[Bug target/35509] New: [avr] 4.3.0: builtin isinf() mismatch to compile-time substitution

[dmixm at marine dot febras dot ru]

The next program is aborted in execution (avr-gcc 4.3.0, -Os):

  int isinf (double);
  void abort (void);
  volatile double x = -1.0/0.0;
  int main ()
  {
    if (isinf (x) != isinf (-__builtin_inf ()))
        abort ();
    return 0;
  }

The second comparison argument is evaluated at compile time: -1 value
is substituted. This is traditional result for isinf(-Inf). The first
call of isinf() is replaced to inline code, which evaluates the -Inf
to +1 value.

The early avr-gcc versions are fine: the extern isinf() function was called.


-- 
           Summary: [avr] 4.3.0: builtin isinf() mismatch to compile-time
                    substitution
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dmixm at marine dot febras dot ru


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35509