From fa48fedaccc49ed00f9c72bf84a9b32754556137 Mon Sep 17 00:00:00 2001
From: cj5716 <125858804+cj5716@users.noreply.github.com>
Date: Wed, 10 Jan 2024 07:12:49 +0800
Subject: [PATCH] Small simplifications (#300)

Also makes certain behaviours explicit

Bench: 7592451
---
 src/nnue.cpp   | 21 +++++++++------------
 src/search.cpp |  4 ++--
 2 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/src/nnue.cpp b/src/nnue.cpp
index 32f0b45b..35c8b04c 100644
--- a/src/nnue.cpp
+++ b/src/nnue.cpp
@@ -90,26 +90,23 @@ void NNUE::update(NNUE::accumulator& board_accumulator, std::vector<std::pair<st
     int subs = NNUESub.size();
     // Quiets
     if (adds == 1 && subs == 1) {
-        auto [whiteAddIdx, blackAddIdx] = NNUEAdd.back();
-        auto [whiteSubIdx, blackSubIdx] = NNUESub.back();
+        auto [whiteAddIdx, blackAddIdx] = NNUEAdd[0];
+        auto [whiteSubIdx, blackSubIdx] = NNUESub[0];
         addSub(board_accumulator, whiteAddIdx, blackAddIdx, whiteSubIdx, blackSubIdx);
     }
     // Captures
     else if (adds == 1 && subs == 2) {
-        auto [whiteAddIdx, blackAddIdx] = NNUEAdd.back();
-        auto [whiteSubIdx1, blackSubIdx1] = NNUESub.back();
-        NNUESub.pop_back();
-        auto [whiteSubIdx2, blackSubIdx2] = NNUESub.back();
+        auto [whiteAddIdx, blackAddIdx] = NNUEAdd[0];
+        auto [whiteSubIdx1, blackSubIdx1] = NNUESub[0];
+        auto [whiteSubIdx2, blackSubIdx2] = NNUESub[1];
         addSubSub(board_accumulator, whiteAddIdx, blackAddIdx, whiteSubIdx1, blackSubIdx1, whiteSubIdx2, blackSubIdx2);
     }
     // Castling
     else {
-        auto [whiteAddIdx1, blackAddIdx1] = NNUEAdd.back();
-        NNUEAdd.pop_back();
-        auto [whiteAddIdx2, blackAddIdx2] = NNUEAdd.back();
-        auto [whiteSubIdx1, blackSubIdx1] = NNUESub.back();
-        NNUESub.pop_back();
-        auto [whiteSubIdx2, blackSubIdx2] = NNUESub.back();
+        auto [whiteAddIdx1, blackAddIdx1] = NNUEAdd[0];
+        auto [whiteAddIdx2, blackAddIdx2] = NNUEAdd[1];
+        auto [whiteSubIdx1, blackSubIdx1] = NNUESub[0];
+        auto [whiteSubIdx2, blackSubIdx2] = NNUESub[1];
         addSub(board_accumulator, whiteAddIdx1, blackAddIdx1, whiteSubIdx1, blackSubIdx1);
         addSub(board_accumulator, whiteAddIdx2, blackAddIdx2, whiteSubIdx2, blackSubIdx2);
     }
diff --git a/src/search.cpp b/src/search.cpp
index 12239754..e69d2ff6 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -636,7 +636,7 @@ int Negamax(int alpha, int beta, int depth, const bool cutNode, S_ThreadData* td
         if (doFullSearch)
         {
             // SF yoink, based on the value returned by our reduced search see if we should search deeper, this is an exact yoink of what SF and frankly i don't care lmao
-            const bool doDeeperSearch = score > (bestScore + 53 + 2 * newDepth);
+            const bool doDeeperSearch = depthReduction && score > (bestScore + 53 + 2 * newDepth);
             score = -Negamax<false>(-alpha - 1, -alpha, newDepth + doDeeperSearch, !cutNode, td, ss + 1);
             if (depthReduction)
             {
@@ -646,7 +646,7 @@ int Negamax(int alpha, int beta, int depth, const bool cutNode, S_ThreadData* td
             }
         }
 
-        // PVS Search: Search the first move and every move that produced a score better than alpha with full depth and a full window
+        // PVS Search: Search the first move and every move that beat alpha with full depth and a full window
         if (pvNode && (movesSearched == 0 || score > alpha))
             score = -Negamax<true>(-beta, -alpha, newDepth, false, td, ss + 1);