private int getFieldAccessOpcode(Handle handle) {
      switch (handle.getTag()) {
        case Opcodes.H_GETFIELD: return Opcodes.GETFIELD;
        case Opcodes.H_GETSTATIC: return Opcodes.GETSTATIC;
        case Opcodes.H_PUTFIELD: return Opcodes.PUTFIELD;
        case Opcodes.H_PUTSTATIC: return Opcodes.PUTSTATIC;
        default: return -1;
      }
    }
private int getFieldAccessOpcode(Handle handle)