Patchwork [13/25] Split up endian.h to minimize exposure of BYTE_ORDER.

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Submitter Zack Weinberg
Date June 26, 2019, 5:50 p.m.
Message ID <20190626175029.4699-4-zackw@panix.com>
Download mbox | patch
Permalink /patch/33431/
State New
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Comments

Zack Weinberg - June 26, 2019, 5:50 p.m.
With only two exceptions (sys/types.h and sys/param.h, both of which
historically might have defined BYTE_ORDER) the public headers that
include <endian.h> only want to be able to test __BYTE_ORDER against
__*_ENDIAN.

This patch creates a new bits/endian.h that can be included by any
header that wants to be able to test __BYTE_ORDER and/or
__FLOAT_WORD_ORDER against the __*_ENDIAN constants, or needs
__LONG_LONG_PAIR.  It only defines macros in the implementation
namespace.

The existing bits/endian.h (which could not be included independently
of endian.h, and only defines __BYTE_ORDER and maybe __FLOAT_WORD_ORDER)
is renamed to bits/endianness.h.  I also took the opportunity to
canonicalize the form of this header, which we are stuck with having
one copy of per architecture.  Since they are so short, this means git
doesn’t understand that they were renamed from existing headers, sigh.

endian.h itself is a nonstandard header and its only remaining use
from a standard header is guarded by __USE_MISC, so I dropped the
__USE_MISC conditionals from around all of the public-namespace things
it defines.  (This means, an application that requests strict library
conformance but includes endian.h will still see the definition of
BYTE_ORDER.)

A few changes to specific bits/endian(ness).h variants deserve
mention:

 - sysdeps/unix/sysv/linux/ia64/bits/endian.h is moved to
   sysdeps/ia64/bits/endianness.h.  If I remember correctly, ia64 did
   have selectable endianness, but we have assembly code in
   sysdeps/ia64 that assumes it’s little-endian, so there is no reason
   to treat the ia64 endianness.h as linux-specific.

 - The C-SKY port does not fully support big-endian mode, but I do
   not think this is sufficient reason to make csky/bits/endian(ness).h
   error out if __CSKYBE__ is defined, so it now defines __BYTE_ORDER
   appropriately for whichever mode the compiler is in.

 - The PowerPC port had extra logic in its bits/endian.h to detect a
   broken compiler, which strikes me as unnecessary, so I removed it.

 - The only files that defined __FLOAT_WORD_ORDER always defined it to
   the same value as __BYTE_ORDER, so I removed those definitions.
   The SH bits/endian(ness).h had comments inconsistent with the
   actual setting of __FLOAT_WORD_ORDER, which I also removed.

 - I *removed* copyright boilerplate from the few bits/endian(ness).h
   headers that had it; these files record a single fact in a fashion
   dictated by an external spec, so I do not think they are copyrightable.

As long as I was changing every copy of ieee754.h in the tree, I
noticed that only the MIPS variant includes float.h, because it uses
LDBL_MANT_DIG to decide among three different versions of
ieee854_long_double.  This patch makes it not include float.h when
GCC’s intrinsic __LDBL_MANT_DIG__ is available.

	* string/endian.h: Unconditionally define LITTLE_ENDIAN,
	BIG_ENDIAN, PDP_ENDIAN, and BYTE_ORDER.	 Condition byteswapping
	macros only on !__ASSEMBLER__.	Move the definitions of
	__BIG_ENDIAN, __LITTLE_ENDIAN, __PDP_ENDIAN, __FLOAT_WORD_ORDER,
	and __LONG_LONG_PAIR to...
	* string/bits/endian.h: ...this new file, which includes
	the renamed header bits/endianness.h for the definition of
	__BYTE_ORDER and possibly __FLOAT_WORD_ORDER.

	* string/Makefile: Install bits/endianness.h.
	* include/bits/endian.h: New wrapper.

	* bits/endian.h: Rename to bits/endianness.h.
	Add multiple-include guard.  Rewrite the comment explaining what
	the machine-specific variants of this file should do.

	* sysdeps/unix/sysv/linux/ia64/bits/endian.h:
	Move to sysdeps/ia64.

	* sysdeps/aarch64/bits/endian.h
	* sysdeps/alpha/bits/endian.h
	* sysdeps/arm/bits/endian.h
	* sysdeps/csky/bits/endian.h
	* sysdeps/hppa/bits/endian.h
	* sysdeps/ia64/bits/endian.h
	* sysdeps/m68k/bits/endian.h
	* sysdeps/microblaze/bits/endian.h
	* sysdeps/mips/bits/endian.h
	* sysdeps/nios2/bits/endian.h
	* sysdeps/powerpc/bits/endian.h
	* sysdeps/riscv/bits/endian.h
	* sysdeps/s390/bits/endian.h
	* sysdeps/sh/bits/endian.h
	* sysdeps/sparc/bits/endian.h
	* sysdeps/x86/bits/endian.h:
	Rename to endianness.h; canonicalize form of file; remove
	redundant definitions of __FLOAT_WORD_ORDER.

	* sysdeps/csky/bits/endianness.h: Do not error out if __CSKYEB__
	is defined.
	* sysdeps/powerpc/bits/endianness.h: Remove logic to check for
	broken compilers.

	* ctype/ctype.h
	* inet/netinet/in.h
	* resolv/arpa/nameser_compat.h
	* sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
	* sysdeps/arm/nptl/bits/pthreadtypes-arch.h
	* sysdeps/csky/nptl/bits/pthreadtypes-arch.h
	* sysdeps/ia64/ieee754.h
	* sysdeps/ieee754/ieee754.h
	* sysdeps/ieee754/ldbl-128/ieee754.h
	* sysdeps/ieee754/ldbl-128ibm/ieee754.h
	* sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
	* sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
	* sysdeps/mips/ieee754/ieee754.h
	* sysdeps/mips/nptl/bits/pthreadtypes-arch.h
	* sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
	* sysdeps/nptl/pthread.h
	* sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
	* sysdeps/sh/nptl/bits/pthreadtypes-arch.h
	* sysdeps/sparc/sparc32/ieee754.h
	* sysdeps/unix/sysv/linux/generic/bits/stat.h
	* sysdeps/unix/sysv/linux/generic/bits/statfs.h
	* sysdeps/unix/sysv/linux/sys/acct.h
	* wctype/bits/wctype-wchar.h:
	Include bits/endian.h, not endian.h.

