[Bug tree-optimization/71575] [6/7 Regression] [graphite] internal compiler error: in copy_cond_phi_nodes, at graphite-isl-ast-to-gimple.c:2500

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71575

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
We run into

#1  0x000000000175ce2f in translate_isl_ast_to_gimple::copy_cond_phi_nodes (
    this=0x7fffffffd9a0, bb=<basic_block 0x7ffff6891410 (6)>, 
    new_bb=<basic_block 0x7ffff69d1138 (33)>, iv_map=...)
    at
/space/rguenther/src/svn/gcc-6-branch/gcc/graphite-isl-ast-to-gimple.c:2498
2498            gcc_unreachable ();
(gdb) l
2493          tree res = gimple_phi_result (phi);
2494          if (virtual_operand_p (res))
2495            continue;
2496          if (is_gimple_reg (res) && scev_analyzable_p (res,
region->region))
2497            /* Cond phi nodes should not be scev_analyzable_p.  */
2498            gcc_unreachable ();
2499
2500          gphi *new_phi = create_phi_node (SSA_NAME_VAR (res), new_bb);
2501          tree new_res = create_new_def_for (res, new_phi,
2502                                             gimple_phi_result_ptr
(new_phi));

the issue went latent on the trunk.