From: aldyh <aldyh@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 17 Sep 2018 06:07:52 +0000 (+0000)
Subject: 	* tree-vrp.c (extract_range_from_unary_expr): Do not special case
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e3fdb3c699ca39f0543a27c81786b7b41c1001e6;p=thirdparty%2Fgcc.git

	* 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.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@264356 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9f6b4b53fc44..59b73ed08980 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+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
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 1adb919a6dfd..622ccbc2df7f 100644
--- a/gcc/tree-vrp.c
+++ b/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);
diff --git a/gcc/wide-int-range.cc b/gcc/wide-int-range.cc
index 8a3dfd256845..a85fe9f9ad70 100644
--- a/gcc/wide-int-range.cc
+++ b/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;
 }