Define HIGH_ORDER_BIT_IS_SET_FOR_SNAN to 0 or 1.

This patch moves the HIGH_ORDER_BIT_IS_SET_FOR_SNAN macro from being
defined or undefined to the preferred convention of always being
defined, to either 0 or 1, so allowing typo-proof tests with #if.

The macro is moved from math_private.h to a new header
nan-high-order-bit.h to make it easy for all architectures to define,
either through the sysdeps/generic version of the header or through
providing their own version of the header, without needing #ifndef in
the generic math_private.h to give a default definition.  The move
also allows the macro to be used without needing math_private.h to be
included; the immediate motivation of this patch is to allow tests to
access this information (to know what kinds of NaNs 0 is a valid
payload for) without needing to include math_private.h.  Existing
C level rather than preprocessor conditionals at all, but this patch
does not make such a change).

Tested for x86_64 and x86 (testsuite); also verified for x86_64, x86,
mips64 and powerpc that installed stripped shared libraries are
unchanged by the patch.

	* sysdeps/generic/nan-high-order-bit.h: New file.
	* sysdeps/hppa/nan-high-order-bit.h: Likewise.
	* sysdeps/mips/nan-high-order-bit.h: Likewise.
	* sysdeps/hppa/math_private.h: Remove file.
	* sysdeps/mips/math_private.h (HIGH_ORDER_BIT_IS_SET_FOR_SNAN): Do
	not define here.
	* sysdeps/ieee754/dbl-64/s_issignaling.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/dbl-64/s_totalorder.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/dbl-64/s_totalordermag.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_issignaling.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_totalorder.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_totalordermag.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/flt-32/s_issignalingf.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/flt-32/s_totalorderf.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/flt-32/s_totalordermagf.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/ldbl-128/s_issignalingl.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/ldbl-128/s_totalorderl.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/ldbl-128/s_totalordermagl.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/ldbl-128ibm/s_issignalingl.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/ldbl-128ibm/s_totalorderl.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/ldbl-128ibm/s_totalordermagl.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/ldbl-96/s_issignalingl.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/ldbl-96/s_totalorderl.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
	* sysdeps/ieee754/ldbl-96/s_totalordermagl.c: Include
	<nan-high-order-bit.h>.
	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.

23 files changed, 167 insertions, 36 deletions

diff --git a/ChangeLog b/ChangeLog
index 3c328b2..5448fad 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,66 @@
+2016-10-17  Joseph Myers  <joseph@codesourcery.com>
+
+	* sysdeps/generic/nan-high-order-bit.h: New file.
+	* sysdeps/hppa/nan-high-order-bit.h: Likewise.
+	* sysdeps/mips/nan-high-order-bit.h: Likewise.
+	* sysdeps/hppa/math_private.h: Remove file.
+	* sysdeps/mips/math_private.h (HIGH_ORDER_BIT_IS_SET_FOR_SNAN): Do
+	not define here.
+	* sysdeps/ieee754/dbl-64/s_issignaling.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/dbl-64/s_totalorder.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/dbl-64/s_totalordermag.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/dbl-64/wordsize-64/s_issignaling.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/dbl-64/wordsize-64/s_totalorder.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/dbl-64/wordsize-64/s_totalordermag.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/flt-32/s_issignalingf.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/flt-32/s_totalorderf.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/flt-32/s_totalordermagf.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/ldbl-128/s_issignalingl.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/ldbl-128/s_totalorderl.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/ldbl-128/s_totalordermagl.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/ldbl-128ibm/s_issignalingl.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/ldbl-128ibm/s_totalorderl.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/ldbl-128ibm/s_totalordermagl.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/ldbl-96/s_issignalingl.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/ldbl-96/s_totalorderl.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+	* sysdeps/ieee754/ldbl-96/s_totalordermagl.c: Include
+	<nan-high-order-bit.h>.
+	[HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Test with #if not #ifdef.
+
 2016-10-17  Stefan Liebler  <stli@linux.vnet.ibm.com>
 
