------- Comment #14 from vlad at demoninsight dot com 2009-12-01 05:50 ------- (In reply to comment #13) > (In reply to comment #12) > > Compile-time. > > configure with --enable-checking=release to turn off checks that are enabled > by > default in pre-release builds, that will give a better comparison between the > 4.4.2 release and 4.5 snapshot >
Thank you for a useful tip. I have re-built the same snapshot: Using built-in specs. COLLECT_GCC=gcc-4.5 COLLECT_LTO_WRAPPER=/sw/lib/gcc4.5.trunk/libexec/gcc/x86_64-apple-darwin10/4.5.0/lto-wrapper Target: x86_64-apple-darwin10 Configured with: ../src/configure --enable-checking=release --prefix=/sw/lib/gcc4.5.trunk --mandir=/sw/share/man --infodir=/sw/share/info --enable-languages=c,c++,fortran --with-gmp=/sw --with-libiconv-prefix=/sw --with-ppl=/sw --with-cloog=/sw --with-system-zlib --x-includes=/usr/X11R6/include --x-libraries=/usr/X11R6/lib --disable-libjava-multilib --build=x86_64-apple-darwin10 --host=x86_64-apple-darwin10 --target=x86_64-apple-darwin10 Thread model: posix gcc version 4.5.0 20091128 (experimental) (GCC) It did make a noticeable difference. With 4.4.2 and 4.5 snapshot installed in parallel dirs, I ran the same build in two shells and simply pointing the builder from one version to another. The times are quite reproducible: 4.4.2: ~ 337 sec 4.5: ~ 466 sec (averages of two runs each). So, 4.5 snapshot is 40% slower at compile time. This is quite a bit better than without --enable-checking=release (which was close to 2x slower) but seems a tad heavy price to pay to just have exceptions working ... -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42159