2019-05-13  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/90402
	* tree-if-conv.c (tree_if_conversion): Value number only
	the loop body by making the latch an exit of the region
	as well.
	* tree-ssa-sccvn.c (process_bb): Add flag whether to skip
	processing PHIs.
	(do_rpo_vn): Deal with multiple edges into the entry block
	that are not backedges inside the region by skipping PHIs
	of the entry block.

	* gcc.dg/torture/pr90402-1.c: New testcase.

From-SVN: r271125