--- old/Makefile.spack
+++ new/Makefile.spack
@@ -0,0 +1,19 @@
+# Set PREFIX to the install location for both building and installing
+
+all: cdd dplex_test
+
+cdd: cdd.lo cddio.lo cddarith.lo dplex.lo setoper.lo
+	libtool --mode=link --tag=CC cc -g -O2 -o $@ $^
+
+dplex_test: dplex.lo dplex_test.lo setoper.lo
+	libtool --mode=link --tag=CC cc -g -O2 -o $@ $^
+
+%.lo: %.c
+	libtool --mode=compile --tag=CC cc -g -O2 -c $*.c
+
+install:
+	mkdir -p $(PREFIX)/bin
+	libtool --mode=install cp cdd $(PREFIX)/bin/cdd
+	libtool --mode=install cp dplex_test $(PREFIX)/bin/dplex_test
+
+.PHONY: all install