Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: some quotes on switch and indirect branches

Author: Dieter Buerssner

Date: 10:41:39 11/20/05

Go up one level in this thread


On November 18, 2005 at 14:38:28, Gerd Isenberg wrote:

>12.3 Branch prediction in PMMX, PPro, P2, and P3   pg 43
>....
>Indirect jumps and calls (PMMX, PPro, P2 and P3)
>There is no pattern recognition for indirect jumps and calls, and the BTB can
>remember no more than one target for an indirect jump. It is simply predicted to
>go to the same target as it did last time.

This might work out well in this case. As you are aware, chess engines do most
work close to the leafs. I don't know Fruit's source and the circumstances in
which the cited code snippet will be executed. I might well be the case, that in
90% of the cases, the switch will jump to the case of depth 0 and 1. Of course,
also "normal" branch prediction for if/else if/else should work excellent under
these circumstances.

Regards,
Dieter




This page took 0.01 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.