I concur with Ben. Profiling can be specified at configure time. To me, switching between opt and dbg is something I do all day long while profiling is generally more deliberate. When I want to profile I am going to set everything up for that and do it for a while. It is much less frequent, and not mixed in with my normal daily development cycle...
Derek Sent from my iPhone On Nov 28, 2012, at 1:51 PM, "Kirk, Benjamin (JSC-EG311)" <benjamin.kir...@nasa.gov> wrote: > > On Nov 28, 2012, at 2:30 PM, Roy Stogner <royst...@ices.utexas.edu> wrote: > >> On Wed, 28 Nov 2012, Kirk, Benjamin (JSC-EG311) wrote: >> >>> If at all possible I'd rather treat that as --enable-gprof and add >>> the flags to the existing dbg, devel, opt flags >> >> The trouble with this is that the gprof and oprof flags aren't without >> cost. IIRC "-pg" adds in extra code (including synchronous writes to >> disk!!); "-fno-omit-frame-pointer" turns off an optimization that even >> "-O" includes by default; and I suppose even "-g" must have some cost >> or we'd have added it to METHOD=opt already. >> >> So if you mix profiling with optimization, the result isn't really >> optimized. >> >> But if you mix profiling with debug/devel modes, then your runtime >> data is all swamped by the costs of internal tests and disabled >> optimizations, so the result isn't really profiling. > > Yeah, but with a --prefix you can put a pure opt somewhere and a gprof, > oprofile, vtune, and whatever else comes along somewhere else. To me anyway > this is much preferable to maintaining multiple method rules and targets. > > opt,dbg, and devel are materially different not so much because of the > compiler flags (important, but doesn't change the fundamental nature of the > code being compiled) but rather the CPPFLAGS - -DNDEBUG, -DDEBUG, <> > respectively. > > Aside - my understanding is the only cost to "-g" is file size, and there are > 'make install-strip' targets for that for those who care - it will strip the > symbols at install time. That's why the default CXXFLAGS unless you do > something special become '-g -O2'. > > -Ben > > > ------------------------------------------------------------------------------ > Keep yourself connected to Go Parallel: > INSIGHTS What's next for parallel hardware, programming and related areas? > Interviews and blogs by thought leaders keep you ahead of the curve. > http://goparallel.sourceforge.net > _______________________________________________ > Libmesh-devel mailing list > Libmesh-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/libmesh-devel ------------------------------------------------------------------------------ Keep yourself connected to Go Parallel: INSIGHTS What's next for parallel hardware, programming and related areas? Interviews and blogs by thought leaders keep you ahead of the curve. http://goparallel.sourceforge.net _______________________________________________ Libmesh-devel mailing list Libmesh-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-devel
