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package org.graalvm.compiler.hotspot.amd64;

import static jdk.vm.ci.amd64.AMD64.rbp;
import static jdk.vm.ci.amd64.AMD64.rsp;
import static jdk.vm.ci.code.ValueUtil.asRegister;
import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.REG;

import org.graalvm.compiler.asm.amd64.AMD64Address;
import org.graalvm.compiler.asm.amd64.AMD64Assembler.ConditionFlag;
import org.graalvm.compiler.asm.amd64.AMD64MacroAssembler;
import org.graalvm.compiler.lir.LIRInstructionClass;
import org.graalvm.compiler.lir.Opcode;
import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
import org.graalvm.compiler.serviceprovider.JavaVersionUtil;

import jdk.vm.ci.code.Register;
import jdk.vm.ci.meta.AllocatableValue;

/**
 * Sets up the arguments for an exception handler in the callers frame, removes the current frame
 * and jumps to the handler.
 */
@Opcode("JUMP_TO_EXCEPTION_HANDLER_IN_CALLER")
final class AMD64HotSpotJumpToExceptionHandlerInCallerOp extends AMD64HotSpotEpilogueBlockEndOp {

    public static final LIRInstructionClass<AMD64HotSpotJumpToExceptionHandlerInCallerOp> TYPE = LIRInstructionClass.create(AMD64HotSpotJumpToExceptionHandlerInCallerOp.class);

    @Use(REG) AllocatableValue handlerInCallerPc;
    @Use(REG) AllocatableValue exception;
    @Use(REG) AllocatableValue exceptionPc;
    private final Register thread;
    private final int isMethodHandleReturnOffset;

    AMD64HotSpotJumpToExceptionHandlerInCallerOp(AllocatableValue handlerInCallerPc, AllocatableValue exception, AllocatableValue exceptionPc, int isMethodHandleReturnOffset, Register thread) {
        super(TYPE);
        this.handlerInCallerPc = handlerInCallerPc;
        this.exception = exception;
        this.exceptionPc = exceptionPc;
        this.isMethodHandleReturnOffset = isMethodHandleReturnOffset;
        this.thread = thread;
    }

    @Override
    public void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler masm) {
        leaveFrameAndRestoreRbp(crb, masm);

        // Discard the return address, thus completing restoration of caller frame
        masm.incrementq(rsp, 8);

        if (JavaVersionUtil.JAVA_SPEC < 8) {
            // Restore rsp from rbp if the exception PC is a method handle call site.
            AMD64Address dst = new AMD64Address(thread, isMethodHandleReturnOffset);
            masm.cmpl(dst, 0);
            masm.cmovq(ConditionFlag.NotEqual, rsp, rbp);
        }

        masm.jmp(asRegister(handlerInCallerPc));
    }
}
