In Movepicker c'tor we access during initialization one of
MainSearchPhaseIndex..QsearchWithoutChecksPhaseIndex globals.
Postpone definition of PhaseTable[] just after them so that
when PhaseTable[] will be accessed later in get_next_move()
it will be already present in L1/L2.
It works like an implicit prefetching of PhaseTable[].
Also shrink PhaseTable[] to fit an L1 cache line of 16 bytes
using uint8_t instead of int.
This apparentely innocuous patch gives an astonish speed
up of 1.6% under MSVC 2010 beta, pgo optimized !
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
- MovePicker::MovegenPhase PhaseTable[32];
int MainSearchPhaseIndex;
int EvasionsPhaseIndex;
int QsearchWithChecksPhaseIndex;
int QsearchWithoutChecksPhaseIndex;
int MainSearchPhaseIndex;
int EvasionsPhaseIndex;
int QsearchWithChecksPhaseIndex;
int QsearchWithoutChecksPhaseIndex;
+ uint8_t PhaseTable[32];
+// Cache line alignment specification
+#if defined(_MSC_VER) || defined(__INTEL_COMPILER)
+#define CACHE_LINE_ALIGNMENT __declspec(align(64))
+#else
+#define CACHE_LINE_ALIGNMENT __attribute__ ((aligned(64)))
+#endif
+
#endif // !defined(TYPES_H_INCLUDED)
#endif // !defined(TYPES_H_INCLUDED)