This adds sign_exten16 to sign extend any signed value shorter than 16 bits to a s16.
Signed-off-by: Martin Kepplinger <[email protected]> --- include/linux/bitops.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 3c2a539..70190f4 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -172,6 +172,17 @@ static inline __s8 sign_extend8(__u8 value, int index) } /** + * sign_extend16 - sign extend a 16-bit value using specified bit as sign-bit + * @value: value to sign extend + * @index: 0 based bit index (0<=index<16) to sign bit + */ +static inline __s16 sign_extend16(__u16 value, int index) +{ + __u8 shift = 15 - index; + return (__s16)(value << shift) >> 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 -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
