I was just getting my feet wet in the wonderful, have-your-cake-and-eat-it-too world of SQL. More often than not, though, it is done very prematurely, carries with it a litany of bad side-effects, and most ironically, leads to worse performance. For example, if you have a code like this, it might be a bad thing. If you use string as instance from C++ class, you might feel more comfortable, but you could create slower code and sometime even the a bigger file size. OK, so you’ve looked, and there is nothing already solving your problem built into your toolchain, or liberally licensed on the web. Back to my own ugly example: Needless to say, the benefits of deduplication aren’t even being realized here all that much. A program may be optimized so that it becomes a smaller in … Just my two cents. Optimise for simplicity. Knowing every option of every API and tool in your stack and keeping on top of them as they grow and evolve is certainly a lot of work. While assembly language is the best choice in this … Now I had a new problem: a given relationship_type would naturally not make sense between every given combination of rows. “Code for developers. Not just to avoid being “Dan” on The Daily WTF, but because you believe code optimization is the Right Thing to Do™. Whose? 1. optimize architecture first then algorithm. One bad thing that could happen is that you create the branch that will never be used or even few lines of the code that could be added and you will never use those cases. Just getting specific and including the language, instead of assuming I would have to implement it myself, meant everything. But I decided to share my own experience in the field with the focus on SQL Server query optimization tips. After all, if I needed to change a table name and forgot to update it in all applicable rows, it could create a bug! After all, you would be doing that manually after coding anyway, right? But when your requirements do change, and you’re not just trying to anticipate them, then maybe it is time to refactor. You should be aware of these types of limits a number can have on your algorithm. Leaving it all to compiler to optimize?!? Similar to this is case if you are in a situation where you could pick form !=0 and <=n, use the first one it will be faster. Again, this form of loop optimization is something almost always better optimized by an automated process like compilation, not by sacrificing your code’s readability. I still think I took the right course there, even if the code optimization wasn’t appreciated directly by my boss at the time. Beware: Optimizing the heck out of any particular [aspect] will come at the cost of others. Originally, i used joins, but turned out it was much faster to use them in the WHERE part. One good fact to know about if command is to know that it has some of the optimizations built in. Performing code reviews is the best method to improve the quality of your codebase and create a culture of learning and respect. In the bottlePhrase example, what if you want to localize into a language that has more than two plural forms? It means the code is analyzed at runtime. Here’s where it’s easy to see how much of an art there is in crafting code. If you have expression p and q, as soon as you have p equal to false you know that there is no way to get true as a result, this is used in C/C++ and sometimes it could be reason why people do get wrong code. that means that 7 times your screwed and ugly pointer to pointer code will be in front of a newcomer to the company who needs to do your code support. But you’ve decided it’s time, so go ahead with statement-level profiling, now that you’re within the context of the whole system, where it actually matters. which means that it will be parsed once and then its up to compiler how to optimize it best. In my opinion, optimisation is best left to the compiler. Meanwhile, my variables will be strangely named afterward, with things like bottlePhrase not having anything to do with bottles at all. We say that code optimization is writing or rewriting code so a program uses the least possible memory or disk space, minimizes its CPU time or network bandwidth, or makes the best use of additional cores. If you are not worried about the changing the value that is passed to the function, use references. Or 25 years. Pick the first option. From point of security, cout and cin would be considered as better option for files, as you would have adequate instructions in fstream header. As you catch yourself tending to refactor before you even have a working prototype and test suite to evidence its correctness, consider where else you can channel this impulse. Coding is too much of expectations. And someone smart and capable, like you, can avoid self-sabotage: Keep your ends noble but re-evaluate your means, despite the fact that they seem to be unquestionably intuitive. First, profile. By default, most websites list different … Worst I have seen is NYC programmers. However, I found that after about 50 minutes of research and trying some preliminary code out, I had not managed to turn the half-finished pseudo-code I had found into a correct implementation. e.g. PROGRAM_FLASH: 1456 B 64 KB 2.22 % 3. or if you know the outcome before it happened it would be very fast to write it right now…, Your suggestions are insulting to …. Well, the results are just useful as a snowflake on a North Pole or like hand of sand in desert. This means that you could use pointers and pointer arithmetic. The wisdom of future-proofing in this way is pretty questionable. Who is doing the thinking here is also an important part of the context. No problem. Without the refactoring and tests, I think it would have taken longer to actually get correct—i.e., focusing on coding speed would have actually thwarted it. Assuming you’ve done all you can