Implement LICM in optimizing compiler.

Change-Id: I9c8afb0a58ef45e568576015473cbfd5f011c242
diff --git a/test/445-checker-licm/src/Main.java b/test/445-checker-licm/src/Main.java
new file mode 100644
index 0000000..91ac2ed
--- /dev/null
+++ b/test/445-checker-licm/src/Main.java
@@ -0,0 +1,123 @@
+/*
+* Copyright (C) 2015 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.
+*/
+
+public class Main {
+
+  // CHECK-START: int Main.div() licm (before)
+  // CHECK-DAG: Div ( loop_header:{{B\d+}} )
+
+  // CHECK-START: int Main.div() licm (after)
+  // CHECK-NOT: Div ( loop_header:{{B\d+}} )
+
+  // CHECK-START: int Main.div() licm (after)
+  // CHECK-DAG: Div ( loop_header:null )
+
+  public static int div() {
+    int result = 0;
+    for (int i = 0; i < 10; ++i) {
+      result += staticField / 42;
+    }
+    return result;
+  }
+
+  // CHECK-START: int Main.innerDiv() licm (before)
+  // CHECK-DAG: Div ( loop_header:{{B\d+}} )
+
+  // CHECK-START: int Main.innerDiv() licm (after)
+  // CHECK-NOT: Div ( loop_header:{{B\d+}} )
+
+  // CHECK-START: int Main.innerDiv() licm (after)
+  // CHECK-DAG: Div ( loop_header:null )
+
+  public static int innerDiv() {
+    int result = 0;
+    for (int i = 0; i < 10; ++i) {
+      for (int j = 0; j < 10; ++j) {
+        result += staticField / 42;
+      }
+    }
+    return result;
+  }
+
+  // CHECK-START: int Main.innerDiv2() licm (before)
+  // CHECK-DAG: Mul ( loop_header:{{B4}} )
+
+  // CHECK-START: int Main.innerDiv2() licm (after)
+  // CHECK-DAG: Mul ( loop_header:{{B2}} )
+
+  public static int innerDiv2() {
+    int result = 0;
+    for (int i = 0; i < 10; ++i) {
+      for (int j = 0; j < 10; ++j) {
+        // The operation has been hoisted out of the inner loop.
+        // Note that we depend on the compiler's block numbering to
+        // check if it has been moved.
+        result += staticField * i;
+      }
+    }
+    return result;
+  }
+
+  // CHECK-START: int Main.innerDiv3(int, int) licm (before)
+  // CHECK-DAG: Div ( loop_header:{{B\d+}} )
+
+  // CHECK-START: int Main.innerDiv3(int, int) licm (after)
+  // CHECK-DAG: Div ( loop_header:{{B\d+}} )
+
+  public static int innerDiv3(int a, int b) {
+    int result = 0;
+    while (b < 5) {
+      // a might be null, so we can't hoist the operation.
+      result += staticField / a;
+      b++;
+    }
+    return result;
+  }
+
+  // CHECK-START: int Main.arrayLength(int[]) licm (before)
+  // CHECK-DAG: [[NullCheck:l\d+]] NullCheck ( loop_header:{{B\d+}} )
+  // CHECK-DAG:                    ArrayLength [ [[NullCheck]] ] ( loop_header:{{B\d+}} )
+
+  // CHECK-START: int Main.arrayLength(int[]) licm (after)
+  // CHECK-NOT:                    NullCheck ( loop_header:{{B\d+}} )
+  // CHECK-NOT:                    ArrayLength ( loop_header:{{B\d+}} )
+
+  // CHECK-START: int Main.arrayLength(int[]) licm (after)
+  // CHECK-DAG: [[NullCheck:l\d+]] NullCheck ( loop_header:null )
+  // CHECK-DAG:                    ArrayLength [ [[NullCheck]] ] ( loop_header:null )
+
+  public static int arrayLength(int[] array) {
+    int result = 0;
+    for (int i = 0; i < array.length; ++i) {
+      result += array[i];
+    }
+    return result;
+  }
+
+  public static int staticField = 42;
+
+  public static void assertEquals(int expected, int actual) {
+    if (expected != actual) {
+      throw new Error("Expected " + expected + ", got " + actual);
+    }
+  }
+
+  public static void main(String[] args) {
+    assertEquals(10, div());
+    assertEquals(100, innerDiv());
+    assertEquals(12, arrayLength(new int[] { 4, 8 }));
+  }
+}