# premature optimization c++

Stattdessen geht es heute um „premature optimization“. We should forget about small efficiencies, say about 97% of the time; premature optimization is the root of all evil. Premature optimization, (probably) because of Donald Knuth’s famous line “premature optimization is the root of all evil,” (see Structured Programming with go to Statements) is, at the very least, a controversial topic.The misconception based on that particular quote is that a programmer, while writing code, should ignore optimization altogether. Spending a lot of resources trying to structure a startup in a way that will allow it to scale to hundreds of millions of users, before having acquired even a single one. This is especially true if a certain ask is relatively minor, since it might take you less time and effort to simply get a trivial 2-minute task done than it is to evaluate it using all of these criteria. You need to make sure you understand your project’s priorities, which could be. awesome incremental search Assuming you have good strategic advice from managers or chief software architects for which areas of your product need improvement, research is a good thing, and it helps cultivate a storehouse of options that can be taken. A few years ago, I was working on a web game called GeoArena Online (I’ve since sold it, and the new owners rebranded to geoarena.io). Frequently Asked Questions Infrequently Asked Questions Recent News Computer Musings Known Errors in My Books Help Wanted Diamond Signs Preprints of Recent Papers In any event, here’s the story: Bright Bill worked for a company that made cotton-combing machinery. Januar 2011 00:00. text/html 07.01.2011 00:53:08 Brad_Schulz 0. Premature optimization is attempting to optimize performance: When first coding an algorithm; Before benchmarks confirm you need to; Before profiling pinpoints where it makes sense to bother optimizing; At a lower level than your project currently dictates; Now, I’m an optimist, Optimus. Who knows where I’ll end up. Spending a lot of resources trying to optimize certain functions in a codebase early on, despite the fact that those optimizations are likely to be rendered irrelevant later, due to changes in the code. Sometimes it quoted in a longer form: "We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil." Januar 2011 00:59; Freitag, 7. Preisvergleich von Hardware und Software sowie Downloads bei Heise Medien. best. Alex Papadimoulis. Of course, optimization (and premature optimization) isn’t limited to programming; for a second example we’ll take another look at the Kittens Game, which I used frequently in my previous article on Amdahl’s Law. You know it is pretty bad when you read premature and micro in the same sentence. This might happen for a variety of reasons, such as because you believe that a small modification could give you a significant benefit, or because the optimization will allow you to deal with a bottleneck in your work, or because avoiding the optimization might lead to significant technical debt later on. Yes, premature optimization is evil. benefit, and both of them state that optimization cannot be considered worthwhile without measurement. Categories . Published by at December 2, 2020. Premature optimization. "Premature optimization" ist kein Fachbegriff, sondern die Kombination 2er gängiger Begriffe in konventioneller Weise und bedeutet das, was ein Attribut mit einem Substantiv immer bedeutet. We will explore the ambiguity surrounding optimization. Yes, it costs me time to do this, but the cost of a simple performance trial is much less expensive than trying it out on the real thing. That’s thousands of times per second, and it can’t be late, without causing a disturbance to the motor. “Premature optimization is the root of all evil” is a famous saying among software developers. The most common reasons why people optimize things prematurely are that they fail to prioritize their tasks properly, or that the premature optimization represents an easy problem for them to handle, which makes it appealing to take it on even if it’s unnecessary. Will the Compiler Optimize this out (7) Say I have something like this in a C Code. Pre-mapture Optimization by Alex Papadimoulis in Feature Articles on 2005-11-23 Edit. why. This is going to be a very short chapter, because the main thing Unix experience teaches us about optimizing for performance is how to know when not to do it. The premature optimization occurs as a result of failure to prioritize tasks properly. Es gibt auch keinen Grund den Ausdruck auf das Programmieren zu beschränken. Premature optimization hits both. INTRODUCTION In this paper, a hypothesis testing method, an effective methodology in statistics, is employed and incorporated into a Particle Swarm Optimization(PSO) based Monte-Carlo Simu- lation(MCS) algorithm to solve the complex network … Here is the full quote from his book The Art of Computer Programming: complicated one. Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. Premature optimization is the act of trying to make things more efficient at a stage when it is too early to do so. If your company is competitive, it has a Golden Goose. If you really need to optimize, then the next step is to make sure you are using the best algorithm for the job. A good programmer will not be lulled into complacency by such reasoning, he will be wise to look carefully at the critical code; but only after that code has been identified.”, — Structured Programming with go to Statements (1974). "premature optimization is the root of all evil." Premature optimization describes the act of trying to make something more efficient at a point where it is too early to do so. Da ich die ganzen Daten aber bei der Arbeit habe und ich gerade eine Woche Urlaub habe, muss ich das leider mal wieder verschieben. Als Antwort markiert ozsql Freitag, 7. The Factors that Determine Your Success at Learning, Bikeshedding and the Law of Triviality: Why People Focus on Minor Issues, Good Enough is Good Enough: Let Go of Perfectionism to Get Things Done, Remember that not all optimization is premature, Structured Programming with go to Statements, How to Make Decisions: A Guide for When You Can’t Choose, Why It’s Hard to Make Decisions (Especially Good, Fast Ones), Tempus Fugit: Time Flies, So Use It Wisely, Reverse Psychology: Getting People to Do Things By Asking for the Opposite, The Napoleon Technique: Postponing Things to Increase Productivity. Diese plakative Aussage findet sich in dem 1974 erschienenen Aufsatz Structured Programming with go to Statements von Donald E. Knuth. As mentioned, you should avoid premature optimization. I for one do not agree that all premature optimization is necessarily bad. Third, you prematurely optimize your planning phase, trying to find solutions to all kinds of problems that may occur. In his paper “Structured Programming with GoTo Statements”, Donald Knuth, one of the eminent minds of computer science, coined the phrase “premature optimization is the root of all evil”. Terraria Thorium Healer, Premature optimization is problematic because it can cause you to waste resources, to get discouraged, to act when you don’t have enough information, or to get locked into a sub-optimal course of action. The programmer is always programming to a VM. I had a 20k rep user today tell me that using a HashSet instead of a List was premature optimization. von Nils Langner in Allgemein 4. However, this approach shouldn’t become an excuse to avoid optimization entirely, but should rather serve as a way to prioritize tasks as effectively as possible. The root-solving process took another 11.9% of total CPU time, Even a one-off project can benefit from optimization, because of repeated iterations during the development cycle. universal experience of programmers who have been using measurement tools has been The conventional wisdom of software development, to paraphrase Knuth, is that worthwhile opportunities for optimization of software are confined to only a few pockets of critical code (the apocryphal 3%), and are much easier to determine by measurement than by intuition. Sometimes it quoted in a longer form: “We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil.” Both are usually attributed to Donald Knuth, but there also seems to be an idea floating around, that the quote was originally due to C. A. R. Hoare, and Knuth only popularised it. It can cause you to waste resources, such as time, money, and effort, which could be better spent elsewhere. However, in most cases, the optimizations described in these examples are premature, and it would be preferable to postpone them until a later stage. [C] "Premature optimization is the root of all evil" Question. Ist++ ich wirklich schneller als ich in for-Schleifen in Java? What Exactly Does An Electrical Engineer Do, Difference Between Internet And Internet2. Written by: In this case, my optimization, being architectural in nature, wasn’t even premature: (We’ll get to it more in my recently published article, How to Avoid the Curse of Premature Optimization .) but why? Premature optimization, (probably) because of Donald Knuth’s famous line “premature optimization is the root of all evil,” (see Structured Programming with go to Statements) is, at the very least, a controversial topic.The misconception based on that particular quote is that a programmer, while writing code, should ignore optimization altogether. Punic Wars Caesar, Doesn't that invite premature optimization? u/maxpowers83. 2 years ago. Optimization on the microcontroller side was fairly limited, and included these efforts: Optimization on the PC side was more interesting. handled poorly. Some were web apps, some were client/server database query apps, etc.. ", and usually premature because most optimizations are. Welches "if" Konstrukt ist schneller-Anweisung oder ternärer Operator? Adjust structure sizes to power of two. Do you agree? Recently the question came up of how much memory to put into a particular part. The optimization problem is that we want to find the value of $$x$$ that maximizes $$f(x)$$. News und Foren zu Computer, IT, Wissenschaft, Medien und Politik. Another pitfall is assuming that the code in question has enough impact on overall performance to be worth optimizing. That would make it an optimization- "I'd rather program in C#, but I have to use C++ because it's faster. measured improvement in server performance. ", and usually premature because most optimizations are. I discovered a real case of premature micro-optimization when you don't measure it. If we