From: Lyudmil Antonov <lantonov.here@gmail.com>
Date: Tue, 12 Jul 2016 09:39:47 +0000 (+0300)
Subject: Workaround gcc stack alignment bug
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=f619f1d38c3d77c315b509ae2fe637926c9059fd

Workaround gcc stack alignment bug

GCC uses SSE instructions to move data but in 32-bit gcc version used
by abrok the stack is not 16-byte aligned due to a bug.

This patch workaround teh bug by not using the stack
to store KingFlank[]

Fixes issue #721.

No functional change.
---

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index b1a85a0f..489422fc 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -481,6 +481,19 @@ namespace {
   // evaluate_threats() assigns bonuses according to the types of the attacking
   // and the attacked pieces.
 
+  const Bitboard WhiteCamp = Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB;
+  const Bitboard BlackCamp = Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB;
+  const Bitboard QueenSide   = FileABB | FileBBB | FileCBB | FileDBB;
+  const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
+  const Bitboard KingSide    = FileEBB | FileFBB | FileGBB | FileHBB;
+
+  const Bitboard KingFlank[COLOR_NB][FILE_NB] = {
+    { QueenSide   & WhiteCamp, QueenSide & WhiteCamp, QueenSide & WhiteCamp, CenterFiles & WhiteCamp,
+      CenterFiles & WhiteCamp, KingSide  & WhiteCamp, KingSide  & WhiteCamp, KingSide    & WhiteCamp },
+    { QueenSide   & BlackCamp, QueenSide & BlackCamp, QueenSide & BlackCamp, CenterFiles & BlackCamp,
+      CenterFiles & BlackCamp, KingSide  & BlackCamp, KingSide  & BlackCamp, KingSide    & BlackCamp },
+  };
+
   template<Color Us, bool DoTrace>
   Score evaluate_threats(const Position& pos, const EvalInfo& ei) {
 
@@ -491,18 +504,6 @@ namespace {
     const Bitboard TRank2BB = (Us == WHITE ? Rank2BB  : Rank7BB);
     const Bitboard TRank7BB = (Us == WHITE ? Rank7BB  : Rank2BB);
 
-    const Bitboard TheirCamp = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB
-                                            : Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB);
-
-    const Bitboard QueenSide   = TheirCamp & (FileABB | FileBBB | FileCBB | FileDBB);
-    const Bitboard CenterFiles = TheirCamp & (FileCBB | FileDBB | FileEBB | FileFBB);
-    const Bitboard KingSide    = TheirCamp & (FileEBB | FileFBB | FileGBB | FileHBB);
-
-    const Bitboard KingFlank[FILE_NB] = {
-      QueenSide, QueenSide, QueenSide, CenterFiles,
-      CenterFiles, KingSide, KingSide, KingSide
-    };
-
     enum { Minor, Rook };
 
     Bitboard b, weak, defended, safeThreats;
@@ -571,7 +572,7 @@ namespace {
     score += ThreatByPawnPush * popcount(b);
 
     // King tropism: firstly, find squares that we attack in the enemy king flank
-    b = ei.attackedBy[Us][ALL_PIECES] & KingFlank[file_of(pos.square<KING>(Them))];
+    b = ei.attackedBy[Us][ALL_PIECES] & KingFlank[Us][file_of(pos.square<KING>(Them))];
 
     // Secondly, add to the bitboard the squares which we attack twice in that flank
     // but which are not protected by a enemy pawn. Note the trick to shift away the