[Bug middle-end/86575] New: -Wimplicit-fallthrough affects code generation

[amonakov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86575

            Bug ID: 86575
           Summary: -Wimplicit-fallthrough affects code generation
           Product: gcc
           Version: 7.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: amonakov at gcc dot gnu.org
  Target Milestone: ---

void
f2 (int a, int b, int c, int d)
{
  switch (b)
    {
    default:
      for (int e = 0; e < c; ++e)
        if (e == d)
          break;
    }
}

ICEs as both C and C++ using 'gcc -fcompare-debug=-Wimplicit-fallthrough'. This
is minimized from pr81275-1.C in the testsuite (the -2 and -3 variants of the
original test also fail).