From 5feba3a7167b54bbebb1bba7159dcbda91b41663 Mon Sep 17 00:00:00 2001
From: Waldemar Pawlaszek <waldemar.pawlaszek@gmail.com>
Date: Sun, 31 Jul 2022 22:26:59 +0200
Subject: [PATCH] More robust popcnt

---
 src/engine/platform/sound/lynx/Mikey.cpp | 105 +++++++++++------------
 1 file changed, 52 insertions(+), 53 deletions(-)

diff --git a/src/engine/platform/sound/lynx/Mikey.cpp b/src/engine/platform/sound/lynx/Mikey.cpp
index 71818003..791336c1 100644
--- a/src/engine/platform/sound/lynx/Mikey.cpp
+++ b/src/engine/platform/sound/lynx/Mikey.cpp
@@ -26,39 +26,11 @@
 #include <algorithm>
 #include <limits>
 
-#if defined(i386) || defined(__i386__) || defined(__i386) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64)
-#define IS_INTEL
-#endif
+#if defined( _MSC_VER )
 
-#ifdef IS_INTEL
-#if defined ( _MSC_VER )
 #include <intrin.h>
 
-static void cpuid( int info[4], int infoType )
-{
-  __cpuidex( info, infoType, 0 );
-}
-
-#else
-#include <cpuid.h>
-
-static void cpuid( int info[4], int infoType )
-{
-  __cpuid_count( infoType, 0, info[0], info[1], info[2], info[3] );
-}
-
-#endif
-#endif
-
-namespace Lynx
-{
-
-namespace
-{
-
-static constexpr int64_t CNT_MAX = std::numeric_limits<int64_t>::max() & ~15;
-
-uint32_t popcnt_generic( uint32_t x )
+static uint32_t popcnt_generic( uint32_t x )
 {
   int v = 0;
   while ( x != 0 )
@@ -69,18 +41,60 @@ uint32_t popcnt_generic( uint32_t x )
   return v;
 }
 
-#ifdef IS_INTEL
-uint32_t popcnt_intrinsic( uint32_t x )
+#if defined( _M_IX86 ) || defined( _M_X64 )
+
+static uint32_t popcnt_intrinsic( uint32_t x )
 {
-#if defined ( _MSC_VER )
   return __popcnt( x );
-#else
-  return __builtin_popcount( x );
-#endif
 }
+
+static uint32_t( *popcnt )( uint32_t );
+
+//detecting popcnt availability on msvc intel
+static void selectPOPCNT()
+{
+  int info[4];
+  __cpuid( info, 1 );
+  if ( ( info[2] & ( (int)1 << 23 ) ) != 0 )
+  {
+    popcnt = &popcnt_intrinsic;
+  }
+  else
+  {
+    popcnt = &popcnt_generic;
+  }
+}
+
+#else //defined( _M_IX86 ) || defined( _M_X64 )
+
+//MSVC non INTEL should use generic implementation
+inline void selectPOPCNT()
+{
+}
+
+#define popcnt popcnt_generic
+
 #endif
 
-static uint32_t( *popcnt )( uint32_t x );
+#else //defined( _MSC_VER )
+
+//non MVSC should use builtin implementation
+
+inline void selectPOPCNT()
+{
+}
+
+#define popcnt __builtin_popcount
+
+#endif
+
+namespace Lynx
+{
+
+namespace
+{
+
+static constexpr int64_t CNT_MAX = std::numeric_limits<int64_t>::max() & ~15;
 
 int32_t clamp( int32_t v, int32_t lo, int32_t hi )
 {
@@ -526,23 +540,8 @@ private:
 
 Mikey::Mikey( uint32_t sampleRate ) : mMikey{ std::make_unique<MikeyPimpl>() }, mQueue{ std::make_unique<ActionQueue>() }, mTick{}, mNextTick{}, mSampleRate{ sampleRate }, mSamplesRemainder{}, mTicksPerSample{ 16000000 / mSampleRate, 16000000 % mSampleRate }
 {
+  selectPOPCNT();
   enqueueSampling();
-
-  //detecting popcnt availability
-#ifdef IS_INTEL
-  int info[4];
-  cpuid( info, 1 );
-  if ( ( info[2] & ( (int)1 << 23 ) ) != 0 )
-  {
-    popcnt = &popcnt_intrinsic;
-  }
-  else
-  {
-    popcnt = &popcnt_generic;
-  }
-#else
-  popcnt = &popcnt_generic;
-#endif
 }
 
 Mikey::~Mikey()