X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitcount.h;h=7a05970d2abcb45a96333a34a070504941ac3b20;hp=4016063383938fe7fbcc9309ff9767a2bfec6a7c;hb=fc234662364386800ec728643d7d6da610a560aa;hpb=e7d3a006cda7822517159cad0ef222eb7e46db00

diff --git a/src/bitcount.h b/src/bitcount.h
index 40160633..7a05970d 100644
--- a/src/bitcount.h
+++ b/src/bitcount.h
@@ -22,33 +22,25 @@
 #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.
 
-// Select type of software bit count function to use
+#if defined(__INTEL_COMPILER) && defined(USE_POPCNT) // Intel compiler
 
-#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
+#include <nmmintrin.h>
 
-#endif
+inline bool cpu_has_popcnt() {
 
+  int CPUInfo[4] = {-1};
+  __cpuid(CPUInfo, 0x00000001);
+  return (CPUInfo[2] >> 23) & 1;
+}
 
-// Select type of intrinsic bit count instruction to use
+#define POPCNT_INTRINSIC(x) _mm_popcnt_u64(x)
 
-#if defined(_MSC_VER) // Microsoft compiler
+#elif defined(_MSC_VER) && defined(USE_POPCNT) // Microsoft compiler
 
 #include <intrin.h>
 
@@ -59,47 +51,63 @@ inline bool cpu_has_popcnt() {
   return (CPUInfo[2] >> 23) & 1;
 }
 
-#define POPCNT_INTRINSIC(x) __popcnt64(x)
+#define POPCNT_INTRINSIC(x) (int)__popcnt64(x)
 
-#elif defined(__INTEL_COMPILER) && (defined(__x86_64) || defined(_M_X64)) // Intel compiler
+#elif defined(__GNUC__) && defined(USE_POPCNT) // Gcc compiler
 
-#include <nmmintrin.h>
+inline void __cpuid(unsigned int op,
+                    unsigned int *eax, unsigned int *ebx,
+                    unsigned int *ecx, unsigned int *edx)
+{
+  *eax = op;
+  *ecx = 0;
+  __asm__("cpuid" : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx)
+                  : "0" (*eax), "2" (*ecx));
+}
 
 inline bool cpu_has_popcnt() {
 
-  int CPUInfo[4] = {-1};
-  __cpuid(CPUInfo, 0x00000001);
-  return (CPUInfo[2] >> 23) & 1;
+  unsigned int eax, ebx, ecx, edx;
+  __cpuid(1, &eax, &ebx, &ecx, &edx);
+  return (ecx >> 23) & 1;
 }
 
-#define POPCNT_INTRINSIC(x) _mm_popcnt_u64(x)
+#define POPCNT_INTRINSIC(x) ({ \
+   unsigned long __ret; \
+   __asm__("popcnt %1, %0" : "=r" (__ret) : "r" (x)); \
+   __ret; })
 
-#else // Safe fallback for unsupported compilers
+#else // Safe fallback for unsupported compilers or when USE_POPCNT is disabled
 
 inline bool cpu_has_popcnt() { return false; }
 
-#define POPCNT_INTRINSIC(x) sw_count_1s(x)
+#define POPCNT_INTRINSIC(x) 0
 
-#endif
+#endif // cpu_has_popcnt() and POPCNT_INTRINSIC() definitions
 
 
 /// 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;
@@ -111,7 +119,7 @@ inline int sw_count_1s(Bitboard b) {
   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;
@@ -122,23 +130,6 @@ inline int sw_count_1s_max_15(Bitboard b) {
   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
 
 
@@ -149,19 +140,28 @@ inline int sw_count_1s_max_15(Bitboard b) {
 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.
-
+// 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.
 const bool CpuHasPOPCNT = cpu_has_popcnt();
 
+
+// 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)