needed 1M slabs, the 14th quarry would be worth building; it would make minerals production about 1.6% (= 2230/2195) faster. I don't think I'm wrong in saying there is a distinction in selecting the right tool for the job versus premature optimization. There were so many specifically turned off. Eigentlich wollte ich ja heute erzählen, wie man External Tools in Eclipse verwendet. But the tone of what I hear in the programming community on the topic of premature optimization seems to imply that nobody has time for anything, unless it can help what they’re working on right now. ~ Stevesliva facing downwards, because the Hobart sprays water up from the bottom, The person handling outgoing items needs to wear heavy rubber gloves; the sterilization cycle rinses with water that is around 82 - 88° C (180 - 190° F), and you can be badly burned by hot metal pots or even the water vapor, Watch the Hobart closely when it’s on, so you can take items out of it as soon as the sterilization cycle is complete, The person at the sink needs to be aware of the person handling outgoing items, to slow down if there’s a backlog, Fill the Hobart reasonably full, but not too full so that some of the surfaces don’t get cleaned, Silverware gets put into a stainless-steel mesh silverware basket; fill it up so you can put it through the Hobart in large batches, When drying trays, stack them alternating crosswise and face down so the remaining water vapor drips off, Make sure the floor stays dry, otherwise you can slip and fall, dividing up the jobs into reasonable tasks, making sure the kitchen is setup so that all dishes, kitchenware, and supplies can be stored in an organized manner, and it is conducive to being cleaned quickly, making sure the kitchen workers get along; animosity among coworkers is poisonous, spreading out the dishwasher workload where possible to make use of available time (for example, send pots/pans/etc. [C] "Premature optimization is the root of all evil" Question. … - Selection from C++ Coding Standards: 101 Rules, Guidelines, and Best Practices [Book] laziness. It's a hidden pitfall to assume that (supposedly) performance-optimized code is actually your first priority, above correctness, clarity, testability, and so on. News und Foren zu Computer, IT, Wissenschaft, Medien und Politik. Premature optimization is the root of all evil. But I have no idea how much work it will take to get the execution time down to a near-optimal level. Difference Between Internet And Internet2, Other things are an easy habit to get into with no case (using ++i instead of i++ in - C++ this can often be a major win with no downside). In fact, this very amenability to optimization in general and late-in-the-game optimization in particular is a large part of what makes this language popular with expert programmers: you really can leave the “small efficiencies,” a few of which we’ve shown, for later. To avoid optimizing things prematurely, before getting started you should make sure to ask yourself why you want to optimize, what are the costs and benefits of doing so, what are the possible negative consequences of this optimization, what are the advantages and disadvantages of waiting, and what else you could be working on. I''ll quote a recent art If this happens too often, your Golden Goose will strain herself and have a prolapsed oviduct. Isn't that kind of anti-Forth? Rather, the important thing is to be aware of these considerations, and use them, at least to some degree, to evaluate tasks when necessary. Your email address will not be published. As outlined by Joe Duffy, LINQ introduces inefficiencies in the form of hidden allocations, from The ‘premature optimization is evil’ myth:. The concept of premature optimization was first made prominent in the field of software engineering. Get it done right? Oleksandr Kaleniuk, “Premature optimization is the root of all evil” is the root of evil, September 2016 There is no point in optimizing an algo that is inherently slow, if there is a better one you could use. Generally good algorithms are easier to implement than bad ones (they are in your standard library), but it takes a little thought to realize how to apply the good algorithm. So your programmers don't have to think? What is premature optimization? Where do you find 0.545 unicorns? Place case labels in narrow range. Here, this focus on efficiency comes at the expense of more important tasks. (c) by Donald Knuth Naomi Nosonovsky, Sr. Programmer-Analyst My blog. The microcontroller would send samples of data at a fixed rate; the PC software would log and analyze that data. There are several reasons why premature optimization is problematic: There are various reasons why people optimize things prematurely: Note: a related concept which has similar roots is called bikeshedding; this represents a phenomenon where people spend a disproportionate amount of resources dealing with relatively minor issues. Place frequent case labels first. Premature optimization is spending a lot of time on something that you may not actually need. For example: They’re tactical because they’re very concrete questions dealing with localized implementation details, and have very little to do with the overall software architecture. Tim Peters, The Zen of Python "Schnelles Pferd" ist