Keep -msse4.2 for amd64

Author: Alex Roitman

setup.py

@@ -16,7 +16,10 @@
 if sys.platform == "win32":
 	cflags = ["/O2"]
 else:
-	cflags = ["-O3", "-march=native"]
+	if platform.machine().lower() in ("x86_64", "amd64"):
+		cflags = ["-O3", "-msse4.2"]
+	else:
+		cflags = ["-O3", "-march=native"]
 
 extensions = [Extension(
 	"metrohash",