>On Sat, 2 Jan 2010 15:37:15 -0500, Jim Mulder <d10j...@us.ibm.com> wrote: >> >> I was told that compressed pointers for storage below 32GB fit >>into a smaller space, so more compressed pointers fit in a cache >>line, leading to more effective cache utilization. Performance is >>all about the caches these days. I am not a Java person. I don't >>know what a compressed pointer is. >>
Just a wild guess. If all pointers are to storage on a doubleword boundary, the address can be shifted right three bits. Then you can point to any doubleword below 32 GB using an unsigned 32-bit address. How that might help performance is a mystery to me. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
