adtools/clib2

#if defined(__PPC__) && defined(__GNUC__)

asm("    .text\n\
    .align 2\n\
    .globl bswap32\n\
    .type    bswap32, @function\n\
bswap32:\n\
    rlwinm    %r4,%r3,8,8,31\n\
    rlwimi    %r4,%r3,24,0,7\n\
    rlwimi    %r4,%r3,24,16,23\n\
    or            %r3,%r4,%r4\n\
    blr\n\
");

#else

#include <stdint.h>

uint32_t bswap32(uint32_t u32)
{
    return(
        ((u32&0xff)<<24)|
        ((u32&0xff00)<<8)|
        ((u32&0xff0000)>>8)|
        ((u32&0xff000000)>>24)
    );
}

#endif