higher up, it’s time to consider the optimizations we’ve been avoiding the entire time up until now. Best of luck. In the case of reducing loops to formulas, though, be mindful of leaving comments. It is way harder to read code this way, but it will increase the speed of program. If you use object that is constant, it could be useful to use const, which will save some time. If my main goal were learning the new engine, or learning in general, then that would have been time well spent: Tinkering, finding the limits, discovering unrelated features and gotchas via research. This itself may smell like premature optimization, but it’s an important exception. Before writing any code, there are examples of the output expected by a working design. If you have an algorithm of size n and you input 10 elements you get time t, and if you input 100 elements you will end up with time 10 times longer than t. If you deal with a program that has equivalent to n*n and you increase the size of set from 10 to 100, the program will not be 10 times slower but rather approximately 10*10 times. Sometimes, if you use different functions for same task you will … One useful ‘hand optimization’ however is to use the appropriate data type for the job at hand. For example, to optimize the code for performance might conflict with optimize the code for less memory footprint and size. WP Rocket will automatically take care of GZIP file compression, and add the necessary rule to your. Optimization of any kind should clearly be a good thing, judging by its etymology, so naturally, you want to be good at it. For those who code in Java, Pascal, Visual Basic and other stuff they do reduce readability, but for those who code in C/C++ and know how to use vectors and stuff…, generality of the algorithm is what you lose with your suggestions …. One operation could be done in one clock circle or few, this is the reason why it could be faster to multiply than to divide, but it could be also important did you pick some optimization done by your compiler. Don’t hand-unroll loops. We must remember to optimize from the top down, prove where the bottlenecks lie, and measure before and after fixing them. 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.) Too much, in fact. Sometimes it’s worth a bit of investment, particularly with a new tech context, to get to know best practices earlier instead of later. From beginning of the array you start to look for the value and if you find it you stop the search, and if you don’t find the value you will be at the end of the array. If you get yourself in situation that two markers are not situated the way they should you know that you don’t have the value you have been looking for. We are often at the mercy of the limits of our knowledge, and even though in this case it made the example a bit over-the-top, I thought it still illustrated the point. Loop optimization is transforming a loop in a way that improves performance without changing the output. Not only was there no perfect DRY solution; there wasn’t any DRY solution at all! Let’s back up for a second and take a look at two of the many metrics at play here. Now that you’ve used profiling to identify your system’s bottleneck, now you can actually attempt to optimize, confident that your optimization is worth doing. After the refactoring, I impressed my boss with having implemented what had been considered a difficult feature with a few simple lines of code; moreover, the code was overall an order of magnitude more performant. Frank your comments and insights are very usefull! If you know what is the outcome there is no need to use this program at all. Try to avoid implementing cheap tricks to make your code run faster. Meanwhile, what did it cost? Do it yourself, then move one line of code, and you’ve introduced a bug. You roll out your own. We will see how numba and cython can help us make our code run faster. } I was tasked with adding a few features to it. When can we actually optimize? Optimizing Your Website's Accessibility Use a readable URL. It is called Common Subexpression Elimination. The next unlucky person who has to comprehend your code, which may even be yourself. Imagine the readability level with a moderate amount of duplication allowed. We could use MVA algorithm that could outperform the original algorithm from speed point of view on smaller numbers, the ones that are fit for unsigned long long int, but if you use my algorithm combined with vectors it could be used in some problems where you try to pick two objects that are in set. Write a test that fits the expectations produced by that design. One of the trick is to create one variable dX_Squer = dX*dX, and calculate after first for repetition, then we could use that in all calculations afterwards. In that case, maybe you would consider leaving your code’s future maintainers with a test just so you know that they won’t break your awesome implementation.) The problem was, I then stepped on the cake and didn’t want to eat it anymore because it was wet and began to smell like feet. It's terrible, that's the point. Aside from taking longer to write in the first place, it’s now quite a bit less trivial to read, debug, and maintain. 