patch-2.1.72 linux/include/linux/byteorder/swabb.h

• Lines: 123
• Date: Fri Dec 5 05:55:56 1997
• Orig file: v2.1.71/linux/include/linux/byteorder/swabb.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.71/linux/include/linux/byteorder/swabb.h linux/include/linux/byteorder/swabb.h
@@ -0,0 +1,122 @@
+#ifndef _LINUX_BYTEORDER_SWABB_H
+#define _LINUX_BYTEORDER_SWABB_H
+
+/*
+ * linux/byteorder/swabb.h
+ * SWAp Bytes Bizarrely
+ *	swaHHXX[ps]?(foo)
+ *
+ * Support for obNUXIous vax-endian and other bizarre architectures...
+ *
+ */
+
+/*
+ * Meaning of the names I chose (vaxlinux people feel free to correct them):
+ * swahw32	swap 16-bit half-words in a 32-bit word
+ * swahb32	swap 8-bit halves of each 16-bit half-word in a 32-bit word
+ *
+ * No 64-bit support yet. I don't know VAX conventions for long longs.
+ * I guarantee it will be a mess when it's there, though :->
+ * It will be even worse if there are conflicting 64-bit conventions for vaxen
+ *
+ * Note that if communicating with vax machines becomes useful in some kernel
+ * FS driver, we'd have to move that mess into byteorder/swab.h, and
+ * create cpu_to_ve32 and suches. Ouch.
+ */
+
+
+#define ___swahw32(x) \
+	((__u32)( \
+		(((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \
+		(((__u32)(x) & (__u32)0xffff0000UL) >> 16) ))
+#define ___swahb32(x) \
+	((__u32)( \
+		(((__u32)(x) & (__u32)0x00ff00ffUL) << 16) | \
+		(((__u32)(x) & (__u32)0xff00ff00UL) >> 16) ))
+
+/*
+ * provide defaults when no architecture-specific optimization is detected
+ */
+#ifndef __arch__swahw32
+#  define __arch__swahw32(x) ___swahw32(x)
+#endif
+#ifndef __arch__swahb32
+#  define __arch__swahb32(x) ___swahb32(x)
+#endif
+
+#ifndef __arch__swahw32p
+#  define __arch__swahw32p(x) __swahw32(*(x))
+#endif
+#ifndef __arch__swahb32p
+#  define __arch__swahb32p(x) __swahb32(*(x))
+#endif
+
+#ifndef __arch__swahw32s
+#  define __arch__swahw32s(x) do { *(x) = __swahw32p((x)); } while (0)
+#endif
+#ifndef __arch__swahb32s
+#  define __arch__swahb32s(x) do { *(x) = __swahb32p((x)); } while (0)
+#endif
+
+
+/*
+ * Allow constant folding
+ */
+#if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__)
+#  define __swahw32(x) \
+(__builtin_constant_p((__u32)(x)) ? \
+ ___swahw32((x)) : \
+ __fswahw32((x)))
+#  define __swahb32(x) \
+(__builtin_constant_p((__u32)(x)) ? \
+ ___swahb32((x)) : \
+ __fswahb32((x)))
+#else
+#  define __swahw32(x) __fswahw32(x)
+#  define __swahb32(x) __fswahb32(x)
+#endif /* OPTIMIZE */
+
+
+extern __inline__ __const__ __u32 __fswahw32(__u32 x)
+{
+	return __arch__swahw32(x);
+}
+extern __inline__ __u32 __swahw32p(__u32 *x)
+{
+	return __arch__swahw32p(x);
+}
+extern __inline__ void __swahw32s(__u32 *addr)
+{
+	__arch__swahw32s(addr);
+}
+
+
+extern __inline__ __const__ __u32 __fswahb32(__u32 x)
+{
+	return __arch__swahb32(x);
+}
+extern __inline__ __u32 __swahb32p(__u32 *x)
+{
+	return __arch__swahb32p(x);
+}
+extern __inline__ void __swahb32s(__u32 *addr)
+{
+	__arch__swahb32s(addr);
+}
+
+#ifdef __BYTEORDER_HAS_U64__
+/*
+ * Not supported yet
+ */
+#endif /* __BYTEORDER_HAS_U64__ */
+
+#if defined(__KERNEL__)
+#define swahw32 __swahw32
+#define swahb32 __swahb32
+#define swahw32p __swahw32p
+#define swahb32p __swahb32p
+#define swahw32s __swahw32s
+#define swahb32s __swahb32s
+#endif
+
+#endif /* _LINUX_BYTEORDER_SWABB_H */