This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug tree-optimization/49365] 436.cactusADM performance regression
- From: "rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Fri, 10 Jun 2011 15:37:21 +0000
- Subject: [Bug tree-optimization/49365] 436.cactusADM performance regression
- Auto-submitted: auto-generated
- References: <bug-49365-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49365
--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-06-10 15:36:49 UTC ---
I'm trying to get my hands on it. Most code differences betweeen good and
bad rev. appear in loop array prefetching. Before aprefetch dumps differ only
for datestamp.c, PUGH/SetupPGV.c and regex.c.
I'm trying binaries with -fno-prefetch-loop-arrays now (well, on Monday
that is).
Prefetching uses tree_num_loop_insns which uses estimate_num_insns.
Prefetching
is enabled by default for barcelona (but also for K8 where I don't see this
issue). So my bet is on prefetching costs getting confused and need
adjustment.