[Bug c++/86569] New: -Wnonnull-compare affects code generation

[amonakov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86569

            Bug ID: 86569
           Summary: -Wnonnull-compare affects code generation
           Product: gcc
           Version: 6.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: amonakov at gcc dot gnu.org
  Target Milestone: ---

bool b;

int main ()
{
  return ((!b) != 0);
}

ICEs with g++ -fcompare-debug=-Wnonnull-compare (this is bool6.C in the
testsuite). It looks as if the warning prevents folding '!b != 0' to '!b'.