_from_table): Restore previous state
	if requested.
	(record_equivalences_from_stmt): Record &x + CST as constant
	&MEM[&x, CST] for further propagation.
	(vuse_eq): New function.
	(lookup_avail_expr): For loads use the alias oracle to see
	whether a candidate from the expr hash is usable.
	(avail_expr_hash): Do not hash VUSEs.

	* gcc.dg/tree-ssa/ssa-dom-cse-2.c: New testcase.
	* gcc.dg/tree-ssa/ssa-dom-cse-3.c: Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@217827 138bc75d-0d04-0410-961f-82ee72b054a4