[jira] Commented: (STDCXX-463) [HP-UX 11.23] printf("%Lg", -NAN) formatted incorrectly

["Martin Sebor (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/STDCXX-463?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12509642 ] 

Martin Sebor commented on STDCXX-463:
-------------------------------------

Response from HP:

-------- Original Message --------
Subject: Re:  HP-UX 11.23 printf("%Lg", -NAN) formatted incorrectly
Date: Thu, 28 Jun 2007 20:14:30 -0700 (PDT)
From: Dennis Handly <dh...@cup.hp.com>
To: acxx@cup.hp.com, sebor@roguewave.com

>From: Martin Sebor <se...@roguewave.com>
>On 11.23/PA, printf("%g") formats negative NaN correctly (by
>prepending the minus) but with "%Lg" it forgets the sign.
>On 11.31/IPF printf() works correctly.

     -std::numeric_limits<long double>::quiet_NaN()

This works correctly on all IPF versions.  Because the IPF libc has
_U_Qfneg and PA doesn't.  The PA compiler uses _U_Qfsub which doesn't
produce negative NaNs.

>Are there plans to backport the fix to prior versions of HP-UX and/or PA?
Martin

I seriously doubt it.  libc would have to change and then all of the
compilers.


There were other CRs about negating NaNs:
JAGaa73927 NaN signs not respected
JAGaa86217 Incorrect printing of long double NaNs
JAGaa91576 Signed NaNs aren't generated correctly (see JAGaa78419 for C equiv)
JAGaa78419 NaN signs not respected (2)
JAGad01217 incorrect display of -nan from printf in libc 


> [HP-UX 11.23] printf("%Lg", -NAN) formatted incorrectly
> -------------------------------------------------------
>
>                 Key: STDCXX-463
>                 URL: https://issues.apache.org/jira/browse/STDCXX-463
>             Project: C++ Standard Library
>          Issue Type: Bug
>          Components: External
>         Environment: HP-UX 11.23 and prior
>            Reporter: Martin Sebor
>
> -------- Original Message --------
> Subject: HP-UX 11.23 printf("%Lg", -NAN) formatted incorrectly
> Date: Thu, 28 Jun 2007 19:34:32 -0600
> From: Martin Sebor <se...@roguewave.com>
> Organization: Rogue Wave Software
> To: acxx@cup.hp.com
> Hi,
> On 11.23/PA, printf("%g") formats negative NaN correctly (by
> prepending the minus) but with "%Lg" it forgets the sign. On
> 11.31/IPF printf() works correctly. Are there plans to backport
> the fix to prior versions of HP-UX and/or PA?
> Thanks
> Martin
> $ cat t.cpp && aCC -AA t.cpp && ./a.out
> #include <assert.h>
> #include <stdio.h>
> #include <string.h>
> #include <limits>
> int main ()
> {
>     char nan [32];
>     char nnan [32];
>     char lnan [32];
>     char nlnan [32];
>     sprintf (nan, "%g", std::numeric_limits<double>::quiet_NaN ());
>     sprintf (nnan, "%g", -std::numeric_limits<double>::quiet_NaN ());
>     sprintf (lnan, "%Lg", std::numeric_limits<long double>::quiet_NaN ());
>     sprintf (nlnan, "%Lg", -std::numeric_limits<long double>::quiet_NaN ());
>     printf ("%s, %s\n%s, %s\n", nan, nnan, lnan, nlnan);
>     assert (0 == strcmp (nan, lnan));
>     assert (0 == strcmp (nnan, nlnan));
> }
> nan, -nan
> nan, nan
> Assertion failed: 0 == strcmp (nnan, nlnan), file t.cpp, line 21
> ABORT instruction (core dumped)

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.