[Bug tree-optimization/82671] New: [8 Regression] ICE in cfg_layout_redirect_edge_and_branch, at cfgrtl.c:4412

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82671

            Bug ID: 82671
           Summary: [8 Regression] ICE in
                    cfg_layout_redirect_edge_and_branch, at cfgrtl.c:4412
           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: hubicka at ucw dot cz
  Target Milestone: ---

Starting from r253910 we ICE on:

$ gcc /home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/torture/pr57676.c 
-freorder-blocks-and-partition -fmodulo-sched -O1
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/torture/pr57676.c: In
function ‘f’:
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/torture/pr57676.c:8:6:
warning: type of ‘p1’ defaults to ‘int’ [-Wimplicit-int]
 void f(p1)
      ^
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/torture/pr57676.c:12:22:
warning: division by zero [-Wdiv-by-zero]
         if(p1 ? : (c /= 0))
                      ^~
during RTL pass: sms
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/torture/pr57676.c:28:1:
internal compiler error: in cfg_layout_redirect_edge_and_branch, at
cfgrtl.c:4412
 }
 ^
0x7667ce cfg_layout_redirect_edge_and_branch
        ../../gcc/cfgrtl.c:4412
0x7667f8 cfg_layout_redirect_edge_and_branch_force
        ../../gcc/cfgrtl.c:4422
0x750673 redirect_edge_and_branch_force(edge_def*, basic_block_def*)
        ../../gcc/cfghooks.c:477
0x751385 make_forwarder_block(basic_block_def*, bool (*)(edge_def*), void
(*)(basic_block_def*))
        ../../gcc/cfghooks.c:892
0x75f9d3 create_preheader(loop*, int)
        ../../gcc/cfgloopmanip.c:1524
0x75fc1e create_preheaders(int)
        ../../gcc/cfgloopmanip.c:1575
0xa0198e apply_loop_flags
        ../../gcc/loop-init.c:64
0xa0246c loop_optimizer_init(unsigned int)
        ../../gcc/loop-init.c:123
0x13c7346 sms_schedule
        ../../gcc/modulo-sched.c:1351
0x13c9bff execute
        ../../gcc/modulo-sched.c:3342