MINOR: compiler: restore the likely() wrapper for gcc 5.x

After some tests, gcc 5.x produces better code with likely()
than without, contrary to gcc 4.x where it was better to disable
it. Let's re-enable it for 5 and above.

diff --git a/include/common/compiler.h b/include/common/compiler.h
index 001b89301d27334f41937075db32fd43492872a9..ee7744c9fd459505dcf56406e70530a89fd3ba87 100644 (file)
--- a/include/common/compiler.h
+++ b/include/common/compiler.h
@@ -89,8 +89,8 @@
 #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 */
+#elif __GNUC__ < 4 || __GNUC__ >= 5
+/* gcc 3.x and 5.x do the best job at this */
 #define likely(x) (__builtin_expect((x) != 0, 1))
 #define unlikely(x) (__builtin_expect((x) != 0, 0))
 #else