libomfs/bits.h

   1 #ifndef _BITS_H
   2 #define _BITS_H
   3
   4 static inline int test_bit(u8* buf, u64 offset)
   5 {
   6         return buf[offset >> 3] & (1<<(offset & 7));
   7 }
   8
   9 static inline void init_bit(u8* buf, u64 offset, int value)
  10 {
  11         int mask = ((value & 1) << (offset & 7));
  12         buf[offset >> 3] &= ~mask;
  13         buf[offset >> 3] |= mask;
  14 }
  15
  16 static inline void clear_bit(u8* buf, u64 offset)
  17 {
  18         buf[offset >> 3] &= ~(1 << (offset & 7));
  19 }
  20
  21 static inline void set_bit(u8* buf, u64 offset)
  22 {
  23         buf[offset >> 3] |= 1 << (offset & 7);
  24 }
  25
  26 static inline int is_power_of_two(int i)
  27 {
  28     return !(i & (i-1));
  29 }
  30
  31 static inline int log_2(int i)
  32 {
  33     int count = 0;
  34
  35     for (i>>=1;i;i>>=1)
  36         count++;
  37     return count;
  38 }
  39
  40 #endif