diff --git a/include/common/compiler.h b/include/common/compiler.h
new file mode 100644
index 0000000..03d82ae
--- /dev/null
+++ b/include/common/compiler.h
@@ -0,0 +1,107 @@
+/*
+ * include/common/compiler.h
+ * This files contains some compiler-specific settings.
+ *
+ * Copyright (C) 2000-2009 Willy Tarreau - w@1wt.eu
+ *
+ * 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, version 2.1
+ * exclusively.
+ *
+ * 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.
+ *
+ * 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
+ */
+
+#ifndef _COMMON_COMPILER_H
+#define _COMMON_COMPILER_H
+
+
+/*
+ * Gcc before 3.0 needs [0] to declare a variable-size array
+ */
+#ifndef VAR_ARRAY
+#if  __GNUC__  < 3
+#define VAR_ARRAY	0
+#else
+#define VAR_ARRAY
+#endif
+#endif
+
+
+/* Support passing function parameters in registers. For this, the
+ * CONFIG_REGPARM macro has to be set to the maximal number of registers
+ * allowed. Some functions have intentionally received a regparm lower than
+ * their parameter count, it is in order to avoid register clobbering where
+ * they are called.
+ */
+#ifndef REGPRM1
+#if CONFIG_REGPARM >= 1 && __GNUC__ >= 3
+#define REGPRM1	__attribute__((regparm(1)))
+#else
+#define REGPRM1
+#endif
+#endif
+
+#ifndef REGPRM2
+#if CONFIG_REGPARM >= 2 && __GNUC__ >= 3
+#define REGPRM2	__attribute__((regparm(2)))
+#else
+#define REGPRM2 REGPRM1
+#endif
+#endif
+
+#ifndef REGPRM3
+#if CONFIG_REGPARM >= 3 && __GNUC__ >= 3
+#define REGPRM3	__attribute__((regparm(3)))
+#else
+#define REGPRM3 REGPRM2
+#endif
+#endif
+
+
+/* By default, gcc does not inline large chunks of code, but we want it to
+ * respect our choices.
+ */
+#if !defined(forceinline)
+#if __GNUC__ < 3
+#define forceinline inline
+#else
+#define forceinline inline __attribute__((always_inline))
+#endif
+#endif
+
+
+/*
+ * Gcc >= 3 provides the ability for the programme to give hints to the
+ * compiler about what branch of an if is most likely to be taken. This
+ * helps the compiler produce the most compact critical paths, which is
+ * generally better for the cache and to reduce the number of jumps.
+ */
+#if !defined(likely)
+#if __GNUC__ < 3
+#define __builtin_expect(x,y) (x)
+#define likely(x) (x)
+#define unlikely(x) (x)
+#elif __GNUC__ < 4
+/* gcc 3.x does the best job at this */
+#define likely(x) (__builtin_expect((x) != 0, 1))
+#define unlikely(x) (__builtin_expect((x) != 0, 0))
+#else
+/* GCC 4.x is stupid, it performs the comparison then compares it to 1,
+ * so we cheat in a dirty way to prevent it from doing this. This will
+ * only work with ints and booleans though.
+ */
+#define likely(x) (x)
+#define unlikely(x) (__builtin_expect((unsigned long)(x), 0))
+#endif
+#endif
+
+
+#endif /* _COMMON_COMPILER_H */