This is with gfortran 4.4.0 20090114 [trunk revision 143364] and the Polyhedron
test suite, http://www.polyhedron.co.uk/MFL6VW74649
on AMD Athlon(tm) 64 X2 Dual Core Processor 4800+ running openSUSE Factory
x86-64.
First the good news: No ICE and no result-checking failures.
The geometric average shows 4% longer runtime for -floop*, which is dominated
by the 70% slower gas_dyn. Other programs are faster such as capacita (by 6%)
or slower such as test_fpu (by 13%). [I picked the extrema; mostly the changes
seem to be only slightly above noise with a slight tendency to better
performance.]
I was using the following options, which yielded the stated run time for
gas_dyn:
gfortran -march=opteron -ffast-math -funroll-loops -ftree-vectorize
-ftree-loop-linear -msse3 -O3
-> Runtime = 11.73 seconds
gfortran -march=opteron -floop-interchange -floop-strip-mine -floop-block
-ffast-math -funroll-loops -ftree-vectorize -ftree-loop-linear -msse3 -O3
-> Runtime = 19.95033
--
Summary: [Graphite] 70% slower using -floop* than without
graphite (gas_dyn of Polyhedron)
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: burnus at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38846
