package midend.llvm.instr;

import backend.mips.MipsBuilder;
import backend.mips.Register;
import backend.mips.instr.MipsLs;
import backend.mips.instr.type.MipsLsType;
import midend.llvm.type.IrPointerType;
import midend.llvm.value.IrValue;

public class LoadInstr extends IrInstr {
    public LoadInstr(IrValue pointer, String name) {
        super(((IrPointerType) pointer.getType()).getPointeeType(), name, IrInstrType.LOAD);
        addUse(pointer);
    }

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

    public String toString() {
        return getName() + " = load " + getType() + ", "
                + getPointer().getType() + " " + getPointer().getName();
    }

    public void toMips() {
        IrValue pointer = getPointer();
        Register reg = MipsBuilder.getRegister(pointer);
        if (reg == null) { // 未分配寄存器情况
            reg = Register.K0;
        }
        loadValueToReg(pointer, reg);
        Register resultReg = MipsBuilder.getRegister(this);
        if (resultReg == null) {
            resultReg = Register.K1;
        }
        new MipsLs(MipsLsType.LW, resultReg, reg, 0);
        saveResult(this, resultReg);
    }
}