Install prerequisites. This program uses GMP, MPFR, and {fmt}. You also need a working C++17 compiler (tested with GCC 10 on Debian 11).

On Debian, run:

sudo apt update
sudo apt install -y build-essential libgmp-dev libmpfr-dev libfmt-dev

Now compile the source:

c++ -opi pi.cc -std=c++17 -O3 -march=native -lgmp -lmpfr -lpthread -lfmt

You'll have pi executable file in the current directory.

The program takes one argument, number of decimal digits to calculate. For example, to calculate 100 digits of pi, run:

./pi 100