[Bug rtl-optimization/83575] New: [8 Regression] ICE: verify_flow_info failed (error: multiple hot/cold transitions found)

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83575

            Bug ID: 83575
           Summary: [8 Regression] ICE: verify_flow_info failed (error:
                    multiple hot/cold transitions found)
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

gcc-8.0.0-alpha20171217 snapshot (r255766) ICEs when compiling the following
snippet w/ -O2 (-O3, -Ofast) -funroll-loops -fno-tree-dominator-opts
-fno-tree-loop-im -fno-code-hoisting -fno-tree-pre
-fno-guess-branch-probability:

int tw, be;

void
fp (void)
{
  if (tw == 0)
    goto gq;
  else if (be == 0)
    goto ob;
  else
    return;

  for (;;)
    if (tw < 1)
      {
        while (tw < 1)
          {
 gq:
            tw = 0;
          }

        while (be < 1)
          {
 ob:
            tw = 0;
          }

        while (be < 1)
          ++be;
      }
}

% gcc-8.0.0-alpha20171217 -O2 -funroll-loops -fno-tree-dominator-opts
-fno-tree-loop-im -fno-code-hoisting -fno-tree-pre
-fno-guess-branch-probability -c c6kesbr0.c
c6kesbr0.c: In function 'fp':
c6kesbr0.c:31:1: error: multiple hot/cold transitions found (bb 7)
 }
 ^
c6kesbr0.c:31:1: error: multiple hot/cold transitions found (bb 13)
during RTL pass: bbro
c6kesbr0.c:31:1: internal compiler error: verify_flow_info failed
0x968002 verify_flow_info()
       
/var/tmp/portage/sys-devel/gcc-8.0.0_alpha20171217/work/gcc-8-20171217/gcc/cfghooks.c:265
0x13a3b11 execute
       
/var/tmp/portage/sys-devel/gcc-8.0.0_alpha20171217/work/gcc-8-20171217/gcc/bb-reorder.c:2576

--- Comment #1 from Arseny Solokha <asolokha at gmx dot com> ---
*** Bug 83578 has been marked as a duplicate of this bug. ***