auch kein Fachbegriff aus dem Reitsport. It could be that A has a theoretical minimum execution time of 10 microseconds and B has a theoretical minimum of 3.7 microseconds — in which case, at first glance, it would be better to optimize section B because it has the higher theoretical gain in execution speed. Or there were errors that I’d have to fix, so I’d need to run it in order to debug. The hot-spot code in our motor control ISR (which might be 40% of the entire codebase) typically looks like this. While it’s very costly to avoid planning, many people never stop planning, which can be just as costly! So that all the programmers are replaceable cogs like in the salt mines of C? Anmelden. poor sound system, while car number two was described negativity, because everywhere I looked, I saw negative The difference between optimization in the mathematical sense, and in the engineering sense, is that mathematical optimization is just a matter of stating a problem in quantitative terms, and finding an appropriate minimum or maximum. Here’s a graph of available slabs over time with the two cases; the red line is 13 quarries and the black line is 14: (For the record, on this particular run of the game, the 15th quarry costs 5126 slabs, adding a further 271 minerals per second, which will allow us to recover the 5126 slabs in 659 seconds, a little bit longer than for the case of the 14th quarry. How much time we should dedicate to performance tuning and optimization is always a balancing act. Sometimes optimization doesn’t mean execution speed. … The new message structure might then be defined as: The first rule of optimization is: Don’t do it. If premature optimization is the root of all evil, then the lack of planned performance during the design and implementation phases is the trunk, branches, and leaves of all evil. 80% Upvoted. Then the magnetics got cheaper and more readily available, because all of a sudden there was this market for low-power switched-mode converters, and the economies of scale kicked in. donald knuth premature optimization. But some level of optimization usually has to take place, and it may vary from just methodically looking through the schematic to see which components can be replaced, one by one, with less-expensive alternatives, to packaging optimization where a more holistic approach is required and more of the work affects the circuit layout. Every few blocks of code, he'll start to panic, worrying that his code isn't fast enough, that he's wasting too many resources, that he's just not doing it perfect. By building a 14th quarry, we’ll decrease the time to our goal from 605.2 seconds to 604.9 seconds, saving 0.3 seconds, just barely making it past the breakeven point. Premature optimization has significantly slowed down your product development cycle and reduced your learning speed. For example, someone who is developing software might optimize things prematurely not because it’s a coping mechanism for dealing with any issues, but rather because they simply don’t know how to plan ahead and figure out which tasks they should be working on during each stage of the development process. Donald Knuth, the patron saint of algorithm analysis, once famously said "We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil." Premature optimization can often end up backfiring, and cause you to waste a lot of resources, such as time, money, and effort, while also increasing the likelihood that you will create future problems. Premature optimization is the root of all evil.--C. Types Of Personal Finance, Optimizing Objective-C programs is, in the end, not necessarily hard. This presents the argument against trying to make premature optimizations, while at the same time acknowledging that it’s nevertheless important to identify areas where optimizations can be necessary, and to then implement those optimizations. 8. Yet we should not pass up our opportunities in that critical 3%. Premature optimization is spending a lot of time on something that you may not actually need. It’s a real feat of engineering, something that wouldn’t have made much business sense to commodity AC adapter manufacturers, but for Apple the idea of premium high-end design was part of their business philosophy, and in the intervening decade other companies on the commodity end have come out with small AC adapters as well. Premature Optimization. Download source code - 13.5 KB; The benchmark is hosted at Github.. share. GameDev.net is your resource for game development with forums, tutorials, blogs, projects, portfolios, news, and more. donald knuth premature optimization. We should forget about small efficiencies, say about 97% of the time; premature optimization is the root of all evil. TechTidBits (Blog) Premature Optimization. The larger a task appears to be, based on the resources that it will require or the effects that it will have, the warier you should be, and the more you should use these criteria to evaluate it. New comments cannot be posted and votes cannot be cast. Remember that this doesn’t mean that you should avoid optimization entirely, but rather that you should think carefully and assess the situation before deciding to move through with a certain optimization. The use case in question was a statically initialized collection thats