Is -O2 supported for world?

David O'Brien obrien at freebsd.org
Tue Mar 8 06:09:13 GMT 2005


On Fri, Mar 04, 2005 at 11:30:07PM -0500, Damian Gerow wrote:
> I'm a little fuzzy on whether -O2 is supported for world or not: I seem to
> remember on x86 it is, but the only references I've seen to amd64 were
> speaking about ports.
> 
> Is -O2 optimization supported in amd64?  It most definitely doesn't work:

It is suppored w/in /usr/src.
 
>     /usr/src/lib/libc/i386/sys/_amd64_get_fsbase.c: In function `_amd64_get_fsbase':
>     /usr/src/lib/libc/i386/sys/_amd64_get_fsbase.c:40: warning: dereferencing type-punned pointer will break strict-aliasing rules
> 
> without -fno-strict-aliasing.  Not that I have any serious desire to run
> with -O2, just curious.

-O2 isn't supported in /usr/ports without -fno-strict-aliasing also.
There are a few ports that aren't happy being compiled with any form of
-O2 (such as the old perl).
 
-- 
-- David  (obrien at FreeBSD.org)


More information about the freebsd-amd64 mailing list