	* sysdeps/unix/sysv/linux/hppa/pthread.h: Don’t include endian.h.

	* sysdeps/mips/ieee754/ieee754.h: Use __LDBL_MANT_DIG__
	in ifdefs, instead of LDBL_MANT_DIG.  Only include float.h
	when __LDBL_MANT_DIG__ is not predefined, in which case
	define __LDBL_MANT_DIG__ to equal LDBL_MANT_DIG.

	* scripts/check-obsolete-constructs.h: Remove most of the
	whitelist entries for endian.h and float.h.
---
 bits/endian.h                                 | 13 -----
 bits/endianness.h                             | 17 +++++++
 ctype/ctype.h                                 |  2 +-
 include/bits/endian.h                         |  1 +
 inet/netinet/in.h                             |  2 +-
 resolv/arpa/nameser_compat.h                  |  2 +-
 scripts/check-obsolete-constructs.py          | 10 +---
 string/Makefile                               |  3 +-
 string/bits/endian.h                          | 48 +++++++++++++++++++
 string/endian.h                               | 39 +++------------
 sysdeps/aarch64/bits/endian.h                 | 30 ------------
 sysdeps/aarch64/bits/endianness.h             | 15 ++++++
 sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h |  2 +-
 sysdeps/alpha/bits/endian.h                   |  7 ---
 sysdeps/alpha/bits/endianness.h               | 11 +++++
 sysdeps/arm/bits/endian.h                     | 10 ----
 sysdeps/arm/bits/endianness.h                 | 15 ++++++
 sysdeps/arm/nptl/bits/pthreadtypes-arch.h     |  2 +-
 sysdeps/csky/bits/endian.h                    |  9 ----
 sysdeps/csky/bits/endianness.h                | 15 ++++++
 sysdeps/csky/nptl/bits/pthreadtypes-arch.h    |  2 +-
 sysdeps/hppa/bits/endian.h                    |  7 ---
 sysdeps/hppa/bits/endianness.h                | 11 +++++
 sysdeps/ia64/bits/endianness.h                | 11 +++++
 sysdeps/ia64/ieee754.h                        |  4 +-
 sysdeps/ieee754/ieee754.h                     |  4 +-
 sysdeps/ieee754/ldbl-128/ieee754.h            |  4 +-
 sysdeps/ieee754/ldbl-128ibm/ieee754.h         |  4 +-
 sysdeps/m68k/bits/endian.h                    |  7 ---
 sysdeps/m68k/bits/endianness.h                | 11 +++++
 sysdeps/m68k/nptl/bits/pthreadtypes-arch.h    |  2 +-
 sysdeps/microblaze/bits/endian.h              | 30 ------------
 sysdeps/microblaze/bits/endianness.h          | 15 ++++++
 .../microblaze/nptl/bits/pthreadtypes-arch.h  |  2 +-
 sysdeps/mips/bits/endian.h                    | 15 ------
 sysdeps/mips/bits/endianness.h                | 16 +++++++
 sysdeps/mips/ieee754/ieee754.h                | 17 ++++---
 sysdeps/mips/nptl/bits/pthreadtypes-arch.h    |  2 +-
 sysdeps/nios2/bits/endian.h                   | 12 -----
 sysdeps/nios2/bits/endianness.h               | 16 +++++++
 sysdeps/nios2/nptl/bits/pthreadtypes-arch.h   |  2 +-
 sysdeps/nptl/pthread.h                        |  2 +-
 sysdeps/powerpc/bits/endian.h                 | 36 --------------
 sysdeps/powerpc/bits/endianness.h             | 16 +++++++
 sysdeps/riscv/bits/endian.h                   |  5 --
 sysdeps/riscv/bits/endianness.h               | 11 +++++
 sysdeps/riscv/nptl/bits/pthreadtypes-arch.h   |  2 +-
 sysdeps/s390/bits/endian.h                    |  7 ---
 sysdeps/s390/bits/endianness.h                | 11 +++++
 sysdeps/sh/bits/endian.h                      | 13 -----
 sysdeps/sh/bits/endianness.h                  | 15 ++++++
 sysdeps/sh/nptl/bits/pthreadtypes-arch.h      |  2 +-
 sysdeps/sparc/bits/endian.h                   | 12 -----
 sysdeps/sparc/bits/endianness.h               | 16 +++++++
 sysdeps/sparc/sparc32/ieee754.h               |  4 +-
 sysdeps/unix/sysv/linux/generic/bits/stat.h   |  2 +-
 sysdeps/unix/sysv/linux/generic/bits/statfs.h |  2 +-
 sysdeps/unix/sysv/linux/hppa/pthread.h        |  1 -
 sysdeps/unix/sysv/linux/ia64/bits/endian.h    |  7 ---
 sysdeps/unix/sysv/linux/powerpc/htm.h         |  2 +-
 sysdeps/unix/sysv/linux/sys/acct.h            |  2 +-
 sysdeps/x86/bits/endian.h                     |  7 ---
 sysdeps/x86/bits/endianness.h                 | 11 +++++
 wctype/bits/wctype-wchar.h                    |  2 +-
 64 files changed, 330 insertions(+), 305 deletions(-)
 delete mode 100644 bits/endian.h
 create mode 100644 bits/endianness.h
 create mode 100644 include/bits/endian.h
 create mode 100644 string/bits/endian.h
 delete mode 100644 sysdeps/aarch64/bits/endian.h
 create mode 100644 sysdeps/aarch64/bits/endianness.h
 delete mode 100644 sysdeps/alpha/bits/endian.h
 create mode 100644 sysdeps/alpha/bits/endianness.h
 delete mode 100644 sysdeps/arm/bits/endian.h
 create mode 100644 sysdeps/arm/bits/endianness.h
 delete mode 100644 sysdeps/csky/bits/endian.h
 create mode 100644 sysdeps/csky/bits/endianness.h
 delete mode 100644 sysdeps/hppa/bits/endian.h
 create mode 100644 sysdeps/hppa/bits/endianness.h
 create mode 100644 sysdeps/ia64/bits/endianness.h
 delete mode 100644 sysdeps/m68k/bits/endian.h
 create mode 100644 sysdeps/m68k/bits/endianness.h
 delete mode 100644 sysdeps/microblaze/bits/endian.h
 create mode 100644 sysdeps/microblaze/bits/endianness.h
 delete mode 100644 sysdeps/mips/bits/endian.h
 create mode 100644 sysdeps/mips/bits/endianness.h
 delete mode 100644 sysdeps/nios2/bits/endian.h
 create mode 100644 sysdeps/nios2/bits/endianness.h
 delete mode 100644 sysdeps/powerpc/bits/endian.h
 create mode 100644 sysdeps/powerpc/bits/endianness.h
 delete mode 100644 sysdeps/riscv/bits/endian.h
 create mode 100644 sysdeps/riscv/bits/endianness.h
 delete mode 100644 sysdeps/s390/bits/endian.h
 create mode 100644 sysdeps/s390/bits/endianness.h
 delete mode 100644 sysdeps/sh/bits/endian.h
 create mode 100644 sysdeps/sh/bits/endianness.h
 delete mode 100644 sysdeps/sparc/bits/endian.h
 create mode 100644 sysdeps/sparc/bits/endianness.h
 delete mode 100644 sysdeps/unix/sysv/linux/ia64/bits/endian.h
 delete mode 100644 sysdeps/x86/bits/endian.h
 create mode 100644 sysdeps/x86/bits/endianness.h

