[Bug middle-end/51521] [4.7 Regression]: build fails on cris-elf building libstdc++-v3: verify_flow_info failed

["rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51521

--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-12-13 14:07:49 UTC ---
(In reply to comment #4)
> (In reply to comment #3)
> > Hi Richard,
> > 
> > May you please take a look at this message where I describe why I had done the
> > change:
> > http://codereview.appspot.com/5486043/#msg6
> > 
> > The edge w/o EDGE_FALLTHRU also causes internal errors when I try to split it.
> > 
> > > The EDGE_FALLTHRU flag is wrong if any of EDGE_TRUE/FALSE_* is added which
> > is probably what happens.  Thus the patch was wrong.
> > 
> > But when I set EDGE_FALLTHRU there is no EDGE_TRUE/FALSE_* yet (the flags were
> > 0). So, isn't it who adds EDGE_TRUE/FALSE_* must reset EDGE_FALLTHRU?
> 
> See at the single user of the function you changed.  It continues to
> add BBs and edges.
> 
> Please debug the new testsuite failures (which you should have seen during
> your testing) and see why your flag setting is incorrect.

'I've done full 3 stage build for all front-ends, then 'make bootstrap', then
diff output of 'make check-gcc -j16 RUNTESTFLAGS="dg.exp"''

That is wrong.  You should do 'make check-gcc -j16', without restricting
the set of testcases run to dg.exp.

Please revert your patch and do proper testing.