The Polyhedron test case rnflow is runs since 20 April 30% slower than before.
gfortran -m32 -march=opteron -ffast-math -funroll-loops -ftree-vectorize -ftree-loop-linear -O3 rnflow.f90 Today's gfortran: real 0m58.205s / user 0m56.600s gfortran 2007-04-20 (r123986): real 0m58.237s / user 0m56.396s gfortran 2007-04-16 (r123859): real 0m43.912s / user 0m42.403s gfortran 4.2.0: real 0m45.449s / user 0m43.859s This only affects that compiliation with that options. Using the following option: gfortran -m32 -march=opteron -ffast-math -funroll-loops -ftree-loop-linear -ftree-vectorize -mfpmath=sse -msse3 -O3 or compiling for a 64bit system does not show this slowdown. See also: http://physik.fu-berlin.de/~tburnus/gcc-trunk/benchmark/run-rnflow.png http://physik.fu-berlin.de/~tburnus/gcc-trunk/benchmark/ and for x86-64 which is not affected, see also: http://www.suse.de/~gcctest/c++bench/polyhedron/polyhedron-summary.txt-2-0.html The benchmark can be obtained from: http://www.polyhedron.co.uk/pb05/polyhedron_benchmark_suite.html directory: pb05/lin/source -- Summary: [Regression 4.3] 30% speed regression with -m32 on Opteron with rnflow Product: gcc Version: 4.3.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3 Component: target AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: burnus at gcc dot gnu dot org GCC target triplet: x86_64-unknown-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31897