+/*
+ * endianness.h
+ *
+ * Macros and inline functions for endianness conversion.
+ *
+ * Author: Eric Biggers
+ * Year: 2014, 2015
+ *
+ * The author dedicates this file to the public domain.
+ * You can do whatever you want with this file.
+ */
+
#ifndef _WIMLIB_ENDIANNESS_H
#define _WIMLIB_ENDIANNESS_H
+#include "wimlib/compiler.h"
#include "wimlib/types.h"
-/* Watch out for conflict with ntfs-3g/endian.h ... */
-
+/* Watch out for conflict with ntfs-3g/endians.h ... */
#ifndef _NTFS_ENDIANS_H
-static inline u16
-bswap16(u16 n)
+#define bswap16_const(n) \
+ ((((u16)(n) & 0x00FF) << 8) | \
+ (((u16)(n) & 0xFF00) >> 8))
+
+#define bswap32_const(n) \
+ ((((u32)(n) & 0x000000FF) << 24) | \
+ (((u32)(n) & 0x0000FF00) << 8) | \
+ (((u32)(n) & 0x00FF0000) >> 8) | \
+ (((u32)(n) & 0xFF000000) >> 24))
+
+#define bswap64_const(n) \
+ ((((u64)(n) & 0x00000000000000FF) << 56) | \
+ (((u64)(n) & 0x000000000000FF00) << 40) | \
+ (((u64)(n) & 0x0000000000FF0000) << 24) | \
+ (((u64)(n) & 0x00000000FF000000) << 8) | \
+ (((u64)(n) & 0x000000FF00000000) >> 8) | \
+ (((u64)(n) & 0x0000FF0000000000) >> 24) | \
+ (((u64)(n) & 0x00FF000000000000) >> 40) | \
+ (((u64)(n) & 0xFF00000000000000) >> 56))
+
+static inline u16 do_bswap16(u16 n)
{
- return (n << 8) | (n >> 8);
+#ifdef compiler_bswap16
+ return compiler_bswap16(n);
+#else
+ return bswap16_const(n);
+#endif
}
-static inline u32
-bswap32(u32 n)
+static inline u32 do_bswap32(u32 n)
{
-#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
- return __builtin_bswap32(n);
+#ifdef compiler_bswap32
+ return compiler_bswap32(n);
#else
- return (n << 24) | ((n & 0xff00) << 8) | ((n & 0xff0000) >> 8) |
- (n >> 24);
+ return bswap32_const(n);
#endif
}
-static inline u64
-bswap64(u64 n)
+static inline u64 do_bswap64(u64 n)
{
-#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
- return __builtin_bswap64(n);
+#ifdef compiler_bswap64
+ return compiler_bswap64(n);
#else
- return (n << 56) | ((n & 0xff00) << 40) | ((n & 0xff0000) << 24) |
- ((n & 0xff000000) << 8) | ((n & 0xff00000000) >> 8) |
- ((n & 0xff0000000000) >> 24) |
- ((n & 0xff000000000000) >> 40) | (n >> 56);
+ return bswap64_const(n);
#endif
}
-# ifdef WORDS_BIGENDIAN
-# define le16_to_cpu(n) bswap16(n)
-# define le32_to_cpu(n) bswap32(n)
-# define le64_to_cpu(n) bswap64(n)
-# define cpu_to_le16(n) bswap16(n)
-# define cpu_to_le32(n) bswap32(n)
-# define cpu_to_le64(n) bswap64(n)
+#define bswap16(n) (__builtin_constant_p(n) ? bswap16_const(n) : do_bswap16(n))
+#define bswap32(n) (__builtin_constant_p(n) ? bswap32_const(n) : do_bswap32(n))
+#define bswap64(n) (__builtin_constant_p(n) ? bswap64_const(n) : do_bswap64(n))
-# define cpu_to_be16(n) (n)
-# define cpu_to_be32(n) (n)
-# define cpu_to_be64(n) (n)
-# define be16_to_cpu(n) (n)
-# define be32_to_cpu(n) (n)
-# define be64_to_cpu(n) (n)
-# else
-# define cpu_to_le16(n) (n)
-# define cpu_to_le32(n) (n)
-# define cpu_to_le64(n) (n)
-# define le16_to_cpu(n) (n)
-# define le32_to_cpu(n) (n)
-# define le64_to_cpu(n) (n)
+#if CPU_IS_BIG_ENDIAN
+# define cpu_to_le16(n) ((_force_attr le16)bswap16(n))
+# define cpu_to_le32(n) ((_force_attr le32)bswap32(n))
+# define cpu_to_le64(n) ((_force_attr le64)bswap64(n))
+# define le16_to_cpu(n) bswap16((_force_attr u16)(le16)(n))
+# define le32_to_cpu(n) bswap32((_force_attr u32)(le32)(n))
+# define le64_to_cpu(n) bswap64((_force_attr u64)(le64)(n))
+# define cpu_to_be16(n) ((_force_attr be16)(u16)(n))
+# define cpu_to_be32(n) ((_force_attr be32)(u32)(n))
+# define cpu_to_be64(n) ((_force_attr be64)(u64)(n))
+# define be16_to_cpu(n) ((_force_attr u16)(be16)(n))
+# define be32_to_cpu(n) ((_force_attr u32)(be32)(n))
+# define be64_to_cpu(n) ((_force_attr u64)(be64)(n))
+#else
+# define cpu_to_le16(n) ((_force_attr le16)(u16)(n))
+# define cpu_to_le32(n) ((_force_attr le32)(u32)(n))
+# define cpu_to_le64(n) ((_force_attr le64)(u64)(n))
+# define le16_to_cpu(n) ((_force_attr u16)(le16)(n))
+# define le32_to_cpu(n) ((_force_attr u32)(le32)(n))
+# define le64_to_cpu(n) ((_force_attr u64)(le64)(n))
+# define cpu_to_be16(n) ((_force_attr be16)bswap16(n))
+# define cpu_to_be32(n) ((_force_attr be32)bswap32(n))
+# define cpu_to_be64(n) ((_force_attr be64)bswap64(n))
+# define be16_to_cpu(n) bswap16((_force_attr u16)(be16)(n))
+# define be32_to_cpu(n) bswap32((_force_attr u32)(be32)(n))
+# define be64_to_cpu(n) bswap64((_force_attr u64)(be64)(n))
+#endif
-# define be16_to_cpu(n) bswap16(n)
-# define be32_to_cpu(n) bswap32(n)
-# define be64_to_cpu(n) bswap64(n)
-# define cpu_to_be16(n) bswap16(n)
-# define cpu_to_be32(n) bswap32(n)
-# define cpu_to_be64(n) bswap64(n)
-# endif
#endif /* _NTFS_ENDIANS_H */
-
#endif /* _WIMLIB_ENDIANNESS_H */
git://wimlib.net / wimlib / blobdiff