58
votes
11
answers
1.9K
views
Why does C++ code for testing the Collatz conjecture run faster than hand-written assembly?
I wrote these two solutions for Project Euler Q14, in assembly and in C++. They implement identical brute forc
64
votes
11
answers
1.9K
views
Replacing a 32-bit loop counter with 64-bit introduces crazy performance deviations with _mm_popcnt_u64 on Intel CPUs
I was looking for the fastest way to popcount large arrays of data. I encountered a very weird effect: Changin
62
votes
14
answers
659
views
Is < faster than <=?
Is if (a < 901) faster than if (a <= 900)? Not exactly as in this simple example, but there are slight p
58
votes
12
answers
931
views
Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?
I am doing some numerical optimization on a scientific application. One thing I noticed is that GCC will optim
67
votes
7
answers
834
views
What is the purpose of a stack? Why do we need it?
So I am learning MSIL right now to learn to debug my C# .NET applications. I've always wondered: what is
57
votes
1
answers
2K
views
fast multiplication of int8 arrays by constants
I wonder if there is a fast way of multiplying int8 arrays, i.e. for(i = 0; i < n; ++i) z[i] = x * y[i]
67
votes
6
answers
557
views
How can one generate and save a file client side using Blazor?
I want to have a SPA that's doing all the work client side and even generating some graphs/visuals. I&ap
