compiler_opts: __builtin_prefetch supported from gcc 3.1

compiler_opt.h

@@ -44,25 +44,37 @@
 #ifndef __compiler_opt_h
 #define __compiler_opt_h
 
+/* likely/unlikely */
 #if __GNUC__ >= 3
+
 #define likely(expr)              __builtin_expect(!!(expr), 1)
 #define unlikely(expr)            __builtin_expect(!!(expr), 0)
 
-#define prefetch(addr)            __builtin_prefetch((addr))
-#define prefetch_w(addr)          __builtin_prefetch((addr), 1)
-#define prefetch_loc_r(addr, loc) __builtin_prefetch((addr), 0, (loc))
-#define prefetch_loc_w(addr, loc) __builtin_prefetch((addr), 1, (loc))
-
 #else /* __GNUC__ */
 
 #warning "No compiler optimizations supported try gcc 4.x"
 #define likely(expr) (expr)
 #define unlikely(expr) (expr)
 
+#endif /* __GNUC__ */
+
+
+
+/* prefetch* */
+#if ( __GNUC__ > 3 ) || ( __GNUC__ == 3 && __GNUC_MINOR__ >= 1 )
+
+#define prefetch(addr)            __builtin_prefetch((addr))
+#define prefetch_w(addr)          __builtin_prefetch((addr), 1)
+#define prefetch_loc_r(addr, loc) __builtin_prefetch((addr), 0, (loc))
+#define prefetch_loc_w(addr, loc) __builtin_prefetch((addr), 1, (loc))
+
+#else
+
 #define prefetch(addr)
 #define prefetch_w(addr)
 #define prefetch_loc_r(addr, loc)
 #define prefetch_loc_w(addr, loc)
-#endif /* __GNUC__ */
+
+#endif /* __GNUC__ > 3  || ( __GNUC__ == 3 && __GNUC_MINOR__ >= 1 ) */
 
 #endif