Components used to build GCC

[vicentesmith]

Hello,
I'm building GCC11 on a system running Ubuntu20.04 (that includes GCC 9.3.0). After downloading the prerequisites, the system is stating:
...
gmp-6.1.0.tar.bz2: OK
mpfr-3.1.6.tar.bz2: OK
mpc-1.0.3.tar.gz: OK
isl-0.18.tar.bz2: OK
All prerequisites downloaded successfully.
My question is whether the GCC build is going to use these versions of GMP, MPFR and MPC or the ones already installed in the system, which are more recent. Thanks.