diff options
Diffstat (limited to 'include/asm-i386/bitops.h')
-rw-r--r-- | include/asm-i386/bitops.h | 53 |
1 files changed, 23 insertions, 30 deletions
diff --git a/include/asm-i386/bitops.h b/include/asm-i386/bitops.h index 9db0b712d57a..ddf1739dc7fd 100644 --- a/include/asm-i386/bitops.h +++ b/include/asm-i386/bitops.h | |||
@@ -311,6 +311,20 @@ static inline int find_first_zero_bit(const unsigned long *addr, unsigned size) | |||
311 | int find_next_zero_bit(const unsigned long *addr, int size, int offset); | 311 | int find_next_zero_bit(const unsigned long *addr, int size, int offset); |
312 | 312 | ||
313 | /** | 313 | /** |
314 | * __ffs - find first bit in word. | ||
315 | * @word: The word to search | ||
316 | * | ||
317 | * Undefined if no bit exists, so code should check against 0 first. | ||
318 | */ | ||
319 | static inline unsigned long __ffs(unsigned long word) | ||
320 | { | ||
321 | __asm__("bsfl %1,%0" | ||
322 | :"=r" (word) | ||
323 | :"rm" (word)); | ||
324 | return word; | ||
325 | } | ||
326 | |||
327 | /** | ||
314 | * find_first_bit - find the first set bit in a memory region | 328 | * find_first_bit - find the first set bit in a memory region |
315 | * @addr: The address to start the search at | 329 | * @addr: The address to start the search at |
316 | * @size: The maximum size to search | 330 | * @size: The maximum size to search |
@@ -320,22 +334,15 @@ int find_next_zero_bit(const unsigned long *addr, int size, int offset); | |||
320 | */ | 334 | */ |
321 | static inline int find_first_bit(const unsigned long *addr, unsigned size) | 335 | static inline int find_first_bit(const unsigned long *addr, unsigned size) |
322 | { | 336 | { |
323 | int d0, d1; | 337 | int x = 0; |
324 | int res; | 338 | |
325 | 339 | while (x < size) { | |
326 | /* This looks at memory. Mark it volatile to tell gcc not to move it around */ | 340 | unsigned long val = *addr++; |
327 | __asm__ __volatile__( | 341 | if (val) |
328 | "xorl %%eax,%%eax\n\t" | 342 | return __ffs(val) + x; |
329 | "repe; scasl\n\t" | 343 | x += (sizeof(*addr)<<3); |
330 | "jz 1f\n\t" | 344 | } |
331 | "leal -4(%%edi),%%edi\n\t" | 345 | return x; |
332 | "bsfl (%%edi),%%eax\n" | ||
333 | "1:\tsubl %%ebx,%%edi\n\t" | ||
334 | "shll $3,%%edi\n\t" | ||
335 | "addl %%edi,%%eax" | ||
336 | :"=a" (res), "=&c" (d0), "=&D" (d1) | ||
337 | :"1" ((size + 31) >> 5), "2" (addr), "b" (addr) : "memory"); | ||
338 | return res; | ||
339 | } | 346 | } |
340 | 347 | ||
341 | /** | 348 | /** |
@@ -360,20 +367,6 @@ static inline unsigned long ffz(unsigned long word) | |||
360 | return word; | 367 | return word; |
361 | } | 368 | } |
362 | 369 | ||
363 | /** | ||
364 | * __ffs - find first bit in word. | ||
365 | * @word: The word to search | ||
366 | * | ||
367 | * Undefined if no bit exists, so code should check against 0 first. | ||
368 | */ | ||
369 | static inline unsigned long __ffs(unsigned long word) | ||
370 | { | ||
371 | __asm__("bsfl %1,%0" | ||
372 | :"=r" (word) | ||
373 | :"rm" (word)); | ||
374 | return word; | ||
375 | } | ||
376 | |||
377 | /* | 370 | /* |
378 | * fls: find last bit set. | 371 | * fls: find last bit set. |
379 | */ | 372 | */ |