From d4fc5bf88d87828300e701c3e77d888c36c97dc2 Mon Sep 17 00:00:00 2001
From: glx <glx@openttd.org>
Date: Tue, 6 Sep 2011 00:10:20 +0000
Subject: [PATCH] (svn r22898) -Codechange: use MSVC compiler intrinsics for
 byte swapping

---
 src/core/bitmath_func.hpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/core/bitmath_func.hpp b/src/core/bitmath_func.hpp
index a881ee81df..d100030079 100644
--- a/src/core/bitmath_func.hpp
+++ b/src/core/bitmath_func.hpp
@@ -355,6 +355,10 @@ static FORCEINLINE T ROR(const T x, const uint8 n)
 	 * warnings if we don't cast those (why?) */
 	#define BSWAP32(x) ((uint32)Endian32_Swap(x))
 	#define BSWAP16(x) ((uint16)Endian16_Swap(x))
+#elif defined(_MSC_VER)
+	/* MSVC has intrinsics for swapping, resulting in faster code */
+	#define BSWAP32(x) (_byteswap_ulong(x))
+	#define BSWAP16(x) (_byteswap_ushort(x))
 #else
 	/**
 	 * Perform a 32 bits endianness bitswap on x.