Re: [Lightning] sse instructions and gcc warnings

[Paolo Bonzini]

On 07/26/2010 09:49 AM, Paulo César Pereira de Andrade wrote:
>    This started happening when I added calls to jit_str_c, jit_str_uc,
> etc, and apparently doesn't happen if there are only calls to
> jit_stxi_s, jit_stxi_us, etc, but I am not 100% sure now.

Yes, jit_str_c and jit_str_uc are indeed responsible.

> > >     Also about @subject, I needed to add a global function to check
> > > if a double is zero, because apparently the i387 goes nonsense if
> > > a function using vector instructions was called.
> >
> > Argument passing in i387 was buggy, it is kind of impossible to get it
> > right due to the stack-like registers. :(
> >
> > I think I'm going to change it to use SSE always except for argument
> > passing.  Would this be a problem?
>
>    I think x86 non sse processors are not manufactured for several
> years, but probably better to require SSE2 or lower

Yes, of couse.

> As long as it
> works, I don't have any objections :-) One thing I noticed is that
> on x86_64, -0.0 literal looses sign when loaded/stored using
> lightning,

Thanks.

Paolo