diff --git a/README.md b/README.md
index ec99630e..d7e8fb63 100644
--- a/README.md
+++ b/README.md
@@ -82,6 +82,7 @@ make install     # this command may require root access
 
 LZ4's `Makefile` supports standard [Makefile conventions],
 including [staged installs], [redirection], or [command redefinition].
+It is compatible with parallel builds (`'-j#'`).
 
 [Makefile conventions]: https://www.gnu.org/prep/standards/html_node/Makefile-Conventions.html
 [staged installs]: https://www.gnu.org/prep/standards/html_node/DESTDIR.html
diff --git a/tests/Makefile b/tests/Makefile
index f00778fa..5b306846 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -30,19 +30,14 @@
 # datagen : generates synthetic data samples for tests & benchmarks
 # ##########################################################################
 
-DESTDIR ?=
-PREFIX  ?= /usr/local
-BINDIR  := $(PREFIX)/bin
-MANDIR  := $(PREFIX)/share/man/man1
 LZ4DIR  := ../lib
 PRGDIR  := ../programs
-VOID    := /dev/null
 TESTDIR := versionsTest
 PYTHON  ?= python3
 
 CFLAGS  ?= -O3 # can select custom optimization flags. For example : CFLAGS=-O2 make
-CFLAGS  += -g -Wall -Wextra -Wundef -Wcast-qual -Wcast-align -Wshadow -Wswitch-enum \
-           -Wdeclaration-after-statement -Wstrict-prototypes \
+CFLAGS  += -g -Wall -Wextra -Wundef -Wcast-qual -Wcast-align -Wshadow \
+           -Wswitch-enum -Wdeclaration-after-statement -Wstrict-prototypes \
            -Wpointer-arith -Wstrict-aliasing=1
 CFLAGS  += $(MOREFLAGS)
 CPPFLAGS:= -I$(LZ4DIR) -I$(PRGDIR) -DXXH_NAMESPACE=LZ4_
@@ -51,9 +46,11 @@ FLAGS    = $(CFLAGS) $(CPPFLAGS) $(LDFLAGS)
 
 # Define *.exe as extension for Windows systems
 ifneq (,$(filter Windows%,$(OS)))
-EXT =.exe
+EXT  =.exe
+VOID = nul
 else
-EXT =
+EXT  =
+VOID = /dev/null
 endif
 LZ4     := $(PRGDIR)/lz4$(EXT)
 
@@ -72,13 +69,13 @@ all32: CFLAGS+=-m32
 all32: all
 
 lz4:
-	$(MAKE) -C $(PRGDIR) clean $@ CFLAGS="$(CFLAGS)"
+	$(MAKE) -C $(PRGDIR) $@ CFLAGS="$(CFLAGS)"
 
 lz4c:
-	$(MAKE) -C $(PRGDIR) clean $@ CFLAGS="$(CFLAGS)"
+	$(MAKE) -C $(PRGDIR) $@ CFLAGS="$(CFLAGS)"
 
 lz4c32:   # create a 32-bits version for 32/64 interop tests
-	$(MAKE) -C $(PRGDIR) clean $@ CFLAGS="-m32 $(CFLAGS)"
+	$(MAKE) -C $(PRGDIR) $@ CFLAGS="-m32 $(CFLAGS)"
 	cp $(LZ4) $(LZ4)c32
 
 fullbench  : $(LZ4DIR)/lz4.o $(LZ4DIR)/lz4hc.o $(LZ4DIR)/lz4frame.o $(LZ4DIR)/xxhash.o fullbench.c
@@ -144,75 +141,75 @@ test32: test
 
