From 7e575512ae53c9992da2e0fe592617beba7bba07 Mon Sep 17 00:00:00 2001
From: Marco Costalba <mcostalba@gmail.com>
Date: Sun, 7 Jul 2013 13:27:31 +0200
Subject: [PATCH] Skip node-level cut-off tests when in check

No functional change.
---
 src/search.cpp | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/search.cpp b/src/search.cpp
index 15a9cde5..220fff5e 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -581,7 +581,10 @@ namespace {
 
     // Step 5. Evaluate the position statically and update parent's gain statistics
     if (inCheck)
+    {
         ss->staticEval = ss->evalMargin = eval = VALUE_NONE;
+        goto iid_start;
+    }
 
     else if (tte)
     {
@@ -618,7 +621,6 @@ namespace {
     // Step 6. Razoring (is omitted in PV nodes)
     if (   !PvNode
         &&  depth < 4 * ONE_PLY
-        && !inCheck
         &&  eval + razor_margin(depth) < beta
         &&  ttMove == MOVE_NONE
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
@@ -638,7 +640,6 @@ namespace {
     if (   !PvNode
         && !ss->skipNullMove
         &&  depth < 4 * ONE_PLY
-        && !inCheck
         &&  eval - futility_margin(depth, (ss-1)->futilityMoveCount) >= beta
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
         &&  abs(eval) < VALUE_KNOWN_WIN
@@ -649,7 +650,6 @@ namespace {
     if (   !PvNode
         && !ss->skipNullMove
         &&  depth > ONE_PLY
-        && !inCheck
         &&  eval >= beta
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
         &&  pos.non_pawn_material(pos.side_to_move()))
@@ -711,7 +711,6 @@ namespace {
     // prune the previous move.
     if (   !PvNode
         &&  depth >= 5 * ONE_PLY
-        && !inCheck
         && !ss->skipNullMove
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY)
     {
@@ -737,6 +736,8 @@ namespace {
             }
     }
 
+iid_start: // When in check we skip early cut tests
+
     // Step 10. Internal iterative deepening
     if (   depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY)
         && ttMove == MOVE_NONE
-- 
2.39.2