NetBSD Problem Report #46659

From campbell@mumble.net  Thu Jul  5 02:23:25 2012
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Date: Thu,  5 Jul 2012 01:25:21 +0000 (UTC)
From: Taylor R Campbell <campbell+netbsd@mumble.net>
Reply-To: Taylor R Campbell <campbell+netbsd@mumble.net>
To: gnats-bugs@gnats.NetBSD.org
Subject: feenableexcept and fedisableexcept return too many bits on x86
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>Number:         46659
>Category:       lib
>Synopsis:       feenableexcept and fedisableexcept return too many bits on x86
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jul 05 02:25:01 +0000 2012
>Closed-Date:    Wed Dec 07 23:29:33 +0000 2016
>Last-Modified:  Wed Dec 07 23:29:33 +0000 2016
>Originator:     Taylor R Campbell <campbell+netbsd@mumble.net>
>Release:        NetBSD 6.99.7
>Organization:
>Environment:
>Description:

	On i386 (i387) and amd64, feenableexcept and fedisableexcept
	return negative results with bits not in FE_ALL_EXCEPT.  -1 is
	supposed to mean failure, and there shouldn't be any bits not
	in FE_ALL_EXCEPT.

>How-To-Repeat:

	Call feenableexcept or fedisableexcept on i386 or amd64.

>Fix:

	Apply the following patch.  OK to commit?

Index: lib/libm/arch/i387/fenv.c
===================================================================
RCS file: /cvsroot/src/lib/libm/arch/i387/fenv.c,v
retrieving revision 1.3
diff -p -u -r1.3 fenv.c
--- lib/libm/arch/i387/fenv.c	1 Aug 2010 06:34:38 -0000	1.3
+++ lib/libm/arch/i387/fenv.c	5 Jul 2012 01:13:14 -0000
@@ -472,7 +472,7 @@ feenableexcept(int mask)
 		__ldmxcsr(mxcsr);
 	}

-	return (~omask);
+	return (FE_ALL_EXCEPT & ~omask);
 }

 int
@@ -496,7 +496,7 @@ fedisableexcept(int mask)
 		__ldmxcsr(mxcsr);
 	}

-	return (~omask);
+	return (FE_ALL_EXCEPT & ~omask);
 }

 int
Index: lib/libm/arch/x86_64/fenv.c
===================================================================
RCS file: /cvsroot/src/lib/libm/arch/x86_64/fenv.c,v
retrieving revision 1.1
diff -p -u -r1.1 fenv.c
--- lib/libm/arch/x86_64/fenv.c	31 Jul 2010 21:47:53 -0000	1.1
+++ lib/libm/arch/x86_64/fenv.c	5 Jul 2012 01:13:14 -0000
@@ -483,7 +483,7 @@ feenableexcept(int mask)
 	mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
 	__ldmxcsr(mxcsr);

-	return (~omask);
+	return (FE_ALL_EXCEPT & ~omask);

 }

@@ -505,7 +505,7 @@ fedisableexcept(int mask)
 	mxcsr |= mask << _SSE_EMASK_SHIFT;
 	__ldmxcsr(mxcsr);

-	return (~omask);
+	return (FE_ALL_EXCEPT & ~omask);
 }

 int

>Release-Note:

>Audit-Trail:

State-Changed-From-To: open->closed
State-Changed-By: maya@NetBSD.org
State-Changed-When: Wed, 07 Dec 2016 23:29:33 +0000
State-Changed-Why:
Changes were committed


>Unformatted:

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