From 7d23be25abb776ed34b7901df4485dc26d2b39a0 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Sun, 13 Mar 2011 01:29:32 +0000
Subject: [PATCH] Now that we are deleting unused live intervals during
 allocation, pointers may be reused.

Use the virtual register number as a cache tag instead. They are not reused.

llvm-svn: 127561
---
 lib/CodeGen/LiveIntervalUnion.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/CodeGen/LiveIntervalUnion.h b/lib/CodeGen/LiveIntervalUnion.h
index 6f9c5f4455e..3734c7f4913 100644
--- a/lib/CodeGen/LiveIntervalUnion.h
+++ b/lib/CodeGen/LiveIntervalUnion.h
@@ -163,7 +163,7 @@ public:
     bool CheckedFirstInterference;
     bool SeenAllInterferences;
     bool SeenUnspillableVReg;
-    unsigned Tag;
+    unsigned Tag, VTag;
 
   public:
     Query(): LiveUnion(), VirtReg() {}
@@ -181,11 +181,12 @@ public:
       SeenAllInterferences = false;
       SeenUnspillableVReg = false;
       Tag = 0;
+      VTag = 0;
     }
 
     void init(LiveInterval *VReg, LiveIntervalUnion *LIU) {
       assert(VReg && LIU && "Invalid arguments");
-      if (VirtReg == VReg && LiveUnion == LIU && !LIU->changedSince(Tag)) {
+      if (VReg->reg == VTag && LiveUnion == LIU && !LIU->changedSince(Tag)) {
         // Retain cached results, e.g. firstInterference.
         return;
       }
@@ -193,6 +194,7 @@ public:
       LiveUnion = LIU;
       VirtReg = VReg;
       Tag = LIU->getTag();
+      VTag = VReg->reg;
     }
 
     LiveInterval &virtReg() const {