From: Marco Costalba <mcostalba@gmail.com>
Date: Wed, 17 Mar 2010 17:09:37 +0000 (+0100)
Subject: Fix POPCNT detection gcc compile error
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=49c50399fe39b7b80ebe1cba1b986e8759633e51

Fix POPCNT detection gcc compile error

Also don't use __cpuid() intrinsic for Intel under
Linux because gives wrong results when detecting HT,
use the gcc version instead. Finally clean up the code.

Error was due to changed __cpuid() signature for
gcc compiler.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
---

diff --git a/src/bitcount.h b/src/bitcount.h
index 43895180..ec638d40 100644
--- a/src/bitcount.h
+++ b/src/bitcount.h
@@ -26,50 +26,18 @@
 
 // Select type of intrinsic bit count instruction to use, see
 // README.txt on how to pgo compile with POPCNT support.
-
-#if defined(__INTEL_COMPILER) && defined(USE_POPCNT) // Intel compiler
-
-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)
-
-#elif defined(_MSC_VER) && defined(USE_POPCNT) // Microsoft compiler
-
-inline bool cpu_has_popcnt() {
-
-  int CPUInfo[4] = {-1};
-  __cpuid(CPUInfo, 0x00000001);
-  return (CPUInfo[2] >> 23) & 1;
-}
-
+#if !defined(USE_POPCNT)
+#define POPCNT_INTRINSIC(x) 0
+#elif defined(_MSC_VER)
 #define POPCNT_INTRINSIC(x) (int)__popcnt64(x)
-
-#elif defined(__GNUC__) && defined(USE_POPCNT) // Gcc compiler
-
-inline bool cpu_has_popcnt() {
-
-  unsigned int eax, ebx, ecx, edx;
-  __cpuid(1, &eax, &ebx, &ecx, &edx);
-  return (ecx >> 23) & 1;
-}
+#elif defined(__GNUC__)
 
 #define POPCNT_INTRINSIC(x) ({ \
    unsigned long __ret; \
    __asm__("popcnt %1, %0" : "=r" (__ret) : "r" (x)); \
    __ret; })
 
-#else // Safe fallback for unsupported compilers or when USE_POPCNT is disabled
-
-inline bool cpu_has_popcnt() { return false; }
-
-#define POPCNT_INTRINSIC(x) 0
-
-#endif // cpu_has_popcnt() and POPCNT_INTRINSIC() definitions
+#endif
 
 
 /// Software implementation of bit count functions
@@ -136,10 +104,23 @@ inline int count_1s_max_15(Bitboard 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
diff --git a/src/types.h b/src/types.h
index 3d0305de..27e2f1dd 100644
--- a/src/types.h
+++ b/src/types.h
@@ -75,9 +75,7 @@ typedef uint64_t Bitboard;
 
 // Define a __cpuid() function for gcc compilers, for Intel and MSVC
 // is already available as an intrinsic.
-#if defined(__INTEL_COMPILER)
-#include <nmmintrin.h>
-#elif defined(_MSC_VER)
+#if defined(_MSC_VER)
 #include <intrin.h>
 #elif defined(__GNUC__)
 inline void __cpuid(int CPUInfo[4], int InfoType)