| Message ID | 7108de698ffdeaa3c61a23997bc0877120bf114e.1496434383.git.stillcompiling@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jun 2, 2017 at 3:30 PM, Joshua Clayton <stillcompiling@gmail.com> wrote: > Add a function to reverse bytes within a 32 bit word. > Operate on a u32 rather than individual bytes. > > Signed-off-by: Joshua Clayton <stillcompiling@gmail.com> Signed-off-by: Alan Tull <atull@kernel.org> > --- > include/linux/bitrev.h | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/include/linux/bitrev.h b/include/linux/bitrev.h > index fb790b8449c1..b97be27e5a85 100644 > --- a/include/linux/bitrev.h > +++ b/include/linux/bitrev.h > @@ -29,6 +29,8 @@ static inline u32 __bitrev32(u32 x) > > #endif /* CONFIG_HAVE_ARCH_BITREVERSE */ > > +#define __bitrev8x4(x) (__bitrev32(swab32(x))) > + > #define __constant_bitrev32(x) \ > ({ \ > u32 __x = x; \ > @@ -50,6 +52,15 @@ static inline u32 __bitrev32(u32 x) > __x; \ > }) > > +#define __constant_bitrev8x4(x) \ > +({ \ > + u32 __x = x; \ > + __x = ((__x & (u32)0xF0F0F0F0UL) >> 4) | ((__x & (u32)0x0F0F0F0FUL) << 4); \ > + __x = ((__x & (u32)0xCCCCCCCCUL) >> 2) | ((__x & (u32)0x33333333UL) << 2); \ > + __x = ((__x & (u32)0xAAAAAAAAUL) >> 1) | ((__x & (u32)0x55555555UL) << 1); \ > + __x; \ > +}) > + > #define __constant_bitrev8(x) \ > ({ \ > u8 __x = x; \ > @@ -75,6 +86,14 @@ static inline u32 __bitrev32(u32 x) > __bitrev16(__x); \ > }) > > +#define bitrev8x4(x) \ > +({ \ > + u32 __x = x; \ > + __builtin_constant_p(__x) ? \ > + __constant_bitrev8x4(__x) : \ > + __bitrev8x4(__x); \ > + }) > + > #define bitrev8(x) \ > ({ \ > u8 __x = x; \ > -- > 2.11.0 >
diff --git a/include/linux/bitrev.h b/include/linux/bitrev.h index fb790b8449c1..b97be27e5a85 100644 --- a/include/linux/bitrev.h +++ b/include/linux/bitrev.h @@ -29,6 +29,8 @@ static inline u32 __bitrev32(u32 x) #endif /* CONFIG_HAVE_ARCH_BITREVERSE */ +#define __bitrev8x4(x) (__bitrev32(swab32(x))) + #define __constant_bitrev32(x) \ ({ \ u32 __x = x; \ @@ -50,6 +52,15 @@ static inline u32 __bitrev32(u32 x) __x; \ }) +#define __constant_bitrev8x4(x) \ +({ \ + u32 __x = x; \ + __x = ((__x & (u32)0xF0F0F0F0UL) >> 4) | ((__x & (u32)0x0F0F0F0FUL) << 4); \ + __x = ((__x & (u32)0xCCCCCCCCUL) >> 2) | ((__x & (u32)0x33333333UL) << 2); \ + __x = ((__x & (u32)0xAAAAAAAAUL) >> 1) | ((__x & (u32)0x55555555UL) << 1); \ + __x; \ +}) + #define __constant_bitrev8(x) \ ({ \ u8 __x = x; \ @@ -75,6 +86,14 @@ static inline u32 __bitrev32(u32 x) __bitrev16(__x); \ }) +#define bitrev8x4(x) \ +({ \ + u32 __x = x; \ + __builtin_constant_p(__x) ? \ + __constant_bitrev8x4(__x) : \ + __bitrev8x4(__x); \ + }) + #define bitrev8(x) \ ({ \ u8 __x = x; \
Add a function to reverse bytes within a 32 bit word. Operate on a u32 rather than individual bytes. Signed-off-by: Joshua Clayton <stillcompiling@gmail.com> --- include/linux/bitrev.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)