redefine __builtin_popcount for MSVC

include/m17cxx/Convolution.h

@@ -5,6 +5,11 @@
 #include <cstdint>
 #include <cstddef>
 
+#ifdef _MSC_VER
+#  include <intrin.h>
+#  define __builtin_popcount __popcnt
+#endif
+
 namespace mobilinkd
 {
 

include/m17cxx/Golay24.h

@@ -8,6 +8,11 @@
 #include <algorithm>
 #include <utility>
 
+#ifdef _MSC_VER
+#  include <intrin.h>
+#  define __builtin_popcount __popcnt
+#endif
+
 namespace mobilinkd {
 
 // Parts are adapted from:

include/m17cxx/M17Synchronizer.h

@@ -4,6 +4,11 @@
 
 #include <cstdint>
 
+#ifdef _MSC_VER
+#  include <intrin.h>
+#  define __builtin_popcount __popcnt
+#endif
+
 namespace mobilinkd
 {