| #ifndef I386_BITOPS_H | |
| #define I386_BITOPS_H | |
| /** | |
| * log2 - Find the truncated log base 2 of x | |
| */ | |
| static inline unsigned long log2(unsigned long x) | |
| { | |
| unsigned long r = 0; | |
| __asm__( | |
| "bsrl %1, %0\n\t" | |
| "jnz 1f\n\t" | |
| "movl $-1, %0\n\t" | |
| "1:\n\t" | |
| : "=r" (r) : "r" (x)); | |
| return r; | |
| } | |
| #endif /* I386_BITOPS_H */ |