Sounds good, albeit true to my commit message, I'm strongly recommending you run both at the same time. I had ORIG_ and NEW_, with ffs calling both and comparing the result.
But perhaps more importantly this may be a good time to create a MI-header for this stuff and do a pass with other archs. We are long past a point where hand-rolled primitives make sense in the common case. On 7/16/20, Mitchell Horne <[email protected]> wrote: > On Thu, Jul 16, 2020 at 8:28 AM Mateusz Guzik <[email protected]> wrote: >> >> Author: mjg >> Date: Thu Jul 16 11:28:24 2020 >> New Revision: 363242 >> URL: https://svnweb.freebsd.org/changeset/base/363242 >> >> Log: >> amd64: patch ffsl to use the compiler builtin >> >> This shortens fdalloc by over 60 bytes. Correctness verified by running >> both >> variants at the same time and comparing the result of each call. >> >> Note someone(tm) should make a pass at converting everything else >> feasible. >> > > I have a local version of such a change. I'll see about getting it up > for review in the next little while. > > Mitchell > >> Modified: >> head/sys/amd64/include/cpufunc.h >> >> Modified: head/sys/amd64/include/cpufunc.h >> ============================================================================== >> --- head/sys/amd64/include/cpufunc.h Thu Jul 16 10:20:35 2020 >> (r363241) >> +++ head/sys/amd64/include/cpufunc.h Thu Jul 16 11:28:24 2020 >> (r363242) >> @@ -167,7 +167,8 @@ enable_intr(void) >> static __inline __pure2 int >> ffsl(long mask) >> { >> - return (mask == 0 ? mask : (int)bsfq((u_long)mask) + 1); >> + >> + return (__builtin_ffsl(mask)); >> } >> >> #define HAVE_INLINE_FFSLL > -- Mateusz Guzik <mjguzik gmail.com> _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
