Re: Misaligned .bss section for PE?

["Zuxy Meng" <zuxy dot meng at gmail dot com>]

"Danny Smith" <dansmister@gmail.com> ååæææé:9c03c2dd0806022004w44abf728u1000465ae1c1c1fc@mail.gmail.com...
> On Mon, Jun 2, 2008 at 8:28 PM, Zuxy Meng <zuxy.meng@gmail.com> wrote:
> > "Danny Smith" <dansmister@gmail.com>
> > ååæææé:9c03c2dd0805291425n38aeb9b1le9b202d2feeda0b@mail.gmail.com...
> > > > > see
> > > > > http://sourceware.org/bugzilla/show_bug.cgi?id=5226, in particular the
> > > > > testcase in comment #1
> > > > >
> > > > > Note PE COFF does not support aligned common , so you may need to add
> > > > > __attribute__((no_common)) to variable.
> > > >
> > > >
> > > > Thanks Danny! I saw that the bug was committed last November and I 
> > > > wonder
> > > > if
> > > > my problematic as (labeling itself as "GNU assembler (GNU Binutils)
> > > > 2.18.50.20080109") has had the fix?
> > >
> > > It should.  Can you provide a testcase where you are getting unexpected
> > > results?
> >
> >
> > I only observe the problem when building mplayer under mingw32, which is
> > quite a big program that uses SSE a lot, so a misaligned static leads to
> > crashes. I'm still trying to figure out a minimal set.
>
> Is mplayer  a multithread app.  If so you will need to take extra care
> with thread-start functions  See gcc info on 'force_align_arg_pointer'
> and mingw-user list archive on SSE multithread isues.


Indeed they've done this for thread entries, but the problem I met has 
nothing to do with multithreading. A static array that has been marked as 
__attribute__((aligned(16))) is actually aligned on 8-byte boundary only, 
and then the program performs a "mulps" over it.
--
Zuxy