Broadening the use of branch hints

More uses of macros 'likely'/'unlikely' (renamed to
'l_likely'/'l_unlikely'), both in range (extended to the
libraries) and in scope (extended to hooks, stack growth).

1 files changed, 20 insertions, 0 deletions

diff --git a/luaconf.h b/luaconf.h
index a44858c4..ae73e2fd 100644
--- a/luaconf.h
+++ b/luaconf.h
@@ -660,6 +660,26 @@
 #define lua_getlocaledecpoint()         (localeconv()->decimal_point[0])
 #endif
 
+
+/*
+** macros to improve jump prediction, used mostly for error handling
+** and debug facilities.
+*/
+#if (defined(LUA_CORE) || defined(LUA_LIB)) && !defined(l_likely)
+
+#include <stdio.h>
+#if defined(__GNUC__)
+#define l_likely(x)     (__builtin_expect(((x) != 0), 1))
+#define l_unlikely(x)   (__builtin_expect(((x) != 0), 0))
+#else
+#define l_likely(x)     (x)
+#define l_unlikely(x)   (x)
+#endif
+
+#endif
+
+
+
 /* }================================================================== */