handle special systems putting x86_64 libs into lib64/ in make.sh, not in Makefile
diff --git a/Makefile b/Makefile
index ecc3d5d..40cc55e 100644
--- a/Makefile
+++ b/Makefile
@@ -30,19 +30,13 @@
DESTDIR ?=
INCDIR = $(DESTDIR)$(PREFIX)/include
-UNAME_M := $(shell uname -m)
UNAME_S := $(shell uname -s)
-LIBDIR = $(DESTDIR)$(PREFIX)/lib
-# on x86_64, we might have /usr/lib64 directory instead of /usr/lib
-ifeq ($(UNAME_M), x86_64)
-# ignore Mac OSX
-ifneq ($(UNAME_S), Darwin)
-ifneq (,$(wildcard $(DESTDIR)$(PREFIX)/lib64))
-LIBDIR = $(DESTDIR)$(PREFIX)/lib64
-endif
-endif
-endif
+LIBDIRARCH ?= lib
+# Uncomment the below line to installs x86_64 libs to lib64/ directory.
+# Or better, pass 'LIBDIRARCH=lib64' to 'make install/uninstall' via 'make.sh'.
+#LIBDIRARCH ?= lib64
+LIBDIR = $(DESTDIR)$(PREFIX)/$(LIBDIRARCH)
ifneq ($(UNAME_S),Darwin)
LDFLAGS += -shared