From 86fb9fdb2000213d3cd5a082e8501cb8fe974a14 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Sun, 8 Feb 2009 08:24:28 +0000
Subject: [PATCH] Strengthen the previous check.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64076 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/CodeGen/LiveInterval.h      | 16 +++++++---------
 lib/CodeGen/SimpleRegisterCoalescing.cpp |  9 +++++----
 2 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/include/llvm/CodeGen/LiveInterval.h b/include/llvm/CodeGen/LiveInterval.h
index f06ca43f2b3..1e8202e5f4b 100644
--- a/include/llvm/CodeGen/LiveInterval.h
+++ b/include/llvm/CodeGen/LiveInterval.h
@@ -272,17 +272,15 @@ namespace llvm {
       return I != kills.end() && *I == KillIdx;
     }
 
-    /// isOnlyKill - Return true if the specified index is the only kill of the
-    /// specified val#.
-    static bool isOnlyKill(const VNInfo *VNI, unsigned KillIdx) {
-      bool Found = false;
-      const SmallVector<unsigned, 4> &kills = VNI->kills;
-      for (unsigned i = 0, e = kills.size(); i != e; ++i) {
-        if (KillIdx != kills[i])
+    /// isOnlyLROfValNo - Return true if the specified live range is the only
+    /// one defined by the its val#.
+    bool isOnlyLROfValNo( const LiveRange *LR) {
+      for (const_iterator I = begin(), E = end(); I != E; ++I) {
+        const LiveRange *Tmp = I;
+        if (Tmp != LR && Tmp->valno == LR->valno)
           return false;
-        Found = true;
       }
-      return Found;
+      return true;
     }
     
     /// MergeValueNumberInto - This method is called when two value nubmers
diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index a7d5d0075d2..db7109e7a63 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -489,7 +489,7 @@ static void removeRange(LiveInterval &li, unsigned Start, unsigned End,
 }
 
 /// TrimLiveIntervalToLastUse - If there is a last use in the same basic block
-/// as the copy instruction, trim the ive interval to the last use and return
+/// as the copy instruction, trim the live interval to the last use and return
 /// true.
 bool
 SimpleRegisterCoalescing::TrimLiveIntervalToLastUse(unsigned CopyIdx,
@@ -867,9 +867,10 @@ SimpleRegisterCoalescing::ShortenDeadCopySrcLiveRange(LiveInterval &li,
   if (LR->valno->def == RemoveStart) {
     // If the def MI defines the val# and this copy is the only kill of the
     // val#, then propagate the dead marker.
-    if (!li.isOnlyKill(LR->valno, RemoveEnd))
-      li.removeKill(LR->valno, RemoveEnd);
-    else {
+    if (!li.isOnlyLROfValNo(LR)) {
+      if (li.isKill(LR->valno, RemoveEnd))
+        li.removeKill(LR->valno, RemoveEnd);
+    } else {
       PropagateDeadness(li, CopyMI, RemoveStart, li_, tri_);
       ++numDeadValNo;
     }