Date: Fri, 1 Dec 1995 16:21:39 -0500 From: "Garrett A. Wollman" <wollman@lcs.mit.edu> To: "Marc G. Fournier" <scrappy@hub.org> Cc: current@freebsd.org Subject: -O6/-fstrength-reduce for kernel (Was: Re: changes in -current...) Message-ID: <9512012121.AA13642@halloran-eldar.lcs.mit.edu> In-Reply-To: <Pine.BSF.3.91.951201141723.18665A-100000@hub.org> References: <199512011252.XAA17404@godzilla.zeta.org.au> <Pine.BSF.3.91.951201141723.18665A-100000@hub.org>
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<<On Fri, 1 Dec 1995 14:20:39 -0500 (EST), "Marc G. Fournier" <scrappy@hub.org> said: > Also, someone mentioned using -fno-strength-reduce? If I > used that, with -O6, would I notice any benefits, or does using > -fno-strength-reduce just about take out any benefits to -O6? Your Mileage May Vary. In the testing I was doing last month on packet send and forwarding rates, I found that using any sort of optimization beyond the default `-O' resulted in a repeatable 1-3% /decrease/ in maximum packet rate. The same was true of `-m486'. I'll be interested to see the results if the Pentium enhancements are ever integrated into the main gcc line. I suspect there may be some funny cache effects going on, but it's next to impossible to tell. -GAWollman -- Garrett A. Wollman | Shashish is simple, it's discreet, it's brief. ... wollman@lcs.mit.edu | Shashish is the bonding of hearts in spite of distance. Opinions not those of| It is a bond more powerful than absence. We like people MIT, LCS, ANA, or NSA| who like Shashish. - Claude McKenzie + Florent Vollant
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