From: Aldy Hernandez <aldyh@redhat.com>
Date: Thu, 11 Jul 2019 07:50:58 +0000 (+0000)
Subject: Do not try to further refine a VR_UNDEFINED result when intersecting
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=435a6d9580fa1675537a4d2a3151802a15064d3d;p=gcc.git

Do not try to further refine a VR_UNDEFINED result when intersecting
value_ranges.

From-SVN: r273377
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ee70694afeb..f1718532e45 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-07-11  Aldy Hernandez  <aldyh@redhat.com>
+
+	* tree-vrp.c (intersect_ranges): If we know the intersection is
+	empty, there is no need to conservatively add anything else to
+	the set.
+
 2019-07-11  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/91131
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index dc7f825efc8..594ee9adc17 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -5977,6 +5977,11 @@ intersect_ranges (enum value_range_kind *vr0type,
 	gcc_unreachable ();
     }
 
+  /* If we know the intersection is empty, there's no need to
+     conservatively add anything else to the set.  */
+  if (*vr0type == VR_UNDEFINED)
+    return;
+
   /* As a fallback simply use { *VRTYPE, *VR0MIN, *VR0MAX } as
      result for the intersection.  That's always a conservative
      correct estimate unless VR1 is a constant singleton range