https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81664
Bug ID: 81664
Summary: __attribute__((target("movbe"))) does not work
Product: gcc
Version: 5.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: bugzi...@poradnik-webmastera.com
Target Milestone: ---
I found this when I tried to benchmark performance of ntohl with and without
movbe. Looka that target attribute with values "movbe" and "no-movbe" are not
supported. Tested on gcc 4.8.5 (RedHat 7) and 5.4.0 (Cygwin).
#include <arpa/inet.h>
__attribute__((target("movbe")))
long ntohl_movbe(long val)
{
return ntohl(val);
}
__attribute__((target("no-movbe")))
long ntohl_no_movbe(long val)
{
return ntohl(val);
}
$ gcc -c -o ntoh-perf.o ntoh-perf.cc -O2 -mmovbe
ntoh-perf.cc:4:26: error: attribute(target("movbe")) is unknown
long ntohl_movbe(long val)
^
ntoh-perf.cc:10:29: error: attribute(target("no-movbe")) is unknown
long ntohl_no_movbe(long val)
^
