diff options
Diffstat (limited to 'arch/cris/include/arch-v32/arch/bitops.h')
-rw-r--r-- | arch/cris/include/arch-v32/arch/bitops.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/cris/include/arch-v32/arch/bitops.h b/arch/cris/include/arch-v32/arch/bitops.h new file mode 100644 index 000000000000..147689d6b624 --- /dev/null +++ b/arch/cris/include/arch-v32/arch/bitops.h @@ -0,0 +1,64 @@ +#ifndef _ASM_CRIS_ARCH_BITOPS_H +#define _ASM_CRIS_ARCH_BITOPS_H + +/* + * Helper functions for the core of the ff[sz] functions. They compute the + * number of leading zeroes of a bits-in-byte, byte-in-word and + * word-in-dword-swapped number. They differ in that the first function also + * inverts all bits in the input. + */ + +static inline unsigned long +cris_swapnwbrlz(unsigned long w) +{ + unsigned long res; + + __asm__ __volatile__ ("swapnwbr %0\n\t" + "lz %0,%0" + : "=r" (res) : "0" (w)); + + return res; +} + +static inline unsigned long +cris_swapwbrlz(unsigned long w) +{ + unsigned long res; + + __asm__ __volatile__ ("swapwbr %0\n\t" + "lz %0,%0" + : "=r" (res) : "0" (w)); + + return res; +} + +/* + * Find First Zero in word. Undefined if no zero exist, so the caller should + * check against ~0 first. + */ +static inline unsigned long +ffz(unsigned long w) +{ + return cris_swapnwbrlz(w); +} + +/* + * Find First Set bit in word. Undefined if no 1 exist, so the caller + * should check against 0 first. + */ +static inline unsigned long +__ffs(unsigned long w) +{ + return cris_swapnwbrlz(~w); +} + +/* + * Find First Bit that is set. + */ +static inline unsigned long +kernel_ffs(unsigned long w) +{ + return w ? cris_swapwbrlz (w) + 1 : 0; +} + +#endif /* _ASM_CRIS_ARCH_BITOPS_H */ |