[Bug fortran/79430] [7/8 Regression] action of statement incorrectly optimised away

[juergen.reuter at desy dot de]

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

--- Comment #63 from Jürgen Reuter <juergen.reuter at desy dot de> ---
(In reply to Thomas Koenig from comment #62)
> (In reply to Jürgen Reuter from comment #61)
> > (In reply to Thomas Koenig from comment #60)
> > > r242780 works.
> > > 
> > > With both r243586 and r244391, plus the patch for r245191
> > > applied, I got numerous failures in the test suite.
> > > 
> > > Apparently, something else was wrong for some time, which
> > > blocks the attempt at bisection for that particular error
> > > in that range.
> > 
> > There was also this PR: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79344
> > fixed in r245194. You don't apply any -fcheck=<something> flags, right?
> 
> No, I don't.
> 
> I appear to have hit a wall in bisecting.
> 
> I keep getting lots of failures in your test suite with additional
> errors. Either I am doing something wrong in testing, or there
> were indeed other errors present which keep the intermediate
> versions from working.
> 
> Could you re-check this, for exapmle by doing "svn update -r 243183"
> in trunk, recompiling the compiler, and then running your testsuite
> again?
> 
> Or how could I just, with a single command, run the test case
> you are interested in, without going through all the other tests?
> 
> I am currently at a loss how to proceed.

Darn.... Did you apply the patch from PR79344? You can run the single test if
you go to the build folder, into the directory tests/functional_test and just
do 
`make check TESTS=mlm_matching_isr.run`. This runs only this one single test. I
tried to produce a smaller test case, but our setup explicitly creates, links
and loads a dynamic library. This is rather hard to emulate. Whenever I tried
to give the routines the input directly, the optimization seems to be gone.