Path: utzoo!mnetor!uunet!husc6!tut.cis.ohio-state.edu!morganucodon.cis.ohio-state.edu!paul
From: paul@morganucodon.cis.ohio-state.edu (Paul Placeway)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Is my Mac II really slow?
Message-ID: <10382@tut.cis.ohio-state.edu>
Date: 12 Apr 88 21:41:10 GMT
References: <11541@duke.cs.duke.edu>
Sender: news@tut.cis.ohio-state.edu
Organization: The Ohio State University Dept of Computer and Information Science
Lines: 24
Keywords: Mac II, floating point, benchmarks

< 	extended dot(x1,y1,z1,x2,y2,z2)
< 	{ return(x1*x2+y1*y2+z1*z2);}

In addition to the Mac-specific floating-point advice, you could
probably get a reasonable speadup on all of the machines (depending on
the smartness of the respective compilers) by replacing this with:

    #define DOT(x1,y1,z1,x2,y2,z2)	(x1*x2+y1*y2+z1*z2)

This will eliminate the overhead of a function call with 6 arguments on
the stack (usually compairable in speed to several FLOPS) , and will
allow you to declare the variables as register (as long as the compiler
understands what a "register double" is).  A really good compiler should
turn this into code that is about as good as tuned (straight-forwared)
assembly code (including exploiting 68881 register values).

Of course, your milage may vary...

		-- Paul
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