Simplify our endian.h implementation.
We can rely on the compiler's builtins. Tested on arm, arm64, mips, x86,
and x86-64.
Change-Id: I0f774ed7e85b3c791a3178d8ef17c6500e6a9ace
diff --git a/libc/include/sys/endian.h b/libc/include/sys/endian.h
index be4c905..c62ba7f 100644
--- a/libc/include/sys/endian.h
+++ b/libc/include/sys/endian.h
@@ -1,5 +1,3 @@
-/* $OpenBSD: endian.h,v 1.17 2006/01/06 18:53:05 millert Exp $ */
-
/*-
* Copyright (c) 1997 Niklas Hallqvist. All rights reserved.
*
@@ -24,155 +22,44 @@
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
-/*
- * Generic definitions for little- and big-endian systems. Other endianesses
- * has to be dealt with in the specific machine/endian.h file for that port.
- *
- * This file is meant to be included from a little- or big-endian port's
- * machine/endian.h after setting _BYTE_ORDER to either 1234 for little endian
- * or 4321 for big..
- */
-
#ifndef _SYS_ENDIAN_H_
#define _SYS_ENDIAN_H_
#include <sys/cdefs.h>
-#include <machine/endian.h>
#include <stdint.h>
#define _LITTLE_ENDIAN 1234
#define _BIG_ENDIAN 4321
#define _PDP_ENDIAN 3412
+#define _BYTE_ORDER _LITTLE_ENDIAN
+#define __LITTLE_ENDIAN_BITFIELD
#if __BSD_VISIBLE
-#define LITTLE_ENDIAN _LITTLE_ENDIAN
-#define BIG_ENDIAN _BIG_ENDIAN
-#define PDP_ENDIAN _PDP_ENDIAN
-#define BYTE_ORDER _BYTE_ORDER
+#define LITTLE_ENDIAN _LITTLE_ENDIAN
+#define BIG_ENDIAN _BIG_ENDIAN
+#define PDP_ENDIAN _PDP_ENDIAN
+#define BYTE_ORDER _BYTE_ORDER
#endif
-#ifdef __GNUC__
+#ifndef __LITTLE_ENDIAN
+#define __LITTLE_ENDIAN _LITTLE_ENDIAN
+#endif
+#ifndef __BIG_ENDIAN
+#define __BIG_ENDIAN _BIG_ENDIAN
+#endif
+#define __BYTE_ORDER _BYTE_ORDER
-#define __swap16gen(x) __statement({ \
- __uint16_t __swap16gen_x = (x); \
- \
- (__uint16_t)((__swap16gen_x & 0xff) << 8 | \
- (__swap16gen_x & 0xff00) >> 8); \
-})
-
-#define __swap32gen(x) __statement({ \
- __uint32_t __swap32gen_x = (x); \
- \
- (__uint32_t)((__swap32gen_x & 0xff) << 24 | \
- (__swap32gen_x & 0xff00) << 8 | \
- (__swap32gen_x & 0xff0000) >> 8 | \
- (__swap32gen_x & 0xff000000) >> 24); \
-})
-
-#define __swap64gen(x) __statement({ \
- __uint64_t __swap64gen_x = (x); \
- \
- (__uint64_t)((__swap64gen_x & 0xff) << 56 | \
- (__swap64gen_x & 0xff00ULL) << 40 | \
- (__swap64gen_x & 0xff0000ULL) << 24 | \
- (__swap64gen_x & 0xff000000ULL) << 8 | \
- (__swap64gen_x & 0xff00000000ULL) >> 8 | \
- (__swap64gen_x & 0xff0000000000ULL) >> 24 | \
- (__swap64gen_x & 0xff000000000000ULL) >> 40 | \
- (__swap64gen_x & 0xff00000000000000ULL) >> 56); \
-})
-
-#else /* __GNUC__ */
-
-/* Note that these macros evaluate their arguments several times. */
-#define __swap16gen(x) \
- (__uint16_t)(((__uint16_t)(x) & 0xff) << 8 | ((__uint16_t)(x) & 0xff00) >> 8)
-
-#define __swap32gen(x) \
- (__uint32_t)(((__uint32_t)(x) & 0xff) << 24 | \
- ((__uint32_t)(x) & 0xff00) << 8 | ((__uint32_t)(x) & 0xff0000) >> 8 |\
- ((__uint32_t)(x) & 0xff000000) >> 24)
-
-#define __swap64gen(x) \
- (__uint64_t)((((__uint64_t)(x) & 0xff) << 56) | \
- ((__uint64_t)(x) & 0xff00ULL) << 40 | \
- ((__uint64_t)(x) & 0xff0000ULL) << 24 | \
- ((__uint64_t)(x) & 0xff000000ULL) << 8 | \
- ((__uint64_t)(x) & 0xff00000000ULL) >> 8 | \
- ((__uint64_t)(x) & 0xff0000000000ULL) >> 24 | \
- ((__uint64_t)(x) & 0xff000000000000ULL) >> 40 | \
- ((__uint64_t)(x) & 0xff00000000000000ULL) >> 56)
-
-#endif /* __GNUC__ */
-
-/*
- * Define MD_SWAP if you provide swap{16,32}md functions/macros that are
- * optimized for your architecture, These will be used for swap{16,32}
- * unless the argument is a constant and we are using GCC, where we can
- * take advantage of the CSE phase much better by using the generic version.
