Re: [RFC] [PATCH] 32-bit pointers in x86-64

2007-12-05 Thread Andrew Pinski
On 12/5/07, Jan Beulich <[EMAIL PROTECTED]> wrote: > >>> "Andrew Pinski" <[EMAIL PROTECTED]> 25.11.07 19:45 >>> > >On 11/25/07, Luca <[EMAIL PROTECTED]> wrote: > >> 7.1. Add __attribute__((pointer_size(XXX))) and #pragma pointer_size > >> to allow 64-bit pointers in 32-bit mode and viceversa > > >

Re: [RFC] [PATCH] 32-bit pointers in x86-64

2007-12-05 Thread Jan Beulich
>>> "Andrew Pinski" <[EMAIL PROTECTED]> 25.11.07 19:45 >>> >On 11/25/07, Luca <[EMAIL PROTECTED]> wrote: >> 7.1. Add __attribute__((pointer_size(XXX))) and #pragma pointer_size >> to allow 64-bit pointers in 32-bit mode and viceversa > >This is already there, try using __attribute__((mode(DI) )).

Re: [RFC] [PATCH] 32-bit pointers in x86-64

2007-11-26 Thread Jan Beulich
>>You can't use conventional 32-bit x86 code, so there seems little or no >>benefit in allowing 32 and 64-bit code to be mixed. > >Why not? Switching between 32- and 64-bit modes doesn't involve anything >(apart from knowing the proper selector register values) that cannot be done >purely in user

Re: [RFC] [PATCH] 32-bit pointers in x86-64

2007-11-26 Thread Jan Beulich
>You can't use conventional 32-bit x86 code, so there seems little or no >benefit in allowing 32 and 64-bit code to be mixed. Why not? Switching between 32- and 64-bit modes doesn't involve anything (apart from knowing the proper selector register values) that cannot be done purely in user mode.

Re: [RFC] [PATCH] 32-bit pointers in x86-64

2007-11-25 Thread Andrew Pinski
On 11/25/07, Luca <[EMAIL PROTECTED]> wrote: > 7.1. Add __attribute__((pointer_size(XXX))) and #pragma pointer_size > to allow 64-bit pointers in 32-bit mode and viceversa This is already there, try using __attribute__((mode(DI) )). -- Pinski

Re: [RFC] [PATCH] 32-bit pointers in x86-64

2007-11-25 Thread Paul Brook
> 7. Add support for loading x86-32 and x86-64 objects in the same > address space, using a single modified 64-bit libc. I'm not convinvinced this is practical, or even possible. I'd expect the restrictions imposed on code to make it work properly to be too onerous for it to be of any real use.