Re: [MinGW-dvlpr] Re: _alloca/_chkstk??

[Luke D. <cod...@ho...>]

----- Original Message ----- 
From: "Ranjit Mathew" <rm...@ho...>
To: "MinGW Developers" <min...@li...>
Sent: Wednesday, October 08, 2003 6:20 PM
Subject: [MinGW-dvlpr] Re: _alloca/_chkstk??


> Luke Dunstan wrote:
> >
> > Then perhaps "-funit-at-a-time" on MinGW should imply
> > "-mno-stack-arg-probe".

On second thought, the stack probe would only need to be omitted in
functions that actually use EAX for arguments, which means only functions
local to a single unit. I agree that this wouldn't be the easiest solution
though.

> This could cause problems when you
> call 4k+ local args containing functions
> compiled by MSVC, couldn't it? In that
> case, the _chkstk of the MSVC generated
> code would be expecting the required
> size on the stack in EAX.

I really don't know what you mean. Disabling stack probes with
"-mno-stack-arg-probe" only affects code generated by GCC, so how could it
affect calling a function that was compiled using MSVC? It does not alter
any calling conventions.

>
> A simpler solution would be to limit
> the registers used by -funit-at-a-time
> to the stock ECX & EDX.

Yes, that would be easier but in theory it would be more efficient if EAX
could be used for arguments where possible. Either way I'm not going to
complain.

Luke