[Bug fortran/40675] sign intrinsic fails for value of 0.0

[twscofi at sandia dot gov]

------- Comment #9 from twscofi at sandia dot gov  2009-07-07 20:54 -------
(In reply to comment #6)
> 
> g77 is no longer supported.  

Per
http://gcc.gnu.org/onlinedocs/gcc-4.4.0/gfortran/GNU-Fortran-and-G77.html#GNU-Fortran-and-G77

[Gfrortran] is an entirely new program that has been designed to ..., as well
as providing backwards compatibility for Fortran 77 

An example of legacy fortran 77 support would be "fno-sign-zero does not print
the negative sign of zero values for compatibility with F77"


A slightly different test:

      program main
      val = 0.0
      test = sign(0.5, val) - sign(0.5, -val)
      write (*,*) 'With val = ', val, ' test = ', test
      if (test .eq. 1) then 
         write(*,*) 'fail'
      elseif (test .eq. 0) then
         write(*,*) 'pass'
      endif

      stop
      end

gfortran -std=legacy fsign.f
./a.out
 With val =    0.0000000      test =   1.00000000
 fail

I'm not sure that -std=legacy would be the best way to implement this, but it
would work for me.


-- 

twscofi at sandia dot gov changed:

           What    |Removed                     |Added
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                 CC|                            |twscofi at sandia dot gov


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40675