X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=0b4a59de55915962e7ed9409ae462be2556366f3;hp=aa57efb600d062b4d772ef3cc20e661f38bb9c92;hb=bae019b53e5c2bfcf0d69b4ebfc52b4f4de762eb;hpb=d07e782e22ca2ed0ec748ac38c33673baec28cc5

diff --git a/src/tt.cpp b/src/tt.cpp
index aa57efb6..0b4a59de 100644
--- a/src/tt.cpp
+++ b/src/tt.cpp
@@ -2,7 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -30,10 +30,10 @@
 
 TranspositionTable TT; // Our global transposition table
 
-/// TTEntry::save saves a TTEntry
-void TTEntry::save(Key k, Value v, bool PvNode, Bound b, Depth d, Move m, Value ev) {
+/// TTEntry::save populates the TTEntry with a new node's data, possibly
+/// overwriting an old position. Update is not atomic and can be racy.
 
-  assert(d / ONE_PLY * ONE_PLY == d);
+void TTEntry::save(Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev) {
 
   // Preserve any existing move for the same position
   if (m || (k >> 48) != key16)
@@ -41,14 +41,16 @@ void TTEntry::save(Key k, Value v, bool PvNode, Bound b, Depth d, Move m, Value
 
   // Overwrite less valuable entries
   if (  (k >> 48) != key16
-      || d / ONE_PLY > depth8 - 4
+      || d - DEPTH_OFFSET > depth8 - 4
       || b == BOUND_EXACT)
   {
+      assert(d >= DEPTH_OFFSET);
+
       key16     = (uint16_t)(k >> 48);
       value16   = (int16_t)v;
       eval16    = (int16_t)ev;
-      genBound8 = (uint8_t)(TT.generation8 | PvNode << 2 | b);
-      depth8    = (int8_t)(d / ONE_PLY);
+      genBound8 = (uint8_t)(TT.generation8 | uint8_t(pv) << 2 | b);
+      depth8    = (uint8_t)(d - DEPTH_OFFSET);
   }
 }