Request for reviews (M): 7079329: Adjust allocation prefetching for T4

[Igor Veresov]

 I think this looks good. 

igor

On Monday, August 15, 2011 at 6:12 PM, Vladimir Kozlov wrote:

> http://cr.openjdk.java.net/~kvn/7079329/webrev
> 
> 7079329: Adjust allocation prefetching for T4
> 
> L2 cache line size is 32 bytes on T4 instead of 64 bytes on T series before. As 
> result BIS instruction prefetches only 32 bytes. Jbb2005 runs show that 
> prefetching 64 bytes is still better on T4 so 2 BIS instructions should be issued.
> 
> BIS can't be use for general prefetching since it may fault. New 
> PrefetchAllocation node was added for allocation prefetching.
> 
> Changed prefetchAlloc_bis parameter from memory to regP.
> 
> Use AllocatePrefetchInstr on Sparc to allow specify what instruction to use for 
> allocation prefetching (0: prefetch write, 1: BIS).
> 
> Added new instructions on Sparc cacheLineAdrX to reduce number of instructions 
> generated for finding next cache line address.
> 
> Added new flag AllocateInstPrefetchLines to specify number of lines to prefetch 
> for instance allocation.
> 
> L1_data_cache_line_size() renamed to prefetch_data_size().