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Export search tunables to tuned.hpp in preparation to SPSA run #335

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Merged
TheRealGioviok merged 2 commits into from
Dec 4, 2025
Merged

Export search tunables to tuned.hpp in preparation to SPSA run #335

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464f4d7
Bench: 11856625
TheRealGioviok Dec 3, 2025
46c534f
lel
TheRealGioviok Dec 4, 2025
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80 changes: 47 additions & 33 deletions src/search.cpp
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Original file line number Diff line number Diff line change
@@ -1,4 +1,3 @@

#include "search.hpp"
#include "board.hpp"
#include "common.hpp"
Expand Down Expand Up @@ -29,7 +28,9 @@ static Value mated_in(i32 ply) {
}

static constexpr i32 stat_bonus(Depth bonus_depth) {
return std::min(1896, 4 * bonus_depth * bonus_depth + 120 * bonus_depth - 120);
return std::min(tuned::stat_bonus_max, tuned::stat_bonus_quad * bonus_depth * bonus_depth
+ tuned::stat_bonus_lin * bonus_depth
- tuned::stat_bonus_sub);
}

std::ostream& operator<<(std::ostream& os, const PV& pv) {
Expand Down Expand Up @@ -256,7 +257,7 @@ Move Worker::iterative_deepening(const Position& root_position) {
// Call search
m_seldepth = 0;
Value alpha = -VALUE_INF, beta = VALUE_INF;
Value delta = 50;
Value delta = tuned::asp_window_delta;
if (search_depth >= 5) {
alpha = last_search_score - delta;
beta = last_search_score + delta;
Expand Down Expand Up @@ -504,8 +505,8 @@ Value Worker::search(
}

// Razoring
if (!PV_NODE && !excluded && !is_in_check && depth <= 7
&& ss->static_eval + 707 * depth < alpha) {
if (!PV_NODE && !excluded && !is_in_check && depth <= tuned::razor_depth
&& ss->static_eval + tuned::razor_margin * depth < alpha) {
const Value razor_score = quiesce<IS_MAIN>(pos, ss, alpha, beta, ply);
if (razor_score <= alpha) {
return razor_score;
Expand All @@ -521,7 +522,8 @@ Value Worker::search(
// node will also fail high (score >= beta) and prune the remaining moves,
// returning the cutoff score immediately. This saves time by not searching
// moves in positions that are likely to be cutoffs anyway.
if (!PV_NODE && !is_in_check && depth >= 5 && !excluded && !is_mate_score(beta)) {
if (!PV_NODE && !is_in_check && depth >= tuned::probcut_min_depth && !excluded
&& !is_mate_score(beta)) {
const Value probcut_beta = beta + tuned::probcut_margin;
const Depth probcut_depth = std::clamp<Depth>(depth - 4, 1, depth - 1);

Expand Down Expand Up @@ -584,34 +586,38 @@ Value Worker::search(

if (!ROOT_NODE && !is_being_mated_score(best_value)) {
// Late Move Pruning (LMP)
if (moves_played >= (3 + depth * depth) / (2 - improving)) {
if (moves_played >= (tuned::lmp_depth_mult + depth * depth) / (2 - improving)) {
break;
}

// Forward Futility Pruning (FFP)
Value futility = ss->static_eval + 500 + 100 * depth + move_history / 32;
if (quiet && !is_in_check && depth <= 8 && futility <= alpha) {
Value futility = ss->static_eval + tuned::ffp_margin_base
+ tuned::ffp_margin_mult * depth + move_history / tuned::ffp_hist_div;
if (quiet && !is_in_check && depth <= tuned::ffp_depth && futility <= alpha) {
moves.skip_quiets();
continue;
}

// Quiet History Pruning
if (depth <= 4 && !is_in_check && quiet && move_history < depth * -2048) {
if (depth <= tuned::qhp_depth && !is_in_check && quiet
&& move_history < depth * tuned::qhp_threshold) {
break;
}

Value see_threshold = quiet ? -67 * depth : -22 * depth * depth;
Value see_threshold =
quiet ? tuned::see_pvs_quiet * depth : tuned::see_pvs_noisy_quad * depth * depth;
// SEE PVS Pruning
if (!SEE::see(pos, m, see_threshold - move_history * 20 / 1024)) {
if (!SEE::see(pos, m, see_threshold - move_history * tuned::see_pvs_hist_mult / 1024)) {
continue;
}
}

