diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/lib/bitops.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/i386/lib/bitops.c')
-rw-r--r-- | arch/i386/lib/bitops.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/arch/i386/lib/bitops.c b/arch/i386/lib/bitops.c new file mode 100644 index 00000000000..97db3853dc8 --- /dev/null +++ b/arch/i386/lib/bitops.c @@ -0,0 +1,70 @@ +#include <linux/bitops.h> +#include <linux/module.h> + +/** + * find_next_bit - find the first set bit in a memory region + * @addr: The address to base the search on + * @offset: The bitnumber to start searching at + * @size: The maximum size to search + */ +int find_next_bit(const unsigned long *addr, int size, int offset) +{ + const unsigned long *p = addr + (offset >> 5); + int set = 0, bit = offset & 31, res; + + if (bit) { + /* + * Look for nonzero in the first 32 bits: + */ + __asm__("bsfl %1,%0\n\t" + "jne 1f\n\t" + "movl $32, %0\n" + "1:" + : "=r" (set) + : "r" (*p >> bit)); + if (set < (32 - bit)) + return set + offset; + set = 32 - bit; + p++; + } + /* + * No set bit yet, search remaining full words for a bit + */ + res = find_first_bit (p, size - 32 * (p - addr)); + return (offset + set + res); +} +EXPORT_SYMBOL(find_next_bit); + +/** + * find_next_zero_bit - find the first zero bit in a memory region + * @addr: The address to base the search on + * @offset: The bitnumber to start searching at + * @size: The maximum size to search + */ +int find_next_zero_bit(const unsigned long *addr, int size, int offset) +{ + unsigned long * p = ((unsigned long *) addr) + (offset >> 5); + int set = 0, bit = offset & 31, res; + + if (bit) { + /* + * Look for zero in the first 32 bits. + */ + __asm__("bsfl %1,%0\n\t" + "jne 1f\n\t" + "movl $32, %0\n" + "1:" + : "=r" (set) + : "r" (~(*p >> bit))); + if (set < (32 - bit)) + return set + offset; + set = 32 - bit; + p++; + } + /* + * No zero yet, search remaining full bytes for a zero + */ + res = find_first_zero_bit (p, size - 32 * (p - (unsigned long *) addr)); + return (offset + set + res); +} +EXPORT_SYMBOL(find_next_zero_bit); |