Patch

diff --git a/bits/endian.h b/bits/endian.h
deleted file mode 100644
index 45afd4ae47..0000000000
diff --git a/bits/endianness.h b/bits/endianness.h
new file mode 100644
index 0000000000..b83040ddec
--- /dev/null
+++ b/bits/endianness.h
@@ -0,0 +1,17 @@ 
+/* This file must be overridden for each supported CPU architecture.
+   It should define __BYTE_ORDER to one of the constants defined in
+   string/bits/endian.h, as appropriate for the machine in
+   question.  If floating-point quantities are not stored in the
+   same byte order as integer quantities, it should also define
+   __FLOAT_WORD_ORDER as appropriate.  */
+
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+#error "Machine byte order unknown."
+
+#endif /* bits/endianness.h */
diff --git a/ctype/ctype.h b/ctype/ctype.h
index 78a455e227..3d070d71bf 100644
--- a/ctype/ctype.h
+++ b/ctype/ctype.h
@@ -36,7 +36,7 @@  __BEGIN_DECLS
    endian).  We define the bit value interpretations here dependent on the
    machine's byte order.  */
 
-# include <endian.h>
+# include <bits/endian.h>
 # if __BYTE_ORDER == __BIG_ENDIAN
 #  define _ISbit(bit)	(1 << (bit))
 # else /* __BYTE_ORDER == __LITTLE_ENDIAN */
diff --git a/include/bits/endian.h b/include/bits/endian.h
new file mode 100644
index 0000000000..ad614f1c1a
--- /dev/null
+++ b/include/bits/endian.h
@@ -0,0 +1 @@ 
+#include <string/bits/endian.h>
diff --git a/inet/netinet/in.h b/inet/netinet/in.h
index 24caf3c77d..b411ba939c 100644
--- a/inet/netinet/in.h
+++ b/inet/netinet/in.h
@@ -380,9 +380,9 @@  extern uint32_t htonl (uint32_t __hostlong)
 extern uint16_t htons (uint16_t __hostshort)
      __THROW __attribute__ ((__const__));
 
-#include <endian.h>
 
 /* Get machine dependent optimized versions of byte swapping functions.  */
+#include <bits/endian.h>
 #include <bits/byteswap.h>
 #include <bits/uintn-identity.h>
 
diff --git a/resolv/arpa/nameser_compat.h b/resolv/arpa/nameser_compat.h
index f1c390f3b9..37c178b524 100644
--- a/resolv/arpa/nameser_compat.h
+++ b/resolv/arpa/nameser_compat.h
@@ -29,7 +29,7 @@ 
 #ifndef _ARPA_NAMESER_COMPAT_
 #define	_ARPA_NAMESER_COMPAT_
 
-#include <endian.h>
+#include <bits/endian.h>
 
 /*%
  * Structure for query header.  The order of the fields is machine- and
diff --git a/scripts/check-obsolete-constructs.py b/scripts/check-obsolete-constructs.py
index e383a304db..4ef5775932 100755
--- a/scripts/check-obsolete-constructs.py
+++ b/scripts/check-obsolete-constructs.py
@@ -511,7 +511,6 @@  HEADER_ALLOWED_INCLUDES = {
     # mandated: inttypes.h -> stdint.h
     #           tgmath.h   -> complex.h, math.h
     #           threads.h  -> time.h
-    "ctype.h":                     [ "endian.h" ],
     "inttypes.h":                  [ "stdint.h" ],
     "signal.h":                    [ "sys/ucontext.h" ],
     "stdlib.h":                    [ "alloca.h", "sys/types.h" ],
@@ -557,7 +556,7 @@  HEADER_ALLOWED_INCLUDES = {
     "netdb.h":                     [ "netinet/in.h", "rpc/netdb.h" ],
     "arpa/inet.h":                 [ "netinet/in.h" ],
     "net/if.h":                    [ "sys/socket.h", "sys/types.h" ],
-    "netinet/in.h":                [ "endian.h", "sys/socket.h" ],
+    "netinet/in.h":                [ "sys/socket.h" ],
     "netinet/tcp.h":               [ "stdint.h", "sys/socket.h",
                                      "sys/types.h" ],
 
@@ -570,7 +569,7 @@  HEADER_ALLOWED_INCLUDES = {
     "envz.h":                      [ "argz.h", "errno.h" ],
     "fts.h":                       [ "sys/types.h" ],
     "gshadow.h":                   [ "paths.h" ],
-    "ieee754.h":                   [ "endian.h", "float.h" ],
+    "ieee754.h":                   [ "float.h" ],
     "lastlog.h":                   [ "utmp.h" ],
     "libintl.h":                   [ "locale.h" ],
     "link.h":                      [ "dlfcn.h", "elf.h", "sys/types.h" ],
@@ -651,7 +650,6 @@  HEADER_ALLOWED_INCLUDES = {
 
