D and Heterogeneous Computing

[Dmitry Olshansky]

On 09.04.2012 6:49, Josh Klontz wrote:
> On Saturday, 7 April 2012 at 18:47:21 UTC, Robert Jacques wrote:
>> On Sat, 07 Apr 2012 11:38:15 -0500, Josh Klontz
>> <josh.klontz at gmail.com> wrote:
>>
>>> Greetings! As someone with a research interest in software
>>> abstractions for image processing, the D programming language
>>> appears to offer unsurpassed language features for constructing
>>> beautiful and efficient programs. With that said, what would
>>> really get me to abandon C++ is if D supported a heterogenous
>>> programming model.
>>>
>>> My personal inclination would be something closer to OpenACC than
>>> anything else I've seen available. Though only in the sense that
>>> I like the idea of writing code once and being able to
>>> compile/run/debug it with or without automatic
>>> vectorization/kernelization. Presumably we could achieve more
>>> elegant syntax with tighter integration into the language. Has
>>> anyone been working on anything like this? Is this something the
>>> community would be interested in seeing? What should the solution
>>> look like?
>>>
>>> One path forward could be a patch to the compiler to generate and
>>> execute OpenCL kernels for appropriately marked-up D code. While
>>> I'm new the the D language, I'd be happy to work on a proof of
>>> concept of this if it is something the community thinks would be
>>> valuable and I could get specific feedback about the right way to
>>> approach it.
>>>
>>
>> I've been using D with CUDA via a high-level wrapper around the driver
>> API. It works very nicely, but it doesn't address the language
>> integration issues. Might I recommend looking into hooking up LDC to
>> the PTX LLVM back-end. That would seem much faster than writing your
>> own back-end.
>
> Yes, I certainly don't want to be in the business of writing back-ends.
> Another idea that came to mind recently was implementing a keyword
> similar in spirit to "asm":
>
> opencl {
> // Valid opencl code here
> }
>
> And have the compiler automatically handle memory copying of D variables
> referenced in the kernel code. Would be entirely back-end independent
> and perhaps pleasant to implement?

Take a look at C++ AMP it's almost exactly this thing added to Visual 
C++ (but of course for now it's DirectCompute):
http://msdn.microsoft.com/en-us/library/hh265136(v=vs.110).aspx

-- 
Dmitry Olshansky