// Singular extensions
int extension = 0;
if (!excluded && tt_data && m == tt_data->move && depth >= 6 && tt_data->depth >= depth - 3
if (!excluded && tt_data && m == tt_data->move && depth >= tuned::sing_min_depth
&& tt_data->depth >= depth - tuned::sing_depth_margin
&& tt_data->bound() != Bound::Upper) {
Value singular_beta = tt_data->score - depth * 5;
Value singular_beta = tt_data->score - depth * tuned::sing_beta_margin;
int singular_depth = depth / 2;

ss->excluded_move = m;
Expand All @@ -623,13 +629,15 @@ Value Worker::search(
extension = 1;

// Double Extension
int double_margin = 40 - (move_history / 512 * quiet);
int double_margin =
tuned::sing_double_margin - (move_history / tuned::sing_hist_div * quiet);
if (!PV_NODE && singular_value <= singular_beta - double_margin) {
extension = 2;
}

// Triple Extension
if (!PV_NODE && quiet && singular_value <= singular_beta - 120) {
if (!PV_NODE && quiet
&& singular_value <= singular_beta - tuned::sing_triple_margin) {
extension = 3;
}
}
Expand Down Expand Up @@ -691,52 +699,58 @@ Value Worker::search(
i32 reduction;

if (quiet) {
reduction =
static_cast<i32>(788 + 208 * log2i(depth) * log2i(moves_played) / (1024 * 1024));
reduction = static_cast<i32>(tuned::lmr_quiet_base
+ tuned::lmr_quiet_div * log2i(depth)
* log2i(moves_played) / (1024 * 1024));
} else {
reduction =
static_cast<i32>(256 + 197 * log2i(depth) * log2i(moves_played) / (1024 * 1024));
reduction = static_cast<i32>(tuned::lmr_noisy_base
+ tuned::lmr_noisy_div * log2i(depth)
* log2i(moves_played) / (1024 * 1024));
}

reduction -= 1024 * PV_NODE;
reduction -= tuned::lmr_pv_node_red * PV_NODE;

reduction += alpha_raises * 512;
reduction += alpha_raises * tuned::lmr_alpha_raise_red;

reduction += (512 * !improving);
reduction += (tuned::lmr_not_improving_red * !improving);

reduction -= 1024 * pos_after.is_in_check();
reduction -= tuned::lmr_in_check_red * pos_after.is_in_check();

if (cutnode) {
reduction += 1024;
reduction += tuned::lmr_cutnode_red;
// If there is no available tt move, increase reduction
if (!tt_data || tt_data->move == Move::none()) {
reduction += 1024;
reduction += tuned::lmr_no_tt_red;
}
}

if (ttpv) {
reduction -= 1024;
reduction -= tuned::lmr_ttpv_red;
}

if (ttpv && tt_data && tt_data->score <= alpha) {
reduction += 1024;
reduction += tuned::lmr_tt_capture_red;
}

if (tt_data && tt_data->move.is_capture() && !m.is_capture()) {
reduction += 1024;
reduction += tuned::lmr_tt_capture_red;
}

if ((ss + 1)->fail_high_count > 3) {
reduction += 1024;
reduction += tuned::lmr_fail_high_red;
}

if (quiet) {
reduction += (1024 - move_history / 8);
reduction += (ss->static_eval + 500 + 100 * depth <= alpha && !is_in_check) * 1024;
reduction += (tuned::lmr_quiet_hist_base - move_history / tuned::lmr_hist_div);
reduction +=
(ss->static_eval + tuned::lmr_fut_red_base + tuned::lmr_fut_red_mult * depth
<= alpha
&& !is_in_check)
* tuned::lmr_fut_red;
}

if (!quiet) {
reduction = std::min(reduction, 3072);
reduction = std::min(reduction, tuned::lmr_max_red);
}

