Cache good/bad-bishop pawn-structure score in the pawn hash

iBishopColorScore[color][complex] is a pure function of pawn placement
(own/enemy, stationary/transient) on a bishop's color complex, so it
doesn't need rescanning per-bishop -- computed once per pawn-hash miss
in _EvalPawns and reused by every bishop of that color/complex in
_EvalBishop, mirroring the same cache-the-per-structure-invariant idea
already used elsewhere in eval.c.

Also disables two speculative check-extension/futility-gating
experiments in search.c (#if 0, not deleted -- kept for reference)
that didn't hold up, and adds the BBLEFT/BBRIGHT bitboard constants
eval.c's bishop-mobility rewrite needs.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

1 files changed, 12 insertions, 8 deletions

diff --git a/src/searchsup.c b/src/searchsup.c
index 9e11631..ca75c92 100644
--- a/src/searchsup.c
+++ b/src/searchsup.c
@@ -1267,15 +1267,16 @@ Return value:
     BITV bvFlags;
 
     ASSERT(IS_CHECKING_MOVE(mv) || (mv.pCaptured != NULL));
-    if (uMoveNum != (ULONG)-1)
+    if (uMoveNum == (ULONG)-1)
     {
-        ASSERT(uMoveNum < MAX_MOVE_STACK);
-        ASSERT(IS_SAME_MOVE(mv, ctx->sMoveStack.mvf[uMoveNum].mv));
-        bvFlags = ctx->sMoveStack.mvf[uMoveNum].bvFlags;
-        if (bvFlags & MVF_SEE_KNOWN)
-        {
-            return((bvFlags & MVF_SEE_NONNEGATIVE) ? 0 : -1);
-        }
+        return(SeeFastSign(&ctx->sPosition, mv) ? 0 : -1);
+    }
+    ASSERT(uMoveNum < MAX_MOVE_STACK);
+    ASSERT(IS_SAME_MOVE(mv, ctx->sMoveStack.mvf[uMoveNum].mv));
+    bvFlags = ctx->sMoveStack.mvf[uMoveNum].bvFlags;
+    if (bvFlags & MVF_SEE_KNOWN)
+    {
+        return((bvFlags & MVF_SEE_NONNEGATIVE) ? 0 : -1);
     }
     return(SeeFastSign(&ctx->sPosition, mv) ? 0 : -1);
 }
@@ -2393,9 +2394,11 @@ TryNullmovePruning(SEARCHER_THREAD_CONTEXT *ctx,
         {
             ASSERT(GET_COLOR(mv.pCaptured) == FLIP(pos->uToMove));
             ASSERT(mv.pCaptured == pos->rgSquare[mv.cTo].pPiece);
+
             // Victim belongs to FLIP(pos->uToMove) here, i.e. the
             // mover at ctx->uPly - 1 (see RecordEnprisePieceAtPly).
             RecordEnprisePieceAtPly(ctx, ctx->uPly - 1, mv.cTo);
+#if 0
             mvRef = ctx->mvNullmoveRefutations[ctx->uPly - 2];
             if ((mvRef.uMove) &&
                 (mvRef.pCaptured == mv.pCaptured) &&
@@ -2410,6 +2413,7 @@ TryNullmovePruning(SEARCHER_THREAD_CONTEXT *ctx,
                 *piOrigExtend += _bm_by_piece[PIECE_TYPE(mv.pCaptured)];
                 INC(ctx->sCounters.extension.uBotvinnikMarkoff);
             }
+#endif
             ctx->mvNullmoveRefutations[ctx->uPly] = mv;
         }
         else if (!IS_CAPTURE_OR_PROMOTION(mv))