Code: Select all
static inline void * memcpy(void * to, const void * from, size_t n)
{
int d0, d1, d2;
__asm__ __volatile__(
"rep ; movsl\n\t"
"testb $2,%b4\n\t"
"je 1f\n\t"
"movsw\n"
"1:\ttestb $1,%b4\n\t"
"je 2f\n\t"
"movsb\n"
"2:"
: "=&c" (d0), "=&D" (d1), "=&S" (d2)
:"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from)
: "memory");
return (to);
}
Have you read anything at all of this thread? These optimizations are BAD. As in the big ol', Bad Thing™, you know?viki wrote:Hi,
From ManRix OS I've found someting interesting:Code: Select all
static inline void * memcpy(void * to, const void * from, size_t n) { int d0, d1, d2; __asm__ __volatile__( "rep ; movsl\n\t" "testb $2,%b4\n\t" "je 1f\n\t" "movsw\n" "1:\ttestb $1,%b4\n\t" "je 2f\n\t" "movsb\n" "2:" : "=&c" (d0), "=&D" (d1), "=&S" (d2) :"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from) : "memory"); return (to); }