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Comment by RobotToaster

21 hours ago

Mostly DSPs

Is there a single esoteric DSP in active use that supports C++20? This is the umpteenth time I've seen DSP's brought up in casual conversations about C/C++ standards, so I did a little digging:

Texas Instruments' compiler seems to be celebrating C++14 support: https://www.ti.com/tool/C6000-CGT

CrossCore Embedded Studio apparently supports C++11 if you pass a switch in requesting it, though this FAQ answer suggests the underlying standard library is still C++03: https://ez.analog.com/dsp/software-and-development-tools/cce...

Everything I've found CodeWarrior related suggests that it is C++03-only: https://community.nxp.com/pwmxy87654/attachments/pwmxy87654/...

Aside from that, from what I can tell, those esoteric architectures are being phased out in lieu of running DSP workloads on Cortex-M, which is just ARM.

I'd love it if someone who was more familiar with DSP workloads would chime in, but it really does seem that trying to be the language for all possible and potential architectures might not be the right play for C++ in 202x.

Besides, it's not like those old standards or compilers are going anywhere.

  • Cadence DSPs have C++17 compatible compiler and will be c++20 soon, new CEVA cores also (both are are clang based). TI C7x is still C++14 (C6000 is ancient core, yet still got c++14 support as you mentioned). AFIR Cadence ASIP generator will give you C++17 toolchain and c++20 is on roadmap, but not 100% sure.

    But for those devices you use limited subset of language features and you would be better of not linking c++ stdlib and even c stdlib at all (so junior developers don't have space for doing stupid things ;))

  • Green Hills Software's compiler supports more recent versions of C++ (it uses the EDG frontend) and targets some DSPs.

    Back when I worked in the embedded space, chips like ZSP were around that used 16-bit bytes. I am twenty years out of date on that space though.

    • How common is it to use Green Hills compilers for those DSP targets? I was under the impression that their bread was buttered by more-familiar-looking embedded targets, and more recently ARM Cortex.

      1 reply →

  • > but it really does seem that trying to be the language for all possible and potential architectures might not be the right play for C++ in 202x.

    Portability was always a selling point of C++. I'd personaly advise those who find it uncomfortable, to choose a different PL, perhaps Rust.

    • > Portability was always a selling point of C++.

      Judging by the lack of modern C++ in these crufty embedded compilers, maybe modern C++ is throwing too much good effort after bad. C++03 isn't going away, and it's not like these compilers always stuck to the standard anyway in terms of runtime type information, exceptions, and full template support.

      Besides, I would argue that the selling point of C++ wasn't portability per se, but the fact that it was largely compatible with existing C codebases. It was embrace, extend, extinguish in language form.

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Non-8-bit-char DSPs would have char8_t support? Definitely not something I expected, links would be cool.

  • Why not? except it is same as `unsigned char` and can be larger than 8 bit

    ISO/IEC 9899:2024 section 7.30

    > char8_t which is an unsigned integer type used for 8-bit characters and is the same type as unsigned char;

    • > Why not?

      Because "it supports Unicode" is not an expected use case for a non-8-bit DSP?

      Do you have a link to a single one that does support it?