X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fbitcount.h;h=9d25a5e5c1b4d7b7bd19c0bd0cd60234209741a5;hb=1b2af05ea69abffff432f7f20685e144bd24055e;hp=12826a9f9a05472c6e48066c202b55e0eea158ea;hpb=3376c68f4bb83dc9fd874eb9d710dab09609ae54;p=stockfish
diff --git a/src/bitcount.h b/src/bitcount.h
index 12826a9f..9d25a5e5 100644
--- a/src/bitcount.h
+++ b/src/bitcount.h
@@ -1,7 +1,7 @@
/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2009 Marco Costalba
+ Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, 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
@@ -18,88 +18,49 @@
along with this program. If not, see .
*/
-
#if !defined(BITCOUNT_H_INCLUDED)
#define BITCOUNT_H_INCLUDED
-#include "bitboard.h"
-
-
-// Select type of software bit count function to use
-
-#if !defined(AUTO_CONFIGURATION) || defined(IS_64BIT)
-
-//#define USE_COMPACT_ROOK_ATTACKS
-//#define USE_32BIT_ATTACKS
-#define USE_FOLDED_BITSCAN
-
-#define BITCOUNT_SWAR_64
-//#define BITCOUNT_SWAR_32
-//#define BITCOUNT_LOOP
-
-#else
-
-#define USE_32BIT_ATTACKS
-#define USE_FOLDED_BITSCAN
-#define BITCOUNT_SWAR_32
-
-#endif
-
-
-// Select type of intrinsic bit count instruction to use
-
-#if defined(_MSC_VER) // Microsoft compiler
-
-#include
-
-inline bool cpu_has_popcnt() {
-
- int CPUInfo[4] = {-1};
- __cpuid(CPUInfo, 0x00000001);
- return (CPUInfo[2] >> 23) & 1;
-}
-
-#define POPCNT_INTRINSIC(x) __popcnt64(x)
-
-#elif defined(__INTEL_COMPILER) && (defined(__x86_64) || defined(_M_X64)) // Intel compiler
-
-#include
-
-inline bool cpu_has_popcnt() {
-
- int CPUInfo[4] = {-1};
- __cpuid(CPUInfo, 0x00000001);
- return (CPUInfo[2] >> 23) & 1;
-}
-
-#define POPCNT_INTRINSIC(x) _mm_popcnt_u64(x)
-
-#else // Safe fallback for unsupported compilers
-
-inline bool cpu_has_popcnt() { return false; }
+#include
+#include "types.h"
-#define POPCNT_INTRINSIC(x) sw_count_1s(x)
-
-#endif
+enum BitCountType {
+ CNT_64,
+ CNT_64_MAX15,
+ CNT_32,
+ CNT_32_MAX15,
+ CNT_HW_POPCNT
+};
+/// Determine at compile time the best popcount<> specialization according if
+/// platform is 32 or 64 bits, to the maximum number of nonzero bits to count or
+/// use hardware popcnt instruction when 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;
-/// Software implementation of bit count functions
-#if defined(BITCOUNT_LOOP)
+/// popcount() counts the number of nonzero bits in a bitboard
+template inline int popcount(Bitboard);
-inline int sw_count_1s(Bitboard b) {
- int r;
- for(r = 0; b; r++, b &= b - 1);
- return r;
+template<>
+inline int popcount(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 sw_count_1s_max_15(Bitboard b) {
- return count_1s(b);
+template<>
+inline int popcount(Bitboard b) {
+ b -= (b>>1) & 0x5555555555555555ULL;
+ b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
+ b *= 0x1111111111111111ULL;
+ return int(b >> 60);
}
-#elif defined(BITCOUNT_SWAR_32)
-
-inline int sw_count_1s(Bitboard b) {
+template<>
+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;
@@ -111,7 +72,8 @@ inline int sw_count_1s(Bitboard b) {
return int(v >> 24);
}
-inline int sw_count_1s_max_15(Bitboard b) {
+template<>
+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;
@@ -122,41 +84,29 @@ inline int sw_count_1s_max_15(Bitboard b) {
return int(v >> 28);
}
-#elif defined(BITCOUNT_SWAR_64)
+template<>
+inline int popcount(Bitboard b) {
-inline int sw_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);
-}
+#if !defined(USE_POPCNT)
-inline int sw_count_1s_max_15(Bitboard b) {
- b -= (b>>1) & 0x5555555555555555ULL;
- b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
- b *= 0x1111111111111111ULL;
- return int(b >> 60);
-}
+ assert(false);
+ return int(b != 0); // Avoid 'b not used' warning
-#endif // BITCOUNT
+#elif defined(_MSC_VER) && defined(__INTEL_COMPILER)
+ return _mm_popcnt_u64(b);
-/// count_1s() counts the number of nonzero bits in a bitboard.
-/// If template parameter is true an intrinsic is called, otherwise
-/// we fallback on a software implementation.
+#elif defined(_MSC_VER)
-template
-inline int count_1s(Bitboard b) {
+ return (int)__popcnt64(b);
- return UseIntrinsic ? POPCNT_INTRINSIC(b) : sw_count_1s(b);
-}
+#else
-template
-inline int count_1s_max_15(Bitboard b) {
+ unsigned long ret;
+ __asm__("popcnt %1, %0" : "=r" (ret) : "r" (b));
+ return ret;
- return UseIntrinsic ? POPCNT_INTRINSIC(b) : sw_count_1s_max_15(b);
+#endif
}
-
#endif // !defined(BITCOUNT_H_INCLUDED)