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“Clean” code, horrible performance

computerenhance.com

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Re: “Clean” code, horrible performance

#161

Post by vntok »

caeril wrote: post #126
vrnvu wrote: post #11

The problem with the contemporary "clean code" concept is that the narrative that performance and efficiency don't matter has been pushed down the throat of all programmers. Re-usability, OOP concepts or pure functional style, design patterns, TDD or XP methodologies are the only things that matter... And if you use them you will write "clean code". Even worse, the more concepts and abstractions you apply to your cod…

One of the most insane things I hear repeated constantly is that "servers are cheaper than programmers", implying that runtime efficiency doesn't matter, only developer efficiency. Which is all well and good, until you need to hire all the network engineers, systems administrators, devops people, security staff, datacenter operations managers, database sharding engineers, etc to manage the 10x more hardware and netwo…

Go full Cloud and you won't need to hire most of these roles ever, except in niche ultra-high performance cases. These roles will be externalized at AWS or Azure, super-paid to work for you 24/7.

Re: “Clean” code, horrible performance

#162

Post by pron »

pkolaczk wrote: post #85
pron wrote: post #81

Much of this is very compiler dependent. For example, Java's compiler is generally able to perform more aggressive optimisations, and even virtual calls are often, and even usually, inlined (so if at a particular call-site only one shape is encountered, there won't even be a branch, just straight inline code, and if there are only two or three shapes, the call would compile to a branch; only if there are more, i.e. a…

> and even virtual calls are often, and even usually, inlined. Last time I checked it could not inline megamorphic call sites, evn if implementations were trivial (returning constants). At the same time I saw C++ compilers able to replace an analogue switch that dispatched to constants with a simple array lookup, with no branching at all.

If I'm not mistaken, C2 inlines up to three targets, but of course, as a JIT, it inlines more aggressively than an AOT compiler, as it does not require a soundness proof.

Re: “Clean” code, horrible performance

#163

Post by cma »

stunpix wrote: post #150

So he puts polymorphic function calls into enormous loops to simulate a heavy load with a huge amount of data to conclude "we have 20x loss in performance everywhere "? He is either a huge troll or he has a typical fallacy of premature optimization: if we would call this virtual method 1 billion times we will lose hours per day, but if we optimize it will take less than a second! The real situation: a virtual method…

The clean code methods can be even worse outside of tight loops, in the tight loop all the vtable lookup stuff was cached.

Re: “Clean” code, horrible performance

#164

Post by cma »

Arnavion wrote: post #9

"Use subclasses over enums" must be some niche advice. I've never heard it. The youtuber seems to be referring to some specific example (he refers to specific advice from "them") so I guess there's some context in the other videos of the series. re: the speedup from moving from subclassing to enums - Compiler isn't pulling its weight if it can't devirtualize in such a simple program. re: the speedup from replacing th…

For interactive applications debug builds also need to be fast.

Re: “Clean” code, horrible performance

#165

Post by eithed »

Given that code in editor is for human consumption I wonder why can't it be restructured for compiler to make it fast. (Or why compiler can't make it fast). After all - you could leave annotations re, for example structs so compiler knows what will be their size, so can optimize for it

Re: “Clean” code, horrible performance

#166

Post by kaba0 »

MikeCampo wrote: post #158
stunpix wrote: post #150

So he puts polymorphic function calls into enormous loops to simulate a heavy load with a huge amount of data to conclude "we have 20x loss in performance everywhere "? He is either a huge troll or he has a typical fallacy of premature optimization: if we would call this virtual method 1 billion times we will lose hours per day, but if we optimize it will take less than a second! The real situation: a virtual method…

Just because you haven't been exposed this issue doesn't mean it doesn't exist. "the real situation", "no one", "in real projects", "never pop up"...give me a break lol.

One can reasonably well guess/know the expected input sizes to their programs. You ain’t (hopefully) loading your whole database into memory, and unless you are writing a simulation/game engine or another specialized application, your application is unlikely to have a single scorching hot loop, that’s just not how most programs look like. If it is, then you should design for it, which may even mean changing programming languages for that part (e.g. for video codecs not even C et al. cut it, you have to do assembly), but more likely you just use a bit less ergonomic primitive of your language.

Re: “Clean” code, horrible performance

#167

Post by kaba0 »

Tomis02 wrote: post #116
xnickb wrote: post #41

Earlier quoted context omitted.

I see your point, but no one uses Windows notepad for coding anymore. There are far worse crimes than having code structure that spans several files.

> There are far worse crimes than having code structure that spans several files. Sure, but what's the advantage of having your code split over several files? Yes, you can jump between them with an IDE, but that's still a disruption, and it makes it harder to see common patterns that can help you simplify the code. As demonstrated in the video, splitting up the switch into multiple classes only hurts readability.

You are only seeing a screenful of code at any time, no matter if they are in one file or multiple ones. I much prefer each “section” of code if you will having a specific name/location I can associate it with, than scrolling as a mad-man. Yeah, I know about markers/closable functions/opening multiple sections of the same file/etc, but at that point whose workflow is more complex?

Re: “Clean” code, horrible performance

#168

Post by kaba0 »

TeMPOraL wrote: post #117
xnickb wrote: post #41

Earlier quoted context omitted.

I see your point, but no one uses Windows notepad for coding anymore. There are far worse crimes than having code structure that spans several files.

> I see your point, but no one uses Windows notepad for coding anymore. Did I miss an IDE that inlines all those things for you automatically? Because ones that only give you a "jump to definition", or maybe a one-at-a-time preview in a context popup, are not much better than Notepad++. You still don't get to see all the relevant things at the same time.

Most real world applications won’t have `print “red”` or the like under a specific implementation. Good luck inlining 6 1000 lines-implementations into a single switch statement.

Re: “Clean” code, horrible performance

#169

Post by andai »

krapp wrote: post #92
thom wrote: post #74

There is no doubting Casey's chops when he talks about performance, but as someone who has spent many hours watching (and enjoying!) his videos, as he stares puzzled at compiler errors, scrolls up and down endlessly at code he no longer remembers writing, and then - when it finally does compile - immediately has to dig into the debugger to work out something else that's gone wrong, I suspect the real answer to progra…

If you're talking about Handmade Hero, the real answer to programmer happiness is not using a language you despise and refusing to leverage the features of, not refusing to use libraries in that language or frameworks, not re-implementing everything from first principles, and to actually have your game designed first (not designing while you code.)

Doing things without libraries (except the stuff built into Windows XP?) is the whole point of the project.

Re: “Clean” code, horrible performance

#170

Post by dang »

jasode wrote: post #24

The original submitted link was a youtube video that's been deleted for some reason. Probably a better link is the blog post because the author updated it with the new replacement video a few minutes ago as of this comment (around 09:12 UTC): https://www.computerenhance.com/p/clean-code-horrible-perfor...

We eventually merged all the threads hither. Thanks!
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