From 04de38d166b968a378222cd85d1c4239b31335d6 Mon Sep 17 00:00:00 2001
From: Fletcher Dunn <fletcherd@valvesoftware.com>
Date: Mon, 6 Apr 2020 10:45:03 -0700
Subject: [PATCH] Promote likely()/unlikely() to public header.

I have been using this in the relay to optimize some branches in inner loop
code, and I want to do that more broadly.  This is an idiom from the linux
kernel.
---
 .../steamnetworkingsockets_internal.h          | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/steamnetworkingsockets/steamnetworkingsockets_internal.h b/src/steamnetworkingsockets/steamnetworkingsockets_internal.h
index 991fe9c..21e80dd 100644
--- a/src/steamnetworkingsockets/steamnetworkingsockets_internal.h
+++ b/src/steamnetworkingsockets/steamnetworkingsockets_internal.h
@@ -107,6 +107,24 @@ struct iovec
 struct iovec;
 #endif
 
+// likely() and unlikely().  Branch hints
+// This is an idiom from the linux kernel
+#ifdef __GNUC__
+	#ifndef likely
+		#define likely(x) __builtin_expect (!!(x), 1)
+	#endif
+	#ifndef unlikely
+		#define unlikely(x) __builtin_expect (!!(x), 0)
+	#endif
+#else
+	#ifndef likely
+		#define likely(x) (x)
+	#endif
+	#ifndef unlikely
+		#define unlikely(x) (x)
+	#endif
+#endif
+
 // Internal stuff goes in a private namespace
 namespace SteamNetworkingSocketsLib {