Libsharp is configured, compiled and installed using GNU autotools.
The most complicated step for the user is selecting the appropriate compiler
flags (and in some cases the compiler).

Here are a few (hopefully helpful) examples:

GCC, OpenMP, portable executable:
CFLAGS="-std=c99 -O3 -ffast-math -flto -fopenmp" ./configure

GCC, OpenMP, specific optimization for the target CPU:
CFLAGS="-std=c99 -O3 -march=native -ffast-math -flto -fopenmp" ./configure

GCC, no OpenMP, specific optimization for the target CPU:
CFLAGS="-std=c99 -O3 -march=native -ffast-math -flto" ./configure

Clang:
CC=clang CFLAGS="-std=c99 -O3 -march=native -ffast-math -flto -fopenmp" ./configure

MPI support:
CC=mpicc CFLAGS="-DUSE_MPI -std=c99 -O3 -march=native -ffast-math -flto" ./configure

Additional GCC flags for pedantic warning and debugging:

-Wall -Wextra -Wshadow -Wmissing-prototypes -Wfatal-errors -pedantic -g
-fsanitize=address