https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110280
--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
In the original case FRE is trying to do the same thing as the reduced
testcase:
```
Successfully combined 4 partial definitions
Setting value number of _39 to { 0, 0, 0, 0 } (changed)
Value numbering stmt = _40 = VEC_PERM_EXPR <_39, _39, { 0, 1, 2, 3, ... }>;
Match-and-simplified VEC_PERM_EXPR <_39, _39, { 0, 1, 2, 3, ... }> to { 0, 0,
0, 0 }
RHS VEC_PERM_EXPR <_39, _39, { 0, 1, 2, 3, ... }> simplified to { 0, 0, 0, 0 }
Setting value number of _40 to { 0, 0, 0, 0 } (changed)
Value numbering stmt = lanes ={v} {CLOBBER(eol)};
Setting value number of .MEM_54 to .MEM_54 (changed)
Value numbering stmt = _41 = [vec_unpack_lo_expr] _40;
```
