include/asm-cris/arch-v32/bitops.h

   1 #ifndef _ASM_CRIS_ARCH_BITOPS_H
   2 #define _ASM_CRIS_ARCH_BITOPS_H
   3
   4 /*
   5  * Helper functions for the core of the ff[sz] functions. They compute the
   6  * number of leading zeroes of a bits-in-byte, byte-in-word and
   7  * word-in-dword-swapped number. They differ in that the first function also
   8  * inverts all bits in the input.
   9  */
  10
  11 static inline unsigned long
  12 cris_swapnwbrlz(unsigned long w)
  13 {
  14         unsigned long res;
  15
  16         __asm__ __volatile__ ("swapnwbr %0\n\t"
  17                               "lz %0,%0"
  18                               : "=r" (res) : "0" (w));
  19
  20         return res;
  21 }
  22
  23 static inline unsigned long
  24 cris_swapwbrlz(unsigned long w)
  25 {
  26         unsigned long res;
  27
  28         __asm__ __volatile__ ("swapwbr %0\n\t"
  29                               "lz %0,%0"
  30                               : "=r" (res) : "0" (w));
  31
  32         return res;
  33 }
  34
  35 /*
  36  * Find First Zero in word. Undefined if no zero exist, so the caller should
  37  * check against ~0 first.
  38  */
  39 static inline unsigned long
  40 ffz(unsigned long w)
  41 {
  42         return cris_swapnwbrlz(w);
  43 }
  44
  45 /*
  46  * Find First Set bit in word. Undefined if no 1 exist, so the caller
  47  * should check against 0 first.
  48  */
  49 static inline unsigned long
  50 __ffs(unsigned long w)
  51 {
  52         return cris_swapnwbrlz(~w);
  53 }
  54
  55 /*
  56  * Find First Bit that is set.
  57  */
  58 static inline unsigned long
  59 kernel_ffs(unsigned long w)
  60 {
  61         return w ? cris_swapwbrlz (w) + 1 : 0;
  62 }
  63
  64 #endif /* _ASM_CRIS_ARCH_BITOPS_H */