2015-08-31  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* tree.h (zerop): New function.
	* tree.c (zerop): Likewise.
	(element_precision): Handle expressions.
	* match.pd (define_predicates): Add zerop.
	(x <= +Inf): Fix comment.
	(abs (x) == 0, A & C == C, A & C != 0): Converted from ...
	* fold-const.c (fold_binary_loc): ... here. Remove.

gcc/testsuite/
	* gcc.dg/tree-ssa/cmp-1.c: New file.

From-SVN: r227346