rtlanal: Fix bits/bytes confusion in set_noop_p (PR68814)

The meaning of ZERO_EXTRACT depends on BITS_BIG_ENDIAN, not on
BYTES_BIG_ENDIAN.  This caused PR68814.


2015-12-11  Segher Boessenkool  <segher@kernel.crashing.org>

	PR rtl-optimization/68814
	* rtlanal.c (set_noop_p): Use BITS_BIG_ENDIAN instead of
	BYTES_BIG_ENDIAN.

From-SVN: r231547

gcc/ChangeLog

+2015-12-11  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	PR rtl-optimization/68814
+	* rtlanal.c (set_noop_p): Use BITS_BIG_ENDIAN instead of
+	BYTES_BIG_ENDIAN.
+
 2015-12-10  Nathan Sidwell  <nathan@acm.org>
 
 	* config/nvptx/nvptx.c (nvptx_function_arg,

gcc/rtlanal.c

@@ -1534,7 +1534,7 @@ set_noop_p (const_rtx set)
 
   if (GET_CODE (dst) == ZERO_EXTRACT)
     return rtx_equal_p (XEXP (dst, 0), src)
-	   && ! BYTES_BIG_ENDIAN && XEXP (dst, 2) == const0_rtx
+	   && !BITS_BIG_ENDIAN && XEXP (dst, 2) == const0_rtx
 	   && !side_effects_p (src);
 
   if (GET_CODE (dst) == STRICT_LOW_PART)