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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 | #ifndef _LINUX_BITOPS_H #define _LINUX_BITOPS_H #include <asm/bitops.h> /* * 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. */ extern __inline__ int generic_fls(int x) { int r = 32; if (!x) return 0; if (!(x & 0xffff0000)) { x <<= 16; r -= 16; } if (!(x & 0xff000000)) { x <<= 8; r -= 8; } if (!(x & 0xf0000000)) { x <<= 4; r -= 4; } if (!(x & 0xc0000000)) { x <<= 2; r -= 2; } if (!(x & 0x80000000)) { x <<= 1; r -= 1; } return r; } extern __inline__ int get_bitmask_order(unsigned int count) { int order; order = fls(count); return order; /* We could be slightly more clever with -1 here... */ } /* * 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); } #include <asm/bitops.h> #endif |