--- /dev/null	2016-05-31 09:42:47.975716356 -0700
+++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.lir.amd64/src/org/graalvm/compiler/lir/amd64/AMD64ArrayEqualsOp.java	2016-12-09 00:53:39.555343710 -0800
@@ -0,0 +1,390 @@
+/*
+ * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package org.graalvm.compiler.lir.amd64;
+
+import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.ILLEGAL;
+import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.REG;
+import static jdk.vm.ci.code.ValueUtil.asRegister;
+
+import java.lang.reflect.Array;
+import java.lang.reflect.Field;
+
+import org.graalvm.compiler.asm.Label;
+import org.graalvm.compiler.asm.amd64.AMD64Address;
+import org.graalvm.compiler.asm.amd64.AMD64Address.Scale;
+import org.graalvm.compiler.asm.amd64.AMD64Assembler.ConditionFlag;
+import org.graalvm.compiler.asm.amd64.AMD64MacroAssembler;
+import org.graalvm.compiler.core.common.LIRKind;
+import org.graalvm.compiler.lir.LIRInstructionClass;
+import org.graalvm.compiler.lir.Opcode;
+import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
+import org.graalvm.compiler.lir.gen.LIRGeneratorTool;
+
+import jdk.vm.ci.amd64.AMD64;
+import jdk.vm.ci.amd64.AMD64.CPUFeature;
+import jdk.vm.ci.amd64.AMD64Kind;
+import jdk.vm.ci.code.Register;
+import jdk.vm.ci.code.TargetDescription;
+import jdk.vm.ci.meta.JavaKind;
+import jdk.vm.ci.meta.Value;
+import sun.misc.Unsafe;
+
+/**
+ * Emits code which compares two arrays of the same length. If the CPU supports any vector
+ * instructions specialized code is emitted to leverage these instructions.
+ */
+@Opcode("ARRAY_EQUALS")
+public final class AMD64ArrayEqualsOp extends AMD64LIRInstruction {
+    public static final LIRInstructionClass<AMD64ArrayEqualsOp> TYPE = LIRInstructionClass.create(AMD64ArrayEqualsOp.class);
+
+    private final JavaKind kind;
+    private final int arrayBaseOffset;
+    private final int arrayIndexScale;
+
+    @Def({REG}) protected Value resultValue;
+    @Alive({REG}) protected Value array1Value;
+    @Alive({REG}) protected Value array2Value;
+    @Alive({REG}) protected Value lengthValue;
+    @Temp({REG}) protected Value temp1;
+    @Temp({REG}) protected Value temp2;
+    @Temp({REG}) protected Value temp3;
+    @Temp({REG}) protected Value temp4;
+    @Temp({REG, ILLEGAL}) protected Value vectorTemp1;
+    @Temp({REG, ILLEGAL}) protected Value vectorTemp2;
+
+    public AMD64ArrayEqualsOp(LIRGeneratorTool tool, JavaKind kind, Value result, Value array1, Value array2, Value length) {
+        super(TYPE);
+        this.kind = kind;
+
+        Class<?> arrayClass = Array.newInstance(kind.toJavaClass(), 0).getClass();
+        this.arrayBaseOffset = UNSAFE.arrayBaseOffset(arrayClass);
+        this.arrayIndexScale = UNSAFE.arrayIndexScale(arrayClass);
+
+        this.resultValue = result;
+        this.array1Value = array1;
+        this.array2Value = array2;
+        this.lengthValue = length;
+
+        // Allocate some temporaries.
+        this.temp1 = tool.newVariable(LIRKind.unknownReference(tool.target().arch.getWordKind()));
+        this.temp2 = tool.newVariable(LIRKind.unknownReference(tool.target().arch.getWordKind()));
+        this.temp3 = tool.newVariable(LIRKind.value(tool.target().arch.getWordKind()));
+        this.temp4 = tool.newVariable(LIRKind.value(tool.target().arch.getWordKind()));
+
+        // We only need the vector temporaries if we generate SSE code.
