X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fbitcount.h;h=199fcf192bd980b0b4b0eed327dfb843566c2011;hb=351ef5c85b6d4b9c71e9da;hp=ec638d40380ef4f8571b146a6913e7aecab0c1f0;hpb=49c50399fe39b7b80ebe1cba1b986e8759633e51;p=stockfish
diff --git a/src/bitcount.h b/src/bitcount.h
index ec638d40..199fcf19 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) 2008-2010 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
@@ -18,33 +18,28 @@
along with this program. If not, see .
*/
-
#if !defined(BITCOUNT_H_INCLUDED)
#define BITCOUNT_H_INCLUDED
#include "types.h"
-// Select type of intrinsic bit count instruction to use, see
-// README.txt on how to pgo compile with POPCNT support.
-#if !defined(USE_POPCNT)
-#define POPCNT_INTRINSIC(x) 0
-#elif defined(_MSC_VER)
-#define POPCNT_INTRINSIC(x) (int)__popcnt64(x)
-#elif defined(__GNUC__)
-
-#define POPCNT_INTRINSIC(x) ({ \
- unsigned long __ret; \
- __asm__("popcnt %1, %0" : "=r" (__ret) : "r" (x)); \
- __ret; })
-
-#endif
-
-
-/// Software implementation of bit count functions
+enum BitCountType {
+ CNT64,
+ CNT64_MAX15,
+ CNT32,
+ CNT32_MAX15,
+ CNT_POPCNT
+};
-#if defined(IS_64BIT)
-
-inline int count_1s(Bitboard b) {
+/// 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);
+
+template<>
+inline int count_1s(Bitboard b) {
b -= ((b>>1) & 0x5555555555555555ULL);
b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
b = ((b>>4) + b) & 0x0F0F0F0F0F0F0F0FULL;
@@ -52,16 +47,16 @@ inline int count_1s(Bitboard b) {
return int(b >> 56);
}
-inline int count_1s_max_15(Bitboard b) {
+template<>
+inline int count_1s(Bitboard b) {
b -= (b>>1) & 0x5555555555555555ULL;
b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
b *= 0x1111111111111111ULL;
return int(b >> 60);
}
-#else // if !defined(IS_64BIT)
-
-inline int count_1s(Bitboard b) {
+template<>
+inline int count_1s(Bitboard b) {
unsigned w = unsigned(b >> 32), v = unsigned(b);
v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
w -= (w >> 1) & 0x55555555;
@@ -73,7 +68,8 @@ inline int count_1s(Bitboard b) {
return int(v >> 24);
}
-inline int count_1s_max_15(Bitboard b) {
+template<>
+inline int count_1s(Bitboard b) {
unsigned w = unsigned(b >> 32), v = unsigned(b);
v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
w -= (w >> 1) & 0x55555555;
@@ -84,51 +80,19 @@ inline int count_1s_max_15(Bitboard b) {
return int(v >> 28);
}
-#endif // BITCOUNT
-
-
-/// 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.
-
-template
-inline int count_1s(Bitboard b) {
-
- return UseIntrinsic ? POPCNT_INTRINSIC(b) : count_1s(b);
-}
-
-template
-inline int count_1s_max_15(Bitboard b) {
-
- return UseIntrinsic ? POPCNT_INTRINSIC(b) : count_1s_max_15(b);
-}
-
-
-// Detect hardware POPCNT support
-inline bool cpu_has_popcnt() {
-
- int CPUInfo[4] = {-1};
- __cpuid(CPUInfo, 0x00000001);
- return (CPUInfo[2] >> 23) & 1;
-}
-
-
-// Global constant initialized at startup that is set to true if
-// CPU on which application runs supports POPCNT intrinsic. Unless
-// USE_POPCNT is not defined.
-#if defined(USE_POPCNT)
-const bool CpuHasPOPCNT = cpu_has_popcnt();
-#else
-const bool CpuHasPOPCNT = false;
-#endif
-
-
-// Global constant used to print info about the use of 64 optimized
-// functions to verify that a 64 bit compile has been correctly built.
-#if defined(IS_64BIT)
-const bool CpuHas64BitPath = true;
-#else
-const bool CpuHas64BitPath = false;
+template<>
+inline int count_1s(Bitboard b) {
+#if !defined(USE_POPCNT)
+ return int(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;
#endif
+}
#endif // !defined(BITCOUNT_H_INCLUDED)