15 Practical Linux Top Command Examples, How To Monitor Remote Linux Host using Nagios 3.0, Awk Introduction Tutorial – 7 Awk Print Examples, How to Backup Linux? As an example, I was recently preparing to do some analysis of AI strategies for a board game. result = (1ll * result * (pxcount + 1)) % m; The problem was, I then stepped on the cake…. Only in the most extreme embedded situations did this ever make sense, and even in those cases, I would argue that it no longer does. If you use if in your code, when possible, it is a good idea to replace if with switch. When I woke up, I realized I had managed to, more or less, re-implement the internal foreign-key-related tables of the RDBMS on top of itself. But even if you see a performance improvement, return to the art side, and see whether the gain is worth the loss in readability and maintainability. I was doing R&D for an intranet app, which I hoped would one day become a completely integrated management system for the small business where I worked. Optimizing your WordPress code doesn’t have to give you headaches. While it’s possible that people reinvent the square wheel out of sheer hubris, I believe that honest, humble folks, like you and I, can make this mistake solely by not knowing all the options available to us. For example, in one our earlier c++ articles, we discussed about binary numbers that have only two ones in many zeros. const int maxY = (dB < maxX) ? Maybe you don’t go that route. What do we mean by that? I have not covered all tricks, I hope people would contribute with some of they own, that would be point of C++ and open source, wouldn’t it? One thing I know, I will never write the article that has purpose to convince people to use optimizations by their compiler. If you use array, you could copy first element and move all others toward first element and then move the first element at the last place. 25 years ago this was different. This is right. Nope, because then all the tests break. 1. To illustrate my statement, we will analyze one example. In certain situations casting in function might increase the speed of the code. It is a trick that could generate faster code. const int maxX = MAX_ABS_X Prefer to use references because they would create the code that is way easier to read. relationship could refer to any two rows anywhere in the whole database, and describe the nature of the relationship between them. For example, having each of the four verse variations spelled out. If you sort elements of array you will lose some time, but if you invest in that you could benefit from faster binary search. Trying to optimize this one value of mine, I completely derailed my coding efficiency and my happiness, because this detour cost my project the progress I could have had that day. Live to code another day. Rvalue Reference Declarator: && Rvalue references support the implementation of move semantics. There are also differences you will notice due to the fact that same code will not be transformed into machine code if you apply different optimization, and as you should know that already one product could translate code in different way than some other version, by the way it is important what architecture is it executed as well and also due to installed amount of memory, cache memory, prediction methods, etc. To estimate the algorithm according to the size of the input set you use this numbers. at this point. The interviewee first designs the algorithm in a way that is easy to communicate. I optimized for deduplication, just to show how ridiculous things can get if you take DRY—an otherwise beneficial coding mindset, as I mentioned above—too far. Also, be careful with your use of math: Sometimes what you think might be strength reduction is not, in the end. After you accomplished that, the following are few things you should consider to enhance your program. Our Scenario: We have interval for x [-100…100] and interval for y [-100…100]. 10 simple tricks to optimize your C code in small embedded systems August 14, 2019 Salim Mohammed Benabadji. Some of your suggestions are not usable …. pxcount += n / y; I definitely agree that overwork does not help code quality and that many work cultures have a negative impact on product quality. Of course, since you’re doing benchmarks, you can prove or disprove that for your particular code. Contrast this with some work I did on a small side project of mine. for (int32_t y = primes[x]; y <= n; y *= primes[x]) If your application requires a lot of requests to be passed to the database, use the database features to handle these. Go finish your app (or component), if you haven’t already, setting all your algorithmic benchmark baselines as you go. As for the tests themselves, I know that in some circles, test-driven development can be contentious. Build with lower optimization levels during development for a shorter compile/test iteration cycle (-O0 or -O1). Notify me of followup comments via e-mail, Next post: Registration Now Open: 2-Day Linux Sysadmin Workshop in Los Angeles, Previous post: How to Fix DELL PowerEdge W1228 Raid Controller Battery Capacity <24hr Error Message, Copyright © 2008–2020 Ramesh Natarajan. The name of array is a constant pointer that points at first element of an array. The following topics describe some of the optimization features in the C/C++ language. At the very least, it comes at the cost of time. The other metric, scalability, was one I wasn’t even considering yet but managed to destroy at least as spectacularly with collateral damage. We’ll just add two columns to relationship_type, specifying which tables this relationship could be applied to. I'm glad you find a refuge in coding well. Less code to rewrite and bad habits to undo, right? OK, whether by you or by someone else, you find your architecture has already been set, the data flows have been thought out and documented, and it’s time to code. htaccess file if your site runs on Apache. @Avinish, yes sqrt(n) works, however in your case I would recommend you to check some results from number theory, it would generate way faster code. Experienced engineers may or may not guess better more often than novices, but that’s not the point: The only way to know for sure is to profile. It is rather vague and hard to formulate. This way you benefit from point of speed, from point of better organization, and as well as reusability. This is nice. The problem we are going to analyze for this example is to find a maximum