Path: utzoo!attcan!uunet!husc6!endor!singer
From: singer@endor.harvard.edu (Rich Siegel)
Newsgroups: comp.sys.mac
Subject: Re: What C compiler generates fastest code?
Message-ID: <4880@husc6.harvard.edu>
Date: 4 Jul 88 15:48:01 GMT
References: <14105@shemp.CS.UCLA.EDU>
Sender: news@husc6.harvard.edu
Reply-To: singer@endor.UUCP (Rich Siegel)
Organization: Symantec/THINK Technologies, Bedford, MA
Lines: 29

In article <14105@shemp.CS.UCLA.EDU> korfhage@CS.UCLA.EDU (Willard Korfhage) writes:
>We just got Lightspeed C (v. 2.15), and someone in the group wrote a
>numerical integration program and said it ran on a Mac II at 1/4 the speed
>of an unloaded vax 11/750.  Quite disappointing, and a bit puzzleing.  A

	Version 2.15 of LightspeedC generates traps to the SANE routines in
the Mac II ROM for floating-point calculation. The SANE routines do eventually
call the 68881, but they're still very much slower than calling the FPCP 
directly.

	The (now available) version 3.0 of LightspeedC has compiler
options to generate code for the FPCP and for the 68020. If you use these
options, combined with the high-performance math libraries (pats self
on back multiple times :-) ) you'll find that the speed of your numerical
integrations will be mcommensurate with the Mac II's true speed.

	-Rich

Rich Siegel
THINK Technologies



Rich Siegel
Quality Assurance Technician
THINK Technologies Division, Symantec Corp.
Internet: singer@endor.harvard.edu
UUCP: ..harvard!endor!singer
Phone: (617) 275-4800 x305