diff --git a/test/Makefile b/test/Makefile
index b942cbcdf..27f7ff456 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -1,41 +1,41 @@
 
-# toplevel makefile for the regression tests
+# top-level makefile for the regression tests
 
-MAKE := make --no-print-dir
+# You can comment this special target when you debug the regression tests.
+# Then, make will give you more progress reports.
+.SILENT:
 
 ifneq ($(shell echo),)
-  CMD_EXE = 1
+  CMD_EXE := 1
 endif
 
 ifdef CMD_EXE
   RM := del /f
   EXE := .exe
-  MKDIR = mkdir
-  RMDIR = rmdir
+  MKDIR := mkdir
+  RMDIR := rmdir
 else
   RM := rm -f
   EXE :=
-  MKDIR = mkdir -p
-  RMDIR = rmdir
+  MKDIR := mkdir -p
+  RMDIR := rmdir
 endif
 
 WORKDIR := ../testwrk
 
-.PHONY: dotests clean
+.PHONY: all dotests continue mostly-clean clean
 
 all: dotests
 
 $(WORKDIR):
-	@$(MKDIR) $(WORKDIR)
+	$(MKDIR) $(WORKDIR)
 
-$(WORKDIR)/bdiff$(EXE): $(WORKDIR)
-	@$(CC) -o $(WORKDIR)/bdiff$(EXE) bdiff.c
+$(WORKDIR)/bdiff$(EXE): bdiff.c | $(WORKDIR)
+	$(CC) -O2 -o $@ $<
 
-dotests: $(WORKDIR)/bdiff$(EXE)
-	@$(MAKE) -C val clean all
-	@$(MAKE) -C ref clean all
-	@$(MAKE) -C err clean all
-	@$(MAKE) -C misc clean all
+.NOTPARALLEL:
+
+dotests: mostly-clean continue
 
 continue: $(WORKDIR)/bdiff$(EXE)
 	@$(MAKE) -C val all
@@ -43,10 +43,12 @@ continue: $(WORKDIR)/bdiff$(EXE)
 	@$(MAKE) -C err all
 	@$(MAKE) -C misc all
 
-clean:
+mostly-clean:
 	@$(MAKE) -C val clean
 	@$(MAKE) -C ref clean
 	@$(MAKE) -C err clean
 	@$(MAKE) -C misc clean
-	@$(RM) $(WORKDIR)/bdiff$(EXE)
-	@$(RMDIR) $(WORKDIR)
+
+clean: mostly-clean
+	$(RM) $(WORKDIR)/bdiff$(EXE)
+	$(RMDIR) $(WORKDIR)
diff --git a/test/err/Makefile b/test/err/Makefile
index 40ccfcb59..4e12323fd 100644
--- a/test/err/Makefile
+++ b/test/err/Makefile
@@ -2,10 +2,10 @@
 # makefile for the tests that MUST NOT compile
 
 ifneq ($(shell echo),)
-  CMD_EXE = 1
+  CMD_EXE := 1
 endif
 
-CC65FLAGS = -t sim6502
+CC65FLAGS := -t sim6502
 
 CL65 := $(if $(wildcard ../../bin/cl65*),../../bin/cl65,cl65)
 
@@ -15,19 +15,12 @@ else
 RM := rm -f
 endif
 
-WORKDIR := ./../../testwrk
+WORKDIR := ../../testwrk
 
 .PHONY: all clean
 
 SOURCES := $(wildcard *.c)
-TESTS := $(SOURCES:%.c=$(WORKDIR)/%.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.o.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.os.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.osi.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.osir.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.oi.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.oir.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.or.prg)
+TESTS := $(foreach option,. .o. .os. .osi. .osir. .oi. .oir. .or.,$(SOURCES:%.c=$(WORKDIR)/%$(option)prg))
 
 all: $(TESTS)
 
