[Bug tree-optimization/79575] New: [7 Regression] ICE in mark_stmt_if_obviously_necessary, at tree-ssa-dce.c:270

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79575

            Bug ID: 79575
           Summary: [7 Regression] ICE in
                    mark_stmt_if_obviously_necessary, at
                    tree-ssa-dce.c:270
           Product: gcc
           Version: unknown
            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: ysrumyan at gmail dot com
  Target Milestone: ---

Running on x86_64:

gcc /home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/torture/pr70396.c -O3
--param vect-epilogues-nomask=1 -mavx512er -mtune=generic -march=x86-64
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/torture/pr70396.c: In
function ‘fn1’:
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/torture/pr70396.c:9:6:
internal compiler error: in mark_stmt_if_obviously_necessary, at
tree-ssa-dce.c:270
 void fn1() {
      ^~~
0xb34ba5 mark_stmt_if_obviously_necessary
        ../../gcc/tree-ssa-dce.c:270
0xb34ba5 find_obviously_necessary_stmts
        ../../gcc/tree-ssa-dce.c:389
0xb34ba5 perform_tree_ssa_dce
        ../../gcc/tree-ssa-dce.c:1599