> So while emit_store_flag_force knows what to do upon NULL return, I'm
> not sure the other users of expand_shift/expand_shift_1 do.  

Revised patch attached, tested on x86-64/Linux, OK for the mainline?


2016-09-26  Eric Botcazou  <ebotcazou@adacore.com>

	* expmed.c (expand_shift_1): Add MAY_FAIL parameter and do not assert
	that the result is non-zero if it is true.
	(maybe_expand_shift): New wrapper around expand_shift_1.
	(emit_store_flag): Call maybe_expand_shift in lieu of expand_shift.

-- 
Eric Botcazou