mrhappy

print out Happy Numbers up to 1,000,000 really fast

build and run

it's CMake remember to set -DCMAKE_BUILD_TYPE=Release

only tested on Ryzen 5 5600X

cmake -DCMAKE_BUILD_TYPE=Release -B build
cmake --build build
./build/mrhappy

it uses an inefficient write loop, but fputs is slower

need to make a buffer that fits in L1D to reduce stalled cycles but don't feel like handling that logic right now