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#include "lib-utils.h"

/* Simple C functions */

/* memcpy */

void* memcpy( void* s1, void* s2, size_t n)

{

  char* r1 = (char *) s1;

  const char* r2 =  (const char*) s2;

#ifdef __BCC__

  while (n--) {

    *r1++ = *r2++;

  }

#else

  while (n) {

    *r1++ = *r2++;

    --n;

  }

#endif

  return s1;

}

/* strlen */

size_t strlen(const char*s)

{

  const char* p;

  for (p=s; *p; p++);

  return p - s;

}

/* memchr */

void *memchr(const void *s, int c, size_t n)

{

         const unsigned char *r = (const unsigned char *) s;

#ifdef __BCC__

        /* bcc can optimize the counter if it thinks it is a pointer... */

        const char *np = (const char *) n;

#else

# define np n

#endif

        while (np) {

                if (*r == ((unsigned char)c)) {

                        return (void *) r;     /* silence the warning */

                }

                ++r;

                --np;

        }

        return NULL;

}

/* --------------------------------------------------------------------------*/

/*!Pseudo-random number generator

   This should return pseudo-random numbers, based on a Galois LFSR

   @return The next pseudo-random number                                     */

/* --------------------------------------------------------------------------*/

unsigned long int

rand ()

{

  static unsigned long int lfsr = RAND_LFSR_SEED;

  static int period = 0;

  /* taps: 32 31 29 1; characteristic polynomial: x^32 + x^31 + x^29 + x + 1 */

  lfsr = (lfsr >> 1) ^ (unsigned long int)((0 - (lfsr & 1u)) & 0xd0000001u);

  ++period;

  return lfsr;

}