| Age | Commit message (Collapse) | Author |
|---|
|
default on
Implements the full board_representation/MOVEGEN_MIGRATION.md scope:
bitboard-backed generators for all six not-in-check piece types plus
the JumpTable-avoiding whole-node dispatch fork (_GenerateAllMovesBB),
the in-check escape path (king flight + block/capture), and
movesup.c's ExposesCheck/FasterExposesCheck/ExposesCheckEp/IsAttacked/
InCheck bitboard equivalents. Nine toggles total
(GENERATE_{KNIGHT,KING,ROOK,BISHOP,QUEEN,PAWN}_BITBOARD,
GENERATE_ESCAPES_{KING,BLOCK}_BITBOARD, EXPOSESCHECK_BITBOARD,
ISATTACKED_BITBOARD), all now on by default in GNUmakefile --
DISABLE_BITBOARD_MOVEGEN=1 opts back into the mailbox path, which
remains fully present and compiled either way.
Correctness verified via perft (Kiwipete, Position 4), the move-set
comparison harness across 20,000 random positions, all nine toggles
combined cleanly (15/15 runs, after fixing a GenerateRandomLegalPosition
en-passant-sentinel bug in the test harness), and sd10 on all three
curated suites showing zero solve-count regression vs head_reference
(the ecm_hard_quick delta traced to unrelated intervening commits).
Speed: most individual generators land near parity by design (mailbox's
per-square walk was already close to O(destination count)); the real,
consistent wins are the dispatch-layer fork (up to 23% in dense
positions) and IsAttackedBB (0.73x-0.93x of mailbox).
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AbHkVrm5KUyzLwWd3GHmo6
|
|
Board-representation migration, sections 2-3 (GetAttacks half):
- board.c: VerifyPositionConsistency's bbPieces consistency check
(migration section 2), verified clean via gmake TEST=1 with the
assert live.
- POSITION.bbPawns[2]: new incrementally-maintained per-color pawn
location bitboard (chess.h), maintained at the same 6 move.c sites
as bbPieces, populated from scratch in fen.c. Distinct from the
pawn-hash-keyed bbPawnLocations; this one needs no
SEARCHER_THREAD_CONTEXT, so it's reachable from GetAttacks's actual
call sites (which only ever have a POSITION*).
- data.c/chess.h/main.c: g_RookRayAll/g_BishopRayAll (all 4 per-square
ray directions pre-ORed) and g_PawnAttackOriginBB[2][128] startup
tables, plus FastFirstBit/FastLastBit (static inline bsf/bsr
wrappers, chess.h) -- supporting tables/helpers for the primitive
below.
- see.c: _WhoAttacksSquareBB (bitboard "who attacks square X" query)
and _GetAttacksBB (SEE_LIST-populating PoC wrapping it), side by
side with the existing SlowGetAttacks/asm GetAttacks -- not wired
into the GetAttacks macro yet (section 6), pure addition.
- testsee.c: SeeListsAreEqual made order-independent (SEE() sorts the
list right after GetAttacks returns, so order was never semantically
significant); TestGetAttacks extended to run _GetAttacksBB as a
third comparison across the existing 20,000-random-position sweep;
added an interleaved asm/Slow/BB cycles-per-call benchmark across
opening/middlegame/endgame positions.
- testsup.c: fixed GenerateRandomLegalPosition (used by the sweep
above) to maintain bbPieces/bbPawns at its two hand-placement sites
-- a latent gap since section 1 that made its own
VerifyPositionConsistency legality gate almost always reject
generated positions, causing large, variable retry-loop slowdowns.
Verified: 20,000-position x every-square x both-colors correctness
sweep passes (gmake TEST=1), precommit_check.sh clean (self-test +
DEBUG smoke test). Benchmark: _GetAttacksBB is ~0.53-0.55x asm
GetAttacks's cycles/call (opening/middlegame) and ~0.89x (endgame) --
faster, not just equivalent, primarily from replacing bbOccupied's
up-to-16-iteration pawn loop with two bbPawns ORs, plus a
g_PawnAttackOriginBB table lookup replacing per-call pawn-delta
arithmetic and per-direction/per-side-group early-outs in the slider
walk. See board_representation/MIGRATION.md section 3 for the full
writeup, including a reverted approach that measured slower and why,
and the CountKingSafetyDefects half's re-scoped (not yet implemented)
design.
