src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.lir.amd64/src/org/graalvm/compiler/lir/amd64/AMD64ArrayEqualsOp.java
--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.lir.amd64/src/org/graalvm/compiler/lir/amd64/AMD64ArrayEqualsOp.java Mon Nov 06 14:12:37 2017 -0500
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.lir.amd64/src/org/graalvm/compiler/lir/amd64/AMD64ArrayEqualsOp.java Mon Nov 06 20:29:49 2017 -0800
@@ -37,6 +37,7 @@
import org.graalvm.compiler.asm.amd64.AMD64Assembler.SSEOp;
import org.graalvm.compiler.asm.amd64.AMD64MacroAssembler;
import org.graalvm.compiler.core.common.LIRKind;
+import org.graalvm.compiler.core.common.NumUtil;
import org.graalvm.compiler.lir.LIRInstructionClass;
import org.graalvm.compiler.lir.Opcode;
import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
@@ -132,12 +133,19 @@
masm.leaq(array2, new AMD64Address(asRegister(array2Value), arrayBaseOffset));
// Get array length in bytes.
- masm.imull(length, asRegister(lengthValue), arrayIndexScale);
+ masm.movl(length, asRegister(lengthValue));
+
+ if (arrayIndexScale > 1) {
+ masm.shll(length, NumUtil.log2Ceil(arrayIndexScale)); // scale length
+ }
+
masm.movl(result, length); // copy
if (supportsAVX2(crb.target)) {
emitAVXCompare(crb, masm, result, array1, array2, length, trueLabel, falseLabel);
} else if (supportsSSE41(crb.target)) {
+ // this code is used for AVX as well because our backend correctly ensures that
+ // VEX-prefixed instructions are emitted if AVX is supported
emitSSE41Compare(crb, masm, result, array1, array2, length, trueLabel, falseLabel);
}