2 files changed, 31 insertions, 16 deletions

diff --git a/include/llvm/ADT/SparseBitVector.h b/include/llvm/ADT/SparseBitVector.h
index 1ed28607ef..4c28682d39 100644
--- a/include/llvm/ADT/SparseBitVector.h
+++ b/include/llvm/ADT/SparseBitVector.h
@@ -89,6 +89,14 @@ public:
     ElementIndex = RHS.ElementIndex;
     std::copy(&RHS.Bits[0], &RHS.Bits[BITWORDS_PER_ELEMENT], Bits);
   }
+  
+  // Assignment 
+  SparseBitVectorElement& operator=(const SparseBitVectorElement& RHS) {
+    ElementIndex = RHS.ElementIndex;
+    std::copy(&RHS.Bits[0], &RHS.Bits[BITWORDS_PER_ELEMENT], Bits);
+    
+    return *this;
+  }
 
   // Comparison.
   bool operator==(const SparseBitVectorElement &RHS) const {
@@ -483,6 +491,21 @@ public:
 
     CurrElementIter = Elements.begin ();
   }
+  
+  // Assignment
+  SparseBitVector& operator=(const SparseBitVector& RHS) {
+    Elements.clear();
+    
+    ElementListConstIter ElementIter = RHS.Elements.begin();
+    while (ElementIter != RHS.Elements.end()) {
+      Elements.push_back(SparseBitVectorElement<ElementSize>(*ElementIter));
+      ++ElementIter;
+    }
+
+    CurrElementIter = Elements.begin ();
+    
+    return *this;
+  }
 
   // Test, Reset, and Set a bit in the bitmap.
   bool test(unsigned Idx) {
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 9a03c21593..91f72c4ba6 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -22,11 +22,11 @@
 #include "llvm/Instructions.h"
 #include "llvm/ParameterAttributes.h"
 #include "llvm/Value.h"
-#include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/SparseBitVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/Dominators.h"
 #include "llvm/Analysis/AliasAnalysis.h"
@@ -590,9 +590,9 @@ namespace {
 class VISIBILITY_HIDDEN ValueNumberedSet {
   private:
     SmallPtrSet<Value*, 8> contents;
-    BitVector numbers;
+    SparseBitVector<64> numbers;
   public:
-    ValueNumberedSet() { numbers.resize(1); }
+    ValueNumberedSet() { }
     ValueNumberedSet(const ValueNumberedSet& other) {
       numbers = other.numbers;
       contents = other.contents;
@@ -610,9 +610,6 @@ class VISIBILITY_HIDDEN ValueNumberedSet {
     size_t size() { return contents.size(); }
     
     void set(unsigned i)  {
-      if (i >= numbers.size())
-        numbers.resize(i+1);
-      
       numbers.set(i);
     }
     
@@ -622,21 +619,12 @@ class VISIBILITY_HIDDEN ValueNumberedSet {
     }
     
     void reset(unsigned i)  {
-      if (i < numbers.size())
-        numbers.reset(i);
+      numbers.reset(i);
     }
     
     bool test(unsigned i)  {
-      if (i >= numbers.size())
-        return false;
-      
       return numbers.test(i);
     }
-    
-    void clear() {
-      contents.clear();
-      numbers.clear();
-    }
 };
 }
 
@@ -1598,6 +1586,10 @@ bool GVN::processInstruction(Instruction *I, ValueNumberedSet &currAvail,
   if (isa<AllocationInst>(I))
     return false;
   
+  // Allocations are always unique, so don't bother value numbering them.
+  if (isa<AllocationInst>(I))
+    return false;
+  
   if (MemCpyInst* M = dyn_cast<MemCpyInst>(I)) {
     MemoryDependenceAnalysis& MD = getAnalysis<MemoryDependenceAnalysis>();