@@ -47,6 +40,7 @@ $(WORKDIR)/%.oir.prg: %.c
 	! $(CL65) -Oir $(CC65FLAGS) $< -o $@
 $(WORKDIR)/%.or.prg: %.c
 	! $(CL65) -Or $(CC65FLAGS) $< -o $@
+
 clean:
 	@$(RM) $(TESTS)
-	@$(RM) $(SOURCES:%.c=$(WORKDIR)/%.o)
+	@$(RM) $(SOURCES:.c=.o)
diff --git a/test/misc/Makefile b/test/misc/Makefile
index b18d9165e..b04321c33 100644
--- a/test/misc/Makefile
+++ b/test/misc/Makefile
@@ -2,11 +2,11 @@
 # makefile for the remaining tests that need special care in one way or another
 
 ifneq ($(shell echo),)
-  CMD_EXE = 1
+  CMD_EXE := 1
 endif
 
-CC65FLAGS = -t sim6502
-SIM65FLAGS = -x 200000000
+CC65FLAGS := -t sim6502
+SIM65FLAGS := -x 200000000
 
 CL65 := $(if $(wildcard ../../bin/cl65*),../../bin/cl65,cl65)
 SIM65 := $(if $(wildcard ../../bin/sim65*),../../bin/sim65,sim65)
@@ -17,51 +17,40 @@ else
 RM := rm -f
 endif
 
-WORKDIR := ./../../testwrk
+WORKDIR := ../../testwrk
 
 DIFF := $(WORKDIR)/bdiff
 
 .PHONY: all clean
 
 SOURCES := $(wildcard *.c)
-TESTS := $(SOURCES:%.c=$(WORKDIR)/%.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.o.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.os.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.osi.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.osir.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.oi.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.oir.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.or.prg)
-
-# FIXME: actually use/build differently optimized programs here
+TESTS := $(foreach option,. .o. .os. .osi. .osir. .oi. .oir. .or.,$(SOURCES:%.c=$(WORKDIR)/%$(option)prg))
 
 all: $(TESTS)
 
 # should compile, but then hangs in an endless loop
 $(WORKDIR)/endless%prg: endless.c
-	$(CL65) $(CC65FLAGS) $< -o $@
+	$(CL65) $(subst .,,$(*:.o%=-O%)) $(CC65FLAGS) $< -o $@
 	! $(SIM65) $(SIM65FLAGS) $@
 
-# these need reference data that cant be generated by a host compiled program
+# these need reference data that can't be generated by a host-compiled program,
 # in a useful way
 $(WORKDIR)/limits%prg: limits.c
-	$(CL65) $(CC65FLAGS) $< -o $@
+	$(CL65) $(subst .,,$(*:.o%=-O%)) $(CC65FLAGS) $< -o $@
 	$(SIM65) $(SIM65FLAGS) $@ > $(WORKDIR)/limits.out
 	$(DIFF) $(WORKDIR)/limits.out limits.ref
 
 # the rest are tests that fail currently for one reason or another
 $(WORKDIR)/fields%prg: fields.c
-	@echo "FIXME: " $@ "will currently fail"
-	$(CL65) $(CC65FLAGS) $< -o $@
+	@echo "FIXME: " $@ "currently will fail."
+	$(CL65) $(subst .,,$(*:.o%=-O%)) $(CC65FLAGS) $< -o $@
 	-$(SIM65) $(SIM65FLAGS) $@
 $(WORKDIR)/sitest%prg: sitest.c
-	@echo "FIXME: " $@ "will currently fail"
-	-$(CL65) $(CC65FLAGS) $< -o $@
-	-$(SIM65) $(SIM65FLAGS) $@
+	@echo "FIXME: " $@ "currently will fail."
+	-$(CL65) $(subst .,,$(*:.o%=-O%)) $(CC65FLAGS) $< -o $@
+#	-$(SIM65) $(SIM65FLAGS) $@
 
 clean:
 	@$(RM) $(TESTS)
-	@$(RM) $(SOURCES:%.c=$(WORKDIR)/%.o)
+	@$(RM) $(SOURCES:.c=.o)
 	@$(RM) $(SOURCES:%.c=$(WORKDIR)/%.out)
-
-
diff --git a/test/ref/Makefile b/test/ref/Makefile
index b752adc1d..3e7a5ad6c 100644
--- a/test/ref/Makefile
+++ b/test/ref/Makefile
@@ -3,11 +3,11 @@
 # compared with reference output
 
 ifneq ($(shell echo),)
-  CMD_EXE = 1
+  CMD_EXE := 1
 endif
 
-CC65FLAGS = -t sim6502
-SIM65FLAGS = -x 200000000
+CC65FLAGS := -t sim6502
+SIM65FLAGS := -x 200000000
 