 test-lz4-sparse: lz4 datagen
 	@echo "\n ---- test sparse file support ----"
-	./datagen -g5M  -P100 > tmpSrc
-	$(LZ4) -B4D tmpSrc | $(LZ4) -dv --sparse > tmpB4
-	$(DIFF) -s tmpSrc tmpB4
-	$(LZ4) -B5D tmpSrc | $(LZ4) -dv --sparse > tmpB5
-	$(DIFF) -s tmpSrc tmpB5
-	$(LZ4) -B6D tmpSrc | $(LZ4) -dv --sparse > tmpB6
-	$(DIFF) -s tmpSrc tmpB6
-	$(LZ4) -B7D tmpSrc | $(LZ4) -dv --sparse > tmpB7
-	$(DIFF) -s tmpSrc tmpB7
-	$(LZ4) tmpSrc | $(LZ4) -dv --no-sparse > tmpNoSparse
-	$(DIFF) -s tmpSrc tmpNoSparse
-	ls -ls tmp*
-	./datagen -s1 -g1200007 -P100 | $(LZ4) | $(LZ4) -dv --sparse > tmpOdd   # Odd size file (to generate non-full last block)
-	./datagen -s1 -g1200007 -P100 | $(DIFF) -s - tmpOdd
-	ls -ls tmpOdd
-	@$(RM) tmp*
+	./datagen -g5M  -P100 > tmplsdg5M
+	$(LZ4) -B4D tmplsdg5M | $(LZ4) -dv --sparse > tmplscB4
+	$(DIFF) -s tmplsdg5M tmplscB4
+	$(LZ4) -B5D tmplsdg5M | $(LZ4) -dv --sparse > tmplscB5
+	$(DIFF) -s tmplsdg5M tmplscB5
+	$(LZ4) -B6D tmplsdg5M | $(LZ4) -dv --sparse > tmplscB6
+	$(DIFF) -s tmplsdg5M tmplscB6
+	$(LZ4) -B7D tmplsdg5M | $(LZ4) -dv --sparse > tmplscB7
+	$(DIFF) -s tmplsdg5M tmplscB7
+	$(LZ4) tmplsdg5M | $(LZ4) -dv --no-sparse > tmplsnosparse
+	$(DIFF) -s tmplsdg5M tmplsnosparse
+	ls -ls tmpls*
+	./datagen -s1 -g1200007 -P100 | $(LZ4) | $(LZ4) -dv --sparse > tmplsodd   # Odd size file (to generate non-full last block)
+	./datagen -s1 -g1200007 -P100 | $(DIFF) -s - tmplsodd
+	ls -ls tmplsodd
+	@$(RM) tmpls*
 	@echo "\n Compatibility with Console :"
 	echo "Hello World 1 !" | $(LZ4) | $(LZ4) -d -c
 	echo "Hello World 2 !" | $(LZ4) | $(LZ4) -d | cat
 	echo "Hello World 3 !" | $(LZ4) --no-frame-crc | $(LZ4) -d -c
 	@echo "\n Compatibility with Append :"
-	./datagen -P100 -g1M > tmp1M
-	cat tmp1M tmp1M > tmp2M
-	$(LZ4) -B5 -v tmp1M tmpC
-	$(LZ4) -d -v tmpC tmpR
-	$(LZ4) -d -v tmpC >> tmpR
+	./datagen -P100 -g1M > tmplsdg1M
+	cat tmplsdg1M tmplsdg1M > tmpls2M
+	$(LZ4) -B5 -v tmplsdg1M tmplsc
+	$(LZ4) -d -v tmplsc tmplsr
+	$(LZ4) -d -v tmplsc >> tmplsr
 	ls -ls tmp*
-	$(DIFF) tmp2M tmpR
-	@$(RM) tmp*
+	$(DIFF) tmpls2M tmplsr
+	@$(RM) tmpls*
 
 test-lz4-contentSize: lz4 datagen
 	@echo "\n ---- test original size support ----"
-	./datagen -g15M > tmp
-	$(LZ4) -v tmp | $(LZ4) -t
-	$(LZ4) -v --content-size tmp | $(LZ4) -d > tmp2
-	$(DIFF) -s tmp tmp2
+	./datagen -g15M > tmplc1
+	$(LZ4) -v tmplc1 | $(LZ4) -t
+	$(LZ4) -v --content-size tmplc1 | $(LZ4) -d > tmplc2
+	$(DIFF) -s tmplc1 tmplc2
 	# test large size [2-4] GB
-	@./datagen -g3G -P100 | $(LZ4) -vv | $(LZ4) --decompress --force --sparse - tmp
-	@ls -ls tmp
-	@./datagen -g3G -P100 | $(LZ4) --quiet --content-size | $(LZ4) --verbose --decompress --force --sparse - tmp2
-	@ls -ls tmp2
-	$(DIFF) -s tmp tmp2
-	@$(RM) tmp*
+	@./datagen -g3G -P100 | $(LZ4) -vv | $(LZ4) --decompress --force --sparse - tmplc1
+	@ls -ls tmplc1
+	@./datagen -g3G -P100 | $(LZ4) --quiet --content-size | $(LZ4) --verbose --decompress --force --sparse - tmplc2
+	@ls -ls tmplc2
+	$(DIFF) -s tmplc1 tmplc2
+	@$(RM) tmplc*
 
