Do not overwrite an input register in shift operations.

'second_reg' is an input register that can survive the instruction.
Instead use the output register as a temporary result.

bug:21667432

(cherry picked from commit a4f3581da73b83484a30ab499c4f8ad43b378dab)

Change-Id: Ic1f399964911b8a9fc57352130c92b2a0a1b8e0d

3 files changed, 108 insertions, 0 deletions

diff --git a/test/514-shifts/expected.txt b/test/514-shifts/expected.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/514-shifts/expected.txt
diff --git a/test/514-shifts/info.txt b/test/514-shifts/info.txt
new file mode 100644
index 0000000..eb93c5f
--- /dev/null
+++ b/test/514-shifts/info.txt
@@ -0,0 +1,2 @@
+Regression test for optimizing that used to miscompile
+shifts on ARM.
diff --git a/test/514-shifts/src/Main.java b/test/514-shifts/src/Main.java
new file mode 100644
index 0000000..6c44eab
--- /dev/null
+++ b/test/514-shifts/src/Main.java
@@ -0,0 +1,106 @@
+/*
+ * 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.
+ */
+
+class Main {
+  public static void main(String[] args) {
+    testIntShiftRight();
+    testIntShiftLeft();
+    testIntUnsignedShiftRight();
+    testLongShiftRight();
+    testLongShiftLeft();
+    testLongUnsignedShiftRight();
+  }
+
+  public static void testIntShiftLeft() {
+    int a = myField;
+    int b = myOtherField << a;
+    if (b != -2147483648) {
+      throw new Error("Expected -2147483648, got " + b);
+    }
+    if (a != 0xFFF) {
+      throw new Error("Expected 0xFFF, got " + a);
+    }
+  }
+
+  public static void testIntShiftRight() {
+    int a = myField;
+    int b = myOtherField >> a;
+    if (b != 0) {
+      throw new Error("Expected 0, got " + b);
+    }
+    if (a != 0xFFF) {
+      throw new Error("Expected 0xFFF, got " + a);
+    }
+  }
+
+  public static void testIntUnsignedShiftRight() {
+    int a = myField;
+    int b = myOtherField >>> a;
+    if (b != 0) {
+      throw new Error("Expected 0, got " + b);
+    }
+    if (a != 0xFFF) {
+      throw new Error("Expected 0xFFF, got " + a);
+    }
+  }
+
+  public static void testLongShiftLeft() {
+    long a = myLongField;
+    long b = myOtherLongField << a;
+    if (b != 0x2468ACF13579BDEL) {
+      throw new Error("Expected 0x2468ACF13579BDEL, got " + b);
+    }
+    // The int conversion will be GVN'ed with the one required
+    // by Java specification of long shift left.
+    if ((int)a != 0x41) {
+      throw new Error("Expected 0x41, got " + a);
+    }
+  }
+
+  public static void testLongShiftRight() {
+    long a = myLongField;
+    long b = myOtherLongField >> a;
+    if (b != 0x91A2B3C4D5E6F7L) {
+      throw new Error("Expected 0x91A2B3C4D5E6F7L, got " + b);
+    }
+    // The int conversion will be GVN'ed with the one required
+    // by Java specification of long shift right.
+    if ((int)a != 0x41) {
+      throw new Error("Expected 0x41, got " + a);
+    }
+  }
+
+  public static void testLongUnsignedShiftRight() {
+    long a = myLongField;
+    long b = myOtherLongField >>> a;
+    if (b != 0x91A2B3C4D5E6F7L) {
+      throw new Error("Expected 0x91A2B3C4D5E6F7L, got " + b);
+    }
+    // The int conversion will be GVN'ed with the one required
+    // by Java specification of long shift right.
+    if ((int)a != 0x41) {
+      throw new Error("Expected 0x41, got " + a);
+    }
+  }
+
+  static int myField = 0xFFF;
+  static int myOtherField = 0x1;
+
+  // Use a value that will need to be masked before doing the shift.
+  // The maximum shift is 0x3F.
+  static long myLongField = 0x41;
+  static long myOtherLongField = 0x123456789abcdefL;
+}