[Bug fortran/79430] [7 Regression] action of statement incorrectly optimised away

[sgk at troutmask dot apl.washington.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79430

--- Comment #14 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Wed, Feb 08, 2017 at 09:30:45PM +0000, juergen.reuter at desy dot de wrote:
> > 
> > > Indeed, it looks as if kind=10 would be real128, but as you said this
> > > is wrong and was fixed by you (I guess it is not yet in the trunk, as
> > > of r245197 at least).
> > 
> > You need r245255 to get the fix.  There is, however, some discussion
> > as to whether I should revert the change.
> 
> Ah ok. Why? Because it is too late for anything than regression fixes now? 

That's one reason.  The other reason given is that it changes
the ABI.  I don't think the ABI change is an issue because the
ABI for libgfortran has alraedy changed, which will require 
a recompile of software.

> As far as we can seen all our constants have valid and consistent
> kind type.  Any try to reduce the code, hasn't worked. Putting print
> statements there are trying to pass the corresponding routine to an
> output routine to access it without the heavy machinery of the whole
> program let's the problem go away.

Hmmm. Adding a print statement suggests stepping off the end 
of an array, accessing memory that has been free, and argument
mismatch in a function/subroutine call.  Have you tried adding
-fcheck=all and/or running the failing code under valgrind?