 test-lz4-frame-concatenation: lz4 datagen
 	@echo "\n ---- test frame concatenation ----"
-	@echo -n > empty.test
-	@echo hi > nonempty.test
-	cat nonempty.test empty.test nonempty.test > orig.test
-	@$(LZ4) -zq empty.test > empty.lz4.test
-	@$(LZ4) -zq nonempty.test > nonempty.lz4.test
-	cat nonempty.lz4.test empty.lz4.test nonempty.lz4.test > concat.lz4.test
-	$(LZ4) -d concat.lz4.test > result.test
-	sdiff orig.test result.test
-	@$(RM) *.test
+	@echo -n > tmp-lfc-empty
+	@echo hi > tmp-lfc-nonempty
+	cat tmp-lfc-nonempty tmp-lfc-empty tmp-lfc-nonempty > tmp-lfc-src
+	@$(LZ4) -zq tmp-lfc-empty > tmp-lfc-empty.lz4
+	@$(LZ4) -zq tmp-lfc-nonempty > tmp-lfc-nonempty.lz4
+	cat tmp-lfc-nonempty.lz4 tmp-lfc-empty.lz4 tmp-lfc-nonempty.lz4 > tmp-lfc-concat.lz4
+	$(LZ4) -d tmp-lfc-concat.lz4 > tmp-lfc-result
+	sdiff tmp-lfc-src tmp-lfc-result
+	@$(RM) tmp-lfc-*
 	@echo frame concatenation test completed
 
 test-lz4-multiple: lz4 datagen
 	@echo "\n ---- test multiple files ----"
-	@./datagen -s1        > tmp1 2> $(VOID)
-	@./datagen -s2 -g100K > tmp2 2> $(VOID)
-	@./datagen -s3 -g1M   > tmp3 2> $(VOID)
-	$(LZ4) -f -m tmp*
-	ls -ls tmp*
-	@$(RM) tmp1 tmp2 tmp3
-	$(LZ4) -df -m *.lz4
-	ls -ls tmp*
-	$(LZ4) -f -m tmp1 notHere tmp2; echo $$?
-	@$(RM) tmp*
+	@./datagen -s1        > tmp-tlm1 2> $(VOID)
+	@./datagen -s2 -g100K > tmp-tlm2 2> $(VOID)
+	@./datagen -s3 -g1M   > tmp-tlm3 2> $(VOID)
+	$(LZ4) -f -m tmp-tlm*
+	ls -ls tmp-tlm*
+	@$(RM) tmp-tlm1 tmp-tlm2 tmp-tlm3
+	$(LZ4) -df -m tmp-tlm*.lz4
+	ls -ls tmp-tlm*
+	$(LZ4) -f -m tmp-tlm1 notHere tmp-tlm2; echo $$?
+	@$(RM) tmp-tlm*
 
 unlz4:
 	@$(MAKE) -C $(PRGDIR) $@ CFLAGS="$(CFLAGS)"
@@ -222,74 +219,73 @@ lz4cat:
 
