Given by a colleague as a puzzle, I cannot figure out how this C program actually compiles and runs. What is this >>>= operator and the strange 1P1 literal? I have tested in Clang and GCC. There are no warnings and the output is “???” #include <stdio.h> int main() { int a[2]={ 10, 1 }; … Read more
Multiplication and division can be achieved using bit operators, for example i*2 = i<<1 i*3 = (i<<1) + i; i*10 = (i<<3) + (i<<1) and so on. Is it actually faster to use say (i<<3)+(i<<1) to multiply with 10 than using i*10 directly? Is there any sort of input that can’t be multiplied or divided … Read more
I’ve been attempting to learn C in my spare time, and other languages (C#, Java, etc.) have the same concept (and often the same operators) … What I’m wondering is, at a core level, what does bit-shifting (<<, >>, >>>) do, what problems can it help solve, and what gotchas lurk around the bend? In … Read more
