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Re:Making bracket pair colorization faster by jjoonathan on Wednesday September 29, 2021 @09:25AM (#28693244)
Stacking abstractions is a great way to give yourself Big O problems. Fighting the height of the stack reduces them, and "Use C++" does tend to fight the height of the stack.
Re:Making bracket pair colorization faster by goldenkey on Wednesday September 29, 2021 @09:39AM (#28693470)
C++ doesn't fight the stack more than any good JIT. In fact, it may be less capable in noticing ways to inline functions given that it's a statically compiled language. It's only current advantage with the stack is tail call optimization which is coming to V8 very soon.

Funny that the C++ guy is talking about abstractions, where them V-Tables at?

Re:Making bracket pair colorization faster by Jensson on Wednesday September 29, 2021 @10:31AM (#28694157)
They talked about stack of libraries beneath you, not the execution stack. If an API call takes 10 microseconds because several "premature optimization is the root of all evil" abstractions in between then doing that just 10k times already nets you 100ms which is a very noticeable stutter. So with that limitation you are now forced to create elaborate data structures with caching etc to try to work around this slow API call. However doing the same querying in C++ without those abstractions where each call takes 10 nanoseconds means that you no longer have to try to create complex data structures to work around that slow API call, even if you do it a million times it would only take 10 milliseconds and maybe drop a frame.
Re:Making bracket pair colorization faster by npigrounet on Wednesday September 29, 2021 @06:31PM (#28700832)
Nowadays JS is as fast as C++, if not faster.
Re:Making bracket pair colorization faster by goldenkey on Wednesday September 29, 2021 @08:00PM (#28701587)
Let me respond for him. He meant abstraction as in "stack of dependencies." Because everyone knows that's what abstraction means, right?! Because we all know NPM is a disaster as opposed to C++ dependency management which doesn't even exist in a standard form. /s
Re:Making bracket pair colorization faster by Jensson on Thursday September 30, 2021 @03:49AM (#28704072)
Microsoft has a C++ API you use to make programs for windows. If you write in C++ you will code directly against that. If you write in Javascript then you will code against someone else's API that they wrote to interface with the Microsoft API. If you write in Javascript another step up then you will code your plugin against the VSCode API which then uses the Electrons wrapper around Microsofts API to do stuff, if there aren't more libraries in between. This stack of abstractions turned out to be too slow to solve the problem mentioned in the article we are talking about, so to solve it they moved the entire thing up one step in the stack.

In these situations it is common to have a problem that is really easy to solve but the API abstractions you have to work with doesn't support the operations at the speeds you need to solve it. If you have never experienced that then you aren't working on performance intensive projects where every bit counts and your input on this topic doesn't matter. I have worked on performance intensive libraries crossing programming language boundaries and the abstraction boundaries absolutely puts a limit on the amount of performance you can get. Well designed abstractions are less obstructive but plenty of them aren't well designed and even the well designed ones have overhead.

Re:Making bracket pair colorization faster by WorldMaker on Thursday September 30, 2021 @11:19AM (#28707364)
Microsoft has a COM API. C++ has a stack of macros and abstractions for communicating with a COM API. If you code in C++ you code in abstraction to an interface to the Microsoft API but not the API.

To get rid of abstractions you almost should be writing more directly in some sort of COM+ language.

(To explain the punchline for those that don't catch the joke: COM+ was the codename/early name of what became .NET.)

Re:Making bracket pair colorization faster by goldenkey on Friday October 01, 2021 @03:27AM (#28715645)
Microsoft has a COM API but when I used to develop, I'd just call kernel32, user32, advapi32, and other system C APIs directly. COM is a POS imo. DirectX is a decently engineered class-based API. But the rest of them have a lot of flaws.

The funny part is OP is talking all about uOPS when if he was really hardcore (like I am) he'd know that these dlls in turn call ntdll, many calls in ntdll are undocumented but much faster than their wrappers in the other dlls. But no sane person is going to strictly do ntdll calls except for the most performance critical code.

OP just doesn't know enough about C and C++, he probably grew up on C++ and forgot about the old C apis. I used to reverse engineer and delve deep into the windows API. I know a little bit more about performance than the average high level programmer.

