------- Comment #9 from kargl at gcc dot gnu dot org 2009-11-07 19:00 -------
Even without acml, there appears to be an issue.
gfortran44 -o one -O2 -pipe -march=native one.f90 -L/usr/local/lib \
-llapack -lblas -fopenmp
./one fred_f_1000
LAPACK Cholesky time = .27 seconds, CPU = .27 seconds
LAPACK solver time = 2.48 seconds, CPU = 2.47 seconds
Coded Cholesky time = .81 seconds, CPU = 1.47 seconds
Coded solver time = 33.76 seconds, CPU = 38.68 seconds
gfortran44 -o one -O2 -pipe -march=native one.f90 \
-L/usr/local/lib -llapack -lblas
./one fred_f_1000
LAPACK Cholesky time = .30 seconds, CPU = .30 seconds
LAPACK solver time = 2.49 seconds, CPU = 2.49 seconds
Coded Cholesky time = 1.36 seconds, CPU = 1.36 seconds
Coded solver time = 2.97 seconds, CPU = 2.96 seconds
OpenMP clearly helps the 'Coded Cholesky time', but it
causes a factor of 10 degradation in the 'Coded solver time'.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41977
