X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fbitcount.h;h=7609da40c30c2282ecc3dab112a70b7185bbef1d;hb=d4af15f682c1967450233ab62cba1a6c5d601df6;hp=72ee37ca98dc997cf6fd9ed46696752a637c1b1e;hpb=8307da0de77c9c7bbf7c56a7d9c8a688ff4dfb4e;p=stockfish
diff --git a/src/bitcount.h b/src/bitcount.h
index 72ee37ca..7609da40 100644
--- a/src/bitcount.h
+++ b/src/bitcount.h
@@ -1,14 +1,14 @@
/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
-
Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
@@ -18,81 +18,88 @@
along with this program. If not, see .
*/
-#if !defined(BITCOUNT_H_INCLUDED)
+#ifndef BITCOUNT_H_INCLUDED
#define BITCOUNT_H_INCLUDED
+#include
+
#include "types.h"
enum BitCountType {
- CNT64,
- CNT64_MAX15,
- CNT32,
- CNT32_MAX15,
- CNT_POPCNT
+ CNT_64,
+ CNT_64_MAX15,
+ CNT_32,
+ CNT_32_MAX15,
+ CNT_HW_POPCNT
};
-/// count_1s() counts the number of nonzero bits in a bitboard.
-/// We have different optimized versions according if platform
-/// is 32 or 64 bits, and to the maximum number of nonzero bits.
-/// We also support hardware popcnt instruction. See Readme.txt
-/// on how to pgo compile with popcnt support.
-template inline int count_1s(Bitboard);
+/// Determine at compile time the best popcount<> specialization according to
+/// whether the platform is 32 or 64 bit, the maximum number of non-zero
+/// bits to count and if the hardware popcnt instruction is available.
+const BitCountType Full = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64 : CNT_32;
+const BitCountType Max15 = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64_MAX15 : CNT_32_MAX15;
+
+
+/// popcount() counts the number of non-zero bits in a bitboard
+template inline int popcount(Bitboard);
template<>
-inline int count_1s(Bitboard b) {
- b -= ((b>>1) & 0x5555555555555555ULL);
- b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
- b = ((b>>4) + b) & 0x0F0F0F0F0F0F0F0FULL;
- b *= 0x0101010101010101ULL;
- return int(b >> 56);
+inline int popcount(Bitboard b) {
+ b -= (b >> 1) & 0x5555555555555555ULL;
+ b = ((b >> 2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
+ b = ((b >> 4) + b) & 0x0F0F0F0F0F0F0F0FULL;
+ return (b * 0x0101010101010101ULL) >> 56;
}
template<>
-inline int count_1s(Bitboard b) {
- b -= (b>>1) & 0x5555555555555555ULL;
- b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
- b *= 0x1111111111111111ULL;
- return int(b >> 60);
+inline int popcount(Bitboard b) {
+ b -= (b >> 1) & 0x5555555555555555ULL;
+ b = ((b >> 2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
+ return (b * 0x1111111111111111ULL) >> 60;
}
template<>
-inline int count_1s(Bitboard b) {
+inline int popcount(Bitboard b) {
unsigned w = unsigned(b >> 32), v = unsigned(b);
- v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
- w -= (w >> 1) & 0x55555555;
- v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
- w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
- v = ((v >> 4) + v) & 0x0F0F0F0F; // 0-8 in 8 bits
- v += (((w >> 4) + w) & 0x0F0F0F0F); // 0-16 in 8 bits
- v *= 0x01010101; // mul is fast on amd procs
- return int(v >> 24);
+ v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
+ w -= (w >> 1) & 0x55555555;
+ v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
+ w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
+ v = ((v >> 4) + v + (w >> 4) + w) & 0x0F0F0F0F;
+ return (v * 0x01010101) >> 24;
}
template<>
-inline int count_1s(Bitboard b) {
+inline int popcount(Bitboard b) {
unsigned w = unsigned(b >> 32), v = unsigned(b);
- v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
- w -= (w >> 1) & 0x55555555;
- v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
- w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
- v += w; // 0-8 in 4 bits
- v *= 0x11111111;
- return int(v >> 28);
+ v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
+ w -= (w >> 1) & 0x55555555;
+ v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
+ w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
+ return ((v + w) * 0x11111111) >> 28;
}
template<>
-inline int count_1s(Bitboard b) {
-#if !defined(USE_POPCNT)
- return int(b != 0); // Avoid 'b not used' warning
+inline int popcount(Bitboard b) {
+
+#ifndef USE_POPCNT
+
+ assert(false);
+ return b != 0; // Avoid 'b not used' warning
+
#elif defined(_MSC_VER) && defined(__INTEL_COMPILER)
+
return _mm_popcnt_u64(b);
+
#elif defined(_MSC_VER)
+
return (int)__popcnt64(b);
-#elif defined(__GNUC__)
- unsigned long ret;
- __asm__("popcnt %1, %0" : "=r" (ret) : "r" (b));
- return ret;
+
+#else // Assumed gcc or compatible compiler
+
+ return __builtin_popcountll(b);
+
#endif
}
-#endif // !defined(BITCOUNT_H_INCLUDED)
+#endif // #ifndef BITCOUNT_H_INCLUDED