Write a Java class with the Dalvik instruction set

Dalvik instruction Set

. class public lcalculate; #定义类名

. super Ljava/lang/object; #定义父类
. method public static main ([ljava/lang/string;) v# declares the static main () method, L indicates that this is a class
. Registers 5 #方法中使用5个寄存器
. Prologue #代码起始指令
NOP #空指令
Nop
Nop
Nop
New-instance V0, LCalculate; #构造一个CalculateInstance
Invoke-direct{v0},lCalculate;-><init> () V #调用构造函数
Sget-object v1,ljava/lang/system;->out:ljava/io/printstream; #静态字段操作指令
CONST/4 v2,0x5 #将5存入寄存器V2
CONST/4 v3,0x3 #将3存入寄存器V3
Invoke-virtual{v0,v2,v3},lCalculate;->foo (II) I #调用LCalculate InstancesThe Foo virtual function (V0 is an implicitLCalculate object reference, followed by two arguments)
Move-result V0 #获取foo函数执行后返回的结果
Invoke-virtual{v1,v0},ljava/io/printstream;->println (I) V #方法调用指令
Return-void #函数从一个void方法返回
The. End Method #方法结束符号


# Direct Methods #表示这是一个直接方法
. Method Public constructor <init> () V #构造函数
. Registers 1 #一个寄存器


. Prologue #Code Start Command
Invoke-direct {p0}, ljava/lang/object;-><init> () V #调用实例的直接方法


Return-void#函数从一个void方法返回

The. End method #方法结束符号

# Virtual Methods #表示这是一个虚方法
. method public Foo (II) I #方法名为foo, two parameters and both are of type int, and the return value is int
. Registers 5 #方法中使用5个寄存器
. Prologue # code Start command
Add-int v0,p1,p2 #p1, p2 two int types, the result is saved in V0
Sub-int v1,p1,p2#p1,p2 two int type subtraction, the result is saved in V1

Mul-int/2addr v0,v1 #v0, v1 Two registers for multiplication, results stored in V0 register
return V0 #返回寄存器V0的值
The. End method #方法结束符号

Java source code:

public class Calculate
{
public int foo (int a,int b) {
Return (A+B) * (A-B);
}
public static void Main (string[] argc)
{
Hello hello=new hello ();
System.out.println (Hello.foo (5,3));
}
}

Write a Java class with the Dalvik instruction set