------- Comment #1 from rguenth at gcc dot gnu dot org 2009-03-09 15:36 -------
You need to specify that the registers are clobbered by the asm. The only
way to do that is to use output constraints ("+D", "+c", etc.) on proper
temporaries.
int lent = len;
char *dstt = dst;
char *srct = src;
__asm__ __volatile__(
"cld\n\t"
"rep movsb"
: "+c" (lent), "+D"(dstt), "+S"(src)
);
Otherwise GCC thinks the registers still hold the original value.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39403
