65
votes
4
answers
2.3K
views
How to run a program without an operating system?
How do you run a program all by itself without an operating system running? Can you create assembly programs t
52
votes
4
answers
663
views
How do I achieve the theoretical maximum of 4 FLOPs per cycle?
How can the theoretical peak performance of 4 floating point operations (double precision) per cycle be achiev
64
votes
17
answers
1.5K
views
What's the purpose of the LEA instruction?
For me, it just seems like a funky MOV. What's its purpose and when should I use it?
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
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]