 	* sysdeps/s390/fpu/fix-fp-int-compare-invalid.h: New file.
diff --git a/sysdeps/generic/nan-high-order-bit.h b/sysdeps/generic/nan-high-order-bit.h
new file mode 100644
index 0000000..1561915
--- /dev/null
+++ b/sysdeps/generic/nan-high-order-bit.h
@@ -0,0 +1,27 @@
+/* Specify NaN high-order bit conventions.  Generic version.
+   Copyright (C) 2016 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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef NAN_HIGH_ORDER_BIT_H
+#define NAN_HIGH_ORDER_BIT_H	1
+
+/* Define this macro to 1 if the high-order bit of a NaN's mantissa is
+   set for signaling NaNs and clear for quiet NaNs, 0 otherwise (the
+   preferred IEEE convention).  */
+#define HIGH_ORDER_BIT_IS_SET_FOR_SNAN 0
+
+#endif /* nan-high-order-bit.h */
diff --git a/sysdeps/hppa/math_private.h b/sysdeps/hppa/nan-high-order-bit.h
index 1acfb9a..a63d6a7 100644
--- a/sysdeps/hppa/math_private.h
+++ b/sysdeps/hppa/nan-high-order-bit.h
@@ -1,5 +1,5 @@
-/* Internal math stuff.  HPPA version.
-   Copyright (C) 2013-2016 Free Software Foundation, Inc.
+/* Specify NaN high-order bit conventions.  HPPA version.
+   Copyright (C) 2016 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
@@ -16,13 +16,12 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#ifndef HPPA_MATH_PRIVATE_H
-#define HPPA_MATH_PRIVATE_H 1
+#ifndef NAN_HIGH_ORDER_BIT_H
+#define NAN_HIGH_ORDER_BIT_H	1
 
-/* One of the few architectures where the meaning of the quiet/signaling bit is
-   inverse to IEEE 754-2008 (as well as common practice for IEEE 754-1985).  */
-#define HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+/* One of the few architectures where the meaning of the
+   quiet/signaling bit is inverse to IEEE 754-2008 (as well as common
+   practice for IEEE 754-1985).  */
+#define HIGH_ORDER_BIT_IS_SET_FOR_SNAN 1
 
