Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!uvaarpa!mcnc!duke!juliet!khera
From: khera@juliet.cs.duke.edu (Vick Khera)
Newsgroups: comp.lang.c
Subject: Re: C optimizer
Keywords: C pure function optimization
Message-ID: <13649@duke.cs.duke.edu>
Date: 24 Feb 89 17:51:44 GMT
References: <515@larry.UUCP> <9648@smoke.BRL.MIL> <1026@frog.UUCP> <9693@smoke.BRL.MIL>
Sender: news@duke.cs.duke.edu
Reply-To: khera@cs.duke.edu (Vick Khera)
Organization: Duke University CS Dept.; Durham, NC
Lines: 24

In article <9693@smoke.BRL.MIL> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) writes:
>In article <1026@frog.UUCP> john@frog.UUCP (John Woods) writes:
>>The 68881 chip has FCOS, FSIN, and (gasp) FSINCOS which simultaneously
>>computes cos() and sin() of the same argument.  A sufficiently clever
>>compiler could potentially make great use of that.
>
>Well, hurray -- I've wanted that for years!  I do hope C implementors
>will perform this optimization; it could help us computer-graphics types
>quite a bit.

The Sun 3 C compiler will use the intrinsic functions of the 68881 chip if
you tell it to compile with the f68881.il inline-expansion file. i beilieve
it is located in /usr/lib/f68881/libm.il under 4.0, and in
/usr/lib/f68881.il in 3.x.

example compile line:

cc -o prog prog.c /usr/lib/f68881.il

						vick.
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