Re: Pari 64bit on Windows

["Jason Moxham" <jason@njkfrudils.plus.com>]

----- Original Message ----- 
From: "Bill Allombert" <Bill.Allombert@math.u-bordeaux1.fr>
To: <pari-dev@list.cr.yp.to>
Sent: Thursday, July 02, 2009 1:40 PM
Subject: Re: Pari 64bit on Windows


> On Wed, Jul 01, 2009 at 11:10:16PM +0100, Jason Moxham wrote:
> > On Wednesday 01 July 2009 17:35:09 Bill Allombert wrote:
> > > On Wed, Jul 01, 2009 at 03:39:03PM +0100, Jason Moxham wrote:
> > > > Hi
> > > >
> > > > I've got Pari-svn running on Windows with/without GMP/MPIR in 64bit 
> > > > mode.
> > > > This is with MSVC , and when MinGW/MSYS goes 64bit it will work with 
> > > > that
> > > > :) The main problem with Windows64 is that it uses a LLP data model
> > > > rather than the usual LP data model , this means that long's are 32 
> > > > bit.
> > > > I'm doing this
> > >
> > > Is there no way to tell the compiler to use the LP model nevertheless ?
> > >
> >
> > I'm afraid not , Microsoft has made the bed , and we have to lie in it :)
>
> I do not have to lie in it. Sorry to insist on that point.

I should of said "I have to lie in it"

> > If there was , it presumably would only work for a statically linked exe 
> > with
> > NO external dependences (even libc)
>
> Not really: we would be restricted to libc functions that does not use 
> long
> arguments. But since we would have most of our data as 64bit, we would not 
> be
> able to use libc functions that deal with 32bit long integers anyway.
> For example consider the function labs. This function takes a long integer 
> and
> returns a long integer. If we were to apply your change to use 
> paritemplong_t,
> this function would still take a long and not a paritemplong_t (a long 
> long) so
> we would need to change labs to llabs.

Yes , I forgot to mention this , and of course printf() etc, I assuming that 
there are not many of these , and at a quick look this appears so.

>  In the LP model, we would still be
> allowed to call llabs((long long) x) so it would still be far less 
> trouble.

Yes , but we dont have that choice for Win64 , all present compilers for 
Win64 are LLP , and as far as I can make out there are no plans for a LP 
compiler.

> The LLP model make much of the traditional C library useless for 64bit 
> objects.

I agree

> Secondly, MS could provide a libc built for the LP model.

They could , but I can't see that happening anytime soon.

> Cheers,
> Bill.