If 'defaultprec' is what one gets by default, and 'strict' and 'precise' are supposed to be more strict than the default, then you don't need any flags in 'strict' and 'precise'.  The behavior one gets when not passing any flags is ISO C and ISO C++ compliant (does not enable any funny optimizations).

In 'loose' and 'veryloose' you don't need anything except -ffast-math, because -ffast-math assumes everything else.