Add release target that uses profile guided optimisation.

Makefile

@@ -1,5 +1,5 @@
-OFLAGS += -Wall -Wno-unused -O3 -DNDEBUG
 GFLAGS += -Wall -Wno-unused -g
+OFLAGS += $(GFLAGS) -O3 -DNDEBUG
 PFLAGS += $(OFLAGS) -pg
 CFLAGS += -D_GNU_SOURCE -I/opt/local/include
 LDLIBS += -L/opt/local/lib
@@ -42,6 +42,13 @@ profile : $(MAIN)-prof
 	./$(MAIN)-prof -O < bench.txt
 	gprof ./$(MAIN)-prof gmon.out
 
+release : .FORCE
+	rm -f *.gcda
+	$(MAKE) clean all GFLAGS="-DNDEBUG -DTYPECODES=1 -DDELOPT=1 -O3 -fprofile-correction -fprofile-generate"
+	./$(MAIN) profile-generate.txt profile-generate.txt profile-generate.txt profile-generate.txt
+	$(MAKE) clean all GFLAGS="-DNDEBUG -DTYPECODES=1 -DDELOPT=1 -O3 -fprofile-correction -fprofile-use"
+	./$(MAIN) profile-generate.txt
+
 FILES = Makefile $(MAIN).leg bench.txt test.txt test2.txt
 
 checkpoint : .FORCE