code: public final static byte reverseIfOpcode(byte opcode) {
          // Actually, because the numbers assigned to the "if" opcodes
          // were so cleverly chosen, all I really need to do is toggle
          // bit 0. I'm not going to do that because I still need to check if 
          // an invalid opcode was passed in.
  
          switch (opcode) {
          case IF_ACMPEQ:
              return IF_ACMPNE;
          case IF_ACMPNE:
              return IF_ACMPEQ;
          case IF_ICMPEQ:
              return IF_ICMPNE;
          case IF_ICMPNE:
              return IF_ICMPEQ;
          case IF_ICMPLT:
              return IF_ICMPGE;
          case IF_ICMPGE:
              return IF_ICMPLT;
          case IF_ICMPGT:
              return IF_ICMPLE;
          case IF_ICMPLE:
              return IF_ICMPGT;
          case IFEQ:
              return IFNE;
          case IFNE:
              return IFEQ;
          case IFLT:
              return IFGE;
          case IFGE:
              return IFLT;
          case IFGT:
              return IFLE;
          case IFLE:
              return IFGT;
          case IFNONNULL:
              return IFNULL;
          case IFNULL:
              return IFNONNULL;
          default:
              throw new IllegalArgumentException
                  ("Opcode not an if instruction: " + getMnemonic(opcode));
          }
      }
docs: Reverses the condition for an "if" opcode. i.e. IFEQ is changed to
  IFNE.