Moving from OpenBSD to FreeBSD trying the 13 BETA out I noticed that GCC-4.8 was available. Given that GCC 4.8 being the first GCC release stating support for most major features of C++11 I thought it was worth giving it a go to see how the compile times compare with the system compiler, clang 11.
pekwm did require some added compatability code for std::put_time, std::stoi, std::stof and std::to_string which all are C++11 but unavailable using GCC-4.8.5 part of FreeBSD.
The older compiler is indeed a lot faster than current clang (and current GCC, no numbers included).
The unscientific numbers for a full build of pekwm including the test applications:
make, clang 11.0.1 104.30 real 100.31 user 4.48 sys make -j4, clang 11.0.1 48.90 real 174.34 user 6.45 sys make, gcc 4.8.5 63.82 real 57.55 user 5.89 sys make -j4, gcc 4.8.5 29.51 real 100.03 user 8.63 sys
Disregarding the absolute numbers there’s quite a bit of time to save during development having almost twice as fast compile times. The generated binaries probably are slower assuming optimizers have become better over the years but looking at this from the developers point of view it might actully be worth using older compilers during part of the development cycle to avoid spending time waiting for the compiler to finish.