Commit 10d8131a authored by Miles Bader's avatar Miles Bader Committed by Linus Torvalds

[PATCH] v850: add find_next_bit

[Since many archs use the same implementation of find_next_bit, it might
be nice to have `generic_find_next_bit' or something.]
Signed-off-by: default avatarMiles Bader <miles@gnu.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent ecd8b3c6
No related merge requests found
......@@ -193,10 +193,86 @@ extern __inline__ int find_next_zero_bit (void *addr, int size, int offset)
return result + ffz (tmp);
}
/* This is the same as generic_ffs, but we can't use that because it's
inline and the #include order mucks things up. */
static inline int generic_ffs_for_find_next_bit(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;
}
/*
* Find next one bit in a bitmap reasonably efficiently.
*/
static __inline__ unsigned long find_next_bit(const unsigned long *addr,
unsigned long size, unsigned long offset)
{
unsigned int *p = ((unsigned int *) addr) + (offset >> 5);
unsigned int result = offset & ~31UL;
unsigned int tmp;
if (offset >= size)
return size;
size -= result;
offset &= 31UL;
if (offset) {
tmp = *p++;
tmp &= ~0UL << offset;
if (size < 32)
goto found_first;
if (tmp)
goto found_middle;
size -= 32;
result += 32;
}
while (size >= 32) {
if ((tmp = *p++) != 0)
goto found_middle;
result += 32;
size -= 32;
}
if (!size)
return result;
tmp = *p;
found_first:
tmp &= ~0UL >> (32 - size);
if (tmp == 0UL) /* Are any bits set? */
return result + size; /* Nope. */
found_middle:
return result + generic_ffs_for_find_next_bit(tmp);
}
#define ffs(x) generic_ffs (x)
#define fls(x) generic_fls (x)
#define __ffs(x) ffs(x)
/*
* This is just `generic_ffs' from <linux/bitops.h>, except that it assumes
* that at least one bit is set, and returns the real index of the bit
......
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