     "arpa/nameser.h":              [ "arpa/nameser_compat.h", "stdint.h",
                                      "sys/param.h", "sys/types.h" ],
-    "arpa/nameser_compat.h":       [ "endian.h" ],
     "net/ethernet.h":              [ "stdint.h", "sys/types.h",
                                      "net/if_ether.h" ],
     "net/if_arp.h":                [ "stdint.h", "sys/socket.h",
@@ -693,15 +691,11 @@  HEADER_ALLOWED_INCLUDES = {
     "bits/fcntl.h":                [ "sys/types.h" ],
     "bits/ipc.h":                  [ "sys/types.h" ],
     "bits/procfs.h":               [ "signal.h", "sys/ucontext.h" ],
-    "bits/pthreadtypes-arch.h":    [ "endian.h" ],
     "bits/sem.h":                  [ "sys/types.h" ],
     "bits/socket.h":               [ "sys/types.h" ],
-    "bits/stat.h":                 [ "endian.h" ],
-    "bits/statfs.h":               [ "endian.h" ],
     "bits/types/res_state.h":      [ "netinet/in.h", "sys/types.h" ],
     "bits/utmp.h":                 [ "paths.h", "sys/time.h", "sys/types.h" ],
     "bits/utmpx.h":                [ "paths.h", "sys/time.h" ],
-    "bits/wctype-wchar.h":         [ "endian.h" ],
 }
 
 # As above, but each group of whitelist entries is only used for
diff --git a/string/Makefile b/string/Makefile
index 38b26a0f8e..3e5721e0f4 100644
--- a/string/Makefile
+++ b/string/Makefile
@@ -25,7 +25,8 @@  include ../Makeconfig
 headers		:= string.h bits/string_fortified.h			\
 		   strings.h bits/strings_fortified.h			\
 		   byteswap.h bits/byteswap.h				\
-		   endian.h bits/endian.h bits/uintn-identity.h		\
+		   endian.h bits/endian.h bits/endianness.h		\
+		   bits/uintn-identity.h				\
 		   memory.h argz.h envz.h
 
 routines	:= strcat strchr strcmp strcoll strcpy strcspn		\
diff --git a/string/bits/endian.h b/string/bits/endian.h
new file mode 100644
index 0000000000..ed2ee578c3
--- /dev/null
+++ b/string/bits/endian.h
@@ -0,0 +1,48 @@ 
+/* Copyright (C) 1992-2019 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 _BITS_ENDIAN_H
+#define _BITS_ENDIAN_H 1
+
+/* Definitions for byte order, according to significance of bytes,
+   from low addresses to high addresses.  The value is what you get by
+   putting '4' in the most significant byte, '3' in the second most
+   significant byte, '2' in the second least significant byte, and '1'
+   in the least significant byte, and then writing down one digit for
+   each byte, starting with the byte at the lowest address at the left,
+   and proceeding to the byte with the highest address at the right.  */
+
+#define	__LITTLE_ENDIAN	1234
+#define	__BIG_ENDIAN	4321
+#define	__PDP_ENDIAN	3412
+
+/* This file defines `__BYTE_ORDER' for the particular machine.  */
+#include <bits/endianness.h>
+
+/* Some machines may need to use a different endianness for floating point
+   values.  */
+#ifndef __FLOAT_WORD_ORDER
+# define __FLOAT_WORD_ORDER __BYTE_ORDER
+#endif
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+# define __LONG_LONG_PAIR(HI, LO) LO, HI
+#elif __BYTE_ORDER == __BIG_ENDIAN
+# define __LONG_LONG_PAIR(HI, LO) HI, LO
+#endif
+
+#endif /* bits/endian.h */
diff --git a/string/endian.h b/string/endian.h
index e62b735625..9d6b10ce62 100644
--- a/string/endian.h
+++ b/string/endian.h
@@ -20,42 +20,15 @@ 
 
 #include <features.h>
 
-/* Definitions for byte order, according to significance of bytes,
-   from low addresses to high addresses.  The value is what you get by
-   putting '4' in the most significant byte, '3' in the second most
-   significant byte, '2' in the second least significant byte, and '1'
-   in the least significant byte, and then writing down one digit for
-   each byte, starting with the byte at the lowest address at the left,
-   and proceeding to the byte with the highest address at the right.  */
-
-#define	__LITTLE_ENDIAN	1234
-#define	__BIG_ENDIAN	4321
-#define	__PDP_ENDIAN	3412
-
-/* This file defines `__BYTE_ORDER' for the particular machine.  */
+/* Get the definitions of __*_ENDIAN, __BYTE_ORDER, and __FLOAT_WORD_ORDER.  */
 #include <bits/endian.h>
 
-/* Some machines may need to use a different endianness for floating point
-   values.  */
-#ifndef __FLOAT_WORD_ORDER
-# define __FLOAT_WORD_ORDER __BYTE_ORDER
-#endif
+#define LITTLE_ENDIAN	__LITTLE_ENDIAN
+#define BIG_ENDIAN	__BIG_ENDIAN
+#define PDP_ENDIAN	__PDP_ENDIAN
+#define BYTE_ORDER	__BYTE_ORDER
 
-#ifdef	__USE_MISC
-# define LITTLE_ENDIAN	__LITTLE_ENDIAN
-# define BIG_ENDIAN	__BIG_ENDIAN
-# define PDP_ENDIAN	__PDP_ENDIAN
-# define BYTE_ORDER	__BYTE_ORDER
-#endif
-
-#if __BYTE_ORDER == __LITTLE_ENDIAN
-# define __LONG_LONG_PAIR(HI, LO) LO, HI
-#elif __BYTE_ORDER == __BIG_ENDIAN
-# define __LONG_LONG_PAIR(HI, LO) HI, LO
-#endif
-
-
-#if defined __USE_MISC && !defined __ASSEMBLER__
+#ifndef __ASSEMBLER__
 /* Conversion interfaces.  */
 # include <bits/byteswap.h>
 # include <bits/uintn-identity.h>
diff --git a/sysdeps/aarch64/bits/endian.h b/sysdeps/aarch64/bits/endian.h
deleted file mode 100644
index c0a40e082a..0000000000
diff --git a/sysdeps/aarch64/bits/endianness.h b/sysdeps/aarch64/bits/endianness.h
new file mode 100644
index 0000000000..300ebc8f9c
--- /dev/null
+++ b/sysdeps/aarch64/bits/endianness.h
@@ -0,0 +1,15 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* AArch64 has selectable endianness.  */
+#ifdef __AARCH64EB__
+# define __BYTE_ORDER __BIG_ENDIAN
+#else
+# define __BYTE_ORDER __LITTLE_ENDIAN
+#endif
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h b/sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
index 8a2a5155db..5b05111be0 100644
--- a/sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
+++ b/sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
@@ -19,7 +19,7 @@ 
 #ifndef _BITS_PTHREADTYPES_ARCH_H
 #define _BITS_PTHREADTYPES_ARCH_H	1
 
