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6 daysFix passed-pawn bitboard bit-clear bug, LMR gate coupling, inline hot ↵Scott Gasch
bitboard helpers - bitboard.c: CoorFromBitBoardRank1ToRank8 cleared the lowest set bit unconditionally instead of the reported (highest) one, silently mis-walking doubled-pawn files in eval.c's passed-pawn detection. - search.c/searchsup.c: move GetLMRReduction's precondition checks from inside the function to the caller in search.c (pre-existing work), finishing the split with a matching gate in split.c's HelpSearch -- the parallel-search call site had no gate at all, letting it call GetLMRReduction unconditionally (including for checking moves), reachable only under real multithreading (--cpus > 1) and the intermittent root cause of assertion crashes seen under --cpus 4. - eval.c: redirect CountBits/CoorFromBitBoardRank8ToRank1/ CoorFromBitBoardRank1ToRank8 to inline compiler-builtin versions (gated !CROUTINES) instead of the real out-of-line asm calls, on eval.c's ~20 existing production call sites. CountBits' asm body isn't O(1) popcnt, it's a Kernighan bit-clearing loop plus call overhead, paid on every Eval() call. Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Jntky4yGUTyQVaGCXms4F2
2016-06-01Initial checkin for typhoon chess engine.Scott Gasch