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From: "jvdelisle at charter dot net" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug libfortran/93727] Fortran 2018: EX edit descriptor Date: Sat, 29 Aug 2020 18:04:53 +0000 [thread overview] Message-ID: <bug-93727-4-xRY6xc2spT@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-93727-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93727 --- Comment #4 from jvdelisle at charter dot net --- An Update. I have the front end and runtime parsing for OUTPUT done and am now looking at the actual implementation. We have the printf series of functions available and can use the %A format specifier to create the hexidecimal float string. I want to note here that on input, apparently the F editing requires one to be able to READ a hexadecimal float with the F descriptor as well as the EX descriptor. See 13.7.2.3.2 part 7. Another aspect I am studying has to do with rounding. On output I assume we must support RU, RD, RN vs truncating. Considering that the purpose of this type of representation of a float is mostly for "looking under the hood" I initially was thinking simple truncation should suffice and if a user does not know they have not specified enough precision for all hexadecimals, tough beans. After all, in hexadecimal, it is always an exact fit. I am curious what others think about this. Regardless, we will need a new rounding function to round the hexadecimals before output. On input, obviously we need to do a new read function and for the F descriptor we will have to look ahead to identify that it is a hexadecimal before processing it, otherwise it just looks like a bad float.
next prev parent reply other threads:[~2020-08-29 18:04 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <bug-93727-4@http.gcc.gnu.org/bugzilla/> 2020-07-12 15:38 ` dominiq at lps dot ens.fr 2020-07-14 12:51 ` jvdelisle at charter dot net 2020-08-11 14:41 ` dominiq at lps dot ens.fr 2020-08-14 21:34 ` jvdelisle at charter dot net 2020-08-29 18:04 ` jvdelisle at charter dot net [this message] 2024-03-06 2:34 ` jvdelisle at gcc dot gnu.org 2024-03-10 3:37 ` jvdelisle at gcc dot gnu.org 2024-03-10 9:41 ` thenlich at gcc dot gnu.org 2024-03-10 17:17 ` jvdelisle at gcc dot gnu.org
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