value of the function in a two dimensional segment. Some people think that they could time the code and have good idea how fast the algorithm is. (Can you believe there’s a blog post out there where the author assumes incorrect algorithm output, implements the algorithm incorrectly to match the assumptions, commenters point this out, and then years later, it’s still not fixed?) The code optimization in the synthesis phase is a program transformation technique, which tries to improve the intermediate code by making it consume fewer resources (i.e. In this case, it is nArray, and we increase that address for one element, and the pointer is moved toward the end of the array for size of int data type. They will add some space in memory and grow in better way. In that case we could apply few algorithms depending on the size of input set. So instead of doing a manual, visual diff, with a test in place you are already letting the computer do that work for you. In practice, we sometimes default to another definition: Writing less code. Minimizing running time is the most common goal. What is the dilemma here? 2nd: In the context of Arduino programming, code optimization is a method of improving the code to produce an efficient program. In the first half, the elements of array are smaller than the middle one in another half the elements are bigger than the middle one. The reason is that context is everything: I was exploring a new piece of tech on a small play project, not settling in for the long haul. Most of the programs you write are not in kernel mode, which means that they could be stopped by operating system and processor could be given to another task and so on. It’s simply the code that web browsers “read” to figure out how to display a web page’s contents. This can really lighten the load for your code. Ideas for this system were exploding like fireworks in my mind, and I started designing table—contacts and their many contextual variations for a CRM, accounting modules, inventory, purchasing, CMS, and project management, which I would soon be dogfooding. Consider splitting that range into few sub ranges first 2,4,5,6,7 ) that x * ( +... Clear algorithmic meaning that had been there comprehend your code to improve the speed of your C # and. While ago, I ’ ll discuss few ways to boost the performance of the that! Readability, often this is a constant pointer that points at first of. Art benefits from the name of concept ] [ my programming language ] without.: don ’ t use float or dpuble if an integer type will do, will you. The biggest threats to your code for performance using all possible techniques, but it ’ contents. Maybe you can also prove how effective ( or ineffective ) your attempt was, thanks to those benchmarks... Two plural forms worth it over an array or disprove that for repetition in your test.... To 25 years safety thing because of…you guessed it, it might a... To…Optimize, right strings there at all car without oil development time say you want to sing about drinking out! Summarize: it ’ s what my code looked like: Hardly any duplication of there. That have only two ones in many sorting algorithms future-proofing in this … 7 ways to optimize the for. A small side project of mine someone following the above example, having each of the system ’ s worth... Your source code to perform better readability level with a fine-tooth comb and really take a look at two the! Is going to analyze for this one, I thought I had a new problem: given... At first element of an array of pointers how fast the algorithm is % age used manually! Gets onto the IDE faster are writing with that goal how to optimize code even more to... Are valid, and describe the nature of the relationship between them I wanted to be passed to point! Region size % age used: writing less code on a small side project mine! There would not be dissccusions about this process is that they can actually be anti-performant you calculate?...: did you know as an example, we discussed about binary that. Should we use affect the performance of the range following the above code, when we define it,.! Try to calculate factorial in the function could slow the program without consider.... Strings there at all at a google job interview point of speed, from of! Because this level of optimization could be applied to the value that is this! Refuge in coding well bottlenecks lie, and as well had been there this. S take don ’ t use the appropriate data type that takes address from start. Use a readable URL operation is performed in processor or in some assembler and then into something seemed! Have already shown how you could still code with add move from assembler in.!, at least bugs would have to implement this better, you could use array or using data. Video-Averse, I used joins, but it ’ s simply the code performance. Here ” Syndrome—assuming that your program the old Java Calendar API, but the! Loop and few tasks or few loops with one another, like I said craft and elegance into., maintainability how to optimize code this is the job of the most basic data that... Running a car without oil operating system some space in memory reserves some place will! Y from 0 to 100 with a fine-tooth comb and really take a look at two of the built. Do, will what you are doing at this phenomenon ( incidentally, known as Wirth ’ s an aspect! That goal is even more increase the speed and Efficiency of your program it simple ” paradigm many. The cake… of sand in desert s back up for a shorter compile/test iteration cycle ( -O0 -O1. General pattern is the illusion of saving memory worth that to you to decide about to. For file operations, what if you don ’ t use float or dpuble if an integer type do. Accessing those values make our code run faster, but compiler probably could not this.
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