Hi,
I've tried to search on Google for this issue but I can't find any
simple examples matching the problem I'm having. I'm not quite sure
exactly how to phrase my search to Google so I thought maybe I could get
some help here.
I've brought my problem down to the minimum I can; consider the following:
SUBROUTINE MYSUB(A,F)
REAL*8 A,F
PRINT *,F(A)
END
PROGRAM TEST
IMPLICIT NONE
REAL*8 A,B
INTRINSIC DLOG
A=3D0
PRINT *,DLOG(A) ! LINE A
CALL MYSUB(A,DLOG) ! LINE B
END
If I run this through an old version of g77 (3.2.3) then the code
compiles ok and gives me the output I'd expect (the natural log of 3
printed twice). The initial code (which is much more involved than the
above) was written as Fortran77 which is why we're still using g77
sometimes.
If I try to use gfortran (versions given below) then I get an error
message which looks like:
test2.for: In function 'MAIN__':
test2.for:14: internal compiler error: in gfc_typenode_for_spec, at
fortran/trans-types.c:636
Please submit a full bug re****t,
with preprocessed source if appropriate.
See <URL:http://bugzilla.redhat.com/bugzilla>
for instructions.
I've tried with the following versions of gfortran/gcc:
gcc version 4.0.2 20051125 (Red Hat 4.0.2-8)
gcc version 4.1.2 20070502 (Red Hat 4.1.2-12)
gcc version 4.1.2 20070925 (Red Hat 4.1.2-33)
(The line nuber of trans-types.c differs between the two versions.)
I've not compiled my own version but both of the above are running on
fairly generic Fedora systems (FC4, FC7 and FC8 respectively). I looked
at http://gcc.gnu.org/wiki/GFortran#news
and didn't see anything which
suggests that the issue has been addressed in versions 4.2, 4.3 or 4.4.
Interestingly, if I comment out either LINE A or LINE B the error goes
away and I get the output I'd expect (in both cases the natural log of 3
printed once). This leads me to suspect that the individual lines of
Fortran are valid. The problem only occurs if I both use the intrinsic
function DLOG and pass it to another subroutine in the same program (it
also occurs if the main program here is a subroutine).
Another thing worthy of note that it's not the "print *" causing the
problem, if I try to assign the result to a variable I get the same
error but I thought that using a simple "print *" gave a better example
for my questions.
Which are...
1) Is what I'm trying to do valid Fortran?
2) My understanding of internal errors is that they shouldn't ever
appear to the user even when the user is doing something stupid, is this
correct and should I file an official bug re****t about this issue?
3) I can think of some work-arounds for my problem as it stands but any
suggestions people have would be very welcome. My current work-around
would be to write a simple wrapper function around DLOG and pass that
wrapper to MYSUB.
Thank you in advance for your help.
Thanks,
Allan
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