FNV32 hash in C

This code is in the NYSL( public domain ).

#define FNV_32_PRIME ((uint32)0x01000193)

#define uint32 unsigned int
uint32 dkcFNV32_INL(const void *buf,size_t len,uint32 hval)

{

  unsigned char *bp = (unsigned char *)buf;  /* start of buffer */

  unsigned char *be = bp + len;    /* beyond end of buffer */
  /*

   * FNV-1 hash each octet in the buffer

   */

  while (bp < be) {
  /* multiply by the 32 bit FNV magic prime mod 2^32 */

#if defined(NO_FNV_GCC_OPTIMIZATION)

    hval *= FNV_32_PRIME;

#else

    hval += (hval<<1) + (hval<<4) + (hval<<7) + (hval<<8) + (hval<<24);

#endif
    /* xor the bottom with the current octet */

    hval ^= (uint32)*bp++;

  }
  return hval;

}