X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;ds=sidebyside;f=src%2Ftt.cpp;h=0396b287cc5734b9517569e1124f91ddf0fcde73;hb=f4140ecc0c78d3d89f4e2459105e3ce3a1ab3ce1;hp=f2313eabf1c72eee350de8cdda7038519944d222;hpb=cd4604b05c2d61928b26ab50c5864c36ef1d3785;p=stockfish diff --git a/src/tt.cpp b/src/tt.cpp index f2313eab..0396b287 100644 --- a/src/tt.cpp +++ b/src/tt.cpp @@ -25,15 +25,19 @@ #include #include #include -#include #include "movegen.h" #include "tt.h" +#if defined(_MSC_VER) +#include +#endif -/// This is the number of TTEntry slots for each position -static const int ClusterSize = 5; +// This is the number of TTEntry slots for each position +static const int ClusterSize = 4; +// The main transposition table +TranspositionTable TT; //// //// Functions @@ -93,6 +97,16 @@ void TranspositionTable::clear() { } +/// TranspositionTable::first_entry returns a pointer to the first +/// entry of a cluster given a position. The low 32 bits of the key +/// are used to get the index in the table. + +inline TTEntry* TranspositionTable::first_entry(const Key posKey) const { + + return entries + ((uint32_t(posKey) & (size - 1)) * ClusterSize); +} + + /// TranspositionTable::store writes a new entry containing a position, /// a value, a value type, a search depth, and a best move to the /// transposition table. Transposition table is organized in clusters of @@ -145,7 +159,7 @@ void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d, TTEntry* TranspositionTable::retrieve(const Key posKey) const { uint32_t posKey32 = posKey >> 32; - TTEntry *tte = first_entry(posKey); + TTEntry* tte = first_entry(posKey); for (int i = 0; i < ClusterSize; i++, tte++) if (tte->key() == posKey32) @@ -154,6 +168,7 @@ TTEntry* TranspositionTable::retrieve(const Key posKey) const { return NULL; } + /// TranspositionTable::prefetch looks up the current position in the /// transposition table and load it in L1/L2 cache. This is a non /// blocking function and do not stalls the CPU waiting for data @@ -163,17 +178,16 @@ TTEntry* TranspositionTable::retrieve(const Key posKey) const { void TranspositionTable::prefetch(const Key posKey) const { +#if defined(_MSC_VER) _mm_prefetch((char*)first_entry(posKey), _MM_HINT_T0); +#else + // We need to force an asm volatile here because gcc builtin + // is optimized away by Intel compiler. + char* addr = (char*)first_entry(posKey); + asm volatile("prefetcht0 %0" :: "m" (addr)); +#endif } -/// TranspositionTable::first_entry returns a pointer to the first -/// entry of a cluster given a position. The low 32 bits of the key -/// are used to get the index in the table. - -inline TTEntry* TranspositionTable::first_entry(const Key posKey) const { - - return entries + ((uint32_t(posKey) & (size - 1)) * ClusterSize); -} /// TranspositionTable::new_search() is called at the beginning of every new /// search. It increments the "generation" variable, which is used to