Linked Questions

Note: the alleged duplicate question is, I think, mostly related to "<" and ">" comparison, but not "==" comparison and hence does not answer my question about performance of the "==" operator. ...

Why does the y[i] < x[i] function take twice the time when array x is always higher in value than y (for ex 1<x<2, and 0<y<1). In addition, when comparing 0.5<x<1.5, and 0<y<...

I have a very big ArrayList in Java (let's call it ArrayA), it have three million elements. I have another ArrayList in Java, that is slightly bigger than arrayA, it have three and a half million ...

I generated two matrices of 1000 x 1000: First Matrix: O and #. Second Matrix: O and B. Using the following code, the first matrix took 8.52 seconds to complete: Random r = new Random(); for (int i ...

I was looking for the fastest way to popcount large arrays of data. I encountered a very weird effect: Changing the loop variable from unsigned to uint64_t made the performance drop by 50% on my PC. ...

I was trying various methods to implement a program that gives the digits of pi sequentially. I tried the Taylor series method, but it proved to converge extremely slowly (when I compared my result ...

Could someone possibly give an example of "cache unfriendly code" and the "cache friendly" version of that code? How can I make sure I write cache-efficient code?

Are there are any cases where you would prefer O(log n) time complexity to O(1) time complexity? Or O(n) to O(log n)? Do you have any examples?

See Related .NET question I'm looking for a quick and easy way to do exactly the opposite of split so that it will cause ["a","b","c"] to become "a,b,c" Iterating through an array requires either ...

I first noticed in 2009 that gcc (at least on my projects and on my machines) have the tendency to generate noticeably faster code if I optimize for size (-Os) instead of speed (-O2 or -O3), and I ...

I read everywhere that ternary operator is supposed to be faster than, or at least the same as, its equivalent if-else block. However, I did the following test and found out it's not the case: ...

I've been digging through some parts of the Linux kernel, and found calls like this: if (unlikely(fd < 0)) { /* Do something */ } or if (likely(!err)) { /* Do something */ } I've found ...

I have a strange habit it seems... according to my co-worker at least. We've been working on a small project together. The way I wrote the classes is (simplified example): [Serializable()] public ...

I have come across a lot of optimization tips which say that you should mark your classes as sealed to get extra performance benefits. I ran some tests to check the performance differential and found ...

I argued with a friend the other day about those two snippets. Which is faster and why ? value = 5; if (condition) { value = 6; } and: if (condition) { value = 6; } else { value = 5; } ...