[Bug libfortran/111022] ES0.0E0 format gave ES0.dE0 output with d too high.

["john.harper at vuw dot ac.nz" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111022

--- Comment #11 from john.harper at vuw dot ac.nz ---
Jerry's test program is identical with mine. 
Because E format is supposed to give no digits before the decimal point 
except possibly a leading zero, E0.0 and E0.0E0 are both pointless, and 
Steve Lionel pointed out in Fortran Discourse that the standard forbids 
them because they would generate an illegal value of k for the kP edit
descriptor (which happens not to be explicitly used here.) So I think
gfortran ought to give a run-time error for it. If I compiled the program 
with ifort and more warning options, the first 2 write statements gave

real kinds 4 8 16 16
With (A,1X, E0.0E0)  *****************************************
forrtl: error (63): output conversion error, unit 6, file /dev/pts/1

The ES result from gfortran was correct and standard-conforming. The EN
one should have said 666.E+0 not 666.

  On Sun, 27 Aug 2023, jvdelisle at gcc dot gnu.org wrote:

> Date: Sun, 27 Aug 2023 15:38:33 +0000
> From: jvdelisle at gcc dot gnu.org <gcc-bugzilla@gcc.gnu.org>
> To: John Harper <john.harper@vuw.ac.nz>
> Subject: [Bug libfortran/111022] ES0.0E0 format gave ES0.dE0 output with d too
>      high.
> Resent-Date: Mon, 28 Aug 2023 03:38:51 +1200 (NZST)
> Resent-From: <john.harper@vuw.ac.nz>
> 
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111022
>
> --- Comment #9 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
> I am using this:
>
> program teste0es0en0
>  integer,parameter::p1 = kind(1e0), p2 = kind(1d0), &
>       p3 = selected_real_kind(precision(1.0_p2)+1), &
>       hp = selected_real_kind(precision(1.0_p3)+1), &
>       p4 = merge(hp,p3,hp>0) ! in gfortran p4 /= p3, in ifort p4 == p3
>  character(*),parameter:: fmt(3) = "(A,1X,"//[" E","ES","EN"]//"0.0E0) "
>  integer ifmt
>  write(*,"(A,4(1X,I0))") 'real kinds',p1,p2,p3,p4
>  do ifmt = 1,3
>     write(*, fmt(ifmt)) 'With '//fmt(ifmt), 666.0_p1
>     write(*, fmt(ifmt)) 'With '//fmt(ifmt), 666.0_p2
>     write(*, fmt(ifmt)) 'With '//fmt(ifmt), 666.0_p3
>     if(p3/=p4) write(*, fmt(ifmt)) 'With '//fmt(ifmt), 666.0_p4
>  end do
> end program teste0es0en0
>
> And I get the following output with some test patching:
>
> $ ./a.out
> real kinds 4 8 10 16
> With (A,1X, E0.0E0)  1.E+3
> With (A,1X, E0.0E0)  1.E+3
> With (A,1X, E0.0E0)  1.E+3
> With (A,1X, E0.0E0)  1.E+3
> With (A,1X,ES0.0E0)  7.E+2
> With (A,1X,ES0.0E0)  7.E+2
> With (A,1X,ES0.0E0)  7.E+2
> With (A,1X,ES0.0E0)  7.E+2
> With (A,1X,EN0.0E0)  666.
> With (A,1X,EN0.0E0)  666.
> With (A,1X,EN0.0E0)  666.
> With (A,1X,EN0.0E0)  666.
>
> -- 
> You are receiving this mail because:
> You reported the bug.
>


-- John Harper, School of Mathematics and Statistics
Victoria Univ. of Wellington, PO Box 600, Wellington 6140, New Zealand.
e-mail john.harper@vuw.ac.nz