Consider the stack-machine instructions ("push y" through "pop to x") to compute x = y + (z*y)*z . Translate these instructions into JVM instructions. Presume that x, y, z are integer variables respectively stored at virtual addresses 0, 1, 2 in the variable area. Use instructions listed in the Selection of Basic JVM Instructions. Stack -machine instruction:

push y // read value of memory cell of y and push it onto the stack push z // read value of memory cell of z and push it onto the stack push y // read value of memory cell of y and push it onto the stack mul // pop top two values of the stack, multiply them, push the result onto the stack push z // read value of memory cell of z and push it onto the stack mul // pop top two values of the stack, multiply them, push the result onto the stack add // pop top two values of the stack, add them, push the result onto the stack pop to x // pop top value of the stack and store it in the memory cell of x

Selection of Basic JVM Instructions.

• push value onto operand stack
  • iconst_k (0 k 5) : push int constant k onto stack
  • iload_k (0 k 3) : push value at address k in variable area onto stack
  • bipush k : push byte int constant k onto stack
  • iload k : push value at address k in variable area onto stack For long, float, double types, replace prefix "i" by "l", "f", "d", respectively (except for bipush).
• pop from operand stack
  • istore_k (0 k 3) : pop stack and store into address k in variable area
  • istore k : pop stack and store into address k in variable area For long, float, double types, replace prefix "i" by "l", "f", "d", respectively.
• arithmetic
  • iadd, isub, imul, idiv : pop top two values from stack, apply operator to stack[top-1] and stack[top], push result onto stack For long, float, double types, replace prefix "i" by "l", "f", "d", respectively.
• conditional jump
  • if_icmpeq k : pop top two int values from stack; if stack[top1] = stack[top] then go to instruction at address k
  • if_icmpne k : pop top two int values from stack; if stack[top1] stack[top] then go to instruction at address k
  • if_icmplt k : pop top two int values from stack; if stack[top1] < stack[top] then go to instruction at address k
  • if_icmple k : pop top two int values from stack; if stack[top1] stack[top] then go to instruction at address k
  • if_icmpgt k : pop top two int values from stack; if stack[top1] > stack[top] then go to instruction at address k
  • if_icmpge k : pop top two int values from stack; if stack[top1] stack[top] then go to instruction at address k
• unconditional jump
  • goto k : go to instruction at address k
• function invocation
  • invokevirtual #k : invoke instance-level function numbered k
  • invokestatic #k : invoke static function numbered k
• function return
  • return : exit from void-type function
  • ireturn : pop top int value from stack, push it onto caller's stack, and exit from function call For long, float, double types, replace prefix "i" by "l", "f", "d", respectively.
• Instructions operating on references have the prefix "a", for example: aconst_null, aload, aload_k (0 k 3), astore, astore_k (0 k 3), areturn.