[Bug c++/69635] 4x increase of build time [4.9 -> 6.0]
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69635 --- Comment #1 from Jonathan Wakely --- Did you build gcc6 with --enable-checking=release ?
[Bug c++/69635] 4x increase of build time [4.9 -> 6.0]
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69635 Markus Trippelsdorf changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED CC||trippels at gcc dot gnu.org Resolution|--- |INVALID --- Comment #2 from Markus Trippelsdorf --- You can speed up the build time by using -flto=. With -flto=4 it compiles in ~5 minutes on my machine with gcc-6 (checking=release). Closing as invalid.
[Bug c++/69635] 4x increase of build time [4.9 -> 6.0]
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69635 --- Comment #3 from h2+bugs at fsfe dot org --- Thank you for the quick replies! > Did you build gcc6 with --enable-checking=release ? I am using the pre-built FreeBSD packages, I have checked, and it seems it is not the case. That likely explains it... I will double-check with the package maintainer. > You can speed up the build time by using -flto=. Ah, that's very interesting! I hadn't seen -flto with a number yet. Is there more documentation on it? Is this the "WHOPR" mode described here: https://gcc.gnu.org/onlinedocs/gccint/LTO-Overview.html ? I had previously thought flto was only useful when linking multiple translation units... Does it have an effect on the produced binary?
[Bug c++/69635] 4x increase of build time [4.9 -> 6.0]
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69635 --- Comment #4 from Markus Trippelsdorf --- (In reply to h2+bugs from comment #3) > Thank you for the quick replies! > > > Did you build gcc6 with --enable-checking=release ? > > I am using the pre-built FreeBSD packages, I have checked, and it seems it > is not the case. That likely explains it... I will double-check with the > package maintainer. > > > You can speed up the build time by using -flto=. > > Ah, that's very interesting! I hadn't seen -flto with a number yet. Is there > more documentation on it? Sure, in the compiler manual. > Is this the "WHOPR" mode described here: > https://gcc.gnu.org/onlinedocs/gccint/LTO-Overview.html ? > I had previously thought flto was only useful when linking multiple > translation units... Does it have an effect on the produced binary? For a single translation unit generally no. It just runs some optimizations and the code generation in parallel, hence the speedup.
