On 08/12/2015 08:59 AM, Wilco Dijkstra wrote: > I looked at the statistics of AArch64 immediate generation a while ago. > The interesting thing is ~95% of calls are queries, and the same query is on > average repeated 10 times in a row. So (a) it is not important to cache the > expansions, and (b) the high repetition rate means a single-entry cache > has a 90% hitrate. We already have a patch for this and could collect stats > comparing the approaches. If a single-entry cache can provide a similar > benefit as caching all immediates then my preference would be to keep things > simple and just cache the last query.
Interesting. That's already more detailed investigation than I'd done. I had no idea the queries were so clustered. I assumed that the queries would be scattered across various passes, and so the various constants across the function would get checked in sequence. I would be very interested in seeing those stats when you've done. r~
