Re: [Xen-devel] [PATCH v4 06/19] x86/boot/reloc: create generic alloc and copy functions

[Daniel Kiper <daniel.kiper@xxxxxxxxxx>]

On Thu, Aug 11, 2016 at 08:17:58AM -0600, Jan Beulich wrote:
> >>> On 11.08.16 at 16:12, <JBeulich@xxxxxxxx> wrote:
> >>>> On 06.08.16 at 01:04, <daniel.kiper@xxxxxxxxxx> wrote:
> >> --- a/xen/arch/x86/boot/reloc.c
> >> +++ b/xen/arch/x86/boot/reloc.c
> >> @@ -32,60 +32,69 @@ typedef unsigned int u32;
> >>
> >>  static u32 alloc;
> >>
> >> -static void *reloc_mbi_struct(void *old, unsigned int bytes)
> >> +static u32 alloc_mem(u32 bytes)
> >
> > Conversion of alloc to be of pointer type (in the earlier patch), and
> > then making the return type here and ...
> >
> >> +static u32 copy_mem(u32 src, u32 bytes)
> >
> > ... all of the types here follow suit would apparently be quite
> > beneficial to the number of casts needed.
>
> Or maybe, considering patch 8, in a slight variation thereof: Do
> the conversion as suggested, but have a helper wrapper of the
> type above, taking care of all the casting. That way both the
> actual implementation and the callers can stay (mostly) cast free.

We should take into account patch 9 here too. Looking at code after
it I think that right now it is very well optimized in terms of casts.
I cannot see room for further improvement. Every change you proposed
here and there does not improve final code. It justs move/change casts
to/in different places. So, I think that it does not pay change casts
here and in earlier patches. At least in the way you proposed until now.

Daniel

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