Most C/C++ code for old or new programs runs on a desktop or server OS where you have lots of perf breathing room. That’s my experience. And that’s frankly your experience too, if you use Linux, Windows, or Apple’s OSes

> how would trying to run a JIT like V8 inside Fil-C go?

You’d get a Fil-C panic. Fil-C wouldn’t allow you to PROT_EXEC lol

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johncolanduoni 5 days ago | parent | next [-]

Thanks for telling me what my experience is, but I can think of plenty of C/C++ code on my machine that would draw ire from ~all it's users if it got 2x slower. I already mentioned browsers but I would also be pretty miffed if any of these CPU-bound programs got 2x slower:

* Compilers (including clang)

* Most interpreters (Python, Ruby, etc.)

* Any simulation-heavy video game (and some others)

* VSCode (guess I should've stuck with Sublime)

* Any scientific computing tools/libraries

Sure, I probably won't notice if zsh or bash got 2x slower and cp will be IO bound anyway. But if someone made a magic clang pass that made most programs 2x faster they'd be hailed as a once-in-a-generation genius, not blown off with "who really cares about C/C++ performance anyway?". I'm not saying there's no place for trading these overheads for making C/C++ safer, but treating it as a niche use-case for C/C++ is ludicrous.

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spacechild1 5 days ago | parent | next [-]

I would like to add:

* DAWs and audio plugins

* video editors

Audio plugins in particular need to run as fast as possible because they share the tiny time budget of a few milliseconds with dozens or even hundreds of other plugins instances. If everthing is suddenly 2x slower, some projects simply won't anymore in realtime.

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pjmlp 5 days ago | parent | prev | next [-]

Many compilers are bootstrapped.

Ruby is partially written in Rust nowadays.

VSCode uses plenty of Rust and .NET AOT on its extensions, alongside C++, and more recently Webassembly, hence why it is the only Electron garbage with acceptable performance.

Unity and Unreal share a great deal of games, with plenty of C#, Blueprints, Verse, and a GC for C++.

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pizlonator 4 days ago | parent | prev | next [-]

I’m already living on a Fil-C compiled CPython. It doesn’t matter.

And a Fil-C compiled text editor. Not VSCode, but still

I absolutely do think you could make the browser 5x slower (in CPU time - not in IO time) and you wouldn’t care. For example Lockdown Mode really doesn’t change your UX. Or using a browser on a 5x slower computer. You barely notice.

And most of the extant C++ code doesn’t fit into any of the categories you listed.

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zelphirkalt 5 days ago | parent | prev [-]

Question is, whether one would really notice a slowdown of factor 2 in a browser. For example, if it takes some imaginary 2ms to close a tab, would one notice, if it now took 4ms? And for page rendering the bottleneck might be retrieving those pages.

	▲	const_cast 5 days ago \| parent \| next [-]
		2 - 4 ms? No. The problem is that many web applications are already extremely slow and bogged down in the browser. 500 ms - 1s? Yes, definitely people will notice. Although that only really applies to React applications that do too much, network latency isn't affected.
	▲	saagarjha 5 days ago \| parent \| prev [-]
		Yes, people will absolutely notice. There's plenty of interactions that take 500ms that will now take a second.

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addaon 5 days ago | parent | prev [-]

> Most C/C++ code for old or new programs runs on a desktop or server OS where you have lots of perf breathing room. That’s my experience. And that’s frankly your experience too, if you use Linux, Windows, or Apple’s OSes

What if I also use cars, and airplanes, and dishwashers, and garage doors, and dozens of other systems? At what point does most of the code I interact with /not/ have lots of breathing room? Or does the embedded code that makes the modern world run not count as "programs"?

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pizlonator 5 days ago | parent | next [-]

You have a good point!

First of all, I’m not advocating that people use Fil-C in places where it makes no sense. I wouldn’t want my car’s control system to use it.

But car systems are big if they have 100 million lines of code or maybe a billion. But your desktop OS is at like 10 billion and growing! Throw in the code that runs in servers that you rely on and we might be at 100 billion lines of C or C++

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pjmlp 5 days ago | parent | prev [-]

Some of that is thankfully running Ada.

	▲	addaon 5 days ago \| parent [-]
		Not in my case.