??? 11/03/06 09:53 Modified: 11/03/06 09:56 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#127308 - I second this. Responding to: ???'s previous message |
You (or your friends) might want to read the chapter on branch cache in the datasheet, it is very interesting, even if not giving an absolutely complete information.
I believe the pipeline cannot be blamed for seemingly "unpredictable" behavior - usually, it is well documented what kind of operations incur pipeline penalties, and how many penalty cycles. However, the description of the problem ("changes its timing if the loop is longer than X instructions") is an indicator for a prefetch/caching algorithm at work. Maybe you need to look at the behavior of the prefetch/caching algorithm and how it can be modified (I believe I saw some information about this in the datasheet). |