[Bug middle-end/50913] [4.7 Regression] ICE in scan_tree_for_params_right_scev, at graphite-sese-to-poly.c:633 compiling libgfortran with -floop-interchange -m32

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50913

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.7.0

--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-11-07 13:07:53 UTC ---
Looks like a genuine graphite bug though

718       switch (TREE_CODE (e))
719         {
720         case POLYNOMIAL_CHREC:
721           scan_tree_for_params_right_scev (s, CHREC_RIGHT (e),
722                                            CHREC_VARIABLE (e), c);
(gdb) call debug_generic_expr (e)
{0B, +, (sizetype) pretmp.6_31}_2

632           |   a [i * p] = ...   */
633           gcc_assert (TREE_CODE (e) == INTEGER_CST);

where e here is CHREC_RIGHT (e).  Looks like sth assumes this form
of a SCEV does not happen.

#(Data Ref: 
#  bb: 4 
#  stmt: *dest_35 = D.2240_13;
#  ref: *dest_35;
#  base_object: *rptr_1;
#  Access function 0: {0B, +, (sizetype) pretmp.6_31}_2
#)

Note that data-ref analysis fails with

failed: evolution of base is not affine

but graphite still forces access functions to be generated.