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yaml
---
r: 24199
b: refs/heads/master
c: e9bebd6
h: refs/heads/master
i:
  24197: 0b0dff6
  24195: a0cb124
  24191: ab7fad1
v: v3
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Akinobu Mita authored and Linus Torvalds committed Mar 26, 2006
1 parent 22695a8 commit dbfc070
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Showing 2 changed files with 2 additions and 124 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: b9a2838cc26c4c5369fbd2482acbc5ab60573479
refs/heads/master: e9bebd6f3acee68fa07d44726895b40733cb1dc0
124 changes: 1 addition & 123 deletions trunk/include/linux/bitops.h
Original file line number Diff line number Diff line change
Expand Up @@ -2,89 +2,12 @@
#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;
Expand All @@ -103,54 +26,9 @@ static __inline__ int get_count_order(unsigned int count)
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);
return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
}

/*
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