Backport PRs 64516, 68528, 80171, 80362

Backport PRs 64516, 68528, 80171, 80362

2017-09-18  Richard Biener  <rguenther@suse.de>

	Backport from mainline
	2017-04-10  Richard Biener  <rguenther@suse.de>

	PR middle-end/80362
	* fold-const.c (fold_binary_loc): Look at unstripped ops when
	looking for NEGATE_EXPR in -A / -B to A / B folding.

	* gcc.dg/torture/pr80362.c: New testcase.

	2015-11-25  Richard Biener  <rguenther@suse.de>

	PR middle-end/68528
	* fold-const.c (fold_binary_loc): Do not call negate_expr_p
	on stripped operands.

	* gcc.dg/torture/pr68528.c: New testcase.

	2017-03-27  Richard Biener  <rguenther@suse.de>

	PR middle-end/80171
	* gimple-fold.c (fold_ctor_reference): Properly guard against
	NULL return value from canonicalize_constructor_val.

	* g++.dg/torture/pr80171.C: New testcase.

	2016-06-13  Richard Biener  <rguenther@suse.de>

	PR middle-end/64516
	* fold-const.c (fold_unary_loc): Preserve alignment when
	folding a VIEW_CONVERT_EXPR into a MEM_REF.

	* gcc.dg/align-3.c: New testcase.

From-SVN: r252926