Re: [PATCH 7/7] Cygwin: remove miscellaneous 32-bit code

[Yaakov Selkowitz <yselkowitz@cygwin.com>]

On Thu, 2022-06-09 at 17:23 +0200, Corinna Vinschen wrote:
> On May 29 17:26, Ken Brown wrote:
> > On 5/29/2022 9:39 AM, Jon Turney wrote:
> > > On 26/05/2022 20:17, Ken Brown wrote:
> > > >   winsup/cygwin/autoload.cc                | 136 ---------------------
> > > > --
> > > 
> > > Looks good.
> > > 
> > > I think that perhaps the stdcall decoration number n is unused on
> > > x86_64, so can be removed also in a followup?
> > 
> > Thanks, I missed that.
> > 
> > Also, I guess most or all of the uses of __stdcall and __cdecl can be
> > removed from the code.
> 
> Yes, that's right, given there's only one calling convention on 64 bit.
> 
> I have a minor objection in terms of this patch.
> 
> When implementing support for AMD64, there were basically 2 problems to
> solve. One of them was to support 64 bit systems, the other one was to
> support AMD64.  At that time, only IA-64 and AMD64 64 bit systems
> existed, and since we never considered IA-64 to run Cygwin on, we
> subsumed all 64 bit code paths under the __x86_64__ macro.
> 
> But should we *ever* support ARM64, as unlikely as it is, we have to
> make sure to find all the places where the code is specificially AMD64.
> That goes, for instance, for all places calling assembler code, or
> for exception handling accessing CPU registers, etc.
> 
> I'm open to discussion, but I think the code being CPU-specific
> should still be enclosed into #ifdef __x86_64__ brackets, with an
> #else #error alternative.
> 
> Right?  Wrong?  Useless complication?

Highly recommended.

-- 
Yaakov