And ultimately, .NET does a fine job with performance. C++ coders crapping all over .NET should take a look at the Objective C API of Apple. It's the default and every Objective C call incurs overhead and is basically a wrapper around the undocumented C API. But I don't think anyone ever complained about this abstraction, because it's such a stupid and small amount of performance to harp about. The convenience outweighs the tiny little uOPS loss.

Re:Making bracket pair colorization faster by goldenkey on Thursday September 30, 2021 @10:01AM (#28706414)
Ah, so this is all coming from a Microsoft C++ guy. Well better get to using those undocumented ntdll calls since you really need those uOps. It's not like the standard libraries of other languages is written in C or anything... ;-)
Re:Making bracket pair colorization faster by npigrounet on Thursday September 30, 2021 @08:08AM (#28705387)
JS is almost close to the metal nowadays thanks to the stunningly optimized JIT.
Re:Making bracket pair colorization faster by amw-zero on Friday October 01, 2021 @07:20AM (#28716972)
Can you initialize a kernel with JS?
Re:Making bracket pair colorization faster by goldenkey on Saturday October 02, 2021 @11:07AM (#28729142)
Of course. Have you not seen the VMs written in JS?

https://bellard.org/jslinux/

Re:Making bracket pair colorization faster by amw-zero on Saturday October 02, 2021 @03:10PM (#28731130)
That is a VM running in a web browser. If I was thinking about a joke that was so comically far away from the metal, that’s pretty much what I would use as an example.

This is why it’s very difficult to have conversations. Most programmers really don’t even know how computers work.

Re:Making bracket pair colorization faster by goldenkey on Wednesday October 06, 2021 @02:17PM (#28776339)
Heh, I know plenty about how computers work. You didn't specify what hardware you wanted targeted. Emulated devices are just abstractions.

Here is a real kernel: https://news.ycombinator.com/item?id=7958194

It's so difficult to have conversations with engineers that don't know x86 assembly. They never stop complaining. If only I could NOP them! ;-)

Re:Making bracket pair colorization faster by int_19h on Wednesday September 29, 2021 @11:07PM (#28702756)
Claims that JITs can produce code that's routinely faster than C++ have been around since Java. So far, the promised gains haven't really materialized. It appears that optimizations that can be gleaned from dynamically profiling a running program simply don't provide enough benefit to account for optimization opportunities lost because the JIT has to be "fast enough", and from language semantics that is inherently hard to compile to fast code (of which C++, quite intentionally, has little). V8 is not an exception.

Your specific example - inlining functions - is not particularly illustrative, since C++ can inline just fine across translation unit (and thus also static library) boundaries with link-time optimization. What it can't do is inline across shared library boundaries, but large C++ apps are usually mostly statically linked for redist anyway.

Re:Making bracket pair colorization faster by pjmlp on Thursday September 30, 2021 @05:44AM (#28704594)
Except Windows loves COM, and it is all about DLLs and out-of-process IPC.

Those gains have materialized in distributed computing, where the 1% cases where C++ wins in micro-benchmarks don't really matter, when network latency, databases, load balancers and the whole lot come into play.

Re:Making bracket pair colorization faster by goldenkey on Thursday September 30, 2021 @01:00AM (#28703350)
Java is not V8, it isn't Dalvik either. Java is a memory hungry turd that never delivered, agreed. But let's not forget that Google made their own runtime for Android and invested millions into V8.

https://news.ycombinator.com/item?id=17648139

> What it can't do is inline across shared library boundaries, but large C++ apps are usually mostly statically linked for redist anyway.

I'm guessing you've never looked inside System32 on Windows or /usr/*/lib on Unix. I don't see shared libraries as a bad thing, they are great for reducing disk and memory usage. Let's not make bullshit up about how most applications are statically compiled with all their dependencies ;-)

Re:Making bracket pair colorization faster by int_19h on Thursday September 30, 2021 @03:14PM (#28710123)
Java is not V8, of course, because one is a language, and the other one is a VM.

