[Bug tree-optimization/16282] New: -fno-exception miscompiles POOMA testcase

[rguenth at tat dot physik dot uni-tuebingen dot de]

The tramp3d-v3 testcase is miscompiled by -O2 -fno-exceptions compared to -O2.
http://www.tat.physik.uni-tuebingen.de/~rguenth/gcc/tramp3d-v3.cpp.gz

g++ (GCC) 3.5.0 20040629 (experimental)

The testcase segfaults like:

(gdb) run -n 1
Starting program:
/net/natasa/scratch/natasa/rguenth/gcc-obj-3.5/tramp3d-v3.leafify -n 1

Program received signal SIGSEGV, Segmentation fault.
KernelEvaluator<InlineKernelTag>::evaluate<Field<UniformRectilinearMesh<MeshTraits<3,
double, UniformRectilinearTag, CartesianTag, 3> >, Vector<3, double, Full>,
BrickView>, OpAssign, Array<3, Vector<3, double, Full>, ConstantFunction> >
(lhs=@0x60000fffffff8270, 
    op=@0x60000fffffffb658, rhs=@0x60000fffffff8300) at ../src/tramp3d-v3.cpp:4047
4047	    dom = DomainTraits<T>::getFirst(newdom);
(gdb) bt
#0 
KernelEvaluator<InlineKernelTag>::evaluate<Field<UniformRectilinearMesh<MeshTraits<3,
double, UniformRectilinearTag, CartesianTag, 3> >, Vector<3, double, Full>,
BrickView>, OpAssign, Array<3, Vector<3, double, Full>, ConstantFunction> >
(lhs=@0x60000fffffff8270, 
    op=@0x60000fffffffb658, rhs=@0x60000fffffff8300) at ../src/tramp3d-v3.cpp:4047
#1  0x4000000000120180 in assign<UniformRectilinearMesh<MeshTraits<3, double,
UniformRectilinearTag, CartesianTag, 3> >, Vector<3, double, Full>,
MultiPatchView<GridTag, Remote<Brick>, 3>, Vector<3, double, Full>, OpAssign>
(lhs=@0x60000fffffff8c90, 
    rhs=@0x60000fffffff8d20, op=@0x60000fffffffb658) at ../src/tramp3d-v3.cpp:27733
#2  0x4000000000019040 in main (argc=1, argv=0x1) at ../src/tramp3d-v3.cpp:48677

The math evaluator kernel that segfaults is only miscompiled if using the
leafify patch, but maybe "careful" tuning of some inlining parameters could
reveal the same failure.

I believe this is not a recent failure, as I remember this failing on tree-ssa, too.

-- 
           Summary: -fno-exception miscompiles POOMA testcase
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at tat dot physik dot uni-tuebingen dot de
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: ia64-unknown-linux
  GCC host triplet: ia64-unknown-linux
GCC target triplet: ia64-unknown-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16282