http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49365
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2011.06.14 10:49:14
CC| |changpeng.fang at amd dot
| |com
Ever Confirmed|0 |1
--- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-06-14
10:49:14 UTC ---
Indeed, for the important loop in StaggeredLeapfrog2.F we now have
Ahead 1, unroll factor 1, trip count -1
insn count 919, mem ref count 100, prefetch count 100
Not prefetching -- instruction to prefetch ratio (9) too small
while before the patch we had
insn count 1019, mem ref count 100, prefetch count 100
as we now have half the cost for the vectorized mem-refs (100 instead of 200).
Building with --param min-insn-to-prefetch-ratio=9 fixes it.
