leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

bitops.h: improve sign_extend32()'s documentation

Browse Source 
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 <martin.kepplinger@theobroma-systems.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: George Spelvin <linux@horizon.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Martin Kepplinger 2015-11-06 16:30:58 -08:00 committed by Linus Torvalds
parent cd2c3e7f94
commit e2eb53aa96
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/bitops.h
View File

@ -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)
{