diff options
Diffstat (limited to 'linux/src/include/asm-i386')
| -rw-r--r-- | linux/src/include/asm-i386/bitops.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/linux/src/include/asm-i386/bitops.h b/linux/src/include/asm-i386/bitops.h index e3ea8f5..d3ed1fb 100644 --- a/linux/src/include/asm-i386/bitops.h +++ b/linux/src/include/asm-i386/bitops.h @@ -134,4 +134,34 @@ extern __inline__ unsigned long ffz(unsigned long word) return word; } +#ifdef __KERNEL__ + +/* + * 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). + */ + +extern __inline__ int ffs(int x) +{ + int r; + + __asm__("bsfl %1,%0\n\t" + "jnz 1f\n\t" + "movl $-1,%0\n" + "1:" : "=r" (r) : "g" (x)); + return r+1; +} + +/* + * hweightN: returns the hamming weight (i.e. the number + * of bits set) of a N-bit word + */ + +#define hweight32(x) generic_hweight32(x) +#define hweight16(x) generic_hweight16(x) +#define hweight8(x) generic_hweight8(x) + +#endif /* __KERNEL__ */ + #endif /* _I386_BITOPS_H */ |