-#include <endian.h>
+#include <bits/endian.h>
 
 #ifdef __ILP32__
 # define __SIZEOF_PTHREAD_ATTR_T        32
diff --git a/sysdeps/alpha/bits/endian.h b/sysdeps/alpha/bits/endian.h
deleted file mode 100644
index 8a16e14e24..0000000000
diff --git a/sysdeps/alpha/bits/endianness.h b/sysdeps/alpha/bits/endianness.h
new file mode 100644
index 0000000000..69f9a147f6
--- /dev/null
+++ b/sysdeps/alpha/bits/endianness.h
@@ -0,0 +1,11 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* Alpha is little-endian.  */
+#define __BYTE_ORDER __LITTLE_ENDIAN
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/arm/bits/endian.h b/sysdeps/arm/bits/endian.h
deleted file mode 100644
index f49f6ab1c9..0000000000
diff --git a/sysdeps/arm/bits/endianness.h b/sysdeps/arm/bits/endianness.h
new file mode 100644
index 0000000000..2d671fff66
--- /dev/null
+++ b/sysdeps/arm/bits/endianness.h
@@ -0,0 +1,15 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* ARM has selectable endianness.  */
+#ifdef __ARMEB__
+#define __BYTE_ORDER __BIG_ENDIAN
+#else
+#define __BYTE_ORDER __LITTLE_ENDIAN
+#endif
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/arm/nptl/bits/pthreadtypes-arch.h b/sysdeps/arm/nptl/bits/pthreadtypes-arch.h
index 332b288067..734828a0bb 100644
--- a/sysdeps/arm/nptl/bits/pthreadtypes-arch.h
+++ b/sysdeps/arm/nptl/bits/pthreadtypes-arch.h
@@ -18,7 +18,7 @@ 
 #ifndef _BITS_PTHREADTYPES_ARCH_H
 #define _BITS_PTHREADTYPES_ARCH_H	1
 
-#include <endian.h>
+#include <bits/endian.h>
 
 #define __SIZEOF_PTHREAD_ATTR_T 36
 #define __SIZEOF_PTHREAD_MUTEX_T 24
diff --git a/sysdeps/csky/bits/endian.h b/sysdeps/csky/bits/endian.h
deleted file mode 100644
index 51df38d8f9..0000000000
diff --git a/sysdeps/csky/bits/endianness.h b/sysdeps/csky/bits/endianness.h
new file mode 100644
index 0000000000..14652f5b37
--- /dev/null
+++ b/sysdeps/csky/bits/endianness.h
@@ -0,0 +1,15 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* C-SKY has selectable endianness.  */
+#ifdef __CSKYBE__
+# define __BYTE_ORDER __BIG_ENDIAN
+#else
+# define __BYTE_ORDER __LITTLE_ENDIAN
+#endif
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/csky/nptl/bits/pthreadtypes-arch.h b/sysdeps/csky/nptl/bits/pthreadtypes-arch.h
index 5a49114eac..0f737a1654 100644
--- a/sysdeps/csky/nptl/bits/pthreadtypes-arch.h
+++ b/sysdeps/csky/nptl/bits/pthreadtypes-arch.h
@@ -19,7 +19,7 @@ 
 #ifndef _BITS_PTHREADTYPES_ARCH_H
 #define _BITS_PTHREADTYPES_ARCH_H	1
 
-#include <endian.h>
+#include <bits/endian.h>
 
 #define __SIZEOF_PTHREAD_ATTR_T			36
 #define __SIZEOF_PTHREAD_MUTEX_T		24
diff --git a/sysdeps/hppa/bits/endian.h b/sysdeps/hppa/bits/endian.h
deleted file mode 100644
index 585db0c0fa..0000000000
diff --git a/sysdeps/hppa/bits/endianness.h b/sysdeps/hppa/bits/endianness.h
new file mode 100644
index 0000000000..96fd5ae5ef
--- /dev/null
+++ b/sysdeps/hppa/bits/endianness.h
@@ -0,0 +1,11 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* HP-PA is big-endian.  */
+#define __BYTE_ORDER __BIG_ENDIAN
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/ia64/bits/endianness.h b/sysdeps/ia64/bits/endianness.h
new file mode 100644
index 0000000000..70c211e569
--- /dev/null
+++ b/sysdeps/ia64/bits/endianness.h
@@ -0,0 +1,11 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* IA64 is little-endian.  */
+#define __BYTE_ORDER __LITTLE_ENDIAN
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/ia64/ieee754.h b/sysdeps/ia64/ieee754.h
index 3c533812c5..f9ff748528 100644
--- a/sysdeps/ia64/ieee754.h
+++ b/sysdeps/ia64/ieee754.h
@@ -16,11 +16,11 @@ 
    <http://www.gnu.org/licenses/>.  */
 
 #ifndef _IEEE754_H
-
 #define _IEEE754_H 1
+
 #include <features.h>
 
-#include <endian.h>
+#include <bits/endian.h>
 
 __BEGIN_DECLS
 
diff --git a/sysdeps/ieee754/ieee754.h b/sysdeps/ieee754/ieee754.h
index a88cbb6943..b457a10b41 100644
--- a/sysdeps/ieee754/ieee754.h
+++ b/sysdeps/ieee754/ieee754.h
@@ -16,11 +16,11 @@ 
    <http://www.gnu.org/licenses/>.  */
 