 test-lz4-basic: lz4 datagen unlz4 lz4cat
 	@echo "\n ---- test lz4 basic compression/decompression ----"
-	./datagen -g0     | $(LZ4) -v     | $(LZ4) -t
-	./datagen -g16KB  | $(LZ4) -9     | $(LZ4) -t
-	./datagen -g20KB > tmpSrc
-	$(LZ4) < tmpSrc   | $(LZ4) -d > tmpRes
-	$(DIFF) -q tmpSrc tmpRes
-	$(LZ4) --no-frame-crc < tmpSrc | $(LZ4) -d > tmpRes
-	$(DIFF) -q tmpSrc tmpRes
-	./datagen         | $(LZ4)        | $(LZ4) -t
-	./datagen -g6M -P99 | $(LZ4) -9BD | $(LZ4) -t
-	./datagen -g17M   | $(LZ4) -9v    | $(LZ4) -qt
-	./datagen -g33M   | $(LZ4) --no-frame-crc | $(LZ4) -t
-	./datagen -g256MB | $(LZ4) -vqB4D | $(LZ4) -t
-	@echo "hello world" > tmp
-	$(LZ4) --rm -f tmp tmp.lz4
-	test ! -f tmp                      # must fail (--rm)
-	test   -f tmp.lz4
-	$(PRGDIR)/lz4cat tmp.lz4           # must display hello world
-	test   -f tmp.lz4
-	$(PRGDIR)/unlz4 --rm tmp.lz4 tmp
-	test   -f tmp
-	test ! -f tmp.lz4                  # must fail (--rm)
-	test ! -f tmp.lz4.lz4              # must fail (unlz4)
-	$(PRGDIR)/lz4cat tmp               # pass-through mode
-	test   -f tmp
-	test ! -f tmp.lz4                  # must fail (lz4cat)
-	$(LZ4) tmp tmp.lz4                 # creates tmp.lz4
-	$(PRGDIR)/lz4cat < tmp.lz4 > tmp3  # checks lz4cat works with stdin (#285)
-	$(DIFF) -q tmp tmp3
-	$(PRGDIR)/lz4cat < tmp > tmp2      # checks lz4cat works with stdin (#285)
-	$(DIFF) -q tmp tmp2
-	cp tmp ./-d
-	$(LZ4) --rm -- -d -d.lz4           # compresses ./d into ./-d.lz4
+	./datagen -g0       | $(LZ4) -v     | $(LZ4) -t
+	./datagen -g16KB    | $(LZ4) -9     | $(LZ4) -t
+	./datagen -g20KB > tmp-tlb-dg20k
+	$(LZ4) < tmp-tlb-dg20k | $(LZ4) -d > tmp-tlb-dec
+	$(DIFF) -q tmp-tlb-dg20k tmp-tlb-dec
+	$(LZ4) --no-frame-crc < tmp-tlb-dg20k | $(LZ4) -d > tmp-tlb-dec
+	$(DIFF) -q tmp-tlb-dg20k tmp-tlb-dec
+	./datagen           | $(LZ4)        | $(LZ4) -t
+	./datagen -g6M -P99 | $(LZ4) -9BD   | $(LZ4) -t
+	./datagen -g17M     | $(LZ4) -9v    | $(LZ4) -qt
+	./datagen -g33M     | $(LZ4) --no-frame-crc | $(LZ4) -t
+	./datagen -g256MB   | $(LZ4) -vqB4D | $(LZ4) -t
+	@echo "hello world" > tmp-tlb-hw
+	$(LZ4) --rm -f tmp-tlb-hw tmp-tlb-hw.lz4
+	test ! -f tmp-tlb-hw                      # must fail (--rm)
+	test   -f tmp-tlb-hw.lz4
+	$(PRGDIR)/lz4cat tmp-tlb-hw.lz4           # must display hello world
+	test   -f tmp-tlb-hw.lz4
+	$(PRGDIR)/unlz4 --rm tmp-tlb-hw.lz4 tmp-tlb-hw
+	test   -f tmp-tlb-hw
+	test ! -f tmp-tlb-hw.lz4                  # must fail (--rm)
+	test ! -f tmp-tlb-hw.lz4.lz4              # must fail (unlz4)
+	$(PRGDIR)/lz4cat tmp-tlb-hw               # pass-through mode
+	test   -f tmp-tlb-hw
+	test ! -f tmp-tlb-hw.lz4                  # must fail (lz4cat)
+	$(LZ4) tmp-tlb-hw tmp-tlb-hw.lz4          # creates tmp-tlb-hw.lz4
+	$(PRGDIR)/lz4cat < tmp-tlb-hw.lz4 > tmp-tlb3  # checks lz4cat works with stdin (#285)
+	$(DIFF) -q tmp-tlb-hw tmp-tlb3
+	$(PRGDIR)/lz4cat < tmp-tlb-hw > tmp-tlb2      # checks lz4cat works in pass-through mode
+	$(DIFF) -q tmp-tlb-hw tmp-tlb2
+	cp tmp-tlb-hw ./-d
+	$(LZ4) --rm -- -d -d.lz4               # compresses ./d into ./-d.lz4
 	test   -f ./-d.lz4
 	test ! -f ./-d
 	mv ./-d.lz4 ./-z
-	$(LZ4) -d --rm -- -z tmp4          # uncompresses ./-z into tmp4
+	$(LZ4) -d --rm -- -z tmp-tlb4          # uncompresses ./-z into tmp-tlb4
 	test ! -f ./-z
-	$(DIFF) -q tmp tmp4
-	$(LZ4) -f tmp
-	cat tmp >> tmp.lz4
-	$(LZ4) -f tmp.lz4         # uncompress valid frame followed by invalid data
-	$(LZ4) -BX tmp -c -q | $(LZ4) -tv  # test block checksum
-	@$(RM) tmp*
+	$(DIFF) -q tmp-tlb-hw tmp-tlb4
+	$(LZ4) -f tmp-tlb-hw
+	cat tmp-tlb-hw >> tmp-tlb-hw.lz4
+	$(LZ4) -f tmp-tlb-hw.lz4               # uncompress valid frame followed by invalid data
+	$(LZ4) -BX tmp-tlb-hw -c -q | $(LZ4) -tv  # test block checksum
+	@$(RM) tmp-tlb*
 
