1*c9945492SAndroid Build Coastguard Worker #include <string.h> 2*c9945492SAndroid Build Coastguard Worker #include <stdint.h> 3*c9945492SAndroid Build Coastguard Worker #include <limits.h> 4*c9945492SAndroid Build Coastguard Worker 5*c9945492SAndroid Build Coastguard Worker #define SS (sizeof(size_t)) 6*c9945492SAndroid Build Coastguard Worker #define ALIGN (sizeof(size_t)-1) 7*c9945492SAndroid Build Coastguard Worker #define ONES ((size_t)-1/UCHAR_MAX) 8*c9945492SAndroid Build Coastguard Worker #define HIGHS (ONES * (UCHAR_MAX/2+1)) 9*c9945492SAndroid Build Coastguard Worker #define HASZERO(x) ((x)-ONES & ~(x) & HIGHS) 10*c9945492SAndroid Build Coastguard Worker memchr(const void * src,int c,size_t n)11*c9945492SAndroid Build Coastguard Workervoid *memchr(const void *src, int c, size_t n) 12*c9945492SAndroid Build Coastguard Worker { 13*c9945492SAndroid Build Coastguard Worker const unsigned char *s = src; 14*c9945492SAndroid Build Coastguard Worker c = (unsigned char)c; 15*c9945492SAndroid Build Coastguard Worker #ifdef __GNUC__ 16*c9945492SAndroid Build Coastguard Worker for (; ((uintptr_t)s & ALIGN) && n && *s != c; s++, n--); 17*c9945492SAndroid Build Coastguard Worker if (n && *s != c) { 18*c9945492SAndroid Build Coastguard Worker typedef size_t __attribute__((__may_alias__)) word; 19*c9945492SAndroid Build Coastguard Worker const word *w; 20*c9945492SAndroid Build Coastguard Worker size_t k = ONES * c; 21*c9945492SAndroid Build Coastguard Worker for (w = (const void *)s; n>=SS && !HASZERO(*w^k); w++, n-=SS); 22*c9945492SAndroid Build Coastguard Worker s = (const void *)w; 23*c9945492SAndroid Build Coastguard Worker } 24*c9945492SAndroid Build Coastguard Worker #endif 25*c9945492SAndroid Build Coastguard Worker for (; n && *s != c; s++, n--); 26*c9945492SAndroid Build Coastguard Worker return n ? (void *)s : 0; 27*c9945492SAndroid Build Coastguard Worker } 28