 #ifndef _IEEE754_H
-
 #define _IEEE754_H 1
+
 #include <features.h>
 
-#include <endian.h>
+#include <bits/endian.h>
 
 __BEGIN_DECLS
 
diff --git a/sysdeps/ieee754/ldbl-128/ieee754.h b/sysdeps/ieee754/ldbl-128/ieee754.h
index 0f206db928..bda95aca4d 100644
--- a/sysdeps/ieee754/ldbl-128/ieee754.h
+++ b/sysdeps/ieee754/ldbl-128/ieee754.h
@@ -16,11 +16,11 @@ 
    <http://www.gnu.org/licenses/>.  */
 
 #ifndef _IEEE754_H
-
 #define _IEEE754_H 1
+
 #include <features.h>
 
-#include <endian.h>
+#include <bits/endian.h>
 
 __BEGIN_DECLS
 
diff --git a/sysdeps/ieee754/ldbl-128ibm/ieee754.h b/sysdeps/ieee754/ldbl-128ibm/ieee754.h
index d0438c1bd5..eeb9d37e0c 100644
--- a/sysdeps/ieee754/ldbl-128ibm/ieee754.h
+++ b/sysdeps/ieee754/ldbl-128ibm/ieee754.h
@@ -16,11 +16,11 @@ 
    <http://www.gnu.org/licenses/>.  */
 
 #ifndef _IEEE754_H
-
 #define _IEEE754_H 1
+
 #include <features.h>
 
-#include <endian.h>
+#include <bits/endian.h>
 
 __BEGIN_DECLS
 
diff --git a/sysdeps/m68k/bits/endian.h b/sysdeps/m68k/bits/endian.h
deleted file mode 100644
index bf4ecb60a4..0000000000
diff --git a/sysdeps/m68k/bits/endianness.h b/sysdeps/m68k/bits/endianness.h
new file mode 100644
index 0000000000..7e5f0d2969
--- /dev/null
+++ b/sysdeps/m68k/bits/endianness.h
@@ -0,0 +1,11 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* m68k is big-endian.  */
+#define __BYTE_ORDER __BIG_ENDIAN
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/m68k/nptl/bits/pthreadtypes-arch.h b/sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
index 731cdec69a..a8497d6816 100644
--- a/sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
+++ b/sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
@@ -19,7 +19,7 @@ 
 #ifndef _BITS_PTHREADTYPES_ARCH_H
 #define _BITS_PTHREADTYPES_ARCH_H	1
 
-#include <endian.h>
+#include <bits/endian.h>
 
 #define __SIZEOF_PTHREAD_ATTR_T 36
 #define __SIZEOF_PTHREAD_MUTEX_T 24
diff --git a/sysdeps/microblaze/bits/endian.h b/sysdeps/microblaze/bits/endian.h
deleted file mode 100644
index 3650f3d564..0000000000
diff --git a/sysdeps/microblaze/bits/endianness.h b/sysdeps/microblaze/bits/endianness.h
new file mode 100644
index 0000000000..c4bb7e5f2e
--- /dev/null
+++ b/sysdeps/microblaze/bits/endianness.h
@@ -0,0 +1,15 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* MicroBlaze has selectable endianness.  */
+#ifdef _BIG_ENDIAN
+# define __BYTE_ORDER __BIG_ENDIAN
+#else
+# define __BYTE_ORDER __LITTLE_ENDIAN
+#endif
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h b/sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
index 838e71f4e1..77b4e6c3d2 100644
--- a/sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
+++ b/sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
@@ -19,7 +19,7 @@ 
 #ifndef _BITS_PTHREADTYPES_ARCH_H
 # define _BITS_PTHREADTYPES_ARCH_H	1
 
-# include <endian.h>
+# include <bits/endian.h>
 
 # define __SIZEOF_PTHREAD_ATTR_T         36
 # define __SIZEOF_PTHREAD_MUTEX_T        24
diff --git a/sysdeps/mips/bits/endian.h b/sysdeps/mips/bits/endian.h
deleted file mode 100644
index 126059799d..0000000000
diff --git a/sysdeps/mips/bits/endianness.h b/sysdeps/mips/bits/endianness.h
new file mode 100644
index 0000000000..09e138b89b
--- /dev/null
+++ b/sysdeps/mips/bits/endianness.h
@@ -0,0 +1,16 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* MIPS has selectable endianness.  */
+#ifdef __MIPSEB
+# define __BYTE_ORDER __BIG_ENDIAN
+#endif
+#ifdef __MIPSEL
+# define __BYTE_ORDER __LITTLE_ENDIAN
+#endif
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/mips/ieee754/ieee754.h b/sysdeps/mips/ieee754/ieee754.h
index d5fb9fce47..e36ef0f5b8 100644
--- a/sysdeps/mips/ieee754/ieee754.h
+++ b/sysdeps/mips/ieee754/ieee754.h
@@ -16,13 +16,16 @@ 
    <http://www.gnu.org/licenses/>.  */
 
 #ifndef _IEEE754_H
-
 #define _IEEE754_H 1
+
 #include <features.h>
 
-#include <endian.h>
+#include <bits/endian.h>
 
-#include <float.h>
+#ifndef __LDBL_MANT_DIG__
+# include <float.h>
+# define __LDBL_MANT_DIG__ LDBL_MANT_DIG
+#endif
 
 __BEGIN_DECLS
 
@@ -127,7 +130,7 @@  union ieee754_double
 
 #define IEEE754_DOUBLE_BIAS	0x3ff /* Added to exponent.  */
 
-#if LDBL_MANT_DIG == 113
+#if __LDBL_MANT_DIG__ == 113
 
 union ieee854_long_double
   {
@@ -184,7 +187,7 @@  union ieee854_long_double
 
 #define IEEE854_LONG_DOUBLE_BIAS 0x3fff /* Added to exponent.  */
 
-#elif LDBL_MANT_DIG == 64
+#elif __LDBL_MANT_DIG__ == 64
 
 union ieee854_long_double
   {
@@ -253,7 +256,7 @@  union ieee854_long_double
 
 #define IEEE854_LONG_DOUBLE_BIAS 0x3fff
 
-#elif LDBL_MANT_DIG == 53
+#elif __LDBL_MANT_DIG__ == 53
 
 union ieee854_long_double
   {
@@ -316,7 +319,7 @@  union ieee854_long_double
 
 #define IEEE854_LONG_DOUBLE_BIAS	0x3ff /* Added to exponent.  */
 
-#endif /* LDBL_MANT_DIG == 53 */
+#endif /* __LDBL_MANT_DIG__ == 53 */
 
 __END_DECLS
 
diff --git a/sysdeps/mips/nptl/bits/pthreadtypes-arch.h b/sysdeps/mips/nptl/bits/pthreadtypes-arch.h
index bebee00258..bf69766897 100644
--- a/sysdeps/mips/nptl/bits/pthreadtypes-arch.h
+++ b/sysdeps/mips/nptl/bits/pthreadtypes-arch.h
@@ -19,7 +19,7 @@ 
 #ifndef _BITS_PTHREADTYPES_ARCH_H
 #define _BITS_PTHREADTYPES_ARCH_H	1
 
