Canqun,

Nice job getting this ready for the current version of gcc!

Question: does gcc now know the difference between prefetching to cache L1 via 
"lfetch", as opposed to prefetching only to level L2 via "lfetch.nt1"?  For 
floating point data, the latter is the only interesting case because float 
loads only access the L2.  Thus using "lfetch" for floating point arrays will 
unnecessarily wipe out the contents of L1.  (gcc 3.2.3 only seems to generate 
"lfetch", which is why I ask...)

Thanks,
Mark 

-----Original Message-----
From: Canqun Yang [mailto:[EMAIL PROTECTED] 
Sent: Friday, June 02, 2006 5:14 AM
To: gcc@gcc.gnu.org; [EMAIL PROTECTED]
Subject: [patch] Improve loop array prefetch for IA-64

Hi, all

This patch results a performance increase of 4% for SPECfp2000 and 13% for NAS 
benchmark suite on
Itanium-2 system, respectively. More performance increase is hopeful by further 
tuning the
parameters and improving the prefetch algorithm at tree level. 


Canqun Yang


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