sole purpose was to serve as a look-up table. Whether this is true or not depends on the type of software. the time, which is just above chance. spontaneous gut decision — chose the best car They were not interested in my explaination that a modulo is a division function, and that a 32 bit divide is going to be dog slow on an 8 bit processor...all they could grasp was that fewer lines of code should run faster. Premature pesimization is just as bad as premature optimization. Vornado Dc Fan, Your email address will not be published. No one actually interprets "premature optimization is the root of all evil" as an argument against all optimizations, do they? 1 Premature Optimization We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. Premature optimization is the root of all evil. In the original quote on the topic, this concept was said to apply to roughly 3% of cases, but your cutoff for what a valid optimization is can be higher or lower than that. Optimizing Objective-C programs is, in the end, not necessarily hard. Oct 21. The third example I will present is a purely mathematical optimization exercise. Close. Archived [C] "Premature optimization is the root of all evil" Question. Unfortunately that’s rarely the case. Don't solve problems that don't exist. The responsibility for strategy lies with whoever is in charge of the kitchen, whereas everyone doing the work needs to be aware of the best tactics. 3 min read. It can cause you to make mistakes, if you make decisions at a stage where you don’t have enough information. James Hague, “Avoid Premature Optimization” Does Not Mean “Write Dumb Code”, August 2011. Another option, which some might call premature optimization, would be to pack the values in a standard “C” style structure, sending the data as packed binary values using a secure TCP socket instead of an https connection. javascript required to view this site. people keep saying premature optimization creates inefficiencies. Premature Optimization # productivity # webdev # computerscience. Founder, The Daily WTF. Optimize only when it's really needed (that is, time critical sections of your program). As a bit of a … At least, I’m going to pretend to be an optimist while I write this article. Knuth. One slight problem with optimization in the mathematical sense, is that it produces fixed outputs only for fixed inputs. premature-optimization (10) Sort By: New Votes. C++ hasn't been a hassle to program in since shared_ptr and std::vector were invented. Although particle swarm optimization (PSO) has been widely used to address various complicated engineering problems, it still needs to overcome the several shortcomings of PSO, e.g., premature convergence and low accuracy. The morale of these stories is always that you should leave optimizations at the end. Check our free transaction tracing tool, Tip: Find application errors and performance problems instantly with Stackify Retrace. Cute, but terribly wrong. Instead of rewriting the program, the fix was to buy a faster processor. Sort by. People make the mistake of trying to optimize things prematurely in many areas of life. However, note that you don’t have to ask yourself all of these questions each time you evaluate a potential task. Once real people use it for real purposes, you can do benchmarks to see where you really need to optimize. What Exactly Does An Electrical Engineer Do, Yet we should not pass up our opportunities in that critical 3%. Yet we should not pass up our opportunities in that critical 3%. Even if multiplication is faster, and making such a change did cause an improvement in performance, it wouldn’t be worth doing unless there was substantial evidence that a program was unacceptably slow and the division was a significant performance bottleneck. Alternatively, to handle the same power, you need a smaller volume of magnetics.) I can see how it could be a problem to write some convoluted optimization in the first place, but mostly I see premature optimization rearing its ugly head in fixing what ain't (known to be) broke. However, this is usually ignorant. Yet we should not pass up our opportunities in that critical 3%. So far, we saw what premature optimization is, why it’s an issue, and why people are prone to it. Randall Hyde, The Fallacy of Premature Optimization, ACM Ubiquity Magazine, February 2009 — Hyde and a few other authors mistakenly attribute the Knuth quote to Tony Hoare, but it is Knuth’s statement. If the compiler is at all intelligent, it will do the best to optimize the result, but nothing can make the next guy not hate you for your crappy bitshifting solution (I love bit manipulation by the way, it’s fun. This thread is archived . Dental Practice Books, For example, premature optimization could involve someone spending a lot of time and money picking out the best possible gear for a certain hobby, despite the fact that they haven’t actually tried out that hobby to make sure they enjoy it. "Premature optimization" is a phrase used to describe a situation where a programmer lets performance considerations affect the design of a piece of code. Quotations by Donald Knuth, American Scientist, Born January 10, 1938. 0. \end{align}. I recently came across a great article over at The Onion: Study Finds Working At Work Improves Productivity.