-#include_next <math_private.h>
-
-#endif
+#endif /* nan-high-order-bit.h */
diff --git a/sysdeps/ieee754/dbl-64/s_issignaling.c b/sysdeps/ieee754/dbl-64/s_issignaling.c
index 4b93d6a..0b845e2 100644
--- a/sysdeps/ieee754/dbl-64/s_issignaling.c
+++ b/sysdeps/ieee754/dbl-64/s_issignaling.c
@@ -18,11 +18,12 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 
 int
 __issignaling (double x)
 {
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   u_int32_t hxi;
   GET_HIGH_WORD (hxi, x);
   /* We only have to care about the high-order bit of x's significand, because
diff --git a/sysdeps/ieee754/dbl-64/s_totalorder.c b/sysdeps/ieee754/dbl-64/s_totalorder.c
index 73ac32f..c4ec917 100644
--- a/sysdeps/ieee754/dbl-64/s_totalorder.c
+++ b/sysdeps/ieee754/dbl-64/s_totalorder.c
@@ -18,6 +18,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -27,7 +28,7 @@ totalorder (double x, double y)
   uint32_t lx, ly;
   EXTRACT_WORDS (hx, lx, x);
   EXTRACT_WORDS (hy, ly, y);
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   uint32_t uhx = hx & 0x7fffffff, uhy = hy & 0x7fffffff;
   /* For the preferred quiet NaN convention, this operation is a
      comparison of the representations of the arguments interpreted as
diff --git a/sysdeps/ieee754/dbl-64/s_totalordermag.c b/sysdeps/ieee754/dbl-64/s_totalordermag.c
index e41dade..3850c33 100644
--- a/sysdeps/ieee754/dbl-64/s_totalordermag.c
+++ b/sysdeps/ieee754/dbl-64/s_totalordermag.c
@@ -18,6 +18,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -29,7 +30,7 @@ totalordermag (double x, double y)
   EXTRACT_WORDS (hy, ly, y);
   hx &= 0x7fffffff;
   hy &= 0x7fffffff;
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   /* For the preferred quiet NaN convention, this operation is a
      comparison of the representations of the absolute values of the
      arguments.  If both arguments are NaNs, invert the
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_issignaling.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_issignaling.c
index c22e608..18d1acd 100644
--- a/sysdeps/ieee754/dbl-64/wordsize-64/s_issignaling.c
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_issignaling.c
@@ -18,13 +18,14 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 
 int
 __issignaling (double x)
 {
   u_int64_t xi;
   EXTRACT_WORDS64 (xi, x);
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   /* We only have to care about the high-order bit of x's significand, because
      having it set (sNaN) already makes the significand different from that
      used to designate infinity.  */
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_totalorder.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_totalorder.c
index 02cd799..dd5587b 100644
--- a/sysdeps/ieee754/dbl-64/wordsize-64/s_totalorder.c
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_totalorder.c
@@ -18,6 +18,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -26,7 +27,7 @@ totalorder (double x, double y)
   int64_t ix, iy;
   EXTRACT_WORDS64 (ix, x);
   EXTRACT_WORDS64 (iy, y);
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   /* For the preferred quiet NaN convention, this operation is a
      comparison of the representations of the arguments interpreted as
      sign-magnitude integers.  If both arguments are NaNs, invert the
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_totalordermag.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_totalordermag.c
index 38f2e1b..999a919 100644
--- a/sysdeps/ieee754/dbl-64/wordsize-64/s_totalordermag.c
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_totalordermag.c
@@ -18,6 +18,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -28,7 +29,7 @@ totalordermag (double x, double y)
   EXTRACT_WORDS64 (iy, y);
   ix &= 0x7fffffffffffffffULL;
   iy &= 0x7fffffffffffffffULL;
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   /* For the preferred quiet NaN convention, this operation is a
      comparison of the representations of the absolute values of the
      arguments.  If both arguments are NaNs, invert the
diff --git a/sysdeps/ieee754/flt-32/s_issignalingf.c b/sysdeps/ieee754/flt-32/s_issignalingf.c
index 2409ff4..965ba92 100644
--- a/sysdeps/ieee754/flt-32/s_issignalingf.c
+++ b/sysdeps/ieee754/flt-32/s_issignalingf.c
@@ -18,13 +18,14 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 
 int
 __issignalingf (float x)
 {
   u_int32_t xi;
   GET_FLOAT_WORD (xi, x);
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   /* We only have to care about the high-order bit of x's significand, because
      having it set (sNaN) already makes the significand different from that
      used to designate infinity.  */
diff --git a/sysdeps/ieee754/flt-32/s_totalorderf.c b/sysdeps/ieee754/flt-32/s_totalorderf.c
index 1ed30d8..243387b 100644
--- a/sysdeps/ieee754/flt-32/s_totalorderf.c
+++ b/sysdeps/ieee754/flt-32/s_totalorderf.c
@@ -18,6 +18,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -26,7 +27,7 @@ totalorderf (float x, float y)
   int32_t ix, iy;
   GET_FLOAT_WORD (ix, x);
   GET_FLOAT_WORD (iy, y);
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   /* For the preferred quiet NaN convention, this operation is a
      comparison of the representations of the arguments interpreted as
      sign-magnitude integers.  If both arguments are NaNs, invert the
diff --git a/sysdeps/ieee754/flt-32/s_totalordermagf.c b/sysdeps/ieee754/flt-32/s_totalordermagf.c
index 7c01edc..be78eae 100644
--- a/sysdeps/ieee754/flt-32/s_totalordermagf.c
+++ b/sysdeps/ieee754/flt-32/s_totalordermagf.c
@@ -18,6 +18,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -28,7 +29,7 @@ totalordermagf (float x, float y)
   GET_FLOAT_WORD (iy, y);
   ix &= 0x7fffffff;
   iy &= 0x7fffffff;
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   /* For the preferred quiet NaN convention, this operation is a
      comparison of the representations of the absolute values of the
      arguments.  If both arguments are NaNs, invert the
diff --git a/sysdeps/ieee754/ldbl-128/s_issignalingl.c b/sysdeps/ieee754/ldbl-128/s_issignalingl.c
index 6af1db4..cb0f2a5 100644
--- a/sysdeps/ieee754/ldbl-128/s_issignalingl.c
+++ b/sysdeps/ieee754/ldbl-128/s_issignalingl.c
@@ -18,13 +18,14 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 
 int
 __issignalingl (_Float128 x)
 {
   u_int64_t hxi, lxi __attribute__ ((unused));
   GET_LDOUBLE_WORDS64 (hxi, lxi, x);
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   /* We only have to care about the high-order bit of x's significand, because
      having it set (sNaN) already makes the significand different from that
      used to designate infinity.  */
diff --git a/sysdeps/ieee754/ldbl-128/s_totalorderl.c b/sysdeps/ieee754/ldbl-128/s_totalorderl.c
index dc76ccf..32ede1f 100644
--- a/sysdeps/ieee754/ldbl-128/s_totalorderl.c
+++ b/sysdeps/ieee754/ldbl-128/s_totalorderl.c
@@ -18,6 +18,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -27,7 +28,7 @@ totalorderl (_Float128 x, _Float128 y)
   uint64_t lx, ly;
   GET_LDOUBLE_WORDS64 (hx, lx, x);
   GET_LDOUBLE_WORDS64 (hy, ly, y);
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   uint64_t uhx = hx & 0x7fffffffffffffffULL;
   uint64_t uhy = hy & 0x7fffffffffffffffULL;
   /* For the preferred quiet NaN convention, this operation is a
diff --git a/sysdeps/ieee754/ldbl-128/s_totalordermagl.c b/sysdeps/ieee754/ldbl-128/s_totalordermagl.c
index bcfeecd..5446809 100644
--- a/sysdeps/ieee754/ldbl-128/s_totalordermagl.c
+++ b/sysdeps/ieee754/ldbl-128/s_totalordermagl.c
@@ -18,6 +18,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -29,7 +30,7 @@ totalordermagl (_Float128 x, _Float128 y)
   GET_LDOUBLE_WORDS64 (hy, ly, y);
   hx &= 0x7fffffffffffffffULL;
   hy &= 0x7fffffffffffffffULL;
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
   /* For the preferred quiet NaN convention, this operation is a
      comparison of the representations of the absolute values of the
      arguments.  If both arguments are NaNs, invert the
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_issignalingl.c b/sysdeps/ieee754/ldbl-128ibm/s_issignalingl.c
index 0915139..94cfffcd 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_issignalingl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_issignalingl.c
@@ -18,6 +18,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 
 int
 __issignalingl (long double x)
@@ -29,7 +30,7 @@ __issignalingl (long double x)
 
