libdivide allows you to replace expensive integer divides with comparatively
cheap multiplication and bitshifts. Compilers usually do this, but only when the
divisor is known at compile time. libdivide allows you to take advantage of it
at runtime. The result is that integer division can become faster - a lot
faster.

Furthermore, libdivide allows you to divide SIMD vectors by runtime constants,
which is especially nice because SIMD typically lacks integer division.

See also: https://github.com/ridiculousfish/libdivide/