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From: martyl@rocksvax.UUCP (Marty Leisner)
Newsgroups: comp.os.minix
Subject: minix C compiler performance
Message-ID: <1131@rocksvax.UUCP>
Date: Sat, 30-May-87 12:01:02 EDT
Article-I.D.: rocksvax.1131
Posted: Sat May 30 12:01:02 1987
Date-Received: Mon, 1-Jun-87 05:44:07 EDT
Organization: Xerox: Henrietta, NY
Lines: 34

Well, I finally got my copy of Minix running on my harddisk on my 10 Mhz PC
AT.

I felt it took an awfully long time to recompile/link the kernel, so once
I was up on a harddisk, I ran dhrystone to get an idea of performance 
(yeah, it ain't perfect, but it is a compute intensive benchmark).   

Under Minix, dhrystone (at least the copy I got from netlib) turned about
250 dhrystones/second.  Under Aztec C/MS-DOS on the same hardware, dhrystone
turned 1200+ dhrystones/second.

A few questions about the Minix C compiler and the distribution disks:
	1) which compiler was the AT kernel/utilities compiled with?
	   When I recompiled the kernel, the sizes of the linked files
	   didn't agree with the distribution versions.
	2) While running dhrystone under the time utility, it reported
	   99%+ time was user (something like 3:00 user, :01 system, 3:02 
           real -- there wasn't anything else running at the time).
	   This would indicate dhrystone did as intended -- benchmark the
	   C compiler and not minix itself.

Are there any plans to improve the Minix C compiler?  Or am I doing something
wrong?  In the Minix book, Andy Tanenbaum asserts clean code is more 
important than highly optimized code -- and I agree with this premise and
feel Minix looks (from a browsing level) like a very clean software project.
But a factor of 5 in C compiler performance is somewhat unacceptable.

Any comments out there?

marty leisner
xerox corp.
leisner.henr@xerox.com
martyl@rocksvax.uucp