[Bug middle-end/66134] New: [CHKP] ICE: Unable to coalesce ssa_names 18 and 17 which are marked as MUST COALESCE

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66134

            Bug ID: 66134
           Summary: [CHKP] ICE: Unable to coalesce ssa_names 18 and 17
                    which are marked as MUST COALESCE
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ienkovich at gcc dot gnu.org
  Target Milestone: ---

Created attachment 35536
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35536&action=edit
reproducer

>gcc -O2 -fcheck-pointer-bounds -mmpx -fno-tree-ccp test.c -c

Unable to coalesce ssa_names 18 and 17 which are marked as MUST COALESCE.
__bound_tmp.0_18(ab) and  __bound_tmp.0_17(ab)
LCK-2257.c: In function 'test.chkp':
LCK-2257.c:7:6: internal compiler error: SSA corruption
 void test (int *p)
      ^
0xd3a93d fail_abnormal_edge_coalesce
        ../../gcc-5/gcc/tree-ssa-coalesce.c:927
0xd3b74c coalesce_partitions
        ../../gcc-5/gcc/tree-ssa-coalesce.c:1230
0xd3bd02 coalesce_ssa_name()
        ../../gcc-5/gcc/tree-ssa-coalesce.c:1375
0xcd82d3 remove_ssa_form
        ../../gcc-5/gcc/tree-outof-ssa.c:1018
0xcd8b3d rewrite_out_of_ssa(ssaexpand*)
        ../../gcc-5/gcc/tree-outof-ssa.c:1252
0x7b5c23 execute
        ../../gcc-5/gcc/cfgexpand.c:5932
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