Path: utzoo!attcan!uunet!steinmetz!davidsen
From: davidsen@steinmetz.ge.com (William E. Davidsen Jr)
Newsgroups: comp.arch
Subject: Re: using (ugh!  yetch!) assembler
Message-ID: <11636@steinmetz.ge.com>
Date: 25 Jul 88 15:16:50 GMT
References: <6341@bloom-beacon.MIT.EDU> <60859@sun.uucp> <474@m3.mfci.UUCP> <2926@utastro.UUCP>
Reply-To: davidsen@crdos1.UUCP (bill davidsen)
Organization: General Electric CRD, Schenectady, NY
Lines: 19


  I wrote a C program to generate Mandelbrot data a year or so ago, and
was able to improve performance over the original implementation as
follows:
	method				improvement %
	================================================================
	improved algorithm in C		600
	recoded innermost loop in
	  assembler (11 instructions)	140

  I fear that the assembler jock would have done the innermost loop
first, said "look how much better assembler is than C," and gone on.
Obviously the Xenix/286 compiler doesn't generate optimal 80287 code,
but I never would have been willing to spend time on the algorithm if
changes took an hour of typing to enter.
-- 
	bill davidsen		(wedu@ge-crd.arpa)
  {uunet | philabs | seismo}!steinmetz!crdos1!davidsen
"Stupidity, like virtue, is its own reward" -me