Le Mon, Aug 04, 2008 at 11:10:02AM +0200, Michel Dänzer a écrit : > On Mon, 2008-08-04 at 10:24 +0900, Charles Plessy wrote: > > http://gcc.gnu.org/onlinedocs/gcc/PowerPC-AltiVec-Built_002din-Functions.html > > These flags are prerequisites for allowing the resulting binaries to > contain Altivec code at all, but on their own they don't cause any such > code to be generated (except maybe for some simple cases like memory > copies). Current versions of GCC can automatically vectorize some code > with -ftree-vectorize, but the results probably still can't compete with > hand-optimized code. > > Also note that these flags will make the resulting binaries unusable on > systems without Altivec support.
Well, it seems that it makes it doubly impossible to get the best performance out of those machines :( Anyway, the example I gave (the building of the exonerate package) is definitely not the best. It does some kind of bootstraping (that made parallel building fail) that I do not understand, nor I know if the speed of bootstrapping reflects the actual speed of the binary. By the way, I uploaded a new upstream release, that took 1h40 to build on amd64, 7h30 on G4, and 8h on MIPS. [OT: I have not data with G5 as I did not want to leave my iMac switched on overnight and the machine I use at work crashed again. Does anybody knows a good equivalent to memtest86?] Another example I have is a map website by Yahoo Japan: http://map.yahoo.co.jp/pl?type=scroll&lat=35.35961995&lon=138.73361576&sc=7&mode=map&pointer=on With Iceweasel it is slow on G5 and fluid on Intel. Again, not so easy to benchmark. I still have that gut feeling that the my G5 machines runnign Debian are abnormally slow compated to my Duo 1.5 Ghz laptop. Have a nice day, -- Charles Plessy Tsurumi, Kanagawa, Japan -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]