asm - Enable use of hand optimized assembly routines (faster execution)
cpudetection - Enables runtime CPU detection (useful for binpkgs, compatibility on other CPUs). This only works on amd64/x86 at present. If this flag is enabled, GMP will work on a variety of amd64/x86 CPUs and load accelerated routines for use at runtime depending on the CPU in use. This makes it suitable for binary packages (binpkgs). If this flag is disabled, GMP will be tuned for the CPU being used at build-time and may not be usable on other machines.
cxx - Build support for C++ (bindings, extra libraries, code generation, ...)
doc - Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally
pic - Force static libraries to be built as PIC to avoid TEXTRELs.
static-libs - Build static versions of dynamic libraries as well