-#include <endian.h>
+#include <bits/endian.h>
 
 #if _MIPS_SIM == _ABI64
 # define __SIZEOF_PTHREAD_ATTR_T 56
diff --git a/sysdeps/nios2/bits/endian.h b/sysdeps/nios2/bits/endian.h
deleted file mode 100644
index 164f9e4d78..0000000000
diff --git a/sysdeps/nios2/bits/endianness.h b/sysdeps/nios2/bits/endianness.h
new file mode 100644
index 0000000000..87e66ebd71
--- /dev/null
+++ b/sysdeps/nios2/bits/endianness.h
@@ -0,0 +1,16 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* Nios II has selectable endianness.  */
+#ifdef __nios2_big_endian__
+# define __BYTE_ORDER __BIG_ENDIAN
+#endif
+#ifdef __nios2_little_endian__
+# define __BYTE_ORDER __LITTLE_ENDIAN
+#endif
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/nios2/nptl/bits/pthreadtypes-arch.h b/sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
index 1091e63eac..459c8bcee0 100644
--- a/sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
+++ b/sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
@@ -19,7 +19,7 @@ 
 #ifndef _BITS_PTHREADTYPES_ARCH_H
 #define _BITS_PTHREADTYPES_ARCH_H	1
 
-#include <endian.h>
+#include <bits/endian.h>
 
 #define __SIZEOF_PTHREAD_ATTR_T 36
 #define __SIZEOF_PTHREAD_MUTEX_T 24
diff --git a/sysdeps/nptl/pthread.h b/sysdeps/nptl/pthread.h
index 704a3c48d6..e5a7efcb1d 100644
--- a/sysdeps/nptl/pthread.h
+++ b/sysdeps/nptl/pthread.h
@@ -19,10 +19,10 @@ 
 #define _PTHREAD_H	1
 
 #include <features.h>
-#include <endian.h>
 #include <sched.h>
 #include <time.h>
 
+#include <bits/endian.h>
 #include <bits/pthreadtypes.h>
 #include <bits/setjmp.h>
 #include <bits/wordsize.h>
diff --git a/sysdeps/powerpc/bits/endian.h b/sysdeps/powerpc/bits/endian.h
deleted file mode 100644
index cd8ae4fc50..0000000000
diff --git a/sysdeps/powerpc/bits/endianness.h b/sysdeps/powerpc/bits/endianness.h
new file mode 100644
index 0000000000..3e7735237e
--- /dev/null
+++ b/sysdeps/powerpc/bits/endianness.h
@@ -0,0 +1,16 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* PowerPC has selectable endianness.  */
+#if defined __BIG_ENDIAN__ || defined _BIG_ENDIAN
+# define __BYTE_ORDER __BIG_ENDIAN
+#endif
+#if defined __LITTLE_ENDIAN__ || defined _LITTLE_ENDIAN
+# define __BYTE_ORDER __LITTLE_ENDIAN
+#endif
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/riscv/bits/endian.h b/sysdeps/riscv/bits/endian.h
deleted file mode 100644
index 4aaf559d4f..0000000000
diff --git a/sysdeps/riscv/bits/endianness.h b/sysdeps/riscv/bits/endianness.h
new file mode 100644
index 0000000000..952d08595a
--- /dev/null
+++ b/sysdeps/riscv/bits/endianness.h
@@ -0,0 +1,11 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* RISC-V is little-endian.  */
+#define __BYTE_ORDER __LITTLE_ENDIAN
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h b/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
index e3fecc3208..22dc949158 100644
--- a/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
+++ b/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
@@ -19,7 +19,7 @@ 
 #ifndef _BITS_PTHREADTYPES_ARCH_H
 #define _BITS_PTHREADTYPES_ARCH_H	1
 
-#include <endian.h>
+#include <bits/endian.h>
 
 #if __riscv_xlen == 64
 # define __SIZEOF_PTHREAD_ATTR_T 		56
diff --git a/sysdeps/s390/bits/endian.h b/sysdeps/s390/bits/endian.h
deleted file mode 100644
index ac27f0119a..0000000000
diff --git a/sysdeps/s390/bits/endianness.h b/sysdeps/s390/bits/endianness.h
new file mode 100644
index 0000000000..c2d34e1c3e
--- /dev/null
+++ b/sysdeps/s390/bits/endianness.h
@@ -0,0 +1,11 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* S/390 is big-endian.  */
+#define __BYTE_ORDER __BIG_ENDIAN
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/sh/bits/endian.h b/sysdeps/sh/bits/endian.h
deleted file mode 100644
index 1fef1ff938..0000000000
diff --git a/sysdeps/sh/bits/endianness.h b/sysdeps/sh/bits/endianness.h
new file mode 100644
index 0000000000..45c7c83a63
--- /dev/null
+++ b/sysdeps/sh/bits/endianness.h
@@ -0,0 +1,15 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* SH has selectable endianness.  */
+#ifdef __LITTLE_ENDIAN__
+#define __BYTE_ORDER __LITTLE_ENDIAN
+#else
+#define __BYTE_ORDER __BIG_ENDIAN
+#endif
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/sh/nptl/bits/pthreadtypes-arch.h b/sysdeps/sh/nptl/bits/pthreadtypes-arch.h
index 64d9d43b3a..3e2d826b56 100644
--- a/sysdeps/sh/nptl/bits/pthreadtypes-arch.h
+++ b/sysdeps/sh/nptl/bits/pthreadtypes-arch.h
@@ -18,7 +18,7 @@ 
 #ifndef _BITS_PTHREADTYPES_ARCH_H
 #define _BITS_PTHREADTYPES_ARCH_H	1
 
