// Copyright (c) 2016, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

package com.android.tools.r8.ir.code;

import com.android.tools.r8.code.Iget;
import com.android.tools.r8.code.IgetBoolean;
import com.android.tools.r8.code.IgetByte;
import com.android.tools.r8.code.IgetChar;
import com.android.tools.r8.code.IgetObject;
import com.android.tools.r8.code.IgetShort;
import com.android.tools.r8.code.IgetWide;
import com.android.tools.r8.dex.Constants;
import com.android.tools.r8.errors.Unreachable;
import com.android.tools.r8.graph.AppInfo;
import com.android.tools.r8.graph.DexEncodedField;
import com.android.tools.r8.graph.DexField;
import com.android.tools.r8.graph.DexType;
import com.android.tools.r8.ir.conversion.DexBuilder;

public class InstanceGet extends FieldInstruction {

  public InstanceGet(MemberType type, Value dest, Value object, DexField field) {
    super(type, field, dest, object);
  }

  public Value dest() {
    return outValue;
  }

  public Value object() {
    assert inValues.size() == 1;
    return inValues.get(0);
  }

  @Override
  public void buildDex(DexBuilder builder) {
    int destRegister = builder.allocatedRegister(dest(), getNumber());
    int objectRegister = builder.allocatedRegister(object(), getNumber());
    com.android.tools.r8.code.Instruction instruction;
    switch (type) {
      case SINGLE:
        instruction = new Iget(destRegister, objectRegister, field);
        break;
      case WIDE:
        instruction = new IgetWide(destRegister, objectRegister, field);
        break;
      case OBJECT:
        instruction = new IgetObject(destRegister, objectRegister, field);
        break;
      case BOOLEAN:
        instruction = new IgetBoolean(destRegister, objectRegister, field);
        break;
      case BYTE:
        instruction = new IgetByte(destRegister, objectRegister, field);
        break;
      case CHAR:
        instruction = new IgetChar(destRegister, objectRegister, field);
        break;
      case SHORT:
        instruction = new IgetShort(destRegister, objectRegister, field);
        break;
      default:
        throw new Unreachable("Unexpected type " + type);
    }
    builder.add(this, instruction);
  }

  @Override
  public boolean instructionTypeCanThrow() {
    return true;
  }

  @Override
  public int maxInValueRegister() {
    return Constants.U4BIT_MAX;
  }

  @Override
  public int maxOutValueRegister() {
    return Constants.U4BIT_MAX;
  }

  @Override
  public boolean identicalNonValueParts(Instruction other) {
    InstanceGet o = other.asInstanceGet();
    return o.field == field && o.type == type;
  }

  public int compareNonValueParts(Instruction other) {
    InstanceGet o = other.asInstanceGet();
    int result = field.slowCompareTo(o.field);
    if (result != 0) {
      return result;
    }
    return type.ordinal() - o.type.ordinal();
  }

  @Override
  DexEncodedField lookupTarget(DexType type, AppInfo appInfo) {
    return appInfo.lookupInstanceTarget(type, field);
  }

  @Override
  public boolean isInstanceGet() {
    return true;
  }

  @Override
  public InstanceGet asInstanceGet() {
    return this;
  }

  @Override
  public String toString() {
    return super.toString() + "; field: " + field.toSourceString();
  }
}