>> Also, is there any significant difference in bootstrap times? > > I haven't actually measured, but subjectively bootstrap does seem to > take longer. I tried this out of curiosity. The numbers below are the bootstrap times on a 64bit 2.6.28 Linux system (Core 2 E8400), building single threaded with --enable-languages=c,c++ --disable-multilib
Regular gcc: real 59m6.914s user 53m53.702s sys 3m24.073s gcc-in-cxx: real 68m15.366s user 61m32.255s sys 4m24.481s Of course the bootstrap times are not that useful themselves, as they compare two quite different compilation tasks (one C, one C++). To get a better idea about the different compiler speeds, I compiled some random (reasonably complex) C++ code I had at hand, and compared the compile times. Regular gcc: real 0m30.478s user 0m27.842s sys 0m1.888s gcc-in-cxx: real 0m35.926s user 0m34.386s sys 0m1.208s Again the comparison is not 100% fair ("regular gcc" is current mainline, while the gcc-in-cxx branch is older), but apparently the C++ version is quite a bit slower. Admittedly gcc-in-cxx just recently managed to bootstrap at all, so perhaps performance comparisons are a bit unfair. But I do not mean this as critique of gcc-in-cxx, I want to help improve it and to bring it to the same speed as regular mainline. Is there any reasonably simple way to find out why the C++ version is slower? I can use something like oprofile, of course, but I thought gcc can somehow give statistics about its internal times, which might be more useful for a first approximation. Thomas