Convert code to IJVM

Question

I have translated the code fragment to IJVM, but not sure if it works or not. Tell me whether I am doing it right or not. Or how can I check whether the code works or not. Here is the code.

a = 0 sum = x  
while( a<= x){
sum += a;
a++;
}

Here is the IJVM code which I did: //folowing 3 lines set a = 0

ILOAD a  
BIPUSH 0 
ISTORE a
//following 2 lines set sum = x
ILOAD x
ISTORE sum
//checking the condition of the loop
L1: ILOAD a 
ILOAD x
ISUB
IFEQ L2 //GO TO BODY OF WHILE LOOP
ILOAD x
ILOAD a
ISUB
IFLT L3 //GO OUT OF WHILE LOOP
GOTO L1 
//L2 IS THE BODY OF WHILE LOOP
L2: ILOAD sum
ILOAD a
IADD
ISTORE sum
ILOAD a
IPUSH 1
IADD
ISTORE a
GOTO L1 //AGAIN GO BACK TO CHECK THE CONDITION OF WHILE LOOP

L3:

Answer 1

The first instruction ILOAD A is not needed. It places A on the stack, but the value is never used.

The first GOTO L1 causes an infinite loop, when A < X. Remove it. Let the code fall to the body of the loop.

BIPUSH 1 instead of IPUSH 1

Instead of ISUB followed by IFEQ, use IF_ICMPEQ.

You have the right idea.

To test the code, do a hand trace. Use pen and paper to write down the initial values of the variables A, X, SUM. Update the values of the variables (in columns) as you step through the code.