Also confirmed (not caused by this work, not fixed here): a
pre-existing non-deterministic MP-race assertion in util.c:1093's PV
printing, reproduced independently on a clean HEAD checkout.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Jntky4yGUTyQVaGCXms4F2
|
|
Board-representation migration, section 1: add POSITION.bbPieces[2][8]
(per-color, per-piece-type location bitboards, indexed like the
existing uNonPawnCount) as incrementally-maintained state, not a
per-Eval()-call rebuild -- the structural fix for why the earlier
attack-presence-bitboard work measured slower, not faster.
- chess.h: bbPieces[2][8] field; extern decls for data.c's
g_RookRayToEdge/g_BishopRayToEdge/g_KnightAttacksBB ray tables and
their Initialize* functions (needed by the planned bitboard-backed
GetAttacks/CountKingSafetyDefects primitive, section 3).
- fen.c: populate bbPieces during piece placement; zeroing is free via
the existing memset(p, 0, sizeof(POSITION)).
- move.c: maintain bbPieces at all 6 non-pawn piece-movement functions
(SlidePiece/LiftPiece/PlacePiece and their WithoutSigs siblings used
by UnmakeMove) -- covers every move type: normal moves, captures,
both-side castling, promotion with/without capture, en passant, and
every undo.
- board.c: extend VerifyPositionConsistency's existing non-pawn
piece-list walk with a parallel bbPieces reconstruction-and-compare,
rather than a separate bespoke check.
- data.c/main.c: pulled ray-to-edge/knight-attack tables from stash
(needed by section 3, not section 1 itself, but zero-risk to land
now).
Also, while verifying: COOR_TO_BB was a table lookup (BBSQUARE[idx])
measured ~5-7% slower than the pure-ALU shift already sitting unused in
SLOWCOOR_TO_BB (whose "SLOW" name reflects a stale assumption about
variable shifts never actually tested on this hardware). Switched
COOR_TO_BB to the shift; fixed testbitboard.c's existing but broken
(dead-code-eliminated, silently reporting "0 cycles/op") comparison
benchmark for both while at it.
Verified via gmake TEST=1 (including TestMakeUnmakeMove's explicit
en-passant/promotion-with-capture/both-castling coverage) and
debug_smoke_test.sh, both clean; release build clean and runs normally.
Nothing reads bbPieces yet -- pure addition, zero behavioral risk.
See board_representation/MIGRATION.md for the full plan.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Jntky4yGUTyQVaGCXms4F2
|
|
Pulled the parts of the stashed LMR work that are genuinely independent
of the reduction logic itself, leaving the actual LMR redesign for
separate review:
- Fix extension-taper table overflow: remove the flat MAX_EXTEND_PER_LINE
cap and instead clamp the depth used to build g_uExtensionReduction[]
so a deep `sd` request can't leave the whole taper table stuck at "0
penalty" (every index unreachable).
- Remove a spuriously-firing ASSERT(fMovesRescoredByIID) in Search():
RescoreMovesViaSearch's own fail-high branch deliberately leaves that
flag FALSE by contract, so the assert could fire on any DEBUG build
given an unlucky rescore, making the DEBUG/TEST harness unreliable.
- Misc correctness/portability fixes: unix.c pointer-truncation casts,
chess.h's CONTAINING_STRUCT/IS_ENPASSANT/ABS_DIFF macro hardening
(plus gating the branchless bit-tricks on _X64_ too, not just _X86_),
removal of dead Slide*WithoutSigs prototypes, main.c's hash default
bumped to 256m and its CPP self-test's arch gate widened to _X64_.
- eval_tune/match_play.py: cosmetic SPRT progress-bar/output rework.
- Delete eval_tune/run_ecm.sh (superseded, unreferenced elsewhere).
- run_tests.sh: parameterize suites/SD/SN via args/env vars instead of
hardcoding the three curated suites and sd10/sn5M (defaults kept
pointing at the existing curated suites, since the stash's own
lmr_sensitive_30/lmr_control_30 default suites aren't present in the
repo).