 test-lz4-hugefile: lz4 datagen
 	@echo "\n ---- test huge files compression/decompression ----"
 	./datagen -g6GB   | $(LZ4) -vB5D  | $(LZ4) -qt
 	./datagen -g6GB   | $(LZ4) -v5BD  | $(LZ4) -qt
-	@$(RM) tmp*
 
 test-lz4-testmode: lz4 datagen
 	@echo "\n ---- bench mode ----"
-	  $(LZ4) -bi1
+	$(LZ4) -bi1
 	@echo "\n ---- test mode ----"
 	! ./datagen | $(LZ4) -t
 	! ./datagen | $(LZ4) -tf
 	@echo "\n ---- pass-through mode ----"
 	! ./datagen | $(LZ4) -d  > $(VOID)
-	  ./datagen | $(LZ4) -df > $(VOID)
-	@echo "Hello World !" > tmp1
-	$(LZ4) -dcf tmp1
-	@echo "from underground..." > tmp2
-	$(LZ4) -dcfm tmp1 tmp2
-	@echo "\n ---- test cli ----"
+	./datagen | $(LZ4) -df > $(VOID)
+	@echo "Hello World !" > tmp-tlt1
+	$(LZ4) -dcf tmp-tlt1
+	@echo "from underground..." > tmp-tlt2
+	$(LZ4) -dcfm tmp-tlt1 tmp-tlt2
+	@echo "\n ---- non-existing source ----"
 	! $(LZ4)     file-does-not-exist
 	! $(LZ4) -f  file-does-not-exist
 	! $(LZ4) -fm file1-dne file2-dne
-	! $(LZ4) -fm file1-dne file2-dne
+	@$(RM) tmp-tlt
 
 test-lz4-opt-parser: lz4 datagen
 	@echo "\n ---- test opt-parser ----"
@@ -304,9 +300,10 @@ test-lz4-opt-parser: lz4 datagen
 	./datagen -g16M -P90  | $(LZ4) -11B5    | $(LZ4) -t
 	./datagen -g32M -P10  | $(LZ4) -11B5D   | $(LZ4) -t
 
-test-lz4: lz4 datagen test-lz4-opt-parser test-lz4-basic test-lz4-multiple test-lz4-sparse \
-          test-lz4-frame-concatenation test-lz4-testmode test-lz4-contentSize \
-          test-lz4-hugefile
+test-lz4: lz4 datagen test-lz4-basic test-lz4-opt-parser test-lz4-multiple \
+          test-lz4-sparse test-lz4-frame-concatenation test-lz4-testmode \
+          test-lz4-contentSize test-lz4-hugefile
+	@$(RM) tmp*
 
 test-lz4c: lz4c datagen
 	@echo "\n ---- test lz4c version ----"
@@ -365,19 +362,19 @@ test-fasttest: fasttest
 test-mem: lz4 datagen fuzzer frametest fullbench
 	@echo "\n ---- valgrind tests : memory analyzer ----"
 	valgrind --leak-check=yes --error-exitcode=1 ./datagen -g50M > $(VOID)
-	./datagen -g16KB > tmp
-	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) -9 -BD -f tmp $(VOID)
-	./datagen -g16KB -s2 > tmp2
-	./datagen -g16KB -s3 > tmp3
-	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) --force --multiple tmp tmp2 tmp3
-	./datagen -g16MB > tmp
-	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) -9 -B5D -f tmp tmp2
-	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) -t tmp2
-	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) -bi1 tmp
-	valgrind --leak-check=yes --error-exitcode=1 ./fullbench -i1 tmp tmp2
-	./datagen -g256MB > tmp
-	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) -B4D -f -vq tmp $(VOID)
-	$(RM) tmp*
+	./datagen -g16KB > ftmdg16K
+	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) -9 -BD -f ftmdg16K $(VOID)
+	./datagen -g16KB -s2 > ftmdg16K2
+	./datagen -g16KB -s3 > ftmdg16K3
+	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) --force --multiple ftmdg16K ftmdg16K2 ftmdg16K3
+	./datagen -g16MB > ftmdg16M
+	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) -9 -B5D -f ftmdg16M ftmdg16K2
+	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) -t ftmdg16K2
+	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) -bi1 ftmdg16M
+	valgrind --leak-check=yes --error-exitcode=1 ./fullbench -i1 ftmdg16M ftmdg16K2
+	./datagen -g256MB > ftmdg256M
+	valgrind --leak-check=yes --error-exitcode=1 $(LZ4) -B4D -f -vq ftmdg256M $(VOID)
+	$(RM) ftm*
 	valgrind --leak-check=yes --error-exitcode=1 ./fuzzer -i64 -t1
 	valgrind --leak-check=yes --error-exitcode=1 ./frametest -i256