Add missing rcu_cmpxchg_pointer define

[urcu.git] / compiler.h

diff --git a/compiler.h b/compiler.h
index 2507ec88a0a6a6fbb11e84f73843bb042a9d850e..99972f30e2ba89726f663c78261f4e9203b6d026 100644 (file)
--- a/compiler.h
+++ b/compiler.h
@@ -8,28 +8,20 @@
  *
  * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
  *
- * This 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.
-*
- * This 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.
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
  *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- * IBM's contributions to this file may be relicensed under LGPLv2 or later.
+ * Permission is hereby granted to use or copy this program
+ * for any purpose,  provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is granted,
+ * provided the above notices are retained, and a notice that the code was
+ * modified is included with the above copyright notice.
  */
 
-/* The "volatile" is due to gcc bugs */
-#define barrier() __asm__ __volatile__("": : :"memory")
+#define likely(x)      __builtin_expect(!!(x), 1)
+#define unlikely(x)    __builtin_expect(!!(x), 0)
 
-#define likely(x)       __builtin_expect(!!(x), 1)
-#define unlikely(x)     __builtin_expect(!!(x), 0)
+#define        barrier()       asm volatile("" : : : "memory");
 
 /*
  * Instruct the compiler to perform only a single access to a variable
@@ -43,6 +35,16 @@
  * use is to mediate communication between process-level code and irq/NMI
  * handlers, all running on the same CPU.
  */
-#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
+#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&x)
+
+#if (__GNUC__ == 4)
+#define __compiler_offsetof(a, b) __builtin_offsetof(a, b)
+#endif
+
+#ifdef __compiler_offsetof
+#define offsetof(TYPE, MEMBER) __compiler_offsetof(TYPE, MEMBER)
+#else
+#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+#endif
 
 #endif /* _COMPILER_H */