[PATCH 09/14] FreeBSD update of __always_inline, etc.

[Sebastian Huber]

newlib/ChangeLog
2013-04-17  Sebastian Huber <sebastian.huber@embedded-brains.de>

	* libc/include/sys/cdefs.h (__always_inline): New define.
	(__exported): Likewise.
	(__fastcall): Likewise.
	(__func__): Likewise.
	(__hidden): Likewise.
	(__malloc_like): Likewise.
	(__noinline): Likewise.
	(__nonnull): Likewise.
	(__offsetof): Likewise.
	(__predict_false): Likewise.
	(__predict_true): Likewise.
	(__pure): Likewise.
	(__rangeof): Likewise.
	(__restrict): Likewise.
	(__returns_twice): Likewise.
---
 newlib/libc/include/sys/cdefs.h |  109 ++++++++++++++++++++++++++++++++++++++-
 1 files changed, 107 insertions(+), 2 deletions(-)

diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index 6f2e8c9..cf343a2 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -305,6 +305,111 @@
 	    __builtin_types_compatible_p(__typeof(expr), t), yes, no)
 #endif
 
+#if __GNUC_PREREQ__(2, 96)
+#define	__malloc_like	__attribute__((__malloc__))
+#define	__pure		__attribute__((__pure__))
+#else
+#define	__malloc_like
+#define	__pure
+#endif
+
+#if __GNUC_PREREQ__(3, 1) || (defined(__INTEL_COMPILER) && __INTEL_COMPILER >= 800)
+#define	__always_inline	__attribute__((__always_inline__))
+#else
+#define	__always_inline
+#endif
+
+#if __GNUC_PREREQ__(3, 1)
+#define	__noinline	__attribute__ ((__noinline__))
+#else
+#define	__noinline
+#endif
+
+#if __GNUC_PREREQ__(3, 3)
+#define __nonnull(x)	__attribute__((__nonnull__(x)))
+#else
+#define __nonnull(x)
+#endif
+
+#if __GNUC_PREREQ__(3, 4)
+#define	__fastcall	__attribute__((__fastcall__))
+#else
+#define	__fastcall
+#endif
+
+#if __GNUC_PREREQ__(4, 1)
+#define	__returns_twice	__attribute__((__returns_twice__))
+#else
+#define	__returns_twice
+#endif
+
+/* XXX: should use `#if __STDC_VERSION__ < 199901'. */
+#if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
+#define	__func__	NULL
+#endif
+
+/*
+ * GCC 2.95 provides `__restrict' as an extension to C90 to support the
+ * C99-specific `restrict' type qualifier.  We happen to use `__restrict' as
+ * a way to define the `restrict' type qualifier without disturbing older
+ * software that is unaware of C99 keywords.
+ */
+#if !(__GNUC__ == 2 && __GNUC_MINOR__ == 95)
+#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901 || defined(lint)
+#define	__restrict
+#else
+#define	__restrict	restrict
+#endif
+#endif
+
+/*
+ * GNU C version 2.96 adds explicit branch prediction so that
+ * the CPU back-end can hint the processor and also so that
+ * code blocks can be reordered such that the predicted path
+ * sees a more linear flow, thus improving cache behavior, etc.
+ *
+ * The following two macros provide us with a way to utilize this
+ * compiler feature.  Use __predict_true() if you expect the expression
+ * to evaluate to true, and __predict_false() if you expect the
+ * expression to evaluate to false.
+ *
+ * A few notes about usage:
+ *
+ *	* Generally, __predict_false() error condition checks (unless
+ *	  you have some _strong_ reason to do otherwise, in which case
+ *	  document it), and/or __predict_true() `no-error' condition
+ *	  checks, assuming you want to optimize for the no-error case.
+ *
+ *	* Other than that, if you don't know the likelihood of a test
+ *	  succeeding from empirical or other `hard' evidence, don't
+ *	  make predictions.
+ *
+ *	* These are meant to be used in places that are run `a lot'.
+ *	  It is wasteful to make predictions in code that is run
+ *	  seldomly (e.g. at subsystem initialization time) as the
+ *	  basic block reordering that this affects can often generate
+ *	  larger code.
+ */
+#if __GNUC_PREREQ__(2, 96)
+#define __predict_true(exp)     __builtin_expect((exp), 1)
+#define __predict_false(exp)    __builtin_expect((exp), 0)
+#else
+#define __predict_true(exp)     (exp)
+#define __predict_false(exp)    (exp)
+#endif
+
+#if __GNUC_PREREQ__(4, 2)
+#define	__hidden	__attribute__((__visibility__("hidden")))
+#define	__exported	__attribute__((__visibility__("default")))
+#else
+#define	__hidden
+#define	__exported
+#endif
+
+#define __offsetof(type, field)	offsetof(type, field)
+#define	__rangeof(type, start, end) \
+	(__offsetof(type, end) - __offsetof(type, start))
+
 /*
  * Given the pointer x to the member m of the struct s, return
  * a pointer to the containing structure.  When using GCC, we first
@@ -314,11 +419,11 @@
 #if __GNUC_PREREQ__(3, 1)
 #define	__containerof(x, s, m) ({					\
 	const volatile __typeof__(((s *)0)->m) *__x = (x);		\
-	__DEQUALIFY(s *, (const volatile char *)__x - offsetof(s, m));\
+	__DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\
 })
 #else
 #define	__containerof(x, s, m)						\
-	__DEQUALIFY(s *, (const volatile char *)(x) - offsetof(s, m))
+	__DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m))
 #endif
 
 #ifndef	__DEQUALIFY
-- 
1.7.7