Date: Thu, 5 Apr 2007 08:42:38 -0700 From: Gary Kline <kline@tao.thought.org> To: scuba@centroin.com.br Cc: freebsd-questions@freebsd.org Subject: Re: unroll-loops - Is it always safe? Message-ID: <20070405154238.GB88189@thought.org> In-Reply-To: <20070405093721.N22331@trex.centroin.com.br> References: <20070405093721.N22331@trex.centroin.com.br>
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On Thu, Apr 05, 2007 at 09:54:08AM -0300, scuba@centroin.com.br wrote: > Hi All, > > Is it always safe to use "-funroll-loops" as a flag to > /etc/make.conf ? Does it realy improve the compiled programs? > > When should I avoid to use it? If you are using gcc42 -funroll-loops can be a win. gcc3.x is less savvy about knowing the limits of complexity to unroll which loops. I'm doing some tests with gcc34 (default) and gcc42. The latter can yield significant improvements iff you know what you're doing. It's no magic bullet. gary > > - Marcelo > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org" -- Gary Kline kline@thought.org www.thought.org Public Service Unix
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