   xhi = ldbl_high (x);
   EXTRACT_WORDS64 (xi, xhi);
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
 # error untested
   /* We only have to care about the high-order bit of x's significand, because
      having it set (sNaN) already makes the significand different from that
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_totalorderl.c b/sysdeps/ieee754/ldbl-128ibm/s_totalorderl.c
index 1535b2f..ff55779 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_totalorderl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_totalorderl.c
@@ -18,6 +18,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -30,7 +31,7 @@ totalorderl (long double x, long double y)
   EXTRACT_WORDS64 (hx, xhi);
   ldbl_unpack (y, &yhi, &ylo);
   EXTRACT_WORDS64 (hy, yhi);
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
 # error not implemented
 #endif
   uint64_t hx_sign = hx >> 63;
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_totalordermagl.c b/sysdeps/ieee754/ldbl-128ibm/s_totalordermagl.c
index 509a23a..739e231 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_totalordermagl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_totalordermagl.c
@@ -18,6 +18,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -30,7 +31,7 @@ totalordermagl (long double x, long double y)
   EXTRACT_WORDS64 (hx, xhi);
   ldbl_unpack (y, &yhi, &ylo);
   EXTRACT_WORDS64 (hy, yhi);
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
 # error not implemented
 #endif
   uint64_t x_sign = hx & 0x8000000000000000ULL;
diff --git a/sysdeps/ieee754/ldbl-96/s_issignalingl.c b/sysdeps/ieee754/ldbl-96/s_issignalingl.c
index 73646ca..364e5db 100644
--- a/sysdeps/ieee754/ldbl-96/s_issignalingl.c
+++ b/sysdeps/ieee754/ldbl-96/s_issignalingl.c
@@ -18,13 +18,14 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 
 int
 __issignalingl (long double x)
 {
   u_int32_t exi, hxi, lxi;
   GET_LDOUBLE_WORDS (exi, hxi, lxi, x);
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
 # error not implemented
 #else
   /* To keep the following comparison simple, toggle the quiet/signaling bit,
diff --git a/sysdeps/ieee754/ldbl-96/s_totalorderl.c b/sysdeps/ieee754/ldbl-96/s_totalorderl.c
index 4f14baf..ddc28b8 100644
--- a/sysdeps/ieee754/ldbl-96/s_totalorderl.c
+++ b/sysdeps/ieee754/ldbl-96/s_totalorderl.c
@@ -19,6 +19,7 @@
 #include <float.h>
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -41,7 +42,7 @@ totalorderl (long double x, long double y)
       if ((expy & 0x7fff) == 0x7fff)
 	hy |= 0x80000000;
     }
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
 # error not implemented
 #endif
   uint32_t x_sign = expx >> 15;
diff --git a/sysdeps/ieee754/ldbl-96/s_totalordermagl.c b/sysdeps/ieee754/ldbl-96/s_totalordermagl.c
index 0167f0f..4ca28e7 100644
--- a/sysdeps/ieee754/ldbl-96/s_totalordermagl.c
+++ b/sysdeps/ieee754/ldbl-96/s_totalordermagl.c
@@ -19,6 +19,7 @@
 #include <float.h>
 #include <math.h>
 #include <math_private.h>
+#include <nan-high-order-bit.h>
 #include <stdint.h>
 