Java is also not JS. Semantics of Java are much better suited to effective compilation than that of JS, due to static typing and (in many cases) early binding. Consequently, modern Java VMs have the best JITs in the industry - faster than V8 - and they're still not on par with C++.

Most applications dynamically link to system libraries. On Linux, this is kinda fuzzy because package managers handle everything; and yes, I agree, on Linux the norm for distro-packaged software is dynamic linking. But stuff packaged as Flatpak etc is much more likely to be statically linked to anything other than libc. And idiomatic C++ tends to involve lots of templates, which are inherently "statically linked".

(Also, native code is broader than C/C++ - it includes e.g. Go, which drops even the libc dependency, and Rust.)

On Windows and macOS, though, where "app is a self-contained folder" has been the rule rather than the exception for a long time now, dependencies that don't come from the OS are often statically linked.

Re:Making bracket pair colorization faster by goldenkey on Friday October 01, 2021 @03:44AM (#28715741)
The JVM is hot garbage. It is slow to start up, a memory hog - and like you mentioned previously, overabstracted - no amount of magic unboxing of primitives like int help its performance. There are 100s of different parameters one can set to control garbage collection and other performance characteristics. It's a job in itself dealing with the beast of JVM. YMMV but every time I've dealt with Java I was dissapointed. I'd much rather use C++, Julia, or pretty much any other AOT or JIT than Oracle/Sun's JVM.

You keep saving face. So you admit Linux is largely dynamically linked. Well Windows is too, even to C stdlib, look at how many versions of MSVC runtimes are in your system32 dir after just a few installs. Templates are preprocessor so obviously they are "statically linked."

Microsoft has a COM API (which a lot of C++ uses) but when I used to develop, I'd just call kernel32, user32, advapi32, and other system C APIs directly. COM is a POS imo. DirectX is a decently engineered class-based API. But the rest of them have a lot of flaws.

If you were really hardcore you'd know that these dlls in turn call ntdll, many calls in ntdll are undocumented but much faster than their wrappers in the other dlls. But no sane person is going to strictly do ntdll calls except for the most performance critical code.

I used to reverse engineer and delve deep into the windows API. I know a little bit more about performance than the average high level programmer.

And ultimately, .NET does a fine job with performance. C++ coders crapping all over .NET should take a look at the Objective C API of Apple. It's the default and every Objective C call incurs overhead and is basically a wrapper around the undocumented C API. But I don't think anyone ever complained about this abstraction, because it's such a stupid and small amount of performance to harp about. The convenience outweighs the tiny little uOPS loss.

Re:Making bracket pair colorization faster by int_19h on Friday October 01, 2021 @12:14PM (#28720319)
JVM is a hog, but when it comes to raw compute perf, it's a very fast hog once it starts running. Do you have any examples of anything better (post-startup)?

Yes, I'm well aware that many system DLLs on Windows in turn call into NTDLL, where the actual syscalls are. And yes, I agree that it hardly matters in practice - but it was your premise that inlining across shared object / DLL boundaries is crucial! In practice, yes, it almost never is. And yes, .NET is perfectly fine perf-wise, and even JS is fast enough for most cases. I've actually spent most of my career writing C# and Python, after writing a bunch of C++, and I very much appreciate the productivity gains those abstractions offer.

But this is a very different point. Native code is still measurably faster where it matters, and JS/V8 can't keep up for very good reasons.

Re:Making bracket pair colorization faster by goldenkey on Friday October 01, 2021 @10:25PM (#28725413)
Well I guess we are finally in agreement. Right, there are few places where it matters these days.
Re:Making bracket pair colorization faster by npigrounet on Thursday September 30, 2021 @02:33AM (#28703755)
So far, JS has beaten C++ in speed on a lot of topics.
Re:Making bracket pair colorization faster by gpderetta on Thursday September 30, 2021 @06:39AM (#28704859)
At the very least, not in writing JS VMs it seems...
Re:Making bracket pair colorization faster by TeMPOraL on Thursday September 30, 2021 @03:36AM (#28704020)
Please name three.
Re:Making bracket pair colorization faster by robpalmer on Thursday September 30, 2021 @02:42AM (#28703800)
TCO is coming to V8? Is there a source for this?