X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Flinux%2Fbitops.h;h=638165f571dacedf7455f0bc9d87e3390b8ee781;hb=refs%2Fheads%2Fvserver;hp=208650b1ad3ac08a340d93e87729890d807a3bdb;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 208650b1a..638165f57 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -2,89 +2,12 @@ #define _LINUX_BITOPS_H #include -/* - * ffs: find first bit set. This is defined the same way as - * the libc and compiler builtin ffs routines, therefore - * differs in spirit from the above ffz (man ffs). - */ - -static inline int generic_ffs(int x) -{ - int r = 1; - - if (!x) - return 0; - if (!(x & 0xffff)) { - x >>= 16; - r += 16; - } - if (!(x & 0xff)) { - x >>= 8; - r += 8; - } - if (!(x & 0xf)) { - x >>= 4; - r += 4; - } - if (!(x & 3)) { - x >>= 2; - r += 2; - } - if (!(x & 1)) { - x >>= 1; - r += 1; - } - return r; -} - -/* - * fls: find last bit set. - */ - -static __inline__ int generic_fls(int x) -{ - int r = 32; - - if (!x) - return 0; - if (!(x & 0xffff0000u)) { - x <<= 16; - r -= 16; - } - if (!(x & 0xff000000u)) { - x <<= 8; - r -= 8; - } - if (!(x & 0xf0000000u)) { - x <<= 4; - r -= 4; - } - if (!(x & 0xc0000000u)) { - x <<= 2; - r -= 2; - } - if (!(x & 0x80000000u)) { - x <<= 1; - r -= 1; - } - return r; -} - /* * Include this here because some architectures need generic_ffs/fls in * scope */ #include - -static inline int generic_fls64(__u64 x) -{ - __u32 h = x >> 32; - if (h) - return fls(h) + 32; - return fls(x); -} - static __inline__ int get_bitmask_order(unsigned int count) { int order; @@ -103,59 +26,13 @@ static __inline__ int get_count_order(unsigned int count) return order; } -/* - * hweightN: returns the hamming weight (i.e. the number - * of bits set) of a N-bit word - */ - -static inline unsigned int generic_hweight32(unsigned int w) -{ - unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555); - res = (res & 0x33333333) + ((res >> 2) & 0x33333333); - res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F); - res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF); - return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF); -} - -static inline unsigned int generic_hweight16(unsigned int w) -{ - unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555); - res = (res & 0x3333) + ((res >> 2) & 0x3333); - res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F); - return (res & 0x00FF) + ((res >> 8) & 0x00FF); -} - -static inline unsigned int generic_hweight8(unsigned int w) -{ - unsigned int res = (w & 0x55) + ((w >> 1) & 0x55); - res = (res & 0x33) + ((res >> 2) & 0x33); - return (res & 0x0F) + ((res >> 4) & 0x0F); -} - -static inline unsigned long generic_hweight64(__u64 w) -{ -#if BITS_PER_LONG < 64 - return generic_hweight32((unsigned int)(w >> 32)) + - generic_hweight32((unsigned int)w); -#else - u64 res; - res = (w & 0x5555555555555555ul) + ((w >> 1) & 0x5555555555555555ul); - res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul); - res = (res & 0x0F0F0F0F0F0F0F0Ful) + ((res >> 4) & 0x0F0F0F0F0F0F0F0Ful); - res = (res & 0x00FF00FF00FF00FFul) + ((res >> 8) & 0x00FF00FF00FF00FFul); - res = (res & 0x0000FFFF0000FFFFul) + ((res >> 16) & 0x0000FFFF0000FFFFul); - return (res & 0x00000000FFFFFFFFul) + ((res >> 32) & 0x00000000FFFFFFFFul); -#endif -} - static inline unsigned long hweight_long(unsigned long w) { - return sizeof(w) == 4 ? generic_hweight32(w) : generic_hweight64(w); + return sizeof(w) == 4 ? hweight32(w) : hweight64(w); } -/* +/** * rol32 - rotate a 32-bit value left - * * @word: value to rotate * @shift: bits to roll */ @@ -164,9 +41,8 @@ static inline __u32 rol32(__u32 word, unsigned int shift) return (word << shift) | (word >> (32 - shift)); } -/* +/** * ror32 - rotate a 32-bit value right - * * @word: value to rotate * @shift: bits to roll */ @@ -175,4 +51,11 @@ static inline __u32 ror32(__u32 word, unsigned int shift) return (word >> shift) | (word << (32 - shift)); } +static inline unsigned fls_long(unsigned long l) +{ + if (sizeof(l) == 4) + return fls(l); + return fls64(l); +} + #endif