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#include <stdint.h>
#if (defined(__i386__))
# define ARCH_HAS_SWAP32
uint32_t bitfn_swap32(uint32_t a)
{
asm ("bswap %0" : "=r" (a) : "0" (a));
return a;
}
/**********************************************************/
# elif (defined(__arm__))
# define ARCH_HAS_SWAP32
uint32_t bitfn_swap32(uint32_t a)
{
uint32_t tmp = a;
asm volatile ("eor %1, %0, %0, ror #16\n"
"bic %1, %1, #0xff0000\n"
"mov %0, %0, ror #8\n"
"eor %0, %0, %1, lsr #8\n"
: "=r" (a), "=r" (tmp) : "0" (a), "1" (tmp));
return a;
}
/**********************************************************/
# elif defined(__x86_64__)
# define ARCH_HAS_SWAP32
# define ARCH_HAS_SWAP64
uint32_t bitfn_swap32(uint32_t a)
{
asm ("bswap %0" : "=r" (a) : "0" (a));
return a;
}
uint64_t bitfn_swap64(uint64_t a)
{
asm ("bswap %0" : "=r" (a) : "0" (a));
return a;
}
# endif
#ifndef ARCH_HAS_SWAP32
uint32_t bitfn_swap32(uint32_t a)
{
return (a << 24) | ((a & 0xff00) << 8) | ((a >> 8) & 0xff00) | (a >> 24);
}
#endif
#ifndef ARCH_HAS_SWAP64
uint64_t bitfn_swap64(uint64_t a)
{
return ((uint64_t) bitfn_swap32((uint32_t) (a >> 32))) |
(((uint64_t) bitfn_swap32((uint32_t) a)) << 32);
}
#endif
uint16_t bitfn_swap16(uint16_t a)
{
return (a << 8) | (a >> 8);
}
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