Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!strath-cs!str-va!clcp16
From: clcp16@vaxa.strath.ac.uk ((Stewart C. Russell))
Newsgroups: comp.sys.amiga.programmer
Subject: Re: NorthC and BYTE sieve demo
Message-ID: <1991Feb27.103025.10323@vaxa.strath.ac.uk>
Date: 27 Feb 91 10:30:25 GMT
References: <45620@nigel.ee.udel.edu> <1991Feb24.041825.428@watdragon.waterloo.edu>
Organization: Strathclyde University VAX Cluster
Lines: 33

In article <1991Feb24.041825.428@watdragon.waterloo.edu>, ccplumb@rose.uwaterloo.ca (Colin Plumb) writes:
> Dennis_Grant@cmr001.bitnet wrote:
>>     My conclusion: The printf was taking a LOT of time to execute.
>>
>>     My question: Is this normal? Could a lowly XT really crank out 1600000
>>printfs faster than my Amiga, or is this a quirk of NorthC? (or did BYTE
>>delete those printfs too?) Any ideas?
> 
> Sorry, but the answer is yes.  An IBM XT has a text screen... it generates
> characters in hardware from a character and an attribute byte.  The Amiga
> finds the character in the font, clips, blits, etc.  It can be done very fast
> in PC-XT like cases (one bitplane, writing directly to screen, monospaced
> font -> no clipping), where you remove the extra checks from the code,
> but if you're printing to a console window on a 2-bitplane workbench screen,
> you're doing a lot more work.
> 
> Then, if your printf isn't that smart (remember, it scans the string
> for % signs; puts() is faster), and uses putchar() for each character,
> and putchar() isn't buffered, then you call the dos.library once per
> character, which sends a packet to the console.device, which is not a
> shining example of tense code, which calls the graphics.library, which
> checks layers, then digs through the font, then queues the blit and
> returns from the mess...  it can become a real pig.

	...coupled with the fact that NorthC's printf looks like it's coming
straight down the line at 300 baud. A reasonable compiler, but the console
IO is unacceptably slow. No problems with any other compiler (even ZC, which
is also based on Sozobon C).


	Stewart C. Russell	University of Strathclyde, Glasgow, Scotland
                                Also at CIX: scruss
				(scruss@cix.compulink.co.uk)