The most upvoted question in the history of StackOverflow(stackoverflow.com)

The most upvoted question in the history of StackOverflow

https://stackoverflow.com/questions/11227809/why-is-processing-a-sorted-array-faster-than-processing-an-unsorted-array

13 comments

We often hear that choosing the right algorithm will get rid of all performance problems. There is no "need" to understand what is happening under the hood and all programmers should only work at higher levels of abstraction.

My take away from this question and and the top answer was that the above is not true. It does not mean that everyone has to code using assembly - it means that good programmers are aware of where their abstractions may leak.

Related reading (can't believe it's almost 20 years since this article was written) - https://www.joelonsoftware.com/2002/11/11/the-law-of-leaky-a...

inglor_cz4 anni fa

Knowing the character of your data is priceless. The only time I was able to throughly beat GCC with optimizations is when I knew that most 32-bit values being calculated upon are actually fairly small (in tens of thousands) and that I could use that to my advantage.

idbehold4 anni fa

I thought for sure it was going to be "How do I exit vim?"

nrook4 anni fa

I was expecting this post, asking the best ways to match HTML tags with regular expressions.

https://stackoverflow.com/questions/1732348/regex-match-open...

Sadly the page is currently locked, likely as a conspiracy to avoid it overtaking the OP.

stuartd4 anni fa

It’s locked so you can’t edit it, but you can still upvote it if you want.

jonas-w4 anni fa

I know it is a joke, but: It "Only" has 4867 votes while the answer has 5947. This seems to be the highest voted "How do I exit vim?" Post. https://stackoverflow.com/questions/11828270/how-do-i-exit-v...

mbrodersen4 anni fa

It is a perfect example of why you need to know the low level gritty details of how modern CPU’s (and Caches/RAM) works to write high performance high level code. A few years ago I optimised a C++ constraint algorithm from 47 minutes to 2 secs by re-arranging how the data access was organised. Writing your code in C++ doesn’t automatically make it fast. You still need to understand the low level details to make fast code.

tromp4 anni fa

Summary: due to deep pipelines and branch prediction, a tight loop with a single if statement goes fastest if the test nearly always comes out the same way as last time, and slowest when it is true or false at random.

altilunium4 anni fa

I'd always been suspicious of all the black magic optimization that my compiler/library implementation/runtime did discreetly behind the hood.

tiagod4 anni fa

In this case, its not the compiler, nor the library, nor the runtime. Its the CPU

tomcam4 anni fa

You’re correct of course but my sentiments are with GP

geoduck144 anni fa

Everyone here should upvote and answer on the page - just to keep it going

aksss4 anni fa

Boo this man!