1 files changed, 35 insertions, 2 deletions
diff --git a/xmrstak/backend/iBackend.hpp b/xmrstak/backend/iBackend.hpp
index 5037028..0be8f0a 100644
--- a/xmrstak/backend/iBackend.hpp
+++ b/xmrstak/backend/iBackend.hpp
@@ -1,18 +1,51 @@
 #pragma once
 
+#include "xmrstak/backend/globalStates.hpp"
+
 #include <atomic>
 #include <cstdint>
+#include <climits>
 
 
 namespace xmrstak
 {
+	// only allowed for unsigned value \todo add static assert
+	template<typename T>
+	T reverseBits(T value)
+	{
+		/* init with value (to get LSB) */
+		T result = value;
+		/* extra shift needed at end */
+		int s = sizeof(T) * CHAR_BIT - 1;
+		for (value >>= 1; value; value >>= 1)
+		{
+			result <<= 1;
+			result |= value & 1;
+			s--;
+		}
+		/* shift when values highest bits are zero */
+		result <<= s;
+		return result;
+	}
 
-	struct IBackend
+	struct iBackend
 	{
+		inline uint32_t calc_start_nonce(uint32_t resume)
+		{
+			return reverseBits<uint32_t>(static_cast<uint32_t>(iThreadNo + globalStates::inst().iThreadCount * resume));
+		}
+
+		// Limited version of the nonce calc above
+		inline uint32_t calc_nicehash_nonce(uint32_t start, uint32_t resume)
+		{
+			return start | ( calc_start_nonce(resume) >> 8u );
+		}
+
 		std::atomic<uint64_t> iHashCount;
 		std::atomic<uint64_t> iTimestamp;
+		uint32_t iThreadNo;
 
-		IBackend() : iHashCount(0), iTimestamp(0)
+		iBackend() : iHashCount(0), iTimestamp(0)
 		{
 		}
 	};