1 /* asm/arch/bitops.h for Linux/CRISv10 */
3 #ifndef _CRIS_ARCH_BITOPS_H
4 #define _CRIS_ARCH_BITOPS_H
7 * Helper functions for the core of the ff[sz] functions, wrapping the
8 * syntactically awkward asms. The asms compute the number of leading
9 * zeroes of a bits-in-byte and byte-in-word and word-in-dword-swapped
10 * number. They differ in that the first function also inverts all bits
13 extern inline unsigned long cris_swapnwbrlz(unsigned long w
)
15 /* Let's just say we return the result in the same register as the
16 input. Saying we clobber the input but can return the result
18 ! __asm__ ("swapnwbr %2\n\tlz %2,%0"
19 ! : "=r,r" (res), "=r,X" (dummy) : "1,0" (w));
20 confuses gcc (sched.c, gcc from cris-dist-1.14). */
23 __asm__ ("swapnwbr %0 \n\t"
25 : "=r" (res
) : "0" (w
));
29 extern inline unsigned long cris_swapwbrlz(unsigned long w
)
32 __asm__ ("swapwbr %0 \n\t"
40 * ffz = Find First Zero in word. Undefined if no zero exists,
41 * so code should check against ~0UL first..
43 extern inline unsigned long ffz(unsigned long w
)
45 return cris_swapnwbrlz(w
);
49 * __ffs - find first bit in word.
50 * @word: The word to search
52 * Undefined if no bit exists, so code should check against 0 first.
54 extern inline unsigned long __ffs(unsigned long word
)
56 return cris_swapnwbrlz(~word
);
60 * ffs - find first bit set
61 * @x: the word to search
63 * This is defined the same way as
64 * the libc and compiler builtin ffs routines, therefore
65 * differs in spirit from the above ffz (man ffs).
68 extern inline unsigned long kernel_ffs(unsigned long w
)
70 return w
? cris_swapwbrlz (w
) + 1 : 0;