From 14722baee34f653ad346449fddcbf8b4d8cb09cb Mon Sep 17 00:00:00 2001
From: shimat <shima@sansan.com>
Date: Fri, 3 Apr 2020 10:06:18 +0900
Subject: [PATCH] fix popcnt error for ARM/ARM64

---
 modules/bgsegm/src/bgfg_gsoc.cpp       |  4 ++--
 modules/line_descriptor/src/bitops.hpp | 10 +++++++++-
 modules/saliency/src/BING/kyheader.hpp | 27 +++++++++++++++-----------
 3 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/modules/bgsegm/src/bgfg_gsoc.cpp b/modules/bgsegm/src/bgfg_gsoc.cpp
index abf18d7b2..0ed676482 100644
--- a/modules/bgsegm/src/bgfg_gsoc.cpp
+++ b/modules/bgsegm/src/bgfg_gsoc.cpp
@@ -63,14 +63,14 @@ namespace
 
 const float LSBPtau = 0.05f;
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !(defined(_M_ARM) || defined(_M_ARM64))
 #include <intrin.h>
 #pragma intrinsic(__popcnt)
 #endif
 inline int LSBPDist32(unsigned n) {
 #if defined(__GNUC__) || defined(__clang__)
     return __builtin_popcount(n);
-#elif defined(_MSC_VER)
+#elif defined(_MSC_VER) && !(defined(_M_ARM) || defined(_M_ARM64))
     return __popcnt(n);
 #else
     // Taken from http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
diff --git a/modules/line_descriptor/src/bitops.hpp b/modules/line_descriptor/src/bitops.hpp
index f2e2a1a52..29182d20b 100644
--- a/modules/line_descriptor/src/bitops.hpp
+++ b/modules/line_descriptor/src/bitops.hpp
@@ -46,12 +46,20 @@
 #include "precomp.hpp"
 
 #ifdef _MSC_VER
+#if defined(_M_ARM) || defined(_M_ARM64)
+static inline UINT32 popcnt(UINT32 v)
+{
+    v = v - ((v >> 1) & 0x55555555);
+    v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
+    return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24;
+}
+#else
 # include <intrin.h>
 # define popcnt __popcnt
 # pragma warning( disable : 4267 )
+#endif
 #else
 # define popcnt __builtin_popcount
-
 #endif
 
 /* LUT */
diff --git a/modules/saliency/src/BING/kyheader.hpp b/modules/saliency/src/BING/kyheader.hpp
index 0a8eeaa7e..42187cdb6 100644
--- a/modules/saliency/src/BING/kyheader.hpp
+++ b/modules/saliency/src/BING/kyheader.hpp
@@ -152,17 +152,6 @@ inline cv::Rect Vec4i2Rect( cv::Vec4i &v )
 }
 
 
-#if defined(_MSC_VER)
-# include <intrin.h>
-# define POPCNT(x) __popcnt(x)
-# define POPCNT64(x) (__popcnt((unsigned)(x)) + __popcnt((unsigned)((uint64_t)(x) >> 32)))
-#endif
-
-#if defined(__GNUC__)
-# define POPCNT(x) __builtin_popcount(x)
-# define POPCNT64(x) __builtin_popcountll(x)
-#endif
-
 inline int popcnt64( uint64_t u )
 {
   u = ( u & 0x5555555555555555 ) + ( ( u >> 1 ) & 0x5555555555555555 );
@@ -252,6 +241,22 @@ inline int popcnt_byte( uint32_t u )
   return (int)c;
 }
 
+#if defined(_MSC_VER)
+#if defined(_M_ARM) || defined(_M_ARM64)
+# define POPCNT(x) popcnt((x))
+# define POPCNT64(x) popcnt64((x))
+#else
+# include <intrin.h>
+# define POPCNT(x) __popcnt(x)
+# define POPCNT64(x) (__popcnt((unsigned)(x)) + __popcnt((unsigned)((uint64_t)(x) >> 32)))
+#endif
+#endif
+
+#if defined(__GNUC__)
+# define POPCNT(x) __builtin_popcount(x)
+# define POPCNT64(x) __builtin_popcountll(x)
+#endif
+
 }
 }