NetBSD Problem Report #46627

From www@NetBSD.org  Mon Jun 25 04:44:47 2012
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Date: Mon, 25 Jun 2012 04:44:45 +0000 (UTC)
From: isaki@NetBSD.org
Reply-To: isaki@NetBSD.org
To: gnats-bugs@NetBSD.org
Subject: ceil() is broken on m68k FPE (FINT emulation is broken)
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>Number:         46627
>Category:       kern
>Synopsis:       ceil() is broken on m68k FPE (FINT emulation is broken)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jun 25 04:45:00 +0000 2012
>Closed-Date:    Tue Jun 26 02:04:58 +0000 2012
>Last-Modified:  Wed Jul 04 20:35:02 +0000 2012
>Originator:     Tetsuya Isaki
>Release:        NetBSD-current/x68k
>Organization:
>Environment:
NetBSD xxxx 6.99.6 NetBSD 6.99.6 (GENERIC) #11: Mon May  7 22:47:21 JST 2012 xxxx@xxxx:xxxx/sys/arch/x68k/compile/GENERIC x68k
>Description:
On m68k FPE (= m68k without the FPU, such as XM6i emulator),
ceil() is broken in |x| < 1.

% uname -srm
NetBSD 6.99.6 x68k
% dmesg|grep FPU
X68030 (m68030 CPU/MMU, emulator FPU, 24MHz clock)
% cat a.c
#include <stdio.h>
#include <math.h>
int main()
{
    double list[]={ -1.5, -1.1, -0.5, -0.1, 0, 0.1, 0.5, 1.1, 1.5, };
    unsigned int i;

    for (i = 0; i < sizeof(list)/sizeof(list[0]); i++) {
        printf("ceil(%g) -> %g\n", list[i], ceil(list[i]));
    }
    return 0;
}
% gcc a.c -lm
% ./a.out
ceil(-1.5) -> -1
ceil(-1.1) -> -1
ceil(-0.5) -> -0.5
ceil(-0.1) -> -0
ceil(0) -> 0
ceil(0.1) -> 0
ceil(0.5) -> 1
ceil(1.1) -> 2
ceil(1.5) -> 2
%

ceil() calls FINT (in lib/libm/arch/m68k/s_ceil.S), and
FINT emulation in FPE does not consider FPCR round mode when
|x| < 1 and something is strange in sys/arch/m68k/fpe/fpu_int.c.
>How-To-Repeat:
See above.
>Fix:
I will fix it.

>Release-Note:

>Audit-Trail:
From: "Tetsuya Isaki" <isaki@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc: 
Subject: PR/46627 CVS commit: src/sys/arch/m68k/fpe
Date: Mon, 25 Jun 2012 04:52:23 +0000

 Module Name:	src
 Committed By:	isaki
 Date:		Mon Jun 25 04:52:23 UTC 2012

 Modified Files:
 	src/sys/arch/m68k/fpe: fpu_int.c

 Log Message:
 Rewrite fpu_int().
 Especially, remove the special treatment when |x| < 1
 because it forgets to consider FPCR round mode.
 See PR/46627 for the detail.  Thanks Y.Sugahara for advice.


 To generate a diff of this commit:
 cvs rdiff -u -r1.10 -r1.11 src/sys/arch/m68k/fpe/fpu_int.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: isaki@NetBSD.org
State-Changed-When: Tue, 26 Jun 2012 02:04:58 +0000
State-Changed-Why:
Fixed.


From: "Julian Coleman" <jdc@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc: 
Subject: PR/46627 CVS commit: [netbsd-6] src/sys/arch/m68k/fpe
Date: Wed, 4 Jul 2012 20:30:00 +0000

 Module Name:	src
 Committed By:	jdc
 Date:		Wed Jul  4 20:30:00 UTC 2012

 Modified Files:
 	src/sys/arch/m68k/fpe [netbsd-6]: fpu_int.c

 Log Message:
 Pull up revision 1.11 (requested by isaki in ticket #384).

 Rewrite fpu_int().
 Especially, remove the special treatment when |x| < 1
 because it forgets to consider FPCR round mode.
 See PR/46627 for the detail.  Thanks Y.Sugahara for advice.


 To generate a diff of this commit:
 cvs rdiff -u -r1.10 -r1.10.8.1 src/sys/arch/m68k/fpe/fpu_int.c

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

>Unformatted:

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