When lapack-atlas builds on sparc, it apparently ignores the CFLAGS from make.conf and substitutes its own. For me on my U60 sparc test system, that means it tosses my CFLAGS="-O2 -mcpu=ultrasparc -pipe" for CFLAGS="-fomit-frame-pointer -O3 -funroll-loops" This guarantees about the worst performance possible on sparc (well, -O0 would be worse) because it forces code to be generated for sparc -mcpu=v7 (instead of cpu=ultrasparc). So, for a heavily numeric application like I believe lapack to be, I suspect most of the time is spent in the kernel busily emulating instructions the compiler does not believe to be available. Unless there are compelling reasons, if performqnce matters (as it does for lapack), a package should leave sparc's CFLAGS alone. (And probably, if Fortran is involved, FFLAGS should default to CFLAGS. You have the same architecture-based performance issues with g77 as with gcc, but lapack seems just to choose -O or -O2 only for g77, apparently depending on its mood at the time: It uses both.) Long discussion at Bug 59506. ciaranm's CFLAGS metabug.
Ferris: I think you helped fixing a similar problem in sci-libs/blas-atlas. Here's the particular code in the ebuild: -- # Added to allow compilation on sparc architecture. The default CCFLAG0 # and MMFLAGS are *bad*. # Danny van Dyk <kugelfang@gentoo.org> 2004/07/02 # reconfigure() { case "`uname -p`" in "sun4m") MY_CCFLAGS="-O3 -mcpu=v8" MY_CXXFLAGS="${MY_CCFLAGS}" MY_MMFLAGS="-O -mcpu=v8" MY_LDFLAGS="" ;; "sun4u") MY_CCFLAGS="-O3 -mcpu=ultrasparc" MY_CXXFLAGS="${MY_CCFLAGS}" MY_MMFLAGS="-O -mcpu=ultrasparc" MY_LDFLAGS="" ;; *) MY_CCFLAGS="${CFLAGS}" MY_CXXFLAGS="${CXXFLAGS}" MY_MMFLAGS="${CFLAGS}" MY_LDFLAGS="${LDFLAGS}" ;; esac MY_FILE="`find -name Make.Linux*`" sed -i -e "s/CCFLAG0 =.*/CCFLAG0 = \$(CDEFS) ${MY_CCFLAGS}/" \ -e "s/CCFLAGS =.*/CCFLAGS = \$(CDEFS) ${MY_CCFLAGS}/" \ -e "s/CLINKFLAGS =.*/CLINKFLAGS =\$(CDEFS) ${MY_LDFLAGS}/" \ -e "s/XCCFLAGS =.*/XCCFLAGS =\$(CDEFS) ${MY_CXXFLAGS}/" \ -e "s/MMFLAGS =.*/MMFLAGS = ${MY_MMFLAGS}/" \ ${MY_FILE} || die "sed didnt complete" } -- Shall i apply this or something similar to lapack-atlas as well?
Yes, although experience has taught us that '-O2' is generally a saner choice on sparc than '-O3'. Let me know if you need testing (although nothing is going to happen with testing before 28 or 29 November because of US holidays). Thanks, Ferris
Danny, did you want to apply your suggested change?
Ping???
The lapack-atlas/blas-atlas ebuilds in ~ARCH (currently 3.7.24) have been completely overhauled and should do the right thing and honor the user's CFLAGS. If one of the sparc folks could check them out and report back with any problems that would be great. Thanks, Markus
With 3.7.24, CFLAGS (and FFLAGS) for both are fine (what I have in make.conf). Thanks.
Hi Ferris, Thanks a lot for testing:) Would it be all right with you if I close this bug then? I'd rather not mess with what we have in stable right now and wait until 3.7.24 (or greater) hits stable. Best, Markus
(In reply to comment #7) > Hi Ferris, > > Thanks a lot for testing:) Would it be all right with you if I close this bug > then? I'd rather not mess with what we have in stable right now and > wait until 3.7.24 (or greater) hits stable. > > Best, > Markus > Markus, It's fixed in 3.7.24 and I'll close it for you. :) Thanks for the help.
