How Java execute z = ++x + ++x + ++x

Disassemble Java z = ++x + ++x + ++x

class test {
    public static void main(String[] args) {
        int x = 2;

        int z = 0;
        z = ++x + ++x + ++x;
        System.out.printf("z = %d\n",z);
    }
}

Disassemble:

iconst_2
istore_1      // int x = 2;
iconst_0
istore_2      // int z = 0;
iinc     1, 1 // x = x + 1
iload_1       // get value x = 3
iinc     1, 1 // x = x + 1
iload_1       // get value x = 4
iadd          // 3 + 4 = 7
iinc     1, 1 // x = x + 1
iload_1       // get value x = 5
iadd          // 7 + 5 = 12
istore_2      // z = 12