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Comment by geezerjay | Hacker News Reader

> and the community wanted to use something else other than C to program their GPGPUs.

This assertion makes no sense. The whole reason why these APIs are specified based on C is that once a C API is available its trivial to develop bindings in any conceivable language. You can't do that if you opt for a flavor of the month.

Furthermore, GPGPU applications are performance-driven, and C is unbeatable in this domain. Thus by providing a standard API in C and by enabling standard implementations to be implemented in C you avoid forcing end-users to pay a performance tax just because someone had an irrational fear of C.

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Furthermore, GPGPU applications are performance-driven, and C is unbeatable in this domain.

One of the reasons CUDA beat OpenCL was that enough people preferred C++ or Fortran to C and CUDA was happy to accommodate them while OpenCL wasn't.

> One of the reasons CUDA beat OpenCL was that enough people preferred C++ or Fortran to C and CUDA was happy to accommodate them while OpenCL wasn't.

Nonsense. We're talking about an API. C provides a bare-bones interface that doesn't impose any performance penalty, but just because the API is C nothing forces anyone to implement core functionality in the best tool they can find.

That's like complaining that an air conditioner doesn't cool the room as well as others just because it uses a type F electrical socket instead of a type C plug.

Proper APIs can be defined via IDLs, C is not needed at all.

> We're talking about an API

I don't think we are. We are talking about languages.

In CUDA, compute kernels are written in a language called "CUDA C++." In OpenCL 1.2, compute kernels are written in a language called "OpenCL C." Somebody else probably could have (likely did) implement a compiler for their own version of C++ for OpenCL kernels, but the point 'pjmlp was making is that the standard platform did not enable C++ to be used for kernels until long after it was available in CUDA.

Tell that to Khronos that is now forced to support HLSL so that most studios bother to port their shaders.

NVidia that created a C++ binding to use Vulkan instead of plain C or AMD that had to create higher level bindings for the CAD industry to even bother to look into Vulkan.

This blind advocacy for straight C APIs will turn Vulkan into another OpenCL.

Yeah, except in actual high-performance computing, almost nobody uses C. It's all C++ and Fortran.

> Furthermore, GPGPU applications are performance-driven, and C is unbeatable in this domain.

CUDA is clearly performance driven, and is a more mature C++ model.

Template functions are a type-safe way to build different (but similar) compute kernels. Its far easier to use C++ Templates Constexpr and whatever to generate constant-code than to use C-based macros.

In practice, CUDA C++ beats OpenCL C in performance. There's a reason why it is so popular, despite being proprietary and locked down to one company.

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