re PR middle-end/66313 (Unsafe factorization of a*b+a*c)

re PR middle-end/66313 (Unsafe factorization of a*b+a*c)

2017-06-01  Richard Biener  <rguenther@suse.de>

	PR middle-end/66313
	* fold-const.c (fold_plusminus_mult_expr): If the factored
	factor may be zero use a wrapping type for the inner operation.
	* tree-tailcall.c (independent_of_stmt_p): Pass in to_move bitmap
	and handle moved defs.
	(process_assignment): Properly guard the unary op case.  Return a
	tri-state indicating that moving the stmt before the call may allow
	to continue.  Pass through to_move.
	(find_tail_calls): Handle moving unrelated defs before
	the call.

	* c-c++-common/ubsan/pr66313.c: New testcase.
	* gcc.dg/tree-ssa/loop-15.c: Adjust.

From-SVN: r248771