Conference turris::fortran

1310.0. "dfav - /opt=tune:ev5 problem" by CSC32::J_HENSON (Don't get even, get ahead!) Wed May 21 1997 17:22

DFAV V7.0, F77, OpenVMS V6.2, Alpha

A customer is reporting that when he compiles using /opt=tune:ev5,
and runs the code on an ev5 machine, he gets about 5% worse
performance than when he compiles with all defaults.

Unfortunately, that's all the details I have at this time.  Mostly
I just want to get a quick check to see if there are any known
problems like this, or if there are known improvements with 
Dec Fortran V7.1.

If not, tell me what else you need to know.  As you might guess,
the customer's code is large, and he would rather not provide the
entire thing.  He has said he could work on a scaled down version
if needed.

Please advise,

Thanks.

Jerry

Who can tell?  Sometimes the non-default tunings do make things worse - it
all depends on what the program does.  We'd have to see the whole program
in order to analyze it.  Maybe it's better in V7.1, but the only way to tell
is to try it.

					Steve