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[/] [openrisc/] [trunk/] [orpsocv2/] [sw/] [lib/] [lib-utils.c] - Blame information for rev 397

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1 393 julius
#include "lib-utils.h"
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/* Simple C functions */
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/* memcpy */
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void* memcpy( void* s1, void* s2, size_t n)
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{
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  char* r1 = s1;
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  const char* r2 = s2;
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#ifdef __BCC__
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  while (n--) {
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    *r1++ = *r2++;
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  }
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#else
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  while (n) {
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    *r1++ = *r2++;
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    --n;
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  }
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#endif
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  return s1;
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}
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/* strlen */
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size_t strlen(const char*s)
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{
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  const char* p;
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  for (p=s; *p; p++);
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  return p - s;
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}
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/* memchr */
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void *memchr(const void *s, int c, size_t n)
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{
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         const unsigned char *r = (const unsigned char *) s;
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#ifdef __BCC__
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        /* bcc can optimize the counter if it thinks it is a pointer... */
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        const char *np = (const char *) n;
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#else
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# define np n
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#endif
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        while (np) {
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                if (*r == ((unsigned char)c)) {
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                        return (void *) r;     /* silence the warning */
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                }
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                ++r;
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                --np;
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        }
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        return NULL;
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}
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/* --------------------------------------------------------------------------*/
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/*!Pseudo-random number generator
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   This should return pseudo-random numbers, based on a Galois LFSR
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   @return The next pseudo-random number                                     */
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/* --------------------------------------------------------------------------*/
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unsigned long int
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rand ()
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{
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  static unsigned long int lfsr = RAND_LFSR_SEED;
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  static int period = 0;
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  /* taps: 32 31 29 1; characteristic polynomial: x^32 + x^31 + x^29 + x + 1 */
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  lfsr = (lfsr >> 1) ^ (unsigned long int)((0 - (lfsr & 1u)) & 0xd0000001u);
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  ++period;
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  return lfsr;
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}

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