Implemented peephole optimizations including null-check elimination, redundant ld/st elimination, ad-hoc register renaming and store sinking.
diff --git a/vm/compiler/codegen/Optimizer.h b/vm/compiler/codegen/Optimizer.h
new file mode 100644
index 0000000..1a891b1
--- /dev/null
+++ b/vm/compiler/codegen/Optimizer.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * 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 "Dalvik.h"
+#include "compiler/CompilerInternals.h"
+
+#ifndef _DALVIK_VM_COMPILER_OPTIMIZATION_H
+#define _DALVIK_VM_COMPILER_OPTIMIZATION_H
+
+/* Forward declarations */
+struct CompilationUnit;
+struct LIR;
+
+/*
+ * Data structure tracking the mapping between a Dalvik register (pair) and a
+ * native register (pair). The idea is to reuse the previously loaded value
+ * if possible, otherwise to keep the value in a native register as long as
+ * possible.
+ */
+typedef struct RegisterScoreboard {
+    BitVector *nullCheckedRegs; // Track which registers have been null-checked
+    int liveDalvikReg;          // Track which Dalvik register is live
+    int nativeReg;              // And the mapped native register
+    int nativeRegHi;            // And the mapped native register
+    bool isWide;                // Whether a pair of registers are alive
+} RegisterScoreboard;
+
+void dvmCompilerApplyLocalOptimizations(struct CompilationUnit *cUnit,
+                                        struct LIR *head,
+                                        struct LIR *tail);
+
+void dvmCompilerApplyGlobalOptimizations(struct CompilationUnit *cUnit);
+
+#endif /* _DALVIK_VM_COMPILER_OPTIMIZATION_H */