diff --git a/acinclude.m4 b/acinclude.m4
index 0392bbea..697e36fa 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -331,6 +331,12 @@ AH_BOTTOM([#if C_HAS_ATTRIBUTE
 #define GCC_ATTRIBUTE(x) /* attribute not supported */
 #endif])
 
+AH_BOTTOM([#if C_HAS_BUILTIN_EXPECT
+#define GCC_UNLIKELY(x) __builtin_expect((x),0)
+#else
+#define GCC_UNLIKELY(x) (x)
+#endif])
+
 AH_BOTTOM([
 typedef         double     Real64;
 
diff --git a/configure.in b/configure.in
index 13ecf042..0a4878bf 100644
--- a/configure.in
+++ b/configure.in
@@ -58,6 +58,17 @@ AC_MSG_CHECKING(if compiler allows __attribute__)
 AC_TRY_COMPILE([], [typedef struct { } __attribute__ ((packed)) junk;], 
     [ AC_MSG_RESULT(yes);AC_DEFINE(C_HAS_ATTRIBUTE)],AC_MSG_RESULT(no))
 
+#Check if the compiler supports __builtin_expect
+AH_TEMPLATE([C_HAS_BUILTIN_EXPECT],[Determines if the compilers supports __builtin_expect for branch prediction.])
+AC_MSG_CHECKING(if compiler allows __builtin_expect)
+AC_TRY_COMPILE([],[
+int main(int argc,char* argv[]){ 
+int x=10;if( __builtin_expect ((x==1),0) ) ;
+return 0; 
+}
+], [ AC_MSG_RESULT(yes);AC_DEFINE(C_HAS_BUILTIN_EXPECT)],AC_MSG_RESULT(no))
+
+
 AM_PATH_ALSA(0.9.0, AC_DEFINE(HAVE_ALSA,1,[Define to 1 to use ALSA for MIDI]) , : )
 
 #Check for big endian machine, should #define WORD_BIGENDIAN if so
diff --git a/src/platform/visualc/config.h b/src/platform/visualc/config.h
index d28a4629..f80fb7ce 100644
--- a/src/platform/visualc/config.h
+++ b/src/platform/visualc/config.h
@@ -52,6 +52,7 @@
 #define C_DIRECTSERIAL 1
 
 #define GCC_ATTRIBUTE(x) /* attribute not supported */
+#define GCC_UNLIKELY(x) (x)
 
 typedef         double		Real64;
 /* The internal types */