Re: [PATCH 10/11] x86: Remove unnecessary ifdefs from i387 code.

[Pekka Enberg]

 Hi Brian,

On 8/30/10 2:38 AM, Brian Gerst wrote:
> On Sun, Aug 29, 2010 at 3:00 PM, Pekka Enberg<penberg@xxxxxxxxxx>  wrote:
> > On Sat, Aug 28, 2010 at 7:04 PM, Brian Gerst<brgerst@xxxxxxxxx>  wrote:
> > > Remove ifdefs for code that the compiler can optimize away on 64-bit.
> > >
> > > Signed-off-by: Brian Gerst<brgerst@xxxxxxxxx>
> > > @@ -74,10 +74,8 @@ static void __cpuinit init_thread_xstate(void)
> > >
> > >         if (cpu_has_fxsr)
> > >                 xstate_size = sizeof(struct i387_fxsave_struct);
> > > -#ifdef CONFIG_X86_32
> > >         else
> > >                 xstate_size = sizeof(struct i387_fsave_struct);
> > > -#endif
> > >   }
> > I guess this is OK but keep in mind that cpu_has_fsxr is _not_
> > optimized by the compiler on 64-bit so the change probably increases
> > kernel text by few bytes.
> FXSR is a required feature on 64-bit, therefore cpu_has_fxsr is always true.
Yes, I realize that but it will still read boot_cpu_data at runtime, no?

            Pekka
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