m4

System: Slackware Linux (version 15.0)
CPUs: Intel(R) Core(TM) i5-3230M CPU @2.60GHz
GPU: Mesa DRI Intel(R) HD Graphics 4000

GNU m4 is a lightweight binary.

It maps directly into memory, and is ready to process in under 1 millisecond.

bash-5.1$ git clone -q -b branch-2.0 https://git.savannah.gnu.org/git/m4.git
bash-5.1$

The development version needs a patch in order for it to build with glibc 2.33.