Use less bit shifting and magic in CasDiskLocation

1 files changed, 18 insertions, 9 deletions

diff --git a/zenstore/compactcas.h b/zenstore/compactcas.h
index 01cfffa52..f9e60aec8 100644
--- a/zenstore/compactcas.h
+++ b/zenstore/compactcas.h
@@ -49,8 +49,20 @@ struct CasDiskLocation
 	}
 
 private:
-	inline uint32_t BlockIndex() const { return (static_cast<uint32_t>(m_BlockIndexAndOffsetHighBits & 0xf) << 16) | m_BlockIndexLowBits; }
-	inline uint64_t Offset() const { return (static_cast<uint64_t>(m_BlockIndexAndOffsetHighBits & 0xfff0) << 12) | m_OffsetLowBits; }
+	inline uint32_t BlockIndex() const
+	{
+		uint64_t PackedOffset = 0;
+		memcpy(&PackedOffset, &m_Offset, sizeof m_Offset);
+		return static_cast<std::uint32_t>(PackedOffset >> MaxOffsetBits);
+	}
+
+	inline uint64_t Offset() const
+	{
+		uint64_t PackedOffset = 0;
+		memcpy(&PackedOffset, &m_Offset, sizeof m_Offset);
+		return PackedOffset & MaxOffset;
+	}
+
 	inline uint64_t Size() const { return m_Size; }
 
 	inline void Init(uint32_t BlockIndex, uint64_t Offset, uint64_t Size)
@@ -59,16 +71,13 @@ private:
 		ZEN_ASSERT(Offset <= MaxOffset);
 		ZEN_ASSERT(Size <= std::numeric_limits<std::uint32_t>::max());
 
-		m_Size						  = static_cast<uint32_t>(Size);
-		m_BlockIndexLowBits			  = static_cast<uint16_t>(BlockIndex & 0xffff);
-		m_OffsetLowBits				  = static_cast<uint16_t>(Offset & 0xffff);
-		m_BlockIndexAndOffsetHighBits = static_cast<uint16_t>(((BlockIndex >> 16) & 0xf) | (((Offset >> 16) & 0xfff) << 4));
+		m_Size				  = static_cast<uint32_t>(Size);
+		uint64_t PackedOffset = (static_cast<uint64_t>(BlockIndex) << MaxOffsetBits) + Offset;
+		memcpy(&m_Offset[0], &PackedOffset, sizeof m_Offset);
 	}
 
 	uint32_t m_Size;
-	uint16_t m_BlockIndexLowBits;
-	uint16_t m_OffsetLowBits;
-	uint16_t m_BlockIndexAndOffsetHighBits;
+	uint8_t	 m_Offset[6];
 };
 
 struct CasDiskIndexEntry