-#include <endian.h>
+#include <bits/endian.h>
 
 #define __SIZEOF_PTHREAD_ATTR_T 36
 #define __SIZEOF_PTHREAD_MUTEX_T 24
diff --git a/sysdeps/sparc/bits/endian.h b/sysdeps/sparc/bits/endian.h
deleted file mode 100644
index 8acfdf5df6..0000000000
diff --git a/sysdeps/sparc/bits/endianness.h b/sysdeps/sparc/bits/endianness.h
new file mode 100644
index 0000000000..0b6f5bf8b2
--- /dev/null
+++ b/sysdeps/sparc/bits/endianness.h
@@ -0,0 +1,16 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* Sparc is big-endian, but v9 supports endian conversion on loads/stores
+   and GCC supports such a mode.  Be prepared.  */
+#ifdef __LITTLE_ENDIAN__
+# define __BYTE_ORDER __LITTLE_ENDIAN
+#else
+# define __BYTE_ORDER __BIG_ENDIAN
+#endif
+
+#endif /* bits/endianness.h */
diff --git a/sysdeps/sparc/sparc32/ieee754.h b/sysdeps/sparc/sparc32/ieee754.h
index 0f206db928..bda95aca4d 100644
--- a/sysdeps/sparc/sparc32/ieee754.h
+++ b/sysdeps/sparc/sparc32/ieee754.h
@@ -16,11 +16,11 @@ 
    <http://www.gnu.org/licenses/>.  */
 
 #ifndef _IEEE754_H
-
 #define _IEEE754_H 1
+
 #include <features.h>
 
-#include <endian.h>
+#include <bits/endian.h>
 
 __BEGIN_DECLS
 
diff --git a/sysdeps/unix/sysv/linux/generic/bits/stat.h b/sysdeps/unix/sysv/linux/generic/bits/stat.h
index e5c2650104..2570c8374a 100644
--- a/sysdeps/unix/sysv/linux/generic/bits/stat.h
+++ b/sysdeps/unix/sysv/linux/generic/bits/stat.h
@@ -23,7 +23,7 @@ 
 #ifndef _BITS_STAT_H
 #define _BITS_STAT_H	1
 
-#include <endian.h>
+#include <bits/endian.h>
 #include <bits/wordsize.h>
 
 /* 64-bit libc uses the kernel's 'struct stat', accessed via the
diff --git a/sysdeps/unix/sysv/linux/generic/bits/statfs.h b/sysdeps/unix/sysv/linux/generic/bits/statfs.h
index 77de4d2fd0..c85187a1de 100644
--- a/sysdeps/unix/sysv/linux/generic/bits/statfs.h
+++ b/sysdeps/unix/sysv/linux/generic/bits/statfs.h
@@ -20,7 +20,7 @@ 
 # error "Never include <bits/statfs.h> directly; use <sys/statfs.h> instead."
 #endif
 
-#include <endian.h>
+#include <bits/endian.h>
 #include <bits/types.h>
 #include <bits/wordsize.h>
 
diff --git a/sysdeps/unix/sysv/linux/hppa/pthread.h b/sysdeps/unix/sysv/linux/hppa/pthread.h
index 45e706c037..78dad4faca 100644
--- a/sysdeps/unix/sysv/linux/hppa/pthread.h
+++ b/sysdeps/unix/sysv/linux/hppa/pthread.h
@@ -19,7 +19,6 @@ 
 #define _PTHREAD_H	1
 
 #include <features.h>
-#include <endian.h>
 #include <sched.h>
 #include <time.h>
 
diff --git a/sysdeps/unix/sysv/linux/ia64/bits/endian.h b/sysdeps/unix/sysv/linux/ia64/bits/endian.h
deleted file mode 100644
index 98a5e23991..0000000000
diff --git a/sysdeps/unix/sysv/linux/powerpc/htm.h b/sysdeps/unix/sysv/linux/powerpc/htm.h
index 93b6d403b1..f17c979ff0 100644
--- a/sysdeps/unix/sysv/linux/powerpc/htm.h
+++ b/sysdeps/unix/sysv/linux/powerpc/htm.h
@@ -50,7 +50,7 @@ 
 
 #else
 
-#include <endian.h>
+#include <bits/endian.h>
 
 /* Official HTM intrinsics interface matching GCC, but works
    on older GCC compatible compilers and binutils.
diff --git a/sysdeps/unix/sysv/linux/sys/acct.h b/sysdeps/unix/sysv/linux/sys/acct.h
index 619824fe4b..4c119dafd2 100644
--- a/sysdeps/unix/sysv/linux/sys/acct.h
+++ b/sysdeps/unix/sysv/linux/sys/acct.h
@@ -20,7 +20,7 @@ 
 
 #include <sys/types.h>
 #include <stdint.h>
-#include <endian.h>
+#include <bits/endian.h>
 #include <bits/types/time_t.h>
 
 __BEGIN_DECLS
diff --git a/sysdeps/x86/bits/endian.h b/sysdeps/x86/bits/endian.h
deleted file mode 100644
index 5a56c726f7..0000000000
diff --git a/sysdeps/x86/bits/endianness.h b/sysdeps/x86/bits/endianness.h
new file mode 100644
index 0000000000..962a9ae4d6
--- /dev/null
+++ b/sysdeps/x86/bits/endianness.h
@@ -0,0 +1,11 @@ 
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endianness.h> directly; include <endian.h> instead."
+#endif
+
+/* i386/x86_64 are little-endian.  */
+#define __BYTE_ORDER __LITTLE_ENDIAN
+
+#endif /* bits/endianness.h */
diff --git a/wctype/bits/wctype-wchar.h b/wctype/bits/wctype-wchar.h
index 22ae0abdeb..f3851a7830 100644
--- a/wctype/bits/wctype-wchar.h
+++ b/wctype/bits/wctype-wchar.h
@@ -42,7 +42,7 @@  typedef unsigned long int wctype_t;
    endian).  We define the bit value interpretations here dependent on the
    machine's byte order.  */
 
-#  include <endian.h>
+#  include <bits/endian.h>
 #  if __BYTE_ORDER == __BIG_ENDIAN
 #   define _ISwbit(bit)	(1 << (bit))
 #  else /* __BYTE_ORDER == __LITTLE_ENDIAN */