tree-vrp (extract_range_from_binary_expr_1): Treat all divisions by zero as VR_UNDEFINED.

	* tree-vrp (extract_range_from_binary_expr_1): Treat all divisions
	by zero as VR_UNDEFINED.

From-SVN: r264203

gcc/ChangeLog

+2018-09-11  Aldy Hernandez  <aldyh@redhat.com>
+
+	* tree-vrp (extract_range_from_binary_expr_1): Treat all divisions
+	by zero as VR_UNDEFINED.
+
 2018-09-10  Uros Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/i386.md (<sincos>xf2): Rename from *<sincos>xf2_i387.

gcc/tree-vrp.c

@@ -1601,12 +1601,7 @@ extract_range_from_binary_expr_1 (value_range *vr,
       /* Special case explicit division by zero as undefined.  */
       if (range_is_null (&vr1))
 	{
-	  /* However, we must not eliminate a division by zero if
-	     flag_non_call_exceptions.  */
-	  if (cfun->can_throw_non_call_exceptions)
-	    set_value_range_to_varying (vr);
-	  else
-	    set_value_range_to_undefined (vr);
+	  set_value_range_to_undefined (vr);
 	  return;
 	}