diff options
| author | Martin Kepplinger <[email protected]> | 2015-11-06 16:30:58 -0800 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2015-11-06 17:50:42 -0800 |
| commit | e2eb53aa96754b97d158eff884dde88abbad925e (patch) | |
| tree | 0159c242d120da9cd02dc3d59a8b7787da811fb8 | |
| parent | cd2c3e7f94f3d8210320bfb9b5712bdcbb12f8db (diff) | |
bitops.h: improve sign_extend32()'s documentation
It is often overlooked that sign_extend32(), despite its name, is safe to
use for 16 and 8 bit types as well. This should help prevent sign
extension being done manually some other way.
Signed-off-by: Martin Kepplinger <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: George Spelvin <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Maxime Coquelin <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Yury Norov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | include/linux/bitops.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index e63553386ae7..5629923a8701 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -164,6 +164,8 @@ static inline __u8 ror8(__u8 word, unsigned int shift) * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit * @value: value to sign extend * @index: 0 based bit index (0<=index<32) to sign bit + * + * This is safe to use for 16- and 8-bit types as well. */ static inline __s32 sign_extend32(__u32 value, int index) { |