[Cfp-interest] Signaling NaNs and Fortran

[Fred J. Tydeman]

Fortran, for some time, has had "support" for signaling NaNs.
The following program is supposed to create single and double
kinds of signaling and quiet NaNs; and then print them.
For those people who have access to Fortran compilers, would
you please run this and report back the results.
This is to help determine how C should print signaling NaNs.

       program ieee_test_nan

       use, intrinsic :: ieee_arithmetic
       implicit none
       real(4) :: ss, sq
       real(8) :: ds, dq

       ss = ieee_value(ss,ieee_signaling_nan)
       sq = ieee_value(sq,ieee_quiet_nan)
       ds = ieee_value(ds,ieee_signaling_nan)
       dq = ieee_value(dq,ieee_quiet_nan)

       write (*,*) "snan, 32-bit prints as: ", ss
       write (*,*) "qnan, 32-bit prints as: ", sq
       write (*,*) "snan, 64-bit prints as: ", ds
       write (*,*) "qnan, 64-bit prints as: ", dq

       end

---
Fred J. Tydeman        Tydeman Consulting
tydeman at tybor.com      Testing, numerics, programming
+1 (775) 358-9748      Vice-chair of PL22.11 (ANSI "C")
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