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

[Takashi Yano <takashi.yano@nifty.ne.jp>]

On Thu, 9 Jun 2022 15:04:29 -0400
Ken Brown wrote:
> On 6/9/2022 12:00 PM, Yaakov Selkowitz wrote:
> > 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.
> 
> OK, I'll make that change.

Isn't the _dll_crt0() code in dcrt0.cc also x86_64 specific?

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>