Simplify futility pruning parent node

[stockfish] / src / tt.h

diff --git a/src/tt.h b/src/tt.h
index 98b054d397207525a45978e6bae6a15055e29181..142afd90e56ca63e1b79691f27b6c51a5a19f966 100644 (file)
--- a/src/tt.h
+++ b/src/tt.h
@@ -57,24 +57,22 @@ private:
 };
 
 
-/// A TranspositionTable consists of a power of 2 number of clusters and each
-/// cluster consists of ClusterSize number of TTEntry. Each non-empty entry
-/// contains information of exactly one position. The size of a cluster should
-/// divide the size of a cache line size, to ensure that clusters never cross
-/// cache lines. This ensures best cache performance, as the cacheline is
-/// prefetched, as soon as possible.
+/// A TranspositionTable is an array of Cluster, of size clusterCount. Each
+/// cluster consists of ClusterSize number of TTEntry. Each non-empty TTEntry
+/// contains information on exactly one position. The size of a Cluster should
+/// divide the size of a cache line for best performance,
+/// as the cacheline is prefetched when possible.
 
 class TranspositionTable {
 
-  static constexpr int CacheLineSize = 64;
   static constexpr int ClusterSize = 3;
 
   struct Cluster {
     TTEntry entry[ClusterSize];
-    char padding[2]; // Align to a divisor of the cache line size
+    char padding[2]; // Pad to 32 bytes
   };
 
-  static_assert(CacheLineSize % sizeof(Cluster) == 0, "Cluster size incorrect");
+  static_assert(sizeof(Cluster) == 32, "Unexpected Cluster size");
 
 public:
  ~TranspositionTable() { free(mem); }