std.math performance (SSE vs. real)

[deadalnix via Digitalmars-d]

On Saturday, 28 June 2014 at 09:07:17 UTC, John Colvin wrote:
> On Saturday, 28 June 2014 at 06:16:51 UTC, Walter Bright wrote:
>> On 6/27/2014 10:18 PM, Walter Bright wrote:
>>> On 6/27/2014 4:10 AM, John Colvin wrote:
>>>> *The number of algorithms that are both numerically 
>>>> stable/correct and benefit
>>>> significantly from > 64bit doubles is very small.
>>>
>>> To be blunt, baloney. I ran into these problems ALL THE TIME 
>>> when doing
>>> professional numerical work.
>>>
>>
>> Sorry for being so abrupt. FP is important to me - it's not 
>> just about performance, it's also about accuracy.
>
> I still maintain that the need for the precision of 80bit reals 
> is a niche demand. Its a very important niche, but it doesn't 
> justify having its relatively extreme requirements be the 
> default. Someone writing a matrix inversion has only themselves 
> to blame if they don't know plenty of numerical analysis and 
> look very carefully at the specifications of all operations 
> they are using.
>
> Paying the cost of moving to/from the fpu, missing out on 
> increasingly large SIMD units, these make everyone pay the 
> price.
>
> inclusion of the 'real' type in D was a great idea, but 
> std.math should be overloaded for float/double/real so people 
> have the choice where they stand on the performance/precision 
> front.

Would thar make sense to have std.mast and std.fastmath, or 
something along these lines ?