| Message ID | 20250301142409.2513835-4-visitorckw@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce and use generic parity16/32/64 helper | expand |
On Sat, Mar 01, 2025 at 10:23:54PM +0800, Kuan-Wei Chiu wrote: > Introduce parity16(), parity32(), and parity64() functions for > computing parity on 16-bit, 32-bit, and 64-bit integers, respectively. > These functions use __builtin_parity() or __builtin_parityll() when > available, ensuring efficient computation. If the input is a > compile-time constant, they expand using the _parity_const() macro to > allow constant folding. > > These additions provide parity computation helpers for larger integer > types, ensuring consistency and performance across different > bit-widths. > > Co-developed-by: Yu-Chun Lin <eleanor15x@gmail.com> > Signed-off-by: Yu-Chun Lin <eleanor15x@gmail.com> > Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com> > --- > include/linux/bitops.h | 63 ++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 63 insertions(+) > > diff --git a/include/linux/bitops.h b/include/linux/bitops.h > index 4c307d9c1545..41e9e7fb894b 100644 > --- a/include/linux/bitops.h > +++ b/include/linux/bitops.h > @@ -276,6 +276,69 @@ static inline __attribute_const__ int parity8(u8 val) > return __builtin_constant_p(val) ? _parity_const(val) : _parity8(val); > } > > +#ifndef _parity16 > +static inline __attribute_const__ int _parity16(u16 val) > +{ > + return __builtin_parity(val); > +} > +#endif > + > +/** > + * parity16 - get the parity of an u16 value > + * @value: the value to be examined nit: This really ought to be @val to match the function signature. Likewise for parity8, parity32, and parity64. > + * > + * Determine the parity of the u16 argument. > + * > + * Returns: > + * 0 for even parity, 1 for odd parity > + */ > +static inline __attribute_const__ int parity16(u16 val) > +{ > + return __builtin_constant_p(val) ? _parity_const(val) : _parity16(val); > +} ...
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 4c307d9c1545..41e9e7fb894b 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -276,6 +276,69 @@ static inline __attribute_const__ int parity8(u8 val) return __builtin_constant_p(val) ? _parity_const(val) : _parity8(val); } +#ifndef _parity16 +static inline __attribute_const__ int _parity16(u16 val) +{ + return __builtin_parity(val); +} +#endif + +/** + * parity16 - get the parity of an u16 value + * @value: the value to be examined + * + * Determine the parity of the u16 argument. + * + * Returns: + * 0 for even parity, 1 for odd parity + */ +static inline __attribute_const__ int parity16(u16 val) +{ + return __builtin_constant_p(val) ? _parity_const(val) : _parity16(val); +} + +#ifndef _parity32 +static inline __attribute_const__ int _parity32(u32 val) +{ + return __builtin_parity(val); +} +#endif + +/** + * parity32 - get the parity of an u32 value + * @value: the value to be examined + * + * Determine the parity of the u32 argument. + * + * Returns: + * 0 for even parity, 1 for odd parity + */ +static inline __attribute_const__ int parity32(u32 val) +{ + return __builtin_constant_p(val) ? _parity_const(val) : _parity32(val); +} + +#ifndef _parity64 +static inline __attribute_const__ int _parity64(u64 val) +{ + return __builtin_parityll(val); +} +#endif + +/** + * parity64 - get the parity of an u64 value + * @value: the value to be examined + * + * Determine the parity of the u64 argument. + * + * Returns: + * 0 for even parity, 1 for odd parity + */ +static inline __attribute_const__ int parity64(u64 val) +{ + return __builtin_constant_p(val) ? _parity_const(val) : _parity64(val); +} + /** * __ffs64 - find first set bit in a 64 bit word * @word: The 64 bit word