re PR tree-optimization/67975 (Failure to optimise equality between two call sequences)

re PR tree-optimization/67975 (Failure to optimise equality between two call sequences)

2015-10-19  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/67975
	* tree-cfg.h (extract_true_false_controlled_edges): Declare.
	* tree-cfg.c (extract_true_false_controlled_edges): Split out
	core worker from ...
	* tree-ssa-loop-im.c (extract_true_false_args_from_phi): ... here.
	* tree-ssa-sccvn.c (vn_phi_compute_hash): Hash number of args
	instead of block number for PHIs with two or one args.
	(vn_phi_eq): Compare edge predicates of PHIs that are in different
	blocks.

	* gcc.dg/tree-ssa/ssa-fre-50.c: New testcase.

From-SVN: r228971