+        if (supportsSSE41(tool.target())) {
+            this.vectorTemp1 = tool.newVariable(LIRKind.value(AMD64Kind.DOUBLE));
+            this.vectorTemp2 = tool.newVariable(LIRKind.value(AMD64Kind.DOUBLE));
+        } else {
+            this.vectorTemp1 = Value.ILLEGAL;
+            this.vectorTemp2 = Value.ILLEGAL;
+        }
+    }
+
+    @Override
+    public void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler masm) {
+        Register result = asRegister(resultValue);
+        Register array1 = asRegister(temp1);
+        Register array2 = asRegister(temp2);
+        Register length = asRegister(temp3);
+
+        Label trueLabel = new Label();
+        Label falseLabel = new Label();
+        Label done = new Label();
+
+        // Load array base addresses.
+        masm.leaq(array1, new AMD64Address(asRegister(array1Value), arrayBaseOffset));
+        masm.leaq(array2, new AMD64Address(asRegister(array2Value), arrayBaseOffset));
+
+        // Get array length in bytes.
+        masm.imull(length, asRegister(lengthValue), arrayIndexScale);
+        masm.movl(result, length); // copy
+
+        if (supportsAVX2(crb.target)) {
+            emitAVXCompare(crb, masm, result, array1, array2, length, trueLabel, falseLabel);
+        } else if (supportsSSE41(crb.target)) {
+            emitSSE41Compare(crb, masm, result, array1, array2, length, trueLabel, falseLabel);
+        }
+
+        emit8ByteCompare(crb, masm, result, array1, array2, length, trueLabel, falseLabel);
+        emitTailCompares(masm, result, array1, array2, length, trueLabel, falseLabel);
+
+        // Return true
+        masm.bind(trueLabel);
+        masm.movl(result, 1);
+        masm.jmpb(done);
+
+        // Return false
+        masm.bind(falseLabel);
+        masm.xorl(result, result);
+
+        // That's it
+        masm.bind(done);
+    }
+
+    /**
+     * Returns if the underlying AMD64 architecture supports SSE 4.1 instructions.
+     *
+     * @param target target description of the underlying architecture
+     * @return true if the underlying architecture supports SSE 4.1
+     */
+    private static boolean supportsSSE41(TargetDescription target) {
+        AMD64 arch = (AMD64) target.arch;
+        return arch.getFeatures().contains(CPUFeature.SSE4_1);
+    }
+
+    /**
+     * Vector size used in {@link #emitSSE41Compare}.
+     */
+    private static final int SSE4_1_VECTOR_SIZE = 16;
+
+    /**
+     * Emits code that uses SSE4.1 128-bit (16-byte) vector compares.
+     */
+    private void emitSSE41Compare(CompilationResultBuilder crb, AMD64MacroAssembler masm, Register result, Register array1, Register array2, Register length, Label trueLabel, Label falseLabel) {
+        assert supportsSSE41(crb.target);
+
+        Register vector1 = asRegister(vectorTemp1, AMD64Kind.DOUBLE);
+        Register vector2 = asRegister(vectorTemp2, AMD64Kind.DOUBLE);
+
+        Label loop = new Label();
+        Label compareTail = new Label();
+
+        // Compare 16-byte vectors
+        masm.andl(result, SSE4_1_VECTOR_SIZE - 1); // tail count (in bytes)
+        masm.andl(length, ~(SSE4_1_VECTOR_SIZE - 1)); // vector count (in bytes)
+        masm.jccb(ConditionFlag.Zero, compareTail);
+
+        masm.leaq(array1, new AMD64Address(array1, length, Scale.Times1, 0));
+        masm.leaq(array2, new AMD64Address(array2, length, Scale.Times1, 0));
+        masm.negq(length);
+
+        // Align the main loop
+        masm.align(crb.target.wordSize * 2);
+        masm.bind(loop);
+        masm.movdqu(vector1, new AMD64Address(array1, length, Scale.Times1, 0));
+        masm.movdqu(vector2, new AMD64Address(array2, length, Scale.Times1, 0));
+        masm.pxor(vector1, vector2);
+        masm.ptest(vector1, vector1);
+        masm.jcc(ConditionFlag.NotZero, falseLabel);
+        masm.addq(length, SSE4_1_VECTOR_SIZE);
+        masm.jcc(ConditionFlag.NotZero, loop);
+
+        masm.testl(result, result);
+        masm.jcc(ConditionFlag.Zero, trueLabel);
+
+        /*
+         * Compare the remaining bytes with an unaligned memory load aligned to the end of the
+         * array.
