Compiling While

Assume the compilation of c will generate a sequence that will leave 0 or 1 on the stack, expressing the truth value of c:

[[ while(c) s ]] =

nStart: [[c]]
        if_eq nAfter
        [[s]]
        goto nStart
nAfter: ...

Example

Java code:

class Test {
    static boolean condition(int n) { ... }
    static void work(int n) { ... }
    static void test() {
	int n = 100;
	while (condition(n)) {
	    n = n - 11;
	    work(n);
	}
    }
}

Bytecodes for test():

static void test();
  Code:
   0:   bipush  100
   2:   istore_0
   3:   iload_0
   4:   invokestatic    #4; //Method condition:(I)Z
   7:   ifeq    22
   10:  iload_0
   11:  bipush  11
   13:  isub
   14:  istore_0
   15:  iload_0
   16:  invokestatic    #5; //Method work:(I)V
   19:  goto    3
   22:  return