1 files changed, 98 insertions, 0 deletions
diff --git a/src/unaligned.h b/src/unaligned.h
new file mode 100644
index 00000000..524b35c8
--- /dev/null
+++ b/src/unaligned.h
@@ -0,0 +1,98 @@
+/* Unaligned memory access functionality.
+   Copyright (C) 2000, 2001, 2002, 2003 Red Hat, Inc.
+   Written by Ulrich Drepper <[email protected]>, 2001.
+
+   This program is Open Source software; you can redistribute it and/or
+   modify it under the terms of the Open Software License version 1.0 as
+   published by the Open Source Initiative.
+
+   You should have received a copy of the Open Software License along
+   with this program; if not, you may obtain a copy of the Open Software
+   License version 1.0 from http://www.opensource.org/licenses/osl.php or
+   by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
+   3001 King Ranch Road, Ukiah, CA 95482.   */
+
+#ifndef _UNALIGNED_H
+#define _UNALIGNED_H	1
+
+#include <byteswap.h>
+#include <endian.h>
+
+
+#ifndef UNALIGNED_ACCESS_CLASS
+# error "UNALIGNED_ACCESS_CLASS must be defined"
+#endif
+
+
+/* Macros to convert from the host byte order to that of the object file.  */
+#if UNALIGNED_ACCESS_CLASS == BYTE_ORDER
+# define target_bswap_16(n) (n)
+# define target_bswap_32(n) (n)
+# define target_bswap_64(n) (n)
+#else
+# define target_bswap_16(n) bswap_16 (n)
+# define target_bswap_32(n) bswap_32 (n)
+# define target_bswap_64(n) bswap_64 (n)
+#endif
+
+
+union u_2ubyte_unaligned
+{
+  uint16_t u;
+  char c[2];
+} __attribute__((packed));
+
+union u_4ubyte_unaligned
+{
+  uint32_t u;
+  char c[4];
+} __attribute__((packed));
+
+union u_8ubyte_unaligned
+{
+  uint64_t u;
+  char c[8];
+} __attribute__((packed));
+
+
+/* Macros to store value at unaligned address.  */
+#define store_2ubyte_unaligned(ptr, value) \
+  (void) (((union u_2ubyte_unaligned *) (ptr))->u = target_bswap_16 (value))
+#define store_4ubyte_unaligned(ptr, value) \
+  (void) (((union u_4ubyte_unaligned *) (ptr))->u = target_bswap_32 (value))
+#define store_8ubyte_unaligned(ptr, value) \
+  (void) (((union u_8ubyte_unaligned *) (ptr))->u = target_bswap_64 (value))
+
+
+/* Macros to add value to unaligned address.  This is a bit more
+   complicated since the value must be read from memory and eventually
+   converted twice.  */
+#if UNALIGNED_ACCESS_CLASS == BYTE_ORDER
+# define add_2ubyte_unaligned(ptr, value) \
+  (void) (((union u_2ubyte_unaligned *) (ptr))->u += value)
+# define add_4ubyte_unaligned(ptr, value) \
+  (void) (((union u_4ubyte_unaligned *) (ptr))->u += value)
+# define add_8ubyte_unaligned(ptr, value) \
+  (void) (((union u_8ubyte_unaligned *) (ptr))->u += value)
+#else
+# define add_2ubyte_unaligned(ptr, value) \
+  do {									      \
+    union u_2ubyte_unaligned *_ptr = (ptr);				      \
+    uint16_t _val = bswap_16 (_ptr->u) + (value);			      \
+    _ptr->u = bswap_16 (_val);						      \
+  } while (0)
+# define add_4ubyte_unaligned(ptr, value) \
+  do {									      \
+    union u_4ubyte_unaligned *_ptr = (ptr);				      \
+    uint32_t _val = bswap_32 (_ptr->u) + (value);			      \
+    _ptr->u = bswap_32 (_val);						      \
+  } while (0)
+# define add_8ubyte_unaligned(ptr, value) \
+  do {									      \
+    union u_8ubyte_unaligned *_ptr = (ptr);				      \
+    uint64_t _val = bswap_64 (_ptr->u) + (value);			      \
+    _ptr->u = bswap_64 (_val);						      \
+  } while (0)
+#endif
+
+#endif /* unaligned.h */