[Bug target/79570] New: [5/6/7 Regression] ICE in sel-sched-ir.c:4534 in pr69956.c

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79570

            Bug ID: 79570
           Summary: [5/6/7 Regression] ICE in sel-sched-ir.c:4534 in
                    pr69956.c
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
  Target Milestone: ---

Starting from GCC 4.9.0 I see following ICE:

gcc /home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr69956.c -O2
-fselective-scheduling2 -fvar-tracking-assignments
cc1: warning: var-tracking-assignments changes selective scheduling
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr69956.c: In function ‘fn1’:
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr69956.c:11:1: internal
compiler error: Segmentation fault
 }
 ^
0xa5f34f crash_signal
        ../../gcc/toplev.c:337
0x7196a0 bb_note(basic_block_def*)
        ../../gcc/cfgrtl.c:670
0xa20bc9 sel_bb_head(basic_block_def*)
        ../../gcc/sel-sched-ir.c:4534
0xa2c74b moveup_expr_cached
        ../../gcc/sel-sched.c:2532
0xa2f5fe move_op_ascend
        ../../gcc/sel-sched.c:6152
0xa31471 code_motion_path_driver
        ../../gcc/sel-sched.c:6649
0xa32383 move_op
        ../../gcc/sel-sched.c:6703
0xa32383 move_exprs_to_boundary
        ../../gcc/sel-sched.c:5226
0xa32383 schedule_expr_on_boundary
        ../../gcc/sel-sched.c:5439
0xa35a81 fill_insns
        ../../gcc/sel-sched.c:5581
0xa35a81 schedule_on_fences
        ../../gcc/sel-sched.c:7355
0xa35a81 sel_sched_region_2
        ../../gcc/sel-sched.c:7493
0xa38659 sel_sched_region_1
        ../../gcc/sel-sched.c:7535
0xa38659 sel_sched_region(int)
        ../../gcc/sel-sched.c:7636
0xa39041 run_selective_scheduling()
        ../../gcc/sel-sched.c:7712
0xa18de5 rest_of_handle_sched2
        ../../gcc/sched-rgn.c:3722
0xa18de5 execute
        ../../gcc/sched-rgn.c:3866