/*
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
#if !defined(BITCOUNT_H_INCLUDED)
#define BITCOUNT_H_INCLUDED
-#include "bitboard.h"
+#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__)
-// 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 <intrin.h>
-
-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 <nmmintrin.h>
-
-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; }
-
-#define POPCNT_INTRINSIC(x) sw_count_1s(x)
+#define POPCNT_INTRINSIC(x) ({ \
+ unsigned long __ret; \
+ __asm__("popcnt %1, %0" : "=r" (__ret) : "r" (x)); \
+ __ret; })
#endif
/// Software implementation of bit count functions
-#if defined(BITCOUNT_LOOP)
+#if defined(IS_64BIT)
-inline int sw_count_1s(Bitboard b) {
- int r;
- for(r = 0; b; r++, b &= b - 1);
- return r;
+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 sw_count_1s_max_15(Bitboard b) {
- return count_1s(b);
+inline int count_1s_max_15(Bitboard b) {
+ b -= (b>>1) & 0x5555555555555555ULL;
+ b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
+ b *= 0x1111111111111111ULL;
+ return int(b >> 60);
}
-#elif defined(BITCOUNT_SWAR_32)
+#else // if !defined(IS_64BIT)
-inline int sw_count_1s(Bitboard b) {
+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;
return int(v >> 24);
}
-inline int sw_count_1s_max_15(Bitboard b) {
+inline int count_1s_max_15(Bitboard b) {
unsigned w = unsigned(b >> 32), v = unsigned(b);
v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
w -= (w >> 1) & 0x55555555;
return int(v >> 28);
}
-#elif defined(BITCOUNT_SWAR_64)
-
-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);
-}
-
-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);
-}
-
#endif // BITCOUNT
template<bool UseIntrinsic>
inline int count_1s(Bitboard b) {
- return UseIntrinsic ? POPCNT_INTRINSIC(b) : sw_count_1s(b);
+ return UseIntrinsic ? POPCNT_INTRINSIC(b) : count_1s(b);
}
template<bool UseIntrinsic>
inline int count_1s_max_15(Bitboard b) {
- return UseIntrinsic ? POPCNT_INTRINSIC(b) : sw_count_1s_max_15(b);
+ return UseIntrinsic ? POPCNT_INTRINSIC(b) : count_1s_max_15(b);
}
-// Global variable initialized at startup that is set to true if
-// CPU on which application runs support POPCNT intrinsic.
+// 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;
+#endif
#endif // !defined(BITCOUNT_H_INCLUDED)