re PR tree-optimization/71059 (gcc ICE at -O3 on valid code on x86_64-linux-gnu in "vn_nary_op_insert_into")

2016-05-12  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/71059
	* tree-ssa-pre.c (phi_translate_1): Fully fold translated
	nary before looking up or entering the expression into the VN
	hashes.
	* tree-ssa-sccvn.c (vn_nary_build_or_lookup): Fix comment typo.
	Make sure to re-use NARYs without result as inserted by
	phi-translation.

	* gcc.dg/torture/pr71059.c: New testcase.

From-SVN: r236175