From d62d0ac48997f9b72da0f554dcf5269694d5999e Mon Sep 17 00:00:00 2001
From: smatz <smatz@openttd.org>
Date: Fri, 5 Feb 2010 17:05:58 +0000
Subject: (svn r19019) -Codechange: use HasExactlyOneBit() and
 HasAtMostOneBit() instead of CountBits() where possible

---
 src/core/bitmath_func.hpp | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

(limited to 'src/core')

diff --git a/src/core/bitmath_func.hpp b/src/core/bitmath_func.hpp
index 6ef67ca7f..85eaee6f9 100644
--- a/src/core/bitmath_func.hpp
+++ b/src/core/bitmath_func.hpp
@@ -254,6 +254,30 @@ static inline uint CountBits(T value)
 	return num;
 }
 
+/**
+ * Test whether \a value has exactly 1 bit set
+ *
+ * @param value the value to test.
+ * @return does \a value have exactly 1 bit set?
+ */
+template <typename T>
+static FORCEINLINE bool HasExactlyOneBit(T value)
+{
+	return value != 0 && (value & (value - 1)) == 0;
+}
+
+/**
+ * Test whether \a value has at most 1 bit set
+ *
+ * @param value the value to test.
+ * @return does \a value have at most 1 bit set?
+ */
+template <typename T>
+static FORCEINLINE bool HasAtMostOneBit(T value)
+{
+	return (value & (value - 1)) == 0;
+}
+
 /**
  * ROtate x Left by n
  *
-- 
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