A little Py Vs C++

[Paulo Pinto]

On Friday, 2 November 2012 at 10:50:56 UTC, Jens Mueller wrote:
> Don Clugston wrote:
>> On 02/11/12 10:01, Jens Mueller wrote:
>> >Jacob Carlborg wrote:
>> >>On 2012-11-01 23:51, Walter Bright wrote:
>> >>
>> >>>What about all your feature requests? I think you've made 
>> >>>more than
>> >>>anyone, by a factor of 10 at least!
>> >>>
>> >>>:-)
>> >>>
>> >>>As for Manu's request
>> >>>
>> >>>http://d.puremagic.com/issues/show_bug.cgi?id=8108
>> >>>
>> >>>I've gone over with him why he needs it, and there's no 
>> >>>other reasonable
>> >>>way. He needs it for real code in a real application.
>> >>
>> >>This is quite interesting. Manu comes in from basically 
>> >>nowhere and
>> >>fairly quickly manage to convince Walter to implement at 
>> >>least two
>> >>feature requests, this one and the SIMD support. I'm not 
>> >>saying that
>> >>they shouldn't have been implemented. Although I think 
>> >>something
>> >>like AST macros could possible solve issue 8108 and a whole 
>> >>bunch of
>> >>other features, a few already present in the language.
>> >
>> >I had the same thought when reading this. Very disappointing. 
>> >An issue
>> >with zero votes is fixed instead of more important ones. Why 
>> >do I vote
>> >anyway?
>> >Regarding SIMD I have the feeling that because it is built 
>> >into the
>> >compiler static vectors have actually failed what they 
>> >promised. I
>> >thought D proposed a portable way of vector operations such 
>> >that you
>> >write
>> >float[4] = a[] + b[]
>> >and the compiler generates SIMD code for you.
>> 
>> Not for short vectors. They are more like the builtin 
>> operations in
>> Fortran, ie designed for large vectors. More for scientific 
>> kinds of
>> applications than games. (The two applications look 
>> superficially
>> similar, but in practice they have little in common).
>
> Okay. For me they look the same. Can you elaborate, please? 
> Assume I
> want to add two float vectors which is common in both games and
> scientific computing. The only difference is in games their 
> length is
> usually 3 or 4 whereas in scientific computing they are of 
> arbitrary
> length. Why do I need instrinsics to support the game setting?
>
> Jens

The auto vectorization code in Visual Studio 2012 seems to work 
pretty well.