[PATCH][BZ #5768 fix SIGFPE in isnan(0 for SNaN

[Steven Munroe]

The attached patch fixes a problem we found in PPC where GCC4.1+ code
motion rearranges the inline asm macros for isnan(). GCC moves the
(x==x) after the original fpscr (with FE_INVALID enabled) is restored.
If a Signaling NaN is passed we will get a SIGFPE.

-------------- next part --------------
2008-02-18  Steven Munroe  <sjmunroe@us.ibm.com>

	[BZ #5768]
	* sysdeps/powerpc/powerpc32/fpu/s_isnan.S: New file.
	* sysdeps/powerpc/powerpc32/fpu/s_isnan.c: Removed.
	* sysdeps/powerpc/powerpc64/fpu/s_isnan.S: New file.
	* sysdeps/powerpc/powerpc64/fpu/s_isnan.c: Removed.

diff -urN libc25-cvstip-20070919/sysdeps/powerpc/powerpc32/fpu/s_isnan.S libc25/sysdeps/powerpc/powerpc32/fpu/s_isnan.S
--- /dev/null	2007-05-04 05:56:50.000000000 -0500
+++ libc25/sysdeps/powerpc/powerpc32/fpu/s_isnan.S	2008-02-07 15:04:51.000000000 -0600
@@ -0,0 +1,56 @@
+/* isnan().  PowerPC32 version.
+   Copyright (C) 2008 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+#include <math_ldbl_opt.h>
+
+/* int __isnan(x)  */
+	.machine power4
+EALIGN (__isnan, 4, 0)	
+	mffs	fp0
+	mtfsb0	4*cr6+lt /* reset_fpscr_bit (FPSCR_VE) */
+	fcmpu	cr7,fp1,fp1
+	mtfsf	255,fp0
+	li	r3,0
+	beqlr+	cr7	/* (x == x) then not a NAN */
+	li	r3,1	/* else must be a NAN */
+	blr
+	END (__isnan)
+
+hidden_def (__isnan)
+weak_alias (__isnan, isnan)
+
+/* It turns out that the 'double' version will also always work for
+   single-precision.  */
+strong_alias (__isnan, __isnanf)
+hidden_def (__isnanf)
+weak_alias (__isnanf, isnanf)
+
+#ifdef NO_LONG_DOUBLE
+strong_alias (__isnan, __isnanl)
+weak_alias (__isnan, isnanl)
+#endif
+
+#ifndef IS_IN_libm
+# if LONG_DOUBLE_COMPAT(libc, GLIBC_2_0)
+compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0);
+compat_symbol (libc, isnan, isnanl, GLIBC_2_0);
+# endif
+#endif
+
diff -urN libc25-cvstip-20070919/sysdeps/powerpc/powerpc32/fpu/s_isnan.c libc25/sysdeps/powerpc/powerpc32/fpu/s_isnan.c
--- libc25-cvstip-20070919/sysdeps/powerpc/powerpc32/fpu/s_isnan.c	2008-01-04 11:53:41.000000000 -0600
+++ /dev/null	2007-05-04 05:56:50.000000000 -0500
@@ -1,7 +0,0 @@
-#include <sysdeps/powerpc/fpu/s_isnan.c>
-#ifndef IS_IN_libm
-# if LONG_DOUBLE_COMPAT(libc, GLIBC_2_0)
-compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0);
-compat_symbol (libc, isnan, isnanl, GLIBC_2_0);
-# endif
-#endif
diff -urN libc25-cvstip-20070919/sysdeps/powerpc/powerpc64/fpu/s_isnan.S libc25/sysdeps/powerpc/powerpc64/fpu/s_isnan.S
--- /dev/null	2007-05-04 05:56:50.000000000 -0500
+++ libc25/sysdeps/powerpc/powerpc64/fpu/s_isnan.S	2008-02-07 15:05:03.000000000 -0600
@@ -0,0 +1,57 @@
+/* isnan().  PowerPC64 version.
+   Copyright (C) 2008 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+#include <math_ldbl_opt.h>
+
+/* int __isnan(x)  */
+	.machine power4
+EALIGN (__isnan, 4, 0)	
+	CALL_MCOUNT 0
+	mffs	fp0
+	mtfsb0	4*cr6+lt /* reset_fpscr_bit (FPSCR_VE) */
+	fcmpu	cr7,fp1,fp1
+	mtfsf	255,fp0
+	li	r3,0
+	beqlr+	cr7	/* (x == x) then not a NAN */
+	li	r3,1	/* else must be a NAN */
+	blr
+	END (__isnan)
+
+hidden_def (__isnan)
+weak_alias (__isnan, isnan)
+
+/* It turns out that the 'double' version will also always work for
+   single-precision.  */
+strong_alias (__isnan, __isnanf)
+hidden_def (__isnanf)
+weak_alias (__isnanf, isnanf)
+
+#ifdef NO_LONG_DOUBLE
+strong_alias (__isnan, __isnanl)
+weak_alias (__isnan, isnanl)
+#endif
+
+#ifndef IS_IN_libm
+# if LONG_DOUBLE_COMPAT(libc, GLIBC_2_0)
+compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0);
+compat_symbol (libc, isnan, isnanl, GLIBC_2_0);
+# endif
+#endif
+
diff -urN libc25-cvstip-20070919/sysdeps/powerpc/powerpc64/fpu/s_isnan.c libc25/sysdeps/powerpc/powerpc64/fpu/s_isnan.c
--- libc25-cvstip-20070919/sysdeps/powerpc/powerpc64/fpu/s_isnan.c	2008-01-04 11:53:50.000000000 -0600
+++ /dev/null	2007-05-04 05:56:50.000000000 -0500
@@ -1,7 +0,0 @@
-#include <sysdeps/powerpc/fpu/s_isnan.c>
-#ifndef IS_IN_libm
-# if LONG_DOUBLE_COMPAT(libc, GLIBC_2_0)
-compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0);
-compat_symbol (libc, isnan, isnanl, GLIBC_2_0);
-# endif
-#endif