package midend.llvm.instr;

import midend.llvm.value.IrValue;
import backend.mips.Register;
import backend.mips.instr.MipsComp;
import backend.mips.instr.type.MipsCompareType;
import midend.llvm.type.IrInterType;
import backend.mips.MipsBuilder;

public class CmpInstr extends IrInstr {
    private CmpType cmpType;

    public CmpInstr(String name, String op, IrValue lhs, IrValue rhs) {
        super(IrInterType.BOOL, name, IrInstrType.CMP);
        cmpType = CmpType.getCmpType(op);
        addUse(lhs);
        addUse(rhs);
    }

    public CmpType getCmpType() {
        return cmpType;
    }

    public IrValue getLhs() {
        return getUse(0);
    }

    public IrValue getRhs() {
        return getUse(1);
    }

    public String toString() {
        return getName() + " = " + "icmp " + cmpType.toString()
                + " i32 " + getLhs().getName() + ", " + getRhs().getName();
    }

    public void toMips() {
        Register leftReg = MipsBuilder.getRegister(getLhs()) != null ? MipsBuilder.getRegister(getLhs()) : Register.K0;
        Register rightReg = MipsBuilder.getRegister(getRhs()) != null ? MipsBuilder.getRegister(getRhs()) : Register.K1;
        Register resultReg = MipsBuilder.getRegister(this) != null ? MipsBuilder.getRegister(this) : Register.K1;
        loadValueToReg(getLhs(), leftReg);
        loadValueToReg(getRhs(), rightReg);
        if (getCmpType() == CmpType.EQ) {
            new MipsComp(MipsCompareType.SEQ, resultReg, leftReg, rightReg);
        } else if (getCmpType() == CmpType.NE) {
            new MipsComp(MipsCompareType.SNE, resultReg, leftReg, rightReg);
        } else if (getCmpType() == CmpType.SGE) {
            new MipsComp(MipsCompareType.SGE, resultReg, leftReg, rightReg);
        } else if (getCmpType() == CmpType.SLE) {
            new MipsComp(MipsCompareType.SLE, resultReg, leftReg, rightReg);
        } else if (getCmpType() == CmpType.SGT) {
            new MipsComp(MipsCompareType.SGT, resultReg, leftReg, rightReg);
        } else if (getCmpType() == CmpType.SLT) {
            new MipsComp(MipsCompareType.SLT, resultReg, leftReg, rightReg);
        }
        saveResult(this, resultReg);
    }
}