Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!killer!vector!gryphon!sarima
From: sarima@gryphon.CTS.COM (Stan Friesen)
Newsgroups: comp.lang.c
Subject: Re: Array indexing vs. pointers...
Message-ID: <7918@gryphon.CTS.COM>
Date: 20 Oct 88 01:08:19 GMT
References: <225800077@uxe.cso.uiuc.edu>
Reply-To: sarima@gryphon.CTS.COM (Stan Friesen)
Organization: Trailing Edge Technology, Redondo Beach, CA
Lines: 17

In article <225800077@uxe.cso.uiuc.edu> mcdonald@uxe.cso.uiuc.edu writes:
>
> Then understand the hardware and instruction set of the
>target computer (portable? what's that? We have already decided to go 
>go the gold medal). Look at the compiler's .asm output. Try changing
>things like x*65 to x<<6+x. It might be faster, might not.

	Well, as far as I can tell, the Portable C Compiler does this
for you, at least with -O set.  I have seen the equivalent of the above
in so many places in the system that I cannot imagine it being in the
source code.  In fact I have seen it in once-executed start-up code,
which very few programmers would bother tweaking to this level.

-- 
Sarima Cardolandion			sarima@gryphon.CTS.COM
aka Stanley Friesen			rutgers!marque!gryphon!sarima
					Sherman Oaks, CA