Deliberately left out of this commit: the stash's actual LMR reduction
logic, the M-SIGNAL-SHADOW diagnostic subsystem, the large PERF_COUNTERS
instrumentation buildout, the history-table gravity rework, and the
FindEnprisePiece pre-move staleness fix (skipped per request pending a
decision on whether to also change EFP's pruning behavior).
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01MjdDfHry3i2jfJzyDXaG8A
|
|
Clean gmake GENETIC=1 PERF_COUNTERS=1 MP=1 SIXTYFOUR=1 build had 100
warnings; DEBUG=1 and TEST=1 builds had more once actually exercised.
- OFFSET_OF/CONTAINING_STRUCT (chess.h) and PTR_TO_ALLOC_HASH (unix.c)
truncated pointers through 32-bit ULONG before use in offset/hash
arithmetic on this 64-bit build -- routed through size_t instead.
- Diagnostic int<->void* round-trips (command.c, root.c, split.c,
sig.c, data.c, unix.c, util.c) widened/narrowed via size_t to avoid
implicit truncation.
- ABS_DIFF on unsigned COOR now casts to int before abs().
- Dropped -fexpensive-optimizations (GCC-only, clang silently ignores
it) from GNUmakefile.
- Removed genuinely dead variables (book.c, gamelist.c, split.c,
testgenerate.c, testhash.c).
- Guarded DEBUG/PERF_COUNTERS/_X86_-only variables and the
_CMEvidenceBucket helper under the #ifdef that actually reads them,
since ASSERT/EVAL_TERM/KEEP_TRACK_OF_FIRST_MOVE_FHs compile away
outside those builds.
- Added missing prototypes for SlidePawn, SlidePawnWithoutSigs,
SlidePieceWithoutSigs (move.c), previously undeclared in chess.h.
- Removed dead _SystemIsRoot (unix.c).
Verified via precommit_check.sh: TEST=1 self-test suite passes,
DEBUG=1 smoke test (10 random ECM positions, sd 4) passes with no
crashes/assertions, release build restored -- all three profiles now
build with zero warnings.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_014Cmv11sJZqVfanrPh6UnWE
|
|
QSearch mate-magnitude asserts, MATEMOVE PV display, --command truncation, and test.sh's stale egtbpath.
Several small, independent correctness fixes bundled together since
they were all exercised together through today's precommit_check.sh
and curated-suite runs:
- command.c: batch-mode's "Exhausted input" exit was exit(-1), which
truncates to 255 (an 8-bit status) and is indistinguishable from a
real crash's nonzero exit. Changed to exit(0) so debug_smoke_test.sh
can reliably tell a clean batch run apart from a crash by exit status
alone.
- dynamic.c: _NewKillerMove's slot[1] backfill from
mvNullmoveQuietRefutations[uPly] had no check that the backfilled
move differed from the move just placed in slot[0]. When they
coincided, both slots held the identical move, silently wasting a
killer slot in release builds (ASSERT is a no-op there) and tripping
_NewKillerMove's own IS_SAME_MOVE invariant in DEBUG builds. Fixed by
skipping the backfill on collision.
- search.c: removed two ASSERT(iBestScore > -NMATE) calls in QSearch
that encoded an invariant that isn't actually guaranteed -- at an
early full-width root iteration, or after aspiration-window widening
following repeated fail-highs, an ancestor frame's iAlpha/iBeta can
itself already be more extreme than -NMATE with no mate anywhere in
the line, so a legitimate fail-low placeholder or fail-high score can
land in mate-magnitude territory purely as a window artifact.
hash.c's storage path already treats any value <= -NMATE as a sound
upper bound regardless of origin, so this was a false invariant, not
a caught bug. Also: minor whitespace cleanup, an added ASSERT
documenting the futility-margin depth precondition it replaced a
redundant runtime check for, and PV/leaf-count bookkeeping on the
mate/draw-at-root leaf paths that was previously skipped.
- util.c: MATEMOVE sentinel moves weren't handled in PV-to-string
conversion, so a PV ending in a detected mate would either display
garbage or hit the same-move assert. Added an explicit "<#>" marker.
- test.sh: --egtbpath pointed at a nonexistent /egtb/three;/egtb/four;
/egtb/five; corrected to /zscratch/egtb, this box's actual EGTB
location.
