Hi,

this test started to fail recently as the result of the work of Richard S., 
but the underlying issue had been latent for a long time.  It boils down to 
this excerpt from the VRP1 dump file:

Found new range for _9: [0, 12]
marking stmt to be not simulated again

Visiting statement:
_3 = _9 %[fl] _11;
Found new range for _3: [0, +INF]

which is plain wrong since the sign of FLOOR_MOD_EXPR is the sign of the 
divisor and not that of the dividend (the latter is for TRUNC_MOD_EXPR).

I have attached a fix for mainline and another one for the 4.9/5 branches.

Tested on x86_64-suse-linux, OK for all active branches?


2015-10-20  Eric Botcazou  <ebotcazou@adacore.com>

	* fold-const.c (tree_binary_nonnegative_warnv_p) <FLOOR_MOD_EXPR>:
	Recurse on operand #1 instead of operand #0.
	<CEIL_MOD_EXPR>: Do not recurse.
	<ROUND_MOD_EXPR>: Likewise.

-- 
Eric Botcazou