FYI -- by default rpmbuild strips symbols, effectively making Release and RelWIthDebinfo the same thing.
On Mon, Jan 27, 2014 at 10:06 AM, Andrew Stitcher <[email protected]>wrote: > On Sat, 2014-01-25 at 16:05 +0000, Fraser Adams wrote: > > > ... > > One of my colleagues mentioned to me that he reckons that there was a > > performance drop off between (I think) 0.12 and 0.18 but I've got no > > evidence other than anecdotal from him and certainly no reproducer. > > I doubt this has anything to do with the change of build system. > > > > > It did get me thinking about CMake though (though my colleague insists > > he was using automake so there might still be an issue). > > > > Am I correct in thinking that with CMake there are different "build > > types" and that in "idiomatic" CMake usage it's "generally" via the use > > of different build types that compiler optimisation flags get set? > > I think that (too lazy to actually go look) in autotools the build > default was -O2 and the Fedora/RHEL packaging set -O3. > > It is completely true that with cmake we've opted to follow the usual > cmake practice (which is standard on Windows too) of having the build > configuration dictate the optimisation/debug flags. I think that in the > Fedora/RHEL packages we now use the RelWithDebInfo build configuration > which corresponds to -O2 -g. > > It is true that if you specify no CMAKE_BUILD_TYPE then you will get no > optimisation or debug flags set which is perhaps a rather bad idea. > > What do you think the default build type should be? (Out of Debug = -g, > Release = -O2 -DNDEBUG, RelWithDebInfo -O2 -DNDEBUG -g, MinSizeRel = -Os > -DNDEBUG) > > It's not clear to me that we should prioritise performance over > debugability in our default build. > > Andrew > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > -- Davin Shearer Engineer 8830 Stanford Blvd, Suite 306 Columbia, MD 21045 443-741-4517
