re PR c/35634 (operand of pre-/postin-/decrement not promoted)

2012-11-28  Richard Biener  <rguenther@suse.de>

	PR c/35634
	* gimple.h (gimplify_self_mod_expr): Declare.
	* gimplify.c (gimplify_self_mod_expr): Export.  Take a different
	type for performing the arithmetic in.
	(gimplify_expr): Adjust.
	* tree-vect-loop-manip.c (vect_can_advance_ivs_p): Strip
	sign conversions we can re-apply after adjusting the IV.

	c-family/
	* c-gimplify.c (c_gimplify_expr): Gimplify self-modify expressions
	here and use a type with proper overflow behavior for types that would
	need to be promoted for the arithmetic.

	* gcc.dg/torture/pr35634.c: New testcase.
	* g++.dg/torture/pr35634.C: Likewise.
	* gcc.dg/vect/pr18536.c: Mark worker function noinline.

From-SVN: r193882