NetBSD Problem Report #50937

From www@NetBSD.org  Fri Mar 11 03:07:04 2016
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Date: Fri, 11 Mar 2016 03:07:03 +0000 (UTC)
From: sibnick@gmail.com
Reply-To: sibnick@gmail.com
To: gnats-bugs@NetBSD.org
Subject: incorrect printf result for subnormal long double values
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>Number:         50937
>Category:       lib
>Synopsis:       incorrect printf result for subnormal long double values
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    lib-bug-people
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Mar 11 03:10:00 +0000 2016
>Closed-Date:    Sun Mar 13 20:20:05 +0000 2016
>Last-Modified:  Sun Mar 13 20:20:05 +0000 2016
>Originator:     Tolstokulakov Nikolay
>Release:        7.0
>Organization:
nsu.ru
>Environment:
NetBSD netbsd.home 7.0 NetBSD 7.0 (GENERIC.201509250726Z) amd64
>Description:
Unexpected and wrong result when print subnormal long double value

SO question & answer http://stackoverflow.com/questions/35090322/netbsd-long-double-trouble
>How-To-Repeat:
 #include <stdio.h>

 int main()
 {
      long double rd = 3.3621e-4932L;
      printf("%Le\n", rd);
      // NetBSD prints 1.681050e-4932
      return 0;
 }
>Fix:

>Release-Note:

>Audit-Trail:
From: Martin Husemann <martin@duskware.de>
To: gnats-bugs@NetBSD.org
Cc: 
Subject: Re: lib/50937: incorrect printf result for subnormal long double values
Date: Fri, 11 Mar 2016 11:56:58 +0100

 Note: this is amd64 specific and still the same in -current. It works
 on sparc64.

 Martin

From: henning petersen <henning.petersen@t-online.de>
To: gnats-bugs@NetBSD.org
Cc: 
Subject: Re: lib/50937: incorrect printf result for subnormal long double
 values
Date: Sun, 13 Mar 2016 17:57:49 +0100

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 With this patch it works on amd64.
 Problem has been solved in FreeBSD PR: 85080.

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From: "Christos Zoulas" <christos@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc: 
Subject: PR/50937 CVS commit: src/lib/libc/gdtoa
Date: Sun, 13 Mar 2016 15:44:58 -0400

 Module Name:	src
 Committed By:	christos
 Date:		Sun Mar 13 19:44:58 UTC 2016

 Modified Files:
 	src/lib/libc/gdtoa: ldtoa.c

 Log Message:
 PR/50937: Henning Petersen: Fix subnormal printf for long double x86. From
 FreeBSD PR 85080.


 To generate a diff of this commit:
 cvs rdiff -u -r1.4 -r1.5 src/lib/libc/gdtoa/ldtoa.c

 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.

State-Changed-From-To: open->closed
State-Changed-By: wiz@NetBSD.org
State-Changed-When: Sun, 13 Mar 2016 20:20:05 +0000
State-Changed-Why:
Fixed by christos, thanks.


>Unformatted:

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