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[/] [openrisc/] [trunk/] [orpsocv2/] [sw/] [lib/] [lib-utils.c] - Rev 733
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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; }
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