Matthew S. Hallacy wrote: >Programs that can take advantage of optimizations usually are, the kernel, >glibc, mplayer, etc. Randomly using optimization flags on all your software >will lead to an unstable system with bugs that you simply can't find. Generating code for a specific processor (.i.e Athlon) rather than 80386 code just makes sense if a machine has this specific processor. That is a trivial (safe) optimization. It should not be considered a complex (potentially unsafe) optimization. Randomly selecting gcc optimization flags without extensive testing is certainly not a good idea and I doubt that Gentoo uses such an approach. Hopefully, Gentoo doesn't use rarely used optimizations by default unless there is a significant performance benefit and no known bugs as a result. The Gentoo approach of compiling all software probably does aid in fixing optimization related bugs more effectively and faster than any binary distribution approach does. While it is true that most software will not benefit from new processor instructions there are some areas in addition to those Matthew mentioned where there is a significant performance benefit. For example, in the Sparc architecture, there is a huge advantage in using Sparc v8 or v9 instructions over just using the base Sparc v7 instructions in openssl for those processors that support the v8 or v9 instructions. Sincerely, Ken Fuchs <kfuchs at winternet.com> _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota http://www.mn-linux.org tclug-list at mn-linux.org https://mailman.real-time.com/mailman/listinfo/tclug-list