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#include <apos/types.h>
#include <apos/attrs.h>
/* Functions for swapping endianness.
*
* Typically you wouldn't call these directly, instead using macros such as
* le16_to_cpu, cpu_to_be32, etc. that take the system endianness into account.
*
* The macros cpu_to_be64 etc. use GCC's and Clang's __builtin_bswap16/32/64, but in
* the case that the arch compiler doesn't provide the __builtin functions they're replaced
* with __bswaphi2/si2/di2 respectively, and it is up to the developer to
* provide these. The naming scheme uses GCC's internal naming scheme, where
*
* HI ~= 16 bits
* SI ~= 32 bits
* DI ~= 64 bits
*
* Here we assume this to be true in all cases, and it probably is, but in the
* case that some architecture is different (SI ~= 64 bits or something) we define
* these functions as __weak, allowing any arch to redefine them.
*/
__weak uint16_t __bswaphi2(uint16_t u)
{
return (u & 0xff00) >> 8 | (u & 0x00ff) << 8;
}
__weak uint32_t __bswapsi2(uint32_t u)
{
return (u & 0xff000000) >> 24 |
(u & 0x00ff0000) >> 8 |
(u & 0x0000ff00) << 8 |
(u & 0x000000ff) << 24;
}
__weak uint64_t __bswapdi2(uint64_t u)
{
return (u & 0xff00000000000000ULL) >> 56 |
(u & 0x00ff000000000000ULL) >> 40 |
(u & 0x0000ff0000000000ULL) >> 24 |
(u & 0x000000ff00000000ULL) >> 8 |
(u & 0x00000000ff000000ULL) << 8 |
(u & 0x0000000000ff0000ULL) << 24 |
(u & 0x000000000000ff00ULL) << 40 |
(u & 0x00000000000000ffULL) << 56;
}
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