tree-vrp.c (extract_range_from_unary_expr): Do not special case symbolics or…

tree-vrp.c (extract_range_from_unary_expr): Do not special case symbolics or VR_VARYING ranges for ABS_EXPR.

	* tree-vrp.c (extract_range_from_unary_expr): Do not special case
	symbolics or VR_VARYING ranges for ABS_EXPR.
	* wide-int-range.cc (wide_int_range_abs): Return positive numbers
	when range will wrap.

From-SVN: r264356

gcc/ChangeLog

+2018-09-17  Aldy Hernandez  <aldyh@redhat.com>
+
+	* tree-vrp.c (extract_range_from_unary_expr): Do not special case
+	symbolics or VR_VARYING ranges for ABS_EXPR.
+	* wide-int-range.cc (wide_int_range_abs): Return positive numbers
+	when range will wrap.
+
 2018-09-15  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR middle-end/86864

gcc/tree-vrp.c

@@ -1894,11 +1894,6 @@ extract_range_from_unary_expr (value_range *vr,
     }
   else if (code == ABS_EXPR)
     {
-      if (vr0.type != VR_RANGE || symbolic_range_p (&vr0))
-	{
-	  set_value_range_to_varying (vr);
-	  return;
-	}
       wide_int wmin, wmax;
       wide_int vr0_min, vr0_max;
       extract_range_into_wide_ints (&vr0, sign, prec, vr0_min, vr0_max);

gcc/wide-int-range.cc

@@ -728,10 +728,13 @@ wide_int_range_abs (wide_int &min, wide_int &max,
     }
 
   /* If the new range has its limits swapped around (MIN > MAX), then
-     the operation caused one of them to wrap around, mark the new
-     range VARYING.  */
+     the operation caused one of them to wrap around.  The only thing
+     we know is that the result is positive.  */
   if (wi::gt_p (min, max, sign))
-      return false;
+    {
+      min = wi::zero (prec);
+      max = max_value;
+    }
   return true;
 }