pow: only support prime calculations on Go 1.8 and above

1 files changed, 0 insertions, 37 deletions

diff --git a/pow/ethash_algo.go b/pow/ethash_algo.go
index f6d05880a..d3fac8d5b 100644
--- a/pow/ethash_algo.go
+++ b/pow/ethash_algo.go
@@ -19,7 +19,6 @@ package pow
 import (
 	"encoding/binary"
 	"io"
-	"math/big"
 	"runtime"
 	"sync"
 	"sync/atomic"
@@ -45,42 +44,6 @@ const (
 	loopAccesses       = 64      // Number of accesses in hashimoto loop
 )
 
-// cacheSize calculates and returns the size of the ethash verification cache that
-// belongs to a certain block number. The cache size grows linearly, however, we
-// always take the highest prime below the linearly growing threshold in order to
-// reduce the risk of accidental regularities leading to cyclic behavior.
-func cacheSize(block uint64) uint64 {
-	// If we have a pre-generated value, use that
-	epoch := int(block / epochLength)
-	if epoch < len(cacheSizes) {
-		return cacheSizes[epoch]
-	}
-	// No known cache size, calculate manually (sanity branch only)
-	size := uint64(cacheInitBytes + cacheGrowthBytes*epoch - hashBytes)
-	for !new(big.Int).SetUint64(size / hashBytes).ProbablyPrime(1) { // Always accurate for n < 2^64
-		size -= 2 * hashBytes
-	}
-	return size
-}
-
-// datasetSize calculates and returns the size of the ethash mining dataset that
-// belongs to a certain block number. The dataset size grows linearly, however, we
-// always take the highest prime below the linearly growing threshold in order to
-// reduce the risk of accidental regularities leading to cyclic behavior.
-func datasetSize(block uint64) uint64 {
-	// If we have a pre-generated value, use that
-	epoch := int(block / epochLength)
-	if epoch < len(datasetSizes) {
-		return datasetSizes[epoch]
-	}
-	// No known dataset size, calculate manually (sanity branch only)
-	size := uint64(datasetInitBytes + datasetGrowthBytes*epoch - mixBytes)
-	for !new(big.Int).SetUint64(size / mixBytes).ProbablyPrime(1) { // Always accurate for n < 2^64
-		size -= 2 * mixBytes
-	}
-	return size
-}
-
 // seedHash is the seed to use for generating a verification cache and the mining
 // dataset.
 func seedHash(block uint64) []byte {