A few years ago we performed timing tests on f90 intrinsics. We wrote
f77-style do loops to perform the same functionality as the intrinsics
and compared timings. These results were not obtained using the
current compiler (we used SGI 7.2), but they address some of the
questions in the original posting in this thread.
Most timings were about the same for the intrinsics and the do loops
with a few significant exceptions. Here some selected results that
showed large differences:
Function Intrinsic (secs) Do Loops (secs) Ratio
all 11.28 9.43 1.20
count 9.29 11.45 0.81
cshift 10.14 5.53 1.83
eoshift 9.22 3.50 2.63
pack 11.29 4.85 2.33
reshape 11.53 4.22 2.73
unpack 11.35 6.41 1.77
Some of these f90 intrinsics could certainly contribute to "f90 being
slower than f77."
A full list, including the source code used to produce the timings, is
available at
http://scv.bu.edu/SCV/Origin2000/intrinsics/F90_serial_times_7.2.html.
___________________________________________________________
Doug Sondak Boston University
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