half and quad

[Don Clugston]

Bill Baxter wrote:
> Anders F Björklund wrote:
>> Olifant wrote:
>>
>>> The keyword "cent" is reserved for 128-bit integers. Could "half" and 
>>> "quad" be reserved for respectively 16-bit and 128-bit floating point 
>>> numbers?
>>
>> I don't think there is any hope for quad or cent, until they're
>> implemented on standard processors... (i.e ones that run Windows)
>>
>> But I do have a port of "half" (from OpenEXR) kicking around here
>> somewhere, it's basically using ushort and converts over to float.
>>
>> See http://www.digitalmars.com/d/archives/digitalmars/D/31899.html
> 
> I wonder if 'half' is really worth it though.  It seems like more of a 
> temporary stop-gap measure to deal with memory and throughput problems 
> on a GPU.  In 5 years maybe people will look at 'half' and laugh about 
> how primitive the architectures were back in the 00's.  Also since D 
> isn't going to run on a GPU any time soon, and CPUs aren't going to 
> implement 'half' any time soon (AFAIK)

Actually 'half' is in AMD's recently announced SSE5. Admittedly the only 
instructions it seems to support are conversions from 'half' to 'float'.
I agree that it probably won't have much future, though.

> 'quad' on the other hand, seems at least as likely to have a future as 
> 'cent' does, so seems reasonable to reserve it to me.
> 
> --bb