On Sun, Sep 04, 2005 at 08:21:47AM +0200, Volker Armin Hemmann wrote > On Sunday 04 September 2005 05:27, [EMAIL PROTECTED] wrote:
> > CFLAGS="-O2 -pipe -fomit-frame-pointer -march=pentium4 -mmmx -msse -msse2 > > -mfpmath=sse" > > emm. I would not do this. > > > -mfpmath=sse seems to be slower than -fpmath=387 > > http://www.anandtech.com/mac/showdoc.aspx?i=2436&p=5 > > has the numbers/made the experience. > > It seems, that gcc is not he best optimizer in the world ;) I've read through the article, and there are a couple of interesting items in it... 1) The bit about sse being slower than 387 only applies to the brand new Xeon Irwindale. 2) The brand new 3.6 ghz Xeon Irwindale ran slower than the older 3.06 ghz Xeon Galatin. That leads to one of two possible conclusions... Really Bad) The Irwindale is at least lame if not totally b0rk3n. Not so Bad) The Irwindale is so new that the gcc developers haven't had an opportunity to implement optimizations for it. In either case, I wouldn't want to extrapolate Xeon Irwindale results to all Intel X86 chips, let alone AMD. /usr/portage/app-benchmarks has several items in it. Does anybody know which ones have floating-point tests? Tinfoil-hat-theory... have you noticed that Microsoft just loves to use Xeons, especially dual-Xeons, in their "get the facts" propaganda? I wonder if they've found a problem with gcc's optimizations for Xeon, and are exploiting that problem to bias all their comparisons. -- Walter Dnes <[EMAIL PROTECTED]> My musings on technology and security at http://tech_sec.blog.ca -- gentoo-user@gentoo.org mailing list
