1 files changed, 59 insertions, 0 deletions
diff --git a/memory/jemalloc/src/include/msvc_compat/strings.h b/memory/jemalloc/src/include/msvc_compat/strings.h
new file mode 100644
index 000000000..a3ee25063
--- /dev/null
+++ b/memory/jemalloc/src/include/msvc_compat/strings.h
@@ -0,0 +1,59 @@
+#ifndef strings_h
+#define strings_h
+
+/* MSVC doesn't define ffs/ffsl. This dummy strings.h header is provided
+ * for both */
+#ifdef _MSC_VER
+#  include <intrin.h>
+#  pragma intrinsic(_BitScanForward)
+static __forceinline int ffsl(long x)
+{
+	unsigned long i;
+
+	if (_BitScanForward(&i, x))
+		return (i + 1);
+	return (0);
+}
+
+static __forceinline int ffs(int x)
+{
+
+	return (ffsl(x));
+}
+
+#  ifdef  _M_X64
+#    pragma intrinsic(_BitScanForward64)
+#  endif
+
+static __forceinline int ffsll(unsigned __int64 x)
+{
+	unsigned long i;
+#ifdef  _M_X64
+	if (_BitScanForward64(&i, x))
+		return (i + 1);
+	return (0);
+#else
+// Fallback for 32-bit build where 64-bit version not available
+// assuming little endian
+	union {
+		unsigned __int64 ll;
+		unsigned   long l[2];
+	} s;
+
+	s.ll = x;
+
+	if (_BitScanForward(&i, s.l[0]))
+		return (i + 1);
+	else if(_BitScanForward(&i, s.l[1]))
+		return (i + 33);
+	return (0);
+#endif
+}
+
+#else
+#  define ffsll(x) __builtin_ffsll(x)
+#  define ffsl(x) __builtin_ffsl(x)
+#  define ffs(x) __builtin_ffs(x)
+#endif
+
+#endif /* strings_h */