------- Additional Comments From jgrimm2 at us dot ibm dot com 2004-11-18 01:32 ------- Hmmm... looks like a couple things (maybe more) come in to play here. First, value-profile code doesn't seem to merge prefetches (among other things). That is, it should be pretty easy (crude?) to track the last prefetch and not prefetch addresses that look close. Doing so seems to help this test case quite a bit (96 prefetches down to 24), but probably not enough..... as it seems that the loop unroller comes through afterwards and does its damage too. Might need to teach the unroller about prefetch a bit too??
-- What |Removed |Added ---------------------------------------------------------------------------- CC| |jgrimm2 at us dot ibm dot | |com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17950