1 files changed, 60 insertions, 0 deletions
diff --git a/include/libc-pointer-arith.h b/include/libc-pointer-arith.h
new file mode 100644
index 0000000000..715cbc1bbe
--- /dev/null
+++ b/include/libc-pointer-arith.h
@@ -0,0 +1,60 @@
+/* Helper macros for pointer arithmetic.
+   Copyright (C) 2012-2017 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _LIBC_POINTER_ARITH_H
+#define _LIBC_POINTER_ARITH_H 1
+
+#include <stdint.h>
+
+/* 1 if 'type' is a pointer type, 0 otherwise.  */
+# define __pointer_type(type) (__builtin_classify_type ((type) 0) == 5)
+
+/* intptr_t if P is true, or T if P is false.  */
+# define __integer_if_pointer_type_sub(T, P) \
+  __typeof__ (*(0 ? (__typeof__ (0 ? (T *) 0 : (void *) (P))) 0 \
+		  : (__typeof__ (0 ? (intptr_t *) 0 : (void *) (!(P)))) 0))
+
+/* intptr_t if EXPR has a pointer type, or the type of EXPR otherwise.  */
+# define __integer_if_pointer_type(expr) \
+  __integer_if_pointer_type_sub(__typeof__ ((__typeof__ (expr)) 0), \
+				__pointer_type (__typeof__ (expr)))
+
+/* Cast an integer or a pointer VAL to integer with proper type.  */
+# define cast_to_integer(val) ((__integer_if_pointer_type (val)) (val))
+
+/* Align a value by rounding down to closest size.
+   e.g. Using size of 4096, we get this behavior:
+	{4095, 4096, 4097} = {0, 4096, 4096}.  */
+#define ALIGN_DOWN(base, size)	((base) & -((__typeof__ (base)) (size)))
+
+/* Align a value by rounding up to closest size.
+   e.g. Using size of 4096, we get this behavior:
+	{4095, 4096, 4097} = {4096, 4096, 8192}.
+
+  Note: The size argument has side effects (expanded multiple times).  */
+#define ALIGN_UP(base, size)	ALIGN_DOWN ((base) + (size) - 1, (size))
+
+/* Same as ALIGN_DOWN(), but automatically casts when base is a pointer.  */
+#define PTR_ALIGN_DOWN(base, size) \
+  ((__typeof__ (base)) ALIGN_DOWN ((uintptr_t) (base), (size)))
+
+/* Same as ALIGN_UP(), but automatically casts when base is a pointer.  */
+#define PTR_ALIGN_UP(base, size) \
+  ((__typeof__ (base)) ALIGN_UP ((uintptr_t) (base), (size)))
+
+#endif