This project is unfinished, if you want to support or help with the development it is not necessary to write me, you can make use of the project as you wish.
made for simple usage where pure C is the safest option.
just download and add BigInt.h and BigInt.c as a static library. It will compile to target with at least 16 bits.
All the function can be seen in BigInt.h, they are commented about the usage.
compiling with -O2 or -O3 will increase the performance considerably. usable with -flto and -Ofast.