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saturn · Joined: 22 Apr 2008 Posts: 12

I am getting a "Floating Point Stack Fault" run-time error when running an FTN95 compiled program under 64-bit Windows XP and Windows 7. The program works fine with 32-bit version of XP and 7.

When debugging, the Debugger stops at a line in the code, which has no relevance to the error type.

Any solutions on this?

PaulLaidler · Posted: Tue Dec 29, 2009 3:32 pm Post subject:

Is it possible to reduce the problem to a few lines in a fully working program?
If you can post this in the forum then someone may be able to help.

saturn · Joined: 22 Apr 2008 Posts: 12

Thanks for the prompt response Paul.

It's not possible to reduce the problem to a few lines in a fully working program. The software consists of 1000s of routines in several source files.

What I can do is provide the extended list file complied with EXPLIST option as well as the corresponding source file with subrotuine where the crash occurs for you to have a look.

Is this OK?

PaulLaidler · Posted: Thu Dec 31, 2009 8:57 am Post subject:

This kind of error message usually occurs when a function is called without its return type being declared. For example you might have a function named foo returning a integer value whilst the compiler expects it to return a real value if it is not explicitly declared.

This would be trapped by using IMPLICIT NONE and you can set this on the FTN95 command line or you can configure the compiler to use it all the time.

Alternatively you could post a few lines of your Fortran code in the vicinity of the failure.

Robert · Joined: 29 Nov 2006 Posts: 445 Location: Manchester

This may be an incidence of an issue we have uncovered relating to the way x64 OSs handle underflows. You would see a floating point stack and the indicated position is not always the one that causes the issue (it can be the next floating point instruction). This can typically happen when a number is converted to an integer.

Would you be willing to test a salflibc for us?

saturn · Joined: 22 Apr 2008 Posts: 12

erom · Joined: 26 Oct 2009 Posts: 4 Location: Los Angeles, CA. USA

At first my Fortran example program did not FTN95 link ok on a win 7 quad 64 bit intel box

'Rebuild' returned lines like:
<clip>
Compilation completed with no errors.
Linking...
Access violation: ...
<clip>

The fix:
From the Plato top ruler, 'Project' > 'Properties...' > Debugging > uncheck, at least, all debugging option boxes, including, from 'Checking code' to 'Fail on underflow'. Then click 'Apply to All'

Now rebuild returns:
<clip>
Compilation completed with no errors.
Linking...
Creating executable: Release\Win32\myfile.exe
Linking completed.

My program example is an F95 main that calls 8 legacy F77 subroutines.

Thanks to all at SilverFrost !!

fmolina · Posted: Tue Feb 09, 2010 8:41 pm Post subject:

Hello all,

I am also trying to run FTN95 on XP 64 bit. Tried on three different machines, the last one with all new installation. A very simple program like this: