From c620d5e5f066e62cf23197d16e40a07c41e2d9f8 Mon Sep 17 00:00:00 2001
From: smatz <smatz@openttd.org>
Date: Tue, 2 Sep 2008 21:11:48 +0000
Subject: (svn r14232) -Codechange: use builtin for byte swapping for gcc >=
 4.3

---
 src/core/bitmath_func.hpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/core/bitmath_func.hpp b/src/core/bitmath_func.hpp
index 6abcdcb80..27168e821 100644
--- a/src/core/bitmath_func.hpp
+++ b/src/core/bitmath_func.hpp
@@ -318,7 +318,12 @@ static FORCEINLINE T ROR(const T x, const uint8 n)
 	 */
 	static FORCEINLINE uint32 BSWAP32(uint32 x)
 	{
+#if defined(__GNUC__) && ((__GNUC__ > 4) || ((__GNUC__ == 4)  && __GNUC_MINOR__ >= 3))
+		/* GCC >= 4.3 provides a builtin, resulting in faster code */
+		return (uint32)__builtin_bswap32((int32)x);
+#else
 		return ((x >> 24) & 0xFF) | ((x >> 8) & 0xFF00) | ((x << 8) & 0xFF0000) | ((x << 24) & 0xFF000000);
+#endif /* defined(__GNUC__) */
 	}
 
 	/**
-- 
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