[Bug tree-optimization/63341] [4.8/4.9/5 Regression] Vectorization miscompilation with -mcpu=power7

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63341

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Hum, from the comment on vect_create_data_ref_ptr I would expect offset to be
in units of the _vector_ size ...

   Output:
   1. Declare a new ptr to vector_type, and have it point to the base of the
      data reference (initial addressed accessed by the data reference).
      For example, for vector of type V8HI, the following code is generated:

      v8hi *ap;
      ap = (v8hi *)initial_address;

      if OFFSET is not supplied:
         initial_address = &a[init];
      if OFFSET is supplied:
         initial_address = &a[init + OFFSET];

      Return the initial_address in INITIAL_ADDRESS.

looking at the implementation it expects byte offsets.