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Newsgroups: comp.os.386bsd.questions Path: sserve!newshost.anu.edu.au!munnari.oz.au!bruce.cs.monash.edu.au!harbinger.cc.monash.edu.au!yeshua.marcam.com!charnel!olivea!ames!cnn.nas.nasa.gov!wilbur.nas.nasa.gov!tweten From: tweten@wilbur.nas.nasa.gov (Dave Tweten) Subject: Re: sqrt(-1) Message-ID: <CM1wLn.Gvs@nas.nasa.gov> Sender: news@nas.nasa.gov (News Administrator) Nntp-Posting-Host: wilbur.nas.nasa.gov Organization: NAS Systems Division, NASA Ames References: <762584248.AA09532@f74.n700.z6.ftn.air.org> <2l1nt3$m0s@Germany.EU.net> Date: Wed, 2 Mar 1994 18:56:10 GMT Lines: 20 In article <2l1nt3$m0s@Germany.EU.net> bs@Germany.EU.net (Bernard Steiner) writes: >In article <762584248.AA09532@f74.n700.z6.ftn.air.org>, Clarence.Chu@f132.n700.z6.ftn.air.org (Clarence Chu) writes: >|> and on compiling libm, why is an -O2 doesn't work? >I assume that -O2 switches on -ffast-math that inlines many of the >library calls to __asm__s. Maybe you can switch it of with -fno-fast-math >or something. Actually, some of the math routines were written by someone who thought a good way to report a mathematically impossible calculation (eg., log(0)) was to return a constant expression which involved dividing by zero. "-O2" does compile-time constant expression evaluation. Oh ... -- --------------------------------------------------------------------------- Dave Tweten tweten@nas.nasa.gov NASA Ames Research Center, M/S 258-5 (415) 604-4416 Moffett Field, CA 94035-1000 FAX: (415) 604-4377