[Bug rtl-optimization/86882] New: [9 Regression] ICE in reg_overlap_mentioned_p, at rtlanal.c:1873

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86882

            Bug ID: 86882
           Summary: [9 Regression] ICE in reg_overlap_mentioned_p, at
                    rtlanal.c:1873
           Product: gcc
           Version: 9.0
            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: ---
            Target: x86_64-unknown-linux-gnu

gcc-9.0.0-alpha20180805 (r263320) ICEs when compiling the following snippet w/
-march=btver1 -O2 (-O3, -Ofast):

unsigned char pe;

unsigned char
ii (int dc)
{
  if (dc != 0)
    {
      int jd = 0x101;

      jd ^= pe;
      pe ^= jd;
    }

  return pe;
}

% x86_64-unknown-linux-gnu-gcc-9.0.0-alpha20180805 -march=btver1 -O2 -c
hpojzrvb.c
during RTL pass: combine
hpojzrvb.c: In function 'ii':
hpojzrvb.c:15:1: internal compiler error: in reg_overlap_mentioned_p, at
rtlanal.c:1873
 }
 ^
0x6487d2 reg_overlap_mentioned_p(rtx_def const*, rtx_def const*)
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180805/work/gcc-9-20180805/gcc/rtlanal.c:1873
0xc4f4db reg_referenced_p(rtx_def const*, rtx_def const*)
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180805/work/gcc-9-20180805/gcc/rtlanal.c:1149
0x1444168 try_combine
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180805/work/gcc-9-20180805/gcc/combine.c:4043
0x1446bca combine_instructions
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180805/work/gcc-9-20180805/gcc/combine.c:1320
0x1446bca rest_of_handle_combine
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180805/work/gcc-9-20180805/gcc/combine.c:14917
0x1446bca execute
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180805/work/gcc-9-20180805/gcc/combine.c:14962