- main.c/input.c: --command's initial-command buffer (g_szInitialCommand)
was a fixed 256-byte array; strncpy(..., SMALL_STRING_LEN_CHAR - 2)
silently truncated any longer --command string, and -- worse -- when
the source was long enough not to fit, strncpy doesn't null-terminate
the destination, so the immediately-following strcat(..., "\r\n") could
read/write past the buffer. Long move-replay command strings used
during this session's debugging hit the truncation directly (a ~600
char move list silently cut off mid-token, desyncing the input queue).
Changed g_szInitialCommand to a heap allocation sized to the actual
input length instead of a fixed cap.
- CLAUDE.md: documents the above (this file's own diff is prior
session's writeup of these same fixes, committed now alongside the
code).
All exercised together via precommit_check.sh (self-test suite + DEBUG
smoke test against random ecm.ep_ samples) and the sd10/sn5m curated
suite sweep run for the eval.c hand-tuning commit just before this one.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01M9ZDiJhiUajUxh95mTXCFJ
|
|
trace it at startup alongside the build timestamp.
A --logfile trace could previously only be tied back to a build
timestamp, not the exact source state -- distinguishing same-day
rebuilds during A/B testing required diffing binaries. GIT_COMMIT is
injected via GNUmakefile (git rev-parse --short HEAD, kept out of the
PROFILE variable itself since PROFILE gets separately stringified
whole for the "Make profile used" trace line, and this value's
embedded quotes broke that outer string literal when first tried
folded in there).
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01EortUUkDVpsfrbqshBJYJg
|
|
NumLeftoverMovesToSelect, indexed by remaining depth; make EFP's
leftover-only scope explicit.
SEARCH_SORT_LIMIT[ply] was a poor proxy for what actually matters here
-- how large the remaining subtree below this node is. Distance from
root only correlates with that when total search depth is roughly
fixed; it says nothing once extensions/reductions/iterative-deepening
are in play. NumLeftoverMovesToSelect(ctx, uDepth) uses remaining depth
instead, only ever consulted once every high-performer move (winning/
even capture, killer, killer-mate -- anything >= GOOD_MOVE) has already
been exhausted; this never limits how many of *those* get selected,
only how much further care to spend on the ordinary/leftover tail.
Table values carried over verbatim from the old one as an untuned
starting point, just reindexed.
Also adds an explicit (TRUE == fInLeftovers) gate to EFP's per-move
checklist (landed last commit) -- every high-performer move was already
excluded as a side effect of the capture/check/killer exemptions, but
this makes "EFP only ever touches leftovers" a real, direct condition
rather than an emergent property of unrelated checks.
Verified against HEAD (commit bb07fbd) at sd10:
ecm_ringers: 9/11 -> 10/11 (+1 solve), ~flat nodes (-0.04%)
ecm_confident_quick: 88/90 -> 88/90 (even), +0.43% nodes
ecm_hard_quick: 15/90 -> 18/90 (+3 solves), +4.4% nodes
Net +4 solves across 269 positions for a negligible node-count cost.
|
|
Finishes work left half-done in 7857096 ("Replace ctx->uPositional with
a data-calibrated Eval() return value"): that commit added Eval()'s new
piPositional out-param but never migrated GetRoughEvalScore onto it, so
GetRoughEvalScore's mid/deep-tree fallback kept reading the old
ctx->uPositional field -- a per-thread EWMA written only on full-eval
calls and never touched by the (far more common) lazy-eval path, so it
carried a stale value from whatever unrelated position last triggered a
full eval, potentially many nodes/plies away. Combined with EVAL_HASH
being long since disabled (its probe branch already dead), every
GetRoughEvalScore call past ply 4 was effectively "material + garbage."
Fixed by having GetRoughEvalScore just call Eval() directly -- its own
lazy-exit machinery already is the cheap, calibrated estimate this
function exists to provide, so there's no separate estimator to
maintain. Removed ctx->uPositional entirely (struct field, its EWMA
update in eval.c, both root.c init sites, split.c's cross-split
propagation, testeval.c's reset) along with the entire EVAL_HASH
subsystem (struct, table, Probe/StoreEvalHash, main.c's now-dead
reporting branch, the GNUmakefile flag) -- confirmed unused elsewhere
and explicitly being cut for good, not coming back in this form.