- */
-#ifdef MD_SWAP
-#if __GNUC__
-
-#define __swap16(x) __statement({ \
- __uint16_t __swap16_x = (x); \
- \
- __builtin_constant_p(x) ? __swap16gen(__swap16_x) : \
- __swap16md(__swap16_x); \
-})
-
-#define __swap32(x) __statement({ \
- __uint32_t __swap32_x = (x); \
- \
- __builtin_constant_p(x) ? __swap32gen(__swap32_x) : \
- __swap32md(__swap32_x); \
-})
-
-#define __swap64(x) __statement({ \
- __uint64_t __swap64_x = (x); \
- \
- __builtin_constant_p(x) ? __swap64gen(__swap64_x) : \
- __swap64md(__swap64_x); \
-})
-
-#endif /* __GNUC__ */
-
-#else /* MD_SWAP */
-#define __swap16 __swap16gen
-#define __swap32 __swap32gen
-#define __swap64 __swap64gen
-#endif /* MD_SWAP */
-
-#define __swap16_multi(v, n) do { \
- __size_t __swap16_multi_n = (n); \
- __uint16_t *__swap16_multi_v = (v); \
- \
- while (__swap16_multi_n) { \
- *__swap16_multi_v = swap16(*__swap16_multi_v); \
- __swap16_multi_v++; \
- __swap16_multi_n--; \
- } \
-} while (0)
+#define __swap16 __builtin_bswap16
+#define __swap32 __builtin_bswap32
+#define __swap64 __builtin_bswap64
#if __BSD_VISIBLE
#define swap16 __swap16
#define swap32 __swap32
#define swap64 __swap64
#define swap16_multi __swap16_multi
-#endif /* __BSD_VISIBLE */
-#if _BYTE_ORDER == _LITTLE_ENDIAN
-
-/* Can be overridden by machine/endian.h before inclusion of this file. */
-#ifndef _QUAD_HIGHWORD
-#define _QUAD_HIGHWORD 1
-#endif
-#ifndef _QUAD_LOWWORD
-#define _QUAD_LOWWORD 0
-#endif
-
-#if __BSD_VISIBLE
#define htobe16 __swap16
#define htobe32 __swap32
#define htobe64 __swap64
@@ -205,49 +92,6 @@
#define htonq(x) __swap64(x)
#define ntohq(x) __swap64(x)
-#define __LITTLE_ENDIAN_BITFIELD
-
-#endif /* _BYTE_ORDER */
-
-#if _BYTE_ORDER == _BIG_ENDIAN
-
-/* Can be overridden by machine/endian.h before inclusion of this file. */
-#ifndef _QUAD_HIGHWORD
-#define _QUAD_HIGHWORD 0
-#endif
-#ifndef _QUAD_LOWWORD
-#define _QUAD_LOWWORD 1
-#endif
-
-#if __BSD_VISIBLE
-#define htole16 __swap16
-#define htole32 __swap32
-#define htole64 __swap64
-#define letoh16 __swap16
-#define letoh32 __swap32
-#define letoh64 __swap64
-
-#define htobe16(x) (x)
-#define htobe32(x) (x)
-#define htobe64(x) (x)
-#define betoh16(x) (x)
-#define betoh32(x) (x)
-#define betoh64(x) (x)
-#endif /* __BSD_VISIBLE */
-
-#define htons(x) (x)
-#define htonl(x) (x)
-#define ntohs(x) (x)
-#define ntohl(x) (x)
-
-/* Bionic additions */
-#define ntohq(x) (x)
-#define htonq(x) (x)
-
-#define __BIG_ENDIAN_BITFIELD
-
-#endif /* _BYTE_ORDER */
-
#if __BSD_VISIBLE
#define NTOHL(x) (x) = ntohl((u_int32_t)(x))
#define NTOHS(x) (x) = ntohs((u_int16_t)(x))
@@ -255,16 +99,6 @@
#define HTONS(x) (x) = htons((u_int16_t)(x))
#endif
-
-#define __BYTE_ORDER _BYTE_ORDER
-#ifndef __LITTLE_ENDIAN
-#define __LITTLE_ENDIAN _LITTLE_ENDIAN
-#endif
-#ifndef __BIG_ENDIAN
-#define __BIG_ENDIAN _BIG_ENDIAN
-#endif
-
-
#ifdef __BSD_VISIBLE
/*
* glibc-compatible beXXtoh/leXXtoh synonyms for htobeXX/htoleXX.