1  /* { dg-do compile } */
       2  /* { dg-options "-O2" } */
       3  
       4  __extension__ typedef __SIZE_TYPE__ size_t;
       5  typedef unsigned char uint8_t;
       6  typedef unsigned short int uint16_t;
       7  typedef unsigned long long int uint64_t;
       8  struct magic {
       9    uint8_t mask_op;
      10    union {
      11     uint64_t _mask;
      12    } _u;
      13    union VALUETYPE {
      14     uint16_t h;
      15    } value;
      16  };
      17  void cvt_16(union VALUETYPE *p, const struct magic *m)
      18  {
      19    if (m->_u._mask)
      20      p->h %= (uint16_t) m->_u._mask;
      21  }