diff --git a/src/Reactor/Optimizer.cpp b/src/Reactor/Optimizer.cpp
new file mode 100644
index 0000000..b528993
--- /dev/null
+++ b/src/Reactor/Optimizer.cpp
@@ -0,0 +1,110 @@
+// Copyright 2016 The SwiftShader Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "Optimizer.hpp"
+
+#include "src/IceCfg.h"
+#include "src/IceCfgNode.h"
+
+#include <map>
+#include <vector>
+
+namespace
+{
+	class Optimizer
+	{
+	public:
+		void run(Ice::Cfg *function);
+
+	private:
+		void analyzeUses(Ice::Cfg *function);
+		void eliminateUnusedAllocas();
+
+		Ice::Cfg *function;
+
+		std::map<Ice::Operand*, std::vector<Ice::Inst*>> uses;
+	};
+
+	void Optimizer::run(Ice::Cfg *function)
+	{
+		this->function = function;
+
+		analyzeUses(function);
+
+		eliminateUnusedAllocas();
+	}
+
+	void Optimizer::eliminateUnusedAllocas()
+	{
+		Ice::CfgNode *entryBlock = function->getEntryNode();
+
+		for(Ice::Inst &alloca : entryBlock->getInsts())
+		{
+			if(!llvm::isa<Ice::InstAlloca>(alloca))
+			{
+				return;   // Allocas are all at the top
+			}
+
+			Ice::Operand *address = alloca.getDest();
+
+			if(uses[address].empty())
+			{
+				alloca.setDeleted();
+			}
+		}
+	}
+
+	void Optimizer::analyzeUses(Ice::Cfg *function)
+	{
+		uses.clear();
+
+		for(Ice::CfgNode *basicBlock : function->getNodes())
+		{
+			for(Ice::Inst &instruction : basicBlock->getInsts())
+			{
+				if(instruction.isDeleted())
+				{
+					continue;
+				}
+
+				for(int i = 0; i < instruction.getSrcSize(); i++)
+				{
+					int unique = 0;
+					for(; unique < i; unique++)
+					{
+						if(instruction.getSrc(i) == instruction.getSrc(unique))
+						{
+							break;
+						}
+					}
+
+					if(i == unique)
+					{
+						uses[instruction.getSrc(i)].push_back(&instruction);
+					}
+				}
+			}
+		}
+	}
+}
+
+namespace sw
+{
+	void optimize(Ice::Cfg *function)
+	{
+		Optimizer optimizer;
+
+		optimizer.run(function);
+	}
+}
\ No newline at end of file