Author: Johan de Koning
Date: 18:23:58 08/25/03
Go up one level in this thread
On August 25, 2003 at 11:32:10, Robert Hyatt wrote: [snip] >>Since I was only interested in cache to cache speed, I simply inserted >>/**/ dummy[d] = pos[d]; >>just before the usual copy/make that starts with >>/**/ pos[d+1] = pos[d]; >> > >There is a danger in your test. It is _possible_ that a good compiler >will recognize that code as "useless" and toss it out silently. I see this >happening all the time with gcc and the Intel compiler I use under Linux. > >If you do something like a=b, and a is not global, and it is not used anywhere >further down in the procedure, it will get eliminated. If a is global, it has >to do the copy of course as the compiler can't tell who might use that value >in another procedure. Yes, I know how to abuse the compiler. :-) And I'm also aware of benchmarking rule #1: watch the code, not the source. ... Johan
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.