1 files changed, 57 insertions, 0 deletions
diff --git a/lib/libstand/bswap.c b/lib/libstand/bswap.c
new file mode 100644
index 0000000..308edda
--- /dev/null
+++ b/lib/libstand/bswap.c
@@ -0,0 +1,57 @@
+/*
+ * Written by Manuel Bouyer <bouyer@netbsd.org>.
+ * Public domain.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char *rcsid = "$NetBSD: bswap32.c,v 1.1 1997/10/09 15:42:33 bouyer Exp $";
+static char *rcsid = "$NetBSD: bswap64.c,v 1.3 2009/03/16 05:59:21 cegger Exp $";
+#endif
+
+#include <sys/types.h>
+
+#undef bswap32
+#undef bswap64
+
+u_int32_t bswap32(u_int32_t x);
+u_int64_t bswap64(u_int64_t x);
+
+u_int32_t
+bswap32(u_int32_t x)
+{
+	return  ((x << 24) & 0xff000000 ) |
+			((x <<  8) & 0x00ff0000 ) |
+			((x >>  8) & 0x0000ff00 ) |
+			((x >> 24) & 0x000000ff );
+}
+
+u_int64_t
+bswap64(u_int64_t x)
+{
+#ifdef __LP64__
+	/*
+	 * Assume we have wide enough registers to do it without touching
+	 * memory.
+	 */
+	return  ( (x << 56) & 0xff00000000000000UL ) |
+		( (x << 40) & 0x00ff000000000000UL ) |
+		( (x << 24) & 0x0000ff0000000000UL ) |
+		( (x <<  8) & 0x000000ff00000000UL ) |
+		( (x >>  8) & 0x00000000ff000000UL ) |
+		( (x >> 24) & 0x0000000000ff0000UL ) |
+		( (x >> 40) & 0x000000000000ff00UL ) |
+		( (x >> 56) & 0x00000000000000ffUL );
+#else
+	/*
+	 * Split the operation in two 32bit steps.
+	 */
+	u_int32_t tl, th;
+
+	th = bswap32((u_int32_t)(x & 0x00000000ffffffffULL));
+	tl = bswap32((u_int32_t)((x >> 32) & 0x00000000ffffffffULL));
+	return ((u_int64_t)th << 32) | tl;
+#endif
+}