| Message ID | 20221202131658.434114-4-tomi.valkeinen+renesas@ideasonboard.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Kieran Bingham |
| Headers | show |
| Series | Support Y210 | expand |
Hi Tomi, Thank you for the patch. On Fri, Dec 02, 2022 at 03:16:57PM +0200, Tomi Valkeinen wrote: > Add simple endianness supporting write function, and, for now, only one > shortcut helper, write16le(). > > Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com> > --- > kms++util/inc/kms++util/endian.h | 46 ++++++++++++++++++++++++++++++++ > 1 file changed, 46 insertions(+) > create mode 100644 kms++util/inc/kms++util/endian.h > > diff --git a/kms++util/inc/kms++util/endian.h b/kms++util/inc/kms++util/endian.h > new file mode 100644 > index 0000000..ea09065 > --- /dev/null > +++ b/kms++util/inc/kms++util/endian.h > @@ -0,0 +1,46 @@ > +#pragma once > + > +#include <type_traits> > +#include <byteswap.h> > +#include <stdint.h> > + > +static_assert((__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) || > + (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__), > + "Unable to detect endianness"); > + > +enum class endian { > + little = __ORDER_LITTLE_ENDIAN__, > + big = __ORDER_BIG_ENDIAN__, > + native = __BYTE_ORDER__ > +}; > + > +template<typename T> > +constexpr T byteswap(T value) noexcept > +{ > + static_assert(std::is_integral<T>(), "Type is not integral"); > + static_assert(sizeof(T) == 2 || > + sizeof(T) == 4 || > + sizeof(T) == 8, > + "Illegal value size"); > + > + switch (sizeof(T)) { > + case 2: return bswap_16(value); > + case 4: return bswap_32(value); > + case 8: return bswap_64(value); > + } > +} > + > +template<endian E, typename T> > +static void write_endian(T val, T* dst) I would have swapped the parameters, common APIs have the destination first and the source second. Same below, and up to you. > +{ > + if constexpr (E != endian::native) > + val = byteswap(val); > + > + *dst = val; > +} > + > +[[maybe_unused]] > +static void write16le(uint16_t val, uint16_t* dst) I wonder if writing using write16le = write_endian<endian::little, uint16_t>; would compile. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > +{ > + write_endian<endian::little, uint16_t>(val, dst); > +}
On 03/12/2022 01:56, Laurent Pinchart wrote: > Hi Tomi, > > Thank you for the patch. > > On Fri, Dec 02, 2022 at 03:16:57PM +0200, Tomi Valkeinen wrote: >> Add simple endianness supporting write function, and, for now, only one >> shortcut helper, write16le(). >> >> Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com> >> --- >> kms++util/inc/kms++util/endian.h | 46 ++++++++++++++++++++++++++++++++ >> 1 file changed, 46 insertions(+) >> create mode 100644 kms++util/inc/kms++util/endian.h >> >> diff --git a/kms++util/inc/kms++util/endian.h b/kms++util/inc/kms++util/endian.h >> new file mode 100644 >> index 0000000..ea09065 >> --- /dev/null >> +++ b/kms++util/inc/kms++util/endian.h >> @@ -0,0 +1,46 @@ >> +#pragma once >> + >> +#include <type_traits> >> +#include <byteswap.h> >> +#include <stdint.h> >> + >> +static_assert((__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) || >> + (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__), >> + "Unable to detect endianness"); >> + >> +enum class endian { >> + little = __ORDER_LITTLE_ENDIAN__, >> + big = __ORDER_BIG_ENDIAN__, >> + native = __BYTE_ORDER__ >> +}; >> + >> +template<typename T> >> +constexpr T byteswap(T value) noexcept >> +{ >> + static_assert(std::is_integral<T>(), "Type is not integral"); >> + static_assert(sizeof(T) == 2 || >> + sizeof(T) == 4 || >> + sizeof(T) == 8, >> + "Illegal value size"); >> + >> + switch (sizeof(T)) { >> + case 2: return bswap_16(value); >> + case 4: return bswap_32(value); >> + case 8: return bswap_64(value); >> + } >> +} >> + >> +template<endian E, typename T> >> +static void write_endian(T val, T* dst) > > I would have swapped the parameters, common APIs have the destination > first and the source second. Same below, and up to you. True, I think that makes sense. >> +{ >> + if constexpr (E != endian::native) >> + val = byteswap(val); >> + >> + *dst = val; >> +} >> + >> +[[maybe_unused]] >> +static void write16le(uint16_t val, uint16_t* dst) > > I wonder if writing > > using write16le = write_endian<endian::little, uint16_t>; > > would compile. No, using needs a type. Tomi
diff --git a/kms++util/inc/kms++util/endian.h b/kms++util/inc/kms++util/endian.h new file mode 100644 index 0000000..ea09065 --- /dev/null +++ b/kms++util/inc/kms++util/endian.h @@ -0,0 +1,46 @@ +#pragma once + +#include <type_traits> +#include <byteswap.h> +#include <stdint.h> + +static_assert((__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) || + (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__), + "Unable to detect endianness"); + +enum class endian { + little = __ORDER_LITTLE_ENDIAN__, + big = __ORDER_BIG_ENDIAN__, + native = __BYTE_ORDER__ +}; + +template<typename T> +constexpr T byteswap(T value) noexcept +{ + static_assert(std::is_integral<T>(), "Type is not integral"); + static_assert(sizeof(T) == 2 || + sizeof(T) == 4 || + sizeof(T) == 8, + "Illegal value size"); + + switch (sizeof(T)) { + case 2: return bswap_16(value); + case 4: return bswap_32(value); + case 8: return bswap_64(value); + } +} + +template<endian E, typename T> +static void write_endian(T val, T* dst) +{ + if constexpr (E != endian::native) + val = byteswap(val); + + *dst = val; +} + +[[maybe_unused]] +static void write16le(uint16_t val, uint16_t* dst) +{ + write_endian<endian::little, uint16_t>(val, dst); +}
Add simple endianness supporting write function, and, for now, only one shortcut helper, write16le(). Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com> --- kms++util/inc/kms++util/endian.h | 46 ++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 kms++util/inc/kms++util/endian.h