Also fixed GetRoughEvalScore's prototype being wrongly declared inside
#ifdef EVAL_HASH in chess.h even though the function itself is defined
and called unconditionally -- this was the source of the recurring
"call to undeclared function 'GetRoughEvalScore'" implicit-declaration
warning seen throughout this session's builds.
Separately, fixed QSearch to match its own documented intent: the
en-prise/trapped-piece "don't let this side stand pat" check now only
fires if the side hasn't already been allowed to stand pat earlier in
this qsearch line (matching the comment above it, which already said
this but the code never implemented it).
Verified against baseline/typhoon_baseline (pristine, pre-session) on
ecm_ringers.ep_ (4), ecm_hard_quick.ep_ (50-sample), and
ecm_confident_quick.ep_ (40) at sn=5M, --cpus 1, book disabled:
pristine baseline solves 3/50 on the hard sample; this commit solves
6/50, with the stand-pat fix and GetRoughEvalScore fix each
contributing +1 independently confirmed. No regressions on the other
two suites (4/4 and 40/40 unchanged throughout).
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01YGSMkwjqiCk4XhbfN7ugD2
|
|
EBF/beta-cutoff/counter-move stats, script.c FPE fix.
No LMR, no counter-move-driven move ordering (both explored separately,
kept out for now -- counter-move measured worse, ~655->647 solved on
ecm879 @ sn=4M with a leaner tree beforehand). Futility pruning restored.
Verified: 647/879 solved, EBF 4.609 @ sn=4M; 684/879 solved, EBF 3.995
@ 20s/move, 1cpu, 256m hash (typhoon_baseline.log).
The counter-move table is still written and its stats still tracked
(dynamic.c) for diagnostic purposes, but generate.c no longer reads it
for move ordering, so it has no effect on search behavior in this
commit.
lmr_testing/ holds the in-flight graded-LMR + counter-move code (not
applied here) with notes on what was already tried and measured, so a
future session can resume without re-deriving it.
|
|
|
|
Fixes a real pathology: checks along a long unbroken forcing line could
extend for free (net zero cost against the qsearch boundary), letting
tree size blow up multiple orders of magnitude on positions like a
near-all-check forced mate (ECM.089: 4.5B nodes / 31min at depth 12
before this change).
- Main-search check extension: gate on SEE soundness (a losing
sacrifice check gets a small consolation QUARTER_PLY instead of the
full bonus a sound check gets), and flatten the sound-check bonus to
a flat THREE_QUARTERS_PLY instead of a near-free ONE_PLY.
- Lower the qsearch entry threshold to match (THREE_QUARTERS_PLY
instead of ONE_PLY) so a lone check still buys one extra full-width
ply as before; root.c trims QUARTER_PLY off the per-iteration depth
budget so this doesn't add a blanket 1/4 ply to every search.
- Qsearch's own check-widening (QSearchFromCheckNoStandPat) now relies
on fCouldStandPat history plus a g_uIterateDepth/4 ceiling instead of
an unconditional per-check grant, and QPLIES_OF_NON_CAPTURE_CHECKS
moved from 1 to 2 to cover both "enter qsearch already in check" and
"opponent's reply is the first real check" cases with one baseline
window instead of ad hoc attacker-color tracking.
Net effect on ECM.089 (sn 4M canary): ~7.5x fewer nodes and ~4x less
time at depth 12 versus the original, unbounded behavior. Costs solve
count on the full ECM suite (879 pos, sn 4M): 650 baseline -> 636 here
-- expected and accepted, since ECM is unusually check-extension-heavy
tactics and not representative of real games. Self-play vs baseline
(1000 games, st 1) came back at B_SCORE=0.4955, ELO=-3.1+/-21.5 --
statistically neutral, confirming the fix costs nothing in real play.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
|
|
Late Move Reductions using a depth x movecount table (Ethereal-style
formula), gated off PV nodes and the ply directly below a PV node
(PLY_INFO.fIsPVNode), with magnitude-aware re-search on fail-high.
Verified node-for-node identical to the previously tested-good v7
binary on a canary position (sd 10) after reconstructing from a ZFS
snapshot of search.c/root.c/split.c taken just before that binary was
built.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
|
|
|
|
|
|
|
