Add sign_extend64() for sign extending any (hardware-)given signed value greater than 32 bits to s64.
Suggested-by: Christoph Muellner <[email protected]> Suggested-by: Peter Zijlstra <[email protected]> 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 336f22b..2fd47c8 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -173,6 +173,17 @@ static inline __s32 sign_extend32(__u32 value, int index) return (__s32)(value << shift) >> shift; } +/** + * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit + * @value: value to sign extend + * @index: 0 based bit index (0<=index<64) to sign bit + */ +static inline __s64 sign_extend64(__u64 value, int index) +{ + __u8 shift = 63 - index; + return (__s64)(value << shift) >> shift; +} + static inline unsigned fls_long(unsigned long l) { if (sizeof(l) == 4) -- 2.1.4 -- 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/