 CL65 := $(if $(wildcard ../../bin/cl65*),../../bin/cl65,cl65)
 SIM65 := $(if $(wildcard ../../bin/sim65*),../../bin/sim65,sim65)
@@ -18,7 +18,7 @@ else
 RM := rm -f
 endif
 
-WORKDIR := ./../../testwrk
+WORKDIR := ../../testwrk
 
 DIFF := $(WORKDIR)/bdiff
 
@@ -26,17 +26,9 @@ CFLAGS := -O2 -Wall -W -Wextra -fwrapv -fno-strict-overflow
 
 .PHONY: all clean
 
-REFS := $(patsubst %.c,$(WORKDIR)/%.ref,$(wildcard *.c))
-
 SOURCES := $(wildcard *.c)
-TESTS := $(SOURCES:%.c=$(WORKDIR)/%.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.o.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.os.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.osi.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.osir.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.oi.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.oir.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.or.prg)
+REFS := $(SOURCES:%.c=$(WORKDIR)/%.ref)
+TESTS := $(foreach option,. .o. .os. .osi. .osir. .oi. .oir. .or.,$(SOURCES:%.c=$(WORKDIR)/%$(option)prg))
 
 all: $(REFS) $(TESTS)
 
@@ -86,7 +78,7 @@ $(WORKDIR)/%.or.prg: %.c $(WORKDIR)/%.ref
 
 clean:
 	@$(RM) $(TESTS)
-	@$(RM) $(SOURCES:%.c=$(WORKDIR)/%.o)
+	@$(RM) $(SOURCES:.c=.o)
 	@$(RM) $(SOURCES:%.c=$(WORKDIR)/%.out)
 	@$(RM) $(SOURCES:%.c=$(WORKDIR)/%.ref)
 	@$(RM) $(SOURCES:%.c=$(WORKDIR)/%.host)
diff --git a/test/val/Makefile b/test/val/Makefile
index 2e0aca278..2efcbd0de 100644
--- a/test/val/Makefile
+++ b/test/val/Makefile
@@ -2,11 +2,11 @@
 # makefile for the regression tests that return an error code on failure
 
 ifneq ($(shell echo),)
-  CMD_EXE = 1
+  CMD_EXE := 1
 endif
 
-CC65FLAGS = -t sim6502
-SIM65FLAGS = -x 200000000
+CC65FLAGS := -t sim6502
+SIM65FLAGS := -x 200000000
 
 CL65 := $(if $(wildcard ../../bin/cl65*),../../bin/cl65,cl65)
 SIM65 := $(if $(wildcard ../../bin/sim65*),../../bin/sim65,sim65)
@@ -17,19 +17,12 @@ else
 RM := rm -f
 endif
 
-WORKDIR := ./../../testwrk
+WORKDIR := ../../testwrk
 
 .PHONY: all clean
 
 SOURCES := $(wildcard *.c)
-TESTS := $(SOURCES:%.c=$(WORKDIR)/%.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.o.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.os.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.osi.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.osir.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.oi.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.oir.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.or.prg)
+TESTS := $(foreach option,. .o. .os. .osi. .osir. .oi. .oir. .or.,$(SOURCES:%.c=$(WORKDIR)/%$(option)prg))
 
 all: $(TESTS)
 
@@ -67,4 +60,4 @@ $(WORKDIR)/%.or.prg: %.c
 
 clean:
 	@$(RM) $(TESTS)
-	@$(RM) $(SOURCES:%.c=$(WORKDIR)/%.o)
+	@$(RM) $(SOURCES:.c=.o)