Comment by kaba0
3 years ago
Just because certain shading languages put on a C-like syntax doesn’t make them anywhere close to C. They have entirely different semantics. So no, C is just terrible when it comes to SIMD, but also when it comes to multi-threading, two areas that are the most important inprovements of modern hardware.
Some are less different than others, for instance:
"The Metal programming language is a C++14-based Specification with extensions and restrictions. Refer to the C++14 Specification (also known as the ISO/IEC JTC1/SC22/WG21 N4431 Language Specification) for a detailed description of the language grammar."
(from: https://developer.apple.com/metal/Metal-Shading-Language-Spe...)
Meaning essentially that MSL is C++14 with a couple of restrictions (mostly concerning pointers), a couple of SIMD data types, and some custom attributes.
...the C++14 could just as well be replaced with some C standard, if the Metal designers wouldn't like C++ so much for mysterious reasons (and that arguably would have been the better choice - because for shader programming C++ really doesn't add that much useful stuff over C).
C++ is very different from C, one language is actually usably expressive the other can’t even express a generic vector data structure without runtime overhead or copy-pasting.
Not going to argue, but if you really want generics in C the usual solution is code generation. Also, it might be surprising to a C++ coder, but there's a lot of problems that can be solved perfectly fine without generics ;)