re PR tree-optimization/57326 (Piecewise folding of operations on PHI nodes)

re PR tree-optimization/57326 (Piecewise folding of operations on PHI nodes)

2016-08-12  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/57326
	* tree-ssa-pre.c (fully_constant_expression): Handle simplification
	returning an SSA name.
	(phi_translate_1): When fully_constant_expression returns a NAME
	make sure we have a leader for it.

	* gcc.dg/tree-ssa/ssa-pre-32.c: New testcase.
	* gcc.dg/tree-ssa/loadpre14.c: Adjust.
	* gcc.dg/tree-ssa/pr35287.c: Likewise.
	* gcc.target/i386/pr45685.c: Likewise.
	* gcc.dg/tree-ssa/predcom-1.c: Disable PRE.
	* gcc.dg/tree-ssa/predcom-2.c: Likewise.
	* gcc.dg/tree-ssa/predcom-3.c: Likewise.
	* gcc.dg/tree-ssa/ssa-sink-10.c: Likewise.
	* gfortran.dg/pr34163.f90: Likewise.

From-SVN: r239414