+         */
+        masm.movdqu(vector1, new AMD64Address(array1, result, Scale.Times1, -SSE4_1_VECTOR_SIZE));
+        masm.movdqu(vector2, new AMD64Address(array2, result, Scale.Times1, -SSE4_1_VECTOR_SIZE));
+        masm.pxor(vector1, vector2);
+        masm.ptest(vector1, vector1);
+        masm.jcc(ConditionFlag.NotZero, falseLabel);
+        masm.jmp(trueLabel);
+
+        masm.bind(compareTail);
+        masm.movl(length, result);
+    }
+
+    /**
+     * Returns if the underlying AMD64 architecture supports AVX instructions.
+     *
+     * @param target target description of the underlying architecture
+     * @return true if the underlying architecture supports AVX
+     */
+    private static boolean supportsAVX2(TargetDescription target) {
+        AMD64 arch = (AMD64) target.arch;
+        return arch.getFeatures().contains(CPUFeature.AVX2);
+    }
+
+    /**
+     * Vector size used in {@link #emitAVXCompare}.
+     */
+    private static final int AVX_VECTOR_SIZE = 32;
+
+    private void emitAVXCompare(CompilationResultBuilder crb, AMD64MacroAssembler masm, Register result, Register array1, Register array2, Register length, Label trueLabel, Label falseLabel) {
+        assert supportsAVX2(crb.target);
+
+        Register vector1 = asRegister(vectorTemp1, AMD64Kind.DOUBLE);
+        Register vector2 = asRegister(vectorTemp2, AMD64Kind.DOUBLE);
+
+        Label loop = new Label();
+        Label compareTail = new Label();
+
+        // Compare 16-byte vectors
+        masm.andl(result, AVX_VECTOR_SIZE - 1); // tail count (in bytes)
+        masm.andl(length, ~(AVX_VECTOR_SIZE - 1)); // vector count (in bytes)
+        masm.jccb(ConditionFlag.Zero, compareTail);
+
+        masm.leaq(array1, new AMD64Address(array1, length, Scale.Times1, 0));
+        masm.leaq(array2, new AMD64Address(array2, length, Scale.Times1, 0));
+        masm.negq(length);
+
+        // Align the main loop
+        masm.align(crb.target.wordSize * 2);
+        masm.bind(loop);
+        masm.vmovdqu(vector1, new AMD64Address(array1, length, Scale.Times1, 0));
+        masm.vmovdqu(vector2, new AMD64Address(array2, length, Scale.Times1, 0));
+        masm.vpxor(vector1, vector1, vector2);
+        masm.vptest(vector1, vector1);
+        masm.jcc(ConditionFlag.NotZero, falseLabel);
+        masm.addq(length, AVX_VECTOR_SIZE);
+        masm.jcc(ConditionFlag.NotZero, loop);
+
+        masm.testl(result, result);
+        masm.jcc(ConditionFlag.Zero, trueLabel);
+
+        /*
+         * Compare the remaining bytes with an unaligned memory load aligned to the end of the
+         * array.
+         */
+        masm.vmovdqu(vector1, new AMD64Address(array1, result, Scale.Times1, -AVX_VECTOR_SIZE));
+        masm.vmovdqu(vector2, new AMD64Address(array2, result, Scale.Times1, -AVX_VECTOR_SIZE));
+        masm.vpxor(vector1, vector1, vector2);
+        masm.vptest(vector1, vector1);
+        masm.jcc(ConditionFlag.NotZero, falseLabel);
+        masm.jmp(trueLabel);
+
+        masm.bind(compareTail);
+        masm.movl(length, result);
+    }
+
+    /**
+     * Vector size used in {@link #emit8ByteCompare}.
+     */
+    private static final int VECTOR_SIZE = 8;
+
+    /**
+     * Emits code that uses 8-byte vector compares.
