1 files changed, 22 insertions, 4 deletions
diff --git a/src/pow.cpp b/src/pow.cpp
index cf7ac387f..bb53ad204 100644
--- a/src/pow.cpp
+++ b/src/pow.cpp
@@ -13,7 +13,7 @@
 
 unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
 {
-    unsigned int nProofOfWorkLimit = params.powLimit.GetCompact();
+    unsigned int nProofOfWorkLimit = UintToArith256(params.powLimit).GetCompact();
 
     // Genesis block
     if (pindexLast == NULL)
@@ -61,6 +61,7 @@ unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nF
         nActualTimespan = params.nPowTargetTimespan*4;
 
     // Retarget
+    const arith_uint256 bnPowLimit = UintToArith256(params.powLimit);
     arith_uint256 bnNew;
     arith_uint256 bnOld;
     bnNew.SetCompact(pindexLast->nBits);
@@ -68,8 +69,8 @@ unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nF
     bnNew *= nActualTimespan;
     bnNew /= params.nPowTargetTimespan;
 
-    if (bnNew > params.powLimit)
-        bnNew = params.powLimit;
+    if (bnNew > bnPowLimit)
+        bnNew = bnPowLimit;
 
     /// debug print
     LogPrintf("GetNextWorkRequired RETARGET\n");
@@ -89,7 +90,7 @@ bool CheckProofOfWork(uint256 hash, unsigned int nBits, const Consensus::Params&
     bnTarget.SetCompact(nBits, &fNegative, &fOverflow);
 
     // Check range
-    if (fNegative || bnTarget == 0 || fOverflow || bnTarget > params.powLimit)
+    if (fNegative || bnTarget == 0 || fOverflow || bnTarget > UintToArith256(params.powLimit))
         return error("CheckProofOfWork(): nBits below minimum work");
 
     // Check proof of work matches claimed amount
@@ -113,3 +114,20 @@ arith_uint256 GetBlockProof(const CBlockIndex& block)
     // or ~bnTarget / (nTarget+1) + 1.
     return (~bnTarget / (bnTarget + 1)) + 1;
 }
+
+int64_t GetBlockProofEquivalentTime(const CBlockIndex& to, const CBlockIndex& from, const CBlockIndex& tip, const Consensus::Params& params)
+{
+    arith_uint256 r;
+    int sign = 1;
+    if (to.nChainWork > from.nChainWork) {
+        r = to.nChainWork - from.nChainWork;
+    } else {
+        r = from.nChainWork - to.nChainWork;
+        sign = -1;
+    }
+    r = r * arith_uint256(params.nPowTargetSpacing) / GetBlockProof(tip);
+    if (r.bits() > 63) {
+        return sign * std::numeric_limits<int64_t>::max();
+    }
+    return sign * r.GetLow64();
+}