backport: [multiple changes]

backport: [multiple changes]

2018-06-21  Richard Biener  <rguenther@suse.de>

	Backport from mainline
	2018-02-28  Richard Biener  <rguenther@suse.de>

	PR middle-end/84607
	* genmatch.c (capture_info::walk_match): Do not mark
	captured expressions without operands as expr_p given
	they act more like predicates and should be subject to
	"lost tail" side-effect preserving.

	* gcc.dg/pr84607.c: New testcase.

	2018-05-04  Richard Biener  <rguenther@suse.de>

	PR middle-end/85588
	* fold-const.c (negate_expr_p): Restrict negation of operand
	zero of a division to when we know that can happen without
	overflow.
	(fold_negate_expr_1): Likewise.

	* gcc.dg/torture/pr85588.c: New testcase.
	* gcc.dg/torture/pr57656.c: Use dg-additional-options.

From-SVN: r261839