[Bug tree-optimization/86038] New: [9 Regression] ICE in to_reg_br_prob_base, at profile-count.h:242

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86038

            Bug ID: 86038
           Summary: [9 Regression] ICE in to_reg_br_prob_base, at
                    profile-count.h:242
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

gcc-9.0.0-alpha20180603 snapshot (r261132) ICEs when compiling the following
snippet w/ -O2 (-O3, -Ofast) -ftracer -ftree-parallelize-loops=2
-fno-tree-scev-cprop --param parloops-schedule=dynamic (=guided, =runtime):

int
sd (int lw)
{
  while (lw < 1)
    ++lw;

  return lw;
}

 gcc-9.0.0-alpha20180603 -O2 -ftracer -ftree-parallelize-loops=2
-fno-tree-scev-cprop --param parloops-schedule=dynamic -c tmzmdwfg.c    
during GIMPLE pass: tracer
tmzmdwfg.c: In function 'sd._loopfn.0':
tmzmdwfg.c:4:9: internal compiler error: in to_reg_br_prob_base, at
profile-count.h:242
   while (lw < 1)
         ^
0x6579a3 profile_probability::to_reg_br_prob_base() const
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180603/work/gcc-9-20180603/gcc/profile-count.h:242
0x6579a3 find_best_successor
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180603/work/gcc-9-20180603/gcc/tracer.c:162
0xc9f64d find_trace
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180603/work/gcc-9-20180603/gcc/tracer.c:208
0xc9f64d tail_duplicate
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180603/work/gcc-9-20180603/gcc/tracer.c:319
0xc9f64d execute
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180603/work/gcc-9-20180603/gcc/tracer.c:429

This is apparently a regression since r260954.