Re: [PATCH, fortran] PR93727 Implement new EX format specifier

Hi Jerry,

Am 11.05.26 um 8:24 PM schrieb Jerry D:
> Hi all,
> 
> This took me a lot longer than I wanted, but finally got it done.
> 
> See the attached patch. Since my last submittal here I started over on 
> using the example demo Harald gave in Comment 18 of the PR using 
> available higher level C functions, fabs, signbit, scalbn, isnan frexp, 
> etc to extract the needed components. Then, using the %H specifier to 
> build the hexadecimal float string in get_float_hex_string(). I added 
> checks for zero, inf, nan, and the sign.
> 
> Once I had this working for kind=8, I repeated the pattern for kind=8, 
> 10, and 16. I used defines around the kind=10 and 16 to avoid where not 
> supported.
> 
> I also created defines for the C functions needed following the examples 
> later in the file. I dont have some of those platforms readily available 
> here so a web searched for those various function, ie not tested yet. I 
> will call it an EWAG. Engineering Wild Assumption and Guess.
> 
> I apologize for the whitespace cleanups. I had them in my worktree from 
> earlier attempts.
> 
> I updated the two test cases added. I probably need to specify targets 
> on those. We can add additional testcases as deemed appropriate.
> 
> Regression tested here on X86_64. Testing by others encouraged.
> 
> OK for mainline. I do not plan any backport and less others think its 
> worth it.

this is already in a quite good shape.  However, I have two
preliminary comments:

- rounding is not yet correct.  Example:

   real(4) :: r4
   r4 = 128.
   write(*,"(*(4x,EX0.2))") r4, abs (nearest(r4,-1.0))

prints

     0X8.00P+4    0XF.FFP+3

but should print

     0X8.00P+4    0X8.00P+4

- real(10) and real(16) are not available everywhere.
   Please have a look at gfortran.dg/ieee/ieee_11.F90
   for one way to solve this.

Best,
Harald

> Best regards,
> 
> Jerry
> 
> PS I will be on travel the next 7 day however I can monitor email.