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-rw-r--r--bits/byteswap.h103
1 files changed, 35 insertions, 68 deletions
diff --git a/bits/byteswap.h b/bits/byteswap.h
index 0effea6899..23974e9083 100644
--- a/bits/byteswap.h
+++ b/bits/byteswap.h
@@ -1,5 +1,5 @@
-/* Macros to swap the order of bytes in integer values.
- Copyright (C) 1997-2016 Free Software Foundation, Inc.
+/* Macros and inline functions to swap the order of bytes in integer values.
+ Copyright (C) 1997-2018 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
@@ -26,87 +26,54 @@
#include <features.h>
#include <bits/types.h>
-/* Swap bytes in 16 bit value. */
-#define __bswap_constant_16(x) \
- ((unsigned short int)((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)))
+/* Swap bytes in 16-bit value. */
+#define __bswap_constant_16(x) \
+ ((__uint16_t) ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8)))
-/* Get __bswap_16. */
-#include <bits/byteswap-16.h>
+static __inline __uint16_t
+__bswap_16 (__uint16_t __bsx)
+{
+#if __GNUC_PREREQ (4, 8)
+ return __builtin_bswap16 (__bsx);
+#else
+ return __bswap_constant_16 (__bsx);
+#endif
+}
-/* Swap bytes in 32 bit value. */
-#define __bswap_constant_32(x) \
- ((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >> 8) | \
- (((x) & 0x0000ff00u) << 8) | (((x) & 0x000000ffu) << 24))
+/* Swap bytes in 32-bit value. */
+#define __bswap_constant_32(x) \
+ ((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >> 8) \
+ | (((x) & 0x0000ff00u) << 8) | (((x) & 0x000000ffu) << 24))
-#ifdef __GNUC__
-# if __GNUC_PREREQ (4, 3)
-static __inline unsigned int
-__bswap_32 (unsigned int __bsx)
+static __inline __uint32_t
+__bswap_32 (__uint32_t __bsx)
{
+#if __GNUC_PREREQ (4, 3)
return __builtin_bswap32 (__bsx);
-}
-# else
-# define __bswap_32(x) \
- (__extension__ \
- ({ unsigned int __bsx = (x); __bswap_constant_32 (__bsx); }))
-# endif
#else
-static __inline unsigned int
-__bswap_32 (unsigned int __bsx)
-{
return __bswap_constant_32 (__bsx);
-}
#endif
+}
-/* Swap bytes in 64 bit value. */
-#if __GNUC_PREREQ (2, 0)
-# define __bswap_constant_64(x) \
- (__extension__ ((((x) & 0xff00000000000000ull) >> 56) \
- | (((x) & 0x00ff000000000000ull) >> 40) \
- | (((x) & 0x0000ff0000000000ull) >> 24) \
- | (((x) & 0x000000ff00000000ull) >> 8) \
- | (((x) & 0x00000000ff000000ull) << 8) \
- | (((x) & 0x0000000000ff0000ull) << 24) \
- | (((x) & 0x000000000000ff00ull) << 40) \
- | (((x) & 0x00000000000000ffull) << 56)))
+/* Swap bytes in 64-bit value. */
+#define __bswap_constant_64(x) \
+ ((((x) & 0xff00000000000000ull) >> 56) \
+ | (((x) & 0x00ff000000000000ull) >> 40) \
+ | (((x) & 0x0000ff0000000000ull) >> 24) \
+ | (((x) & 0x000000ff00000000ull) >> 8) \
+ | (((x) & 0x00000000ff000000ull) << 8) \
+ | (((x) & 0x0000000000ff0000ull) << 24) \
+ | (((x) & 0x000000000000ff00ull) << 40) \
+ | (((x) & 0x00000000000000ffull) << 56))
-# if __GNUC_PREREQ (4, 3)
-static __inline __uint64_t
+__extension__ static __inline __uint64_t
__bswap_64 (__uint64_t __bsx)
{
+#if __GNUC_PREREQ (4, 3)
return __builtin_bswap64 (__bsx);
-}
-# else
-# define __bswap_64(x) \
- (__extension__ \
- ({ union { __extension__ __uint64_t __ll; \
- unsigned int __l[2]; } __w, __r; \
- if (__builtin_constant_p (x)) \
- __r.__ll = __bswap_constant_64 (x); \
- else \
- { \
- __w.__ll = (x); \
- __r.__l[0] = __bswap_32 (__w.__l[1]); \
- __r.__l[1] = __bswap_32 (__w.__l[0]); \
- } \
- __r.__ll; }))
-# endif
#else
-# define __bswap_constant_64(x) \
- ((((x) & 0xff00000000000000ull) >> 56) \
- | (((x) & 0x00ff000000000000ull) >> 40) \
- | (((x) & 0x0000ff0000000000ull) >> 24) \
- | (((x) & 0x000000ff00000000ull) >> 8) \
- | (((x) & 0x00000000ff000000ull) << 8) \
- | (((x) & 0x0000000000ff0000ull) << 24) \
- | (((x) & 0x000000000000ff00ull) << 40) \
- | (((x) & 0x00000000000000ffull) << 56))
-
-static __inline __uint64_t
-__bswap_64 (__uint64_t __bsx)
-{
return __bswap_constant_64 (__bsx);
-}
#endif
+}
#endif /* _BITS_BYTESWAP_H */