Is -O2 supported for world?

[Kris Kennaway]

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:
> 
>     /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 produces broken code on amd64 anyway, and a number of ports will
fail to build or run when world is compiled with -O2, with or without
-fno-strict-aliasing.

Kris