winston@cubsvax.UUCP (Ken Winston) (03/05/86)
It is well know that there are bugs in the optimizer in the f77
compiler (ours is on MicroVax II ULTRIX). I have seen various scary
warnings about these errors, but no actual list. I was beginning to
think the whole thing was overblown when I ran into one the hard way
(I only lost a day tracking it down).
Does anybody have a list of the -O problems on f77? Which ones (if any)
are fixed in the new version of f77?
Here is a program that acts differently when compiled with/without -O.
The "0." gets a little too optimized in the write statement, and
disappears altogether.
dimension array(20)
open (1,file='binar',access='direct',recl=80)
do 10 i=1,10
10 array(i)=i
write(1,rec=1) (array(i),0.,i=1,10)
close (1)
open (1,file='binar',access='direct',recl=80)
read(1,rec=1) array
write(6,*) array
stop
end
Ken Winston Winston Capital Systems, Inc.
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