[Bug target/31897] [4.3 Regression] 30% speed regression with -m32 on Opteron with rnflow

["jakub at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #2 from jakub at gcc dot gnu dot org  2007-07-04 11:57 -------
Can't reproduce this, gcc 4.3 actually seems to be faster (tests done on Intel
quadcore Core2):
/usr/src/gcc-4.2/obj/gcc/gfortran -B /usr/src/gcc-4.2/obj/gcc/ -L
/usr/src/gcc-4.2/obj/x86_64-unknown-linux-gnu/32/libgfortran/.libs/
-Wl,-rpath,/usr/src/gcc-4.2/obj/x86_64-unknown-linux-gnu/32/libgfortran/.libs/
-m32 -march=opteron -ffast-math -funroll-loops -ftree-vectorize
-ftree-loop-linear -O3 rnflow.f90 -o rnflow42
/usr/src/gcc/obj/gcc/gfortran -B /usr/src/gcc/obj/gcc/ -L
/usr/src/gcc/obj/x86_64-unknown-linux-gnu/32/libgfortran/.libs/
-Wl,-rpath,/usr/src/gcc/obj/x86_64-unknown-linux-gnu/32/libgfortran/.libs/ -m32
-march=opteron -ffast-math -funroll-loops -ftree-vectorize -ftree-loop-linear
-O3 rnflow.f90 -o rnflow43
gfortran -m32 -march=opteron -ffast-math -funroll-loops -ftree-vectorize
-ftree-loop-linear -O3 rnflow.f90 -o rnflow41

for i in 1 2 3; do time ./rnflow4$i > /dev/null; time ./rnflow4$i > /dev/null;
done

real    0m30.003s
user    0m29.601s
sys     0m0.399s

real    0m29.811s
user    0m29.436s
sys     0m0.370s

real    0m29.875s
user    0m29.468s
sys     0m0.403s

real    0m29.824s
user    0m29.441s
sys     0m0.378s

real    0m26.007s
user    0m25.627s
sys     0m0.376s

real    0m25.822s
user    0m25.403s
sys     0m0.415s


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31897