| /* asm/arch/bitops.h for Linux/CRISv10 */ |
| |
| #ifndef _CRIS_ARCH_BITOPS_H |
| #define _CRIS_ARCH_BITOPS_H |
| |
| /* |
| * Helper functions for the core of the ff[sz] functions, wrapping the |
| * syntactically awkward asms. The asms compute the number of leading |
| * zeroes of a bits-in-byte and 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) |
| { |
| /* Let's just say we return the result in the same register as the |
| input. Saying we clobber the input but can return the result |
| in another register: |
| ! __asm__ ("swapnwbr %2\n\tlz %2,%0" |
| ! : "=r,r" (res), "=r,X" (dummy) : "1,0" (w)); |
| confuses gcc (core.c, gcc from cris-dist-1.14). */ |
| |
| unsigned long res; |
| __asm__ ("swapnwbr %0 \n\t" |
| "lz %0,%0" |
| : "=r" (res) : "0" (w)); |
| return res; |
| } |
| |
| static inline unsigned long cris_swapwbrlz(unsigned long w) |
| { |
| unsigned res; |
| __asm__ ("swapwbr %0 \n\t" |
| "lz %0,%0" |
| : "=r" (res) |
| : "0" (w)); |
| return res; |
| } |
| |
| /* |
| * ffz = Find First Zero in word. Undefined if no zero exists, |
| * so code should check against ~0UL first.. |
| */ |
| static inline unsigned long ffz(unsigned long w) |
| { |
| return cris_swapnwbrlz(w); |
| } |
| |
| /** |
| * __ffs - find first bit in word. |
| * @word: The word to search |
| * |
| * Undefined if no bit exists, so code should check against 0 first. |
| */ |
| static inline unsigned long __ffs(unsigned long word) |
| { |
| return cris_swapnwbrlz(~word); |
| } |
| |
| /** |
| * ffs - find first bit set |
| * @x: the word to search |
| * |
| * This is defined the same way as |
| * the libc and compiler builtin ffs routines, therefore |
| * differs in spirit from the above ffz (man ffs). |
| */ |
| |
| static inline unsigned long kernel_ffs(unsigned long w) |
| { |
| return w ? cris_swapwbrlz (w) + 1 : 0; |
| } |
| |
| #endif |