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.