[Bug rtl-optimization/83475] New: [8 Regression] ICE: verify_flow_info failed (error: non-cold basic block 3 reachable only by paths crossing the cold partition)

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83475

            Bug ID: 83475
           Summary: [8 Regression] ICE: verify_flow_info failed (error:
                    non-cold basic block 3 reachable only by paths
                    crossing the cold partition)
           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 -floop-nest-optimize -fmodulo-sched:

int fc = 0;
int c2[8];

void
w8 (void)
{
  int g0;

 jn:
  for (g0 = 0; g0 < 2; ++g0)
    {
      int bq;

      for (bq = 0; bq < 8; ++bq)
        c2[bq] = 0;
    }

  for (;;)
    {
      if (c2[fc] != 0)
        goto jn;
      ++fc;
    }
}

% gcc-8.0.0-alpha20171217 -O2 -floop-nest-optimize -fmodulo-sched -c okphcgsy.c
okphcgsy.c: In function 'w8':
okphcgsy.c:24:1: error: non-cold basic block 3 reachable only by paths crossing
the cold partition
 }
 ^
during RTL pass: sms
okphcgsy.c:24:1: internal compiler error: verify_flow_info failed
0x965ec2 verify_flow_info()
       
/var/tmp/portage/sys-devel/gcc-8.0.0_alpha20171217/work/gcc-8-20171217/gcc/cfghooks.c:265
0x97ed0c checking_verify_flow_info
       
/var/tmp/portage/sys-devel/gcc-8.0.0_alpha20171217/work/gcc-8-20171217/gcc/cfghooks.h:198
0x97ed0c cfg_layout_finalize()
       
/var/tmp/portage/sys-devel/gcc-8.0.0_alpha20171217/work/gcc-8-20171217/gcc/cfgrtl.c:4326
0x1494e03 execute
       
/var/tmp/portage/sys-devel/gcc-8.0.0_alpha20171217/work/gcc-8-20171217/gcc/modulo-sched.c:3352