GDC release 0.23

kris foo at bar.com
Wed Mar 7 23:45:14 PST 2007


Walter Bright wrote:
> Daniel Keep wrote:
> 
>>
>> Anders F Björklund wrote:
>>
>>>> ...
>>>>
>>>> Seriously, the viability of D as a numeric computing platform is at
>>>> stake here.
>>>
>>> Only on the PowerPC platform, though. Maybe on SPARC too, not sure.
>>> (it might have real 128-bit ?) But not on the DMD platform: Intel,
>>> there it will have full 80-bit support (even if not too portable).
>>>
>>> --anders
>>
>>
>> Make that x86... I read somewhere a few days ago that there IS no 80-bit
>> real type on x86-64 machines; AMD basically went "80-bit?  Who the hell
>> uses that junk?  Just use SSE you pack of anachronistic pansies!" and
>> nuked the x87 in 64-bit code (you can still use it, but ONLY in 32-bit
>> code).
> 
> 
> The 80 bit ops are available on the AMD-64 in 64 bit mode. But 
> Microsoft's original plan for 80 bit reals was to not save them during a 
> context switch, meaning you couldn't use them. I know a few people at 
> Microsoft <g>, and made a pitch that the 80 bit regs should be saved, 
> and they fixed it.


Looks like AMD adjusted their perspective and presentations at some 
point also. Page 211 of this document clarifies the current situation:
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26569.pdf

However; x87 is referred to as "legacy" support. I guess we should hope 
that native 128bit FP will be supported by the time that legacy support 
is dropped?


More information about the D.gnu mailing list