std.math performance (SSE vs. real)

[Walter Bright via Digitalmars-d]

On 7/4/2014 5:06 AM, Daniel Murphy wrote:
> "Walter Bright"  wrote in message news:lp26l3$qlk$1 at digitalmars.com...
>
>> Per the D spec, 'real' will be the longest type supported by the native hardware.
>
> So if you were targeting a processor with only soft-float real would be
> undefined?  Fixing the widths of the integers was a great idea, and we really
> should have done the same with the floating point types.  We could easily have a
> library alias for what real currently means.

Again, I expect the implementor for Platform X to be able to make a solid 
judgement on what to do for that platform that makes the most sense.


>> Not only that, a marquee feature of D is interoperability with C. We'd need an
>> AWFULLY good reason to throw that under the bus.
> Unfortunately it's a useless definition for portable interop with C++.  real
> needs to always match the size and mangling of long double unless you want to
> stick workarounds all over the bindings.  We have related problems with
> char/char/char and long/longlong/size_t,

Such problems disappear when common sense is applied.


> but luckily relatively few interfaces actually use long double.

I really do not understand what the big problem is. It's trivial to interface 
with C code on Linux that accepts long doubles on all platforms D currently 
supports.