King-safety recalibration, lazy-eval material floor, eval hot-path trimming

Recalibrate iKingSwingP90 against the bitboard-rewritten
CountKingSafetyDefects (~1.28B samples via new CALIBRATE_POSITIONAL/
CALIBRATE_BASE_MARGIN/CALIBRATE_MARGIN_SAFETY diagnostic build flags,
board_representation/EVAL.md section 9). Add LAZY_EVAL_MIN_MATERIAL:
measured the regular lazy exit's real swing exceeding its own assumed
margin 20.6% of the time in near-bare-king endgames (vs <=0.36%
elsewhere) -- skip lazy eval entirely below that material floor.
Double the stale search.c/searchsup.c CountKingSafetyDefects extension
thresholds as a stopgap pending their own recalibration.

Eval hot-path trimming (measured via EVAL_TIME, ~1759 -> ~1386 avg
cycles/eval on a representative middlegame position):
  - Pull _GetFileStormDefects out of EstimatePositionalScore's hot path
    (cost more than the "cheap cached lookup" it was assumed to be,
    running on ~90% of all Eval() calls).
  - Add pos->bbOccupiedSide[2], incrementally maintained alongside
    bbOccupied, so _BuildFriendlySideBB is a field read instead of a
    6-term OR.
  - Switch CoorFromBitBoardRank8ToRank1/Rank1ToRank8 to the existing
    static-inline FastFirstBit/FastLastBit (same bsf/bsr instruction,
    no call/ret overhead).
  - Defer EvalPasserRaces' uRacerDist/fDontCountMeOut past its
    no-passer early return.
  - Remove the mailbox-era "max mobility in a row" term from
    _EvalBishop/_EvalRook (no bitboard-mobility equivalent need for it).
  - Simplify _EvalBishopPairs and rook file-openness/passer bonuses to
    flat DNA-tunable constants instead of distance/pawn-count-scaled
    tables, rook file-openness now a branchless bitboard-indexed lookup.
  - Remove pos->cPiece (write-only, no reader anywhere).
  - Collapse WHITE/BLACK mirror-branches (castle-rights block,
    rook-trapped-in-corner) to color-indexed constants.
  - Close the PAWN_BIT..KING_BIT gap (bits 7-3 -> bits 4-0), removing
    the bvPattern >>= 3 before its KING_COUNTER_BY_ATTACK_PATTERN
    lookup. This also fixes a real bug introduced earlier this session
    when _WhoControlsSquareFast was converted to read these constants
    directly: g_SwapTable is only [32][32], but the old bit values
    (up to 0xF8) indexed far out of bounds on any attacked square --
    data.c's InitializeSwapTable was always built assuming the bits
    0-4 range this change now actually produces.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01XxmVi2sTMwpPp4i6WYFjan

1 files changed, 4 insertions, 4 deletions

diff --git a/src/generate.c b/src/generate.c
index faecc2a..6f92382 100755
--- a/src/generate.c
+++ b/src/generate.c
@@ -867,10 +867,10 @@ Return value:
 
 **/
 {
-    return (pos->bbPieces[uSide][KNIGHT] | pos->bbPieces[uSide][BISHOP] |
-            pos->bbPieces[uSide][ROOK]   | pos->bbPieces[uSide][QUEEN]  |
-            pos->bbPawns[uSide] |
-            COOR_TO_BB(pos->cNonPawns[uSide][0]));
+    // 2026-09-06: was a 6-term OR of bbPieces+bbPawns+king every call --
+    // pos->bbOccupiedSide[uSide] is now incrementally maintained (move.c,
+    // same treatment as pos->bbOccupied) so this is just a field read.
+    return pos->bbOccupiedSide[uSide];
 }
 
 // Non-static (unlike a purely-internal helper would be) so