1 #ifndef _ATOMIC_H 2 #define _ATOMIC_H 3 4 #include <stdint.h> 5 6 #include "atomic_arch.h" 7 8 #ifndef a_ctz_32 9 #define a_ctz_32 a_ctz_32 10 static inline int a_ctz_32(uint32_t x) 11 { 12 #ifdef a_clz_32 13 return 31-a_clz_32(x&-x); 14 #else 15 static const char debruijn32[32] = { 16 0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13, 17 31, 22, 28, 18, 26, 10, 7, 12, 21, 17, 9, 6, 16, 5, 15, 14 18 }; 19 return debruijn32[(x&-x)*0x076be629 >> 27]; 20 #endif 21 } 22 #endif 23 24 #ifndef a_ctz_64 25 #define a_ctz_64 a_ctz_64 26 static inline int a_ctz_64(uint64_t x) 27 { 28 static const char debruijn64[64] = { 29 0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28, 30 62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11, 31 63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10, 32 51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12 33 }; 34 if (sizeof(long) < 8) { 35 uint32_t y = x; 36 if (!y) { 37 y = x>>32; 38 return 32 + a_ctz_32(y); 39 } 40 return a_ctz_32(y); 41 } 42 return debruijn64[(x&-x)*0x022fdd63cc95386dull >> 58]; 43 } 44 #endif 45 46 static inline int a_ctz_l(unsigned long x) 47 { 48 return (sizeof(long) < 8) ? a_ctz_32(x) : a_ctz_64(x); 49 } 50 51 #ifndef a_clz_64 52 #define a_clz_64 a_clz_64 53 static inline int a_clz_64(uint64_t x) 54 { 55 #ifdef a_clz_32 56 if (x>>32) 57 return a_clz_32(x>>32); 58 return a_clz_32(x) + 32; 59 #else 60 uint32_t y; 61 int r; 62 if (x>>32) y=x>>32, r=0; else y=x, r=32; 63 if (y>>16) y>>=16; else r |= 16; 64 if (y>>8) y>>=8; else r |= 8; 65 if (y>>4) y>>=4; else r |= 4; 66 if (y>>2) y>>=2; else r |= 2; 67 return r | !(y>>1); 68 #endif 69 } 70 #endif 71 72 #endif 73