+     */
+    private void emit8ByteCompare(CompilationResultBuilder crb, AMD64MacroAssembler masm, Register result, Register array1, Register array2, Register length, Label trueLabel, Label falseLabel) {
+        Label loop = new Label();
+        Label compareTail = new Label();
+
+        Register temp = asRegister(temp4);
+
+        masm.andl(result, VECTOR_SIZE - 1); // tail count (in bytes)
+        masm.andl(length, ~(VECTOR_SIZE - 1));  // vector count (in bytes)
+        masm.jccb(ConditionFlag.Zero, compareTail);
+
+        masm.leaq(array1, new AMD64Address(array1, length, Scale.Times1, 0));
+        masm.leaq(array2, new AMD64Address(array2, length, Scale.Times1, 0));
+        masm.negq(length);
+
+        // Align the main loop
+        masm.align(crb.target.wordSize * 2);
+        masm.bind(loop);
+        masm.movq(temp, new AMD64Address(array1, length, Scale.Times1, 0));
+        masm.cmpq(temp, new AMD64Address(array2, length, Scale.Times1, 0));
+        masm.jccb(ConditionFlag.NotEqual, falseLabel);
+        masm.addq(length, VECTOR_SIZE);
+        masm.jccb(ConditionFlag.NotZero, loop);
+
+        masm.testl(result, result);
+        masm.jccb(ConditionFlag.Zero, trueLabel);
+
+        /*
+         * Compare the remaining bytes with an unaligned memory load aligned to the end of the
+         * array.
+         */
+        masm.movq(temp, new AMD64Address(array1, result, Scale.Times1, -VECTOR_SIZE));
+        masm.cmpq(temp, new AMD64Address(array2, result, Scale.Times1, -VECTOR_SIZE));
+        masm.jccb(ConditionFlag.NotEqual, falseLabel);
+        masm.jmpb(trueLabel);
+
+        masm.bind(compareTail);
+        masm.movl(length, result);
+    }
+
+    /**
+     * Emits code to compare the remaining 1 to 4 bytes.
+     */
+    private void emitTailCompares(AMD64MacroAssembler masm, Register result, Register array1, Register array2, Register length, Label trueLabel, Label falseLabel) {
+        Label compare2Bytes = new Label();
+        Label compare1Byte = new Label();
+
+        Register temp = asRegister(temp4);
+
+        if (kind.getByteCount() <= 4) {
+            // Compare trailing 4 bytes, if any.
+            masm.testl(result, 4);
+            masm.jccb(ConditionFlag.Zero, compare2Bytes);
+            masm.movl(temp, new AMD64Address(array1, 0));
+            masm.cmpl(temp, new AMD64Address(array2, 0));
+            masm.jccb(ConditionFlag.NotEqual, falseLabel);
+
+            if (kind.getByteCount() <= 2) {
+                // Move array pointers forward.
+                masm.leaq(array1, new AMD64Address(array1, 4));
+                masm.leaq(array2, new AMD64Address(array2, 4));
+
+                // Compare trailing 2 bytes, if any.
+                masm.bind(compare2Bytes);
+                masm.testl(result, 2);
+                masm.jccb(ConditionFlag.Zero, compare1Byte);
+                masm.movzwl(temp, new AMD64Address(array1, 0));
+                masm.movzwl(length, new AMD64Address(array2, 0));
+                masm.cmpl(temp, length);
+                masm.jccb(ConditionFlag.NotEqual, falseLabel);
+
+                // The one-byte tail compare is only required for boolean and byte arrays.
+                if (kind.getByteCount() <= 1) {
+                    // Move array pointers forward before we compare the last trailing byte.
+                    masm.leaq(array1, new AMD64Address(array1, 2));
+                    masm.leaq(array2, new AMD64Address(array2, 2));
+
+                    // Compare trailing byte, if any.
+                    masm.bind(compare1Byte);
+                    masm.testl(result, 1);
+                    masm.jccb(ConditionFlag.Zero, trueLabel);
+                    masm.movzbl(temp, new AMD64Address(array1, 0));
+                    masm.movzbl(length, new AMD64Address(array2, 0));
+                    masm.cmpl(temp, length);
+                    masm.jccb(ConditionFlag.NotEqual, falseLabel);
+                } else {
+                    masm.bind(compare1Byte);
+                }
+            } else {
+                masm.bind(compare2Bytes);
+            }
+        }
+    }
+
+    private static final Unsafe UNSAFE = initUnsafe();
+
+    private static Unsafe initUnsafe() {
+        try {
+            return Unsafe.getUnsafe();
+        } catch (SecurityException se) {
+            try {
+                Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
+                theUnsafe.setAccessible(true);
+                return (Unsafe) theUnsafe.get(Unsafe.class);
+            } catch (Exception e) {
+                throw new RuntimeException("exception while trying to get Unsafe", e);
+            }
+        }
+    }
+}