 int
@@ -43,7 +44,7 @@ totalordermagl (long double x, long double y)
       if (expy == 0x7fff)
 	hy |= 0x80000000;
     }
-#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
 # error not implemented
 #endif
   return expx < expy || (expx == expy && (hx < hy || (hx == hy && lx <= ly)));
diff --git a/sysdeps/mips/math_private.h b/sysdeps/mips/math_private.h
index 2ea3c57..4587d01 100644
--- a/sysdeps/mips/math_private.h
+++ b/sysdeps/mips/math_private.h
@@ -19,14 +19,6 @@
 #ifndef MIPS_MATH_PRIVATE_H
 #define MIPS_MATH_PRIVATE_H 1
 
-#ifdef __mips_nan2008
-/* MIPS aligned to IEEE 754-2008.  */
-#else
-/* One of the few architectures where the meaning of the quiet/signaling bit is
-   inverse to IEEE 754-2008 (as well as common practice for IEEE 754-1985).  */
-# define HIGH_ORDER_BIT_IS_SET_FOR_SNAN
-#endif
-
 /* Inline functions to speed up the math library implementation.  The
    default versions of these routines are in generic/math_private.h
    and call fesetround, feholdexcept, etc.  These routines use inlined
diff --git a/sysdeps/mips/nan-high-order-bit.h b/sysdeps/mips/nan-high-order-bit.h
new file mode 100644
index 0000000..0aaef0f
--- /dev/null
+++ b/sysdeps/mips/nan-high-order-bit.h
@@ -0,0 +1,32 @@
+/* Specify NaN high-order bit conventions.  MIPS version.
+   Copyright (C) 2016 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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef NAN_HIGH_ORDER_BIT_H
+#define NAN_HIGH_ORDER_BIT_H	1
+
+#ifdef __mips_nan2008
+/* MIPS aligned to IEEE 754-2008.  */
+# define HIGH_ORDER_BIT_IS_SET_FOR_SNAN 0
+#else
+/* One of the few architectures where the meaning of the
+   quiet/signaling bit is inverse to IEEE 754-2008 (as well as common
+   practice for IEEE 754-1985).  */
+# define HIGH_ORDER_BIT_IS_SET_FOR_SNAN 1
+#endif
+
+#endif /* nan-high-order-bit.h */