[Bug tree-optimization/82449] code-gen error in get_rename_from_scev

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82449

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2017-10-06
                 CC|                            |spop at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
This is because we have a SCEV like

{(integer(kind=4)) {0, +, {1, +, 1}_1}_1, + 1}_2

which is affine and passes all other tests in scev_analyzable_p.  But we really
need to have all SCEVs that pass this test pass get_rename_from_scev which
means we should be able to call chrec_apply on it.

I have a patch.