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Revert LMR reduction based on thinking time

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After 500 games at 5+0 on my QUAD (3 days) there
is no difference with old version, so probably it
is a feature that doesn't scale with search depth.

So revert for now, perhaps we should readd under a
different form.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba 2010-03-28 12:04:41 +01:00
parent 8fabd69d4a
commit 2a14123550
1 changed files with 13 additions and 38 deletions
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51
src/search.cpp
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@ -215,14 +215,12 @@ namespace {
// Step 14. Reduced search
int ReductionLevel; // 0 = most aggressive reductions, 7 = minimum reductions
// Reduction lookup tables (initialized at startup) and their getter functions
int8_t PVReductionMatrix[8][64][64]; // [depth][moveNumber]
int8_t NonPVReductionMatrix[8][64][64]; // [depth][moveNumber]
int8_t PVReductionMatrix[64][64]; // [depth][moveNumber]
int8_t NonPVReductionMatrix[64][64]; // [depth][moveNumber]
inline Depth pv_reduction(Depth d, int mn) { return (Depth) PVReductionMatrix[ReductionLevel][Min(d / 2, 63)][Min(mn, 63)]; }
inline Depth nonpv_reduction(Depth d, int mn) { return (Depth) NonPVReductionMatrix[ReductionLevel][Min(d / 2, 63)][Min(mn, 63)]; }
inline Depth pv_reduction(Depth d, int mn) { return (Depth) PVReductionMatrix[Min(d / 2, 63)][Min(mn, 63)]; }
inline Depth nonpv_reduction(Depth d, int mn) { return (Depth) NonPVReductionMatrix[Min(d / 2, 63)][Min(mn, 63)]; }
// Common adjustments
@ -546,30 +544,20 @@ bool think(const Position& pos, bool infinite, bool ponder, int side_to_move,
return !Quit;
}
// init_reduction_tables() is called by init_search() and initializes
// the tables used by LMR.
static void init_reduction_tables(int8_t pvTable[64][64], int8_t nonPvTable[64][64], int pvInhib, int nonPvInhib)
{
double pvBase = 1.001 - log(3.0) * log(16.0) / pvInhib;
double nonPvBase = 1.001 - log(3.0) * log(4.0) / nonPvInhib;
/// init_search() is called during startup. It initializes various lookup tables
void init_search() {
// Init our reduction lookup tables
for (int i = 1; i < 64; i++) // i == depth (OnePly = 1)
for (int j = 1; j < 64; j++) // j == moveNumber
{
double pvRed = pvBase + log(double(i)) * log(double(j)) / pvInhib;
double nonPVRed = nonPvBase + log(double(i)) * log(double(j)) / nonPvInhib;
pvTable[i][j] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(OnePly)) : 0);
nonPvTable[i][j] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(OnePly)) : 0);
double pvRed = 0.5 + log(double(i)) * log(double(j)) / 6.0;
double nonPVRed = 0.5 + log(double(i)) * log(double(j)) / 3.0;
PVReductionMatrix[i][j] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(OnePly)) : 0);
NonPVReductionMatrix[i][j] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(OnePly)) : 0);
}
}
// init_search() is called during startup. It initializes various lookup tables
void init_search() {
// Init reduction lookup tables
for (int i = 0; i < 8; i++)
init_reduction_tables(PVReductionMatrix[i], NonPVReductionMatrix[i], int(4 * pow(1.3, i)), int(2 * pow(1.3, i)));
// Init futility margins array
for (int i = 0; i < 16; i++) // i == depth (OnePly = 2)
@ -672,19 +660,6 @@ namespace {
beta = Min(ValueByIteration[Iteration - 1] + AspirationDelta, VALUE_INFINITE);
}
// Choose optimum reduction level
ReductionLevel = 2;
if (UseTimeManagement)
{
int level = int(floor(log(float(MaxSearchTime) / current_search_time()) / log(2.0) + 1.0));
ReductionLevel = Min(Max(level, 0), 7);
}
else
{
//FIXME
}
// Search to the current depth, rml is updated and sorted, alpha and beta could change
value = root_search(p, ss, rml, &alpha, &beta);