reduction /= 1024;
Expand Down
57 changes: 57 additions & 0 deletions src/tuned.hpp
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -23,11 +23,68 @@ namespace Clockwork::tuned {
/* ProbCut Values */ \
TUNE(probcut_margin, 300, 100, 500, 10, 0.002) \
TUNE(probcut_see, 100, 0, 200, 10, 0.002) \
NO_TUNE(probcut_min_depth, 5, 1, 20, 0.5, 0.002) \
\
/* SEE Values */ \
TUNE(quiesce_see_threshold, 0, -1000, 100, 20, 0.002) \
TUNE(movepicker_see_capthist_divisor, 48, 16, 192, 10, 0.002) \
\
/* Stat Bonus */ \
TUNE(stat_bonus_max, 1896, 948, 3792, 142, 0.002) \
TUNE(stat_bonus_quad, 4, 2, 8, .5, 0.002) \
TUNE(stat_bonus_lin, 120, 60, 240, 9, 0.002) \
TUNE(stat_bonus_sub, 120, 60, 240, 9, 0.002) \
\
/* Search Params */ \
TUNE(asp_window_delta, 50, 25, 100, 4, 0.002) \
NO_TUNE(razor_depth, 7, 1, 20, 0.5, 0.002) \
TUNE(razor_margin, 707, 353, 1414, 53, 0.002) \
NO_TUNE(lmp_depth_mult, 3, 1, 20, 0.5, 0.002) \
\
/* Futility Pruning */ \
TUNE(ffp_margin_base, 500, 250, 1000, 38, 0.002) \
TUNE(ffp_margin_mult, 100, 50, 200, 8, 0.002) \
TUNE(ffp_hist_div, 32, 16, 64, 3, 0.002) \
NO_TUNE(ffp_depth, 8, 1, 20, 0.5, 0.002) \
\
/* Quiet History Pruning */ \
NO_TUNE(qhp_depth, 4, 1, 20, 0.5, 0.002) \
TUNE(qhp_threshold, -2048, -4096, -1024, 154, 0.002) \
\
/* SEE PVS */ \
TUNE(see_pvs_quiet, -67, -134, -33, 5, 0.002) \
TUNE(see_pvs_noisy_quad, -22, -44, -11, 2, 0.002) \
TUNE(see_pvs_hist_mult, 20, 10, 40, 2, 0.002) \
\
/* Singular Extensions */ \
NO_TUNE(sing_min_depth, 6, 1, 20, 0.5, 0.002) \
NO_TUNE(sing_depth_margin, 3, 1, 20, 0.5, 0.002) \
TUNE(sing_beta_margin, 5, 2, 10, 1, 0.002) \
TUNE(sing_double_margin, 40, 20, 80, 3, 0.002) \
TUNE(sing_hist_div, 512, 256, 1024, 39, 0.002) \
TUNE(sing_triple_margin, 120, 60, 240, 9, 0.002) \
\
/* LMR */ \
TUNE(lmr_quiet_base, 788, 394, 1576, 59, 0.002) \
TUNE(lmr_quiet_div, 208, 104, 416, 16, 0.002) \
TUNE(lmr_noisy_base, 256, 128, 512, 20, 0.002) \
TUNE(lmr_noisy_div, 197, 98, 394, 15, 0.002) \
TUNE(lmr_pv_node_red, 1024, 512, 2048, 77, 0.002) \
TUNE(lmr_alpha_raise_red, 512, 256, 1024, 38, 0.002) \
TUNE(lmr_not_improving_red, 512, 256, 1024, 38, 0.002) \
TUNE(lmr_in_check_red, 1024, 512, 2048, 77, 0.002) \
TUNE(lmr_cutnode_red, 1024, 512, 2048, 77, 0.002) \
TUNE(lmr_no_tt_red, 1024, 512, 2048, 77, 0.002) \
TUNE(lmr_ttpv_red, 1024, 512, 2048, 77, 0.002) \
TUNE(lmr_tt_capture_red, 1024, 512, 2048, 77, 0.002) \
TUNE(lmr_fail_high_red, 1024, 512, 2048, 77, 0.002) \
TUNE(lmr_quiet_hist_base, 1024, 512, 2048, 77, 0.002) \
TUNE(lmr_hist_div, 8, 4, 16, 2, 0.002) \
TUNE(lmr_fut_red_base, 500, 250, 1000, 38, 0.002) \
TUNE(lmr_fut_red_mult, 100, 50, 200, 8, 0.002) \
TUNE(lmr_fut_red, 1024, 512, 2048, 77, 0.002) \
TUNE(lmr_max_red, 3072, 1536, 6144, 231, 0.002) \
\
/* End of Tunables */

#define DEFINE_VARIABLE(NAME, DEFAULT, ...) inline i32 NAME = DEFAULT;
Expand Down
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