HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-20 17:16:33 +08:00
Code Issues Packages Projects Releases Wiki Activity

Make engine ONE_PLY value independent

Browse Source 
This non-functional change patch is a deep work to allow SF to be independent
from the actual value of ONE_PLY (currently set to 1). I have verified SF is
now independent for ONE_PLY values 1, 2, 4, 8, 16, 32 and 256.

This patch gives consistency to search code and enables future work, opening
the door to safely tweaking the ONE_PLY value for any reason.

Verified for no speed regression at STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 95643 W: 17728 L: 17737 D: 60178

No functional change.
This commit is contained in:
Marco Costalba
2016-08-19 12:17:38 +02:00
parent 133808851d
commit 4c5cbb1b14
4 changed files with 45 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
src/tt.h
View File

@@ -39,18 +39,20 @@ struct TTEntry {
Move move() const { return (Move )move16; }
Value value() const { return (Value)value16; }
Value eval() const { return (Value)eval16; }
Depth depth() const { return (Depth)depth8; }
Depth depth() const { return (Depth)(depth8 * ONE_PLY); }
Bound bound() const { return (Bound)(genBound8 & 0x3); }
void save(Key k, Value v, Bound b, Depth d, Move m, Value ev, uint8_t g) {
assert(d / ONE_PLY * ONE_PLY == d);
// Preserve any existing move for the same position
if (m || (k >> 48) != key16)
move16 = (uint16_t)m;
// Don't overwrite more valuable entries
if ( (k >> 48) != key16
|| d > depth8 - 4
|| d / ONE_PLY > depth8 - 4
/* || g != (genBound8 & 0xFC) // Matching non-zero keys are already refreshed by probe() */
|| b == BOUND_EXACT)
{
@@ -58,7 +60,7 @@ struct TTEntry {
value16 = (int16_t)v;
eval16 = (int16_t)ev;
genBound8 = (uint8_t)(g | b);
depth8 = (int8_t)d;
depth8 = (int8_t)(d / ONE_PLY);
}
}