[Bug tree-optimization/81373] New: [7/8 Regression] Graphite ICE in ssa_default_def at gcc/tree-dfa.c:305

["marxin at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81373

            Bug ID: 81373
           Summary: [7/8 Regression] Graphite ICE in ssa_default_def at
                    gcc/tree-dfa.c:305
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: rguenth at gcc dot gnu.org
  Target Milestone: ---

Following fails starting with r239357:

$ gcc /home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/graphite/scop-2.c
-fno-tree-scev-cprop -fgraphite-identity -O1

during GIMPLE pass: graphite
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/graphite/scop-2.c: In
function ‘toto’:
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/graphite/scop-2.c:3:5:
internal compiler error: Segmentation fault
 int toto()
     ^~~~
0xbd4e9f crash_signal
        ../../gcc/toplev.c:338
0xc2bb67 ssa_default_def(function*, tree_node*)
        ../../gcc/tree-dfa.c:305
0xc2e400 get_or_create_ssa_default_def(function*, tree_node*)
        ../../gcc/tree-dfa.c:362
0xc66dc3 get_reaching_def
        ../../gcc/tree-into-ssa.c:1227
0xc677a5 rewrite_update_phi_arguments
        ../../gcc/tree-into-ssa.c:2111
0xc677a5 rewrite_update_dom_walker::before_dom_children(basic_block_def*)
        ../../gcc/tree-into-ssa.c:2231
0x1395d43 dom_walker::walk(basic_block_def*)
        ../../gcc/domwalk.c:265
0xc6395f rewrite_blocks
        ../../gcc/tree-into-ssa.c:2288
0xc6c71c update_ssa(unsigned int)
        ../../gcc/tree-into-ssa.c:3463
0x13d267c graphite_regenerate_ast_isl(scop*)
        ../../gcc/graphite-isl-ast-to-gimple.c:3051
0x13c8ed8 graphite_transform_loops()
        ../../gcc/graphite.c:344
0x13c9820 graphite_transforms
        ../../gcc/graphite.c:376
0x13c9820 execute
        ../../gcc/graphite.c:453