186 lines
3.7 KiB
C
186 lines
3.7 KiB
C
#ifndef _LINUX_BITOPS_H
|
|
#define _LINUX_BITOPS_H
|
|
#include <asm/types.h>
|
|
|
|
/*
|
|
* ffs: find first bit set. 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 int generic_ffs(int x)
|
|
{
|
|
int r = 1;
|
|
|
|
if (!x)
|
|
return 0;
|
|
if (!(x & 0xffff)) {
|
|
x >>= 16;
|
|
r += 16;
|
|
}
|
|
if (!(x & 0xff)) {
|
|
x >>= 8;
|
|
r += 8;
|
|
}
|
|
if (!(x & 0xf)) {
|
|
x >>= 4;
|
|
r += 4;
|
|
}
|
|
if (!(x & 3)) {
|
|
x >>= 2;
|
|
r += 2;
|
|
}
|
|
if (!(x & 1)) {
|
|
x >>= 1;
|
|
r += 1;
|
|
}
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* fls: find last bit set.
|
|
*/
|
|
|
|
static __inline__ int generic_fls(int x)
|
|
{
|
|
int r = 32;
|
|
|
|
if (!x)
|
|
return 0;
|
|
if (!(x & 0xffff0000u)) {
|
|
x <<= 16;
|
|
r -= 16;
|
|
}
|
|
if (!(x & 0xff000000u)) {
|
|
x <<= 8;
|
|
r -= 8;
|
|
}
|
|
if (!(x & 0xf0000000u)) {
|
|
x <<= 4;
|
|
r -= 4;
|
|
}
|
|
if (!(x & 0xc0000000u)) {
|
|
x <<= 2;
|
|
r -= 2;
|
|
}
|
|
if (!(x & 0x80000000u)) {
|
|
x <<= 1;
|
|
r -= 1;
|
|
}
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Include this here because some architectures need generic_ffs/fls in
|
|
* scope
|
|
*/
|
|
#include <asm/bitops.h>
|
|
|
|
|
|
static inline int generic_fls64(__u64 x)
|
|
{
|
|
__u32 h = x >> 32;
|
|
if (h)
|
|
return fls(h) + 32;
|
|
return fls(x);
|
|
}
|
|
|
|
static __inline__ int get_bitmask_order(unsigned int count)
|
|
{
|
|
int order;
|
|
|
|
order = fls(count);
|
|
return order; /* We could be slightly more clever with -1 here... */
|
|
}
|
|
|
|
static __inline__ int get_count_order(unsigned int count)
|
|
{
|
|
int order;
|
|
|
|
order = fls(count) - 1;
|
|
if (count & (count - 1))
|
|
order++;
|
|
return order;
|
|
}
|
|
|
|
/*
|
|
* hweightN: returns the hamming weight (i.e. the number
|
|
* of bits set) of a N-bit word
|
|
*/
|
|
|
|
static inline unsigned int generic_hweight32(unsigned int w)
|
|
{
|
|
unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555);
|
|
res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
|
|
res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F);
|
|
res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF);
|
|
return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF);
|
|
}
|
|
|
|
static inline unsigned int generic_hweight16(unsigned int w)
|
|
{
|
|
unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555);
|
|
res = (res & 0x3333) + ((res >> 2) & 0x3333);
|
|
res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F);
|
|
return (res & 0x00FF) + ((res >> 8) & 0x00FF);
|
|
}
|
|
|
|
static inline unsigned int generic_hweight8(unsigned int w)
|
|
{
|
|
unsigned int res = (w & 0x55) + ((w >> 1) & 0x55);
|
|
res = (res & 0x33) + ((res >> 2) & 0x33);
|
|
return (res & 0x0F) + ((res >> 4) & 0x0F);
|
|
}
|
|
|
|
static inline unsigned long generic_hweight64(__u64 w)
|
|
{
|
|
#if BITS_PER_LONG < 64
|
|
return generic_hweight32((unsigned int)(w >> 32)) +
|
|
generic_hweight32((unsigned int)w);
|
|
#else
|
|
u64 res;
|
|
res = (w & 0x5555555555555555ul) + ((w >> 1) & 0x5555555555555555ul);
|
|
res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
|
|
res = (res & 0x0F0F0F0F0F0F0F0Ful) + ((res >> 4) & 0x0F0F0F0F0F0F0F0Ful);
|
|
res = (res & 0x00FF00FF00FF00FFul) + ((res >> 8) & 0x00FF00FF00FF00FFul);
|
|
res = (res & 0x0000FFFF0000FFFFul) + ((res >> 16) & 0x0000FFFF0000FFFFul);
|
|
return (res & 0x00000000FFFFFFFFul) + ((res >> 32) & 0x00000000FFFFFFFFul);
|
|
#endif
|
|
}
|
|
|
|
static inline unsigned long hweight_long(unsigned long w)
|
|
{
|
|
return sizeof(w) == 4 ? generic_hweight32(w) : generic_hweight64(w);
|
|
}
|
|
|
|
/*
|
|
* rol32 - rotate a 32-bit value left
|
|
*
|
|
* @word: value to rotate
|
|
* @shift: bits to roll
|
|
*/
|
|
static inline __u32 rol32(__u32 word, unsigned int shift)
|
|
{
|
|
return (word << shift) | (word >> (32 - shift));
|
|
}
|
|
|
|
/*
|
|
* ror32 - rotate a 32-bit value right
|
|
*
|
|
* @word: value to rotate
|
|
* @shift: bits to roll
|
|
*/
|
|
static inline __u32 ror32(__u32 word, unsigned int shift)
|
|
{
|
|
return (word >> shift) | (word << (32 - shift));
|
|
}
|
|
|
|
static inline unsigned fls_long(unsigned long l)
|
|
{
|
|
if (sizeof(l) == 4)
|
|
return fls(l);
|
|
return fls64(l);
|
|
}
|
|
|
|
#endif
|