[Bug target/94238] New: [10 Regression] ICE in ix86_cc_mode, at config/i386/i386.c:15285 since r10-7268-g529ea7d9596b26ba

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94238

            Bug ID: 94238
           Summary: [10 Regression] ICE in ix86_cc_mode, at
                    config/i386/i386.c:15285 since
                    r10-7268-g529ea7d9596b26ba
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: law at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-linux-gnu
            Target: x86_64-linux-gnu

I see the following ICE (isolated from linux kernel):

$ cat kernel.i
enum { false, true } a;
int b, c, d, e, f;
int fn3();
void fn2();

void fn1() {
  _Bool g, h = false, i = false;
  int j;
  c = b && f || d;
  if (c) {
    if (d)
      i = true;
    _Bool k = b;
    int l = e, m = a;
    g = k && l < m || l > m;
  }
  if (g)
    h = true;
  if (i)
    fn2();
  h &&j &&fn3();
}

$ gcc kernel.i -c -O2
during RTL pass: combine
kernel.i: In function ‘fn1’:
kernel.i:22:1: internal compiler error: in ix86_cc_mode, at
config/i386/i386.c:15285
   22 | }
      | ^
0x783f93 ix86_cc_mode(rtx_code, rtx_def*, rtx_def*)
        ../../gcc/config/i386/i386.c:15285
0x16d3bef simplify_set
        ../../gcc/combine.c:6938
0x16d5887 combine_simplify_rtx
        ../../gcc/combine.c:6440
0x16d74ca subst
        ../../gcc/combine.c:5719
0x16d7674 subst
        ../../gcc/combine.c:5581
0x16da961 try_combine
        ../../gcc/combine.c:3479
0x16e1532 combine_instructions
        ../../gcc/combine.c:1469
0x16e1532 rest_of_handle_combine
        ../../gcc/combine.c:15059
0x16e1532 execute
        ../../gcc/combine.c:15104
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