minor boundary change

improves compression ratio at low levels

Makefile

@@ -296,9 +296,9 @@ msanregressiontest:
 
 update_regressionResults : REGRESS_RESULTS_DIR := /tmp/regress_results_dir/
 update_regressionResults:
-	$(MAKE) -C programs zstd
-	$(MAKE) -C tests/regression test
-	$(RM) -rf $(REGRESS_RESULTS_DIR)
+	$(MAKE) -j -C programs zstd
+	$(MAKE) -j -C tests/regression test
+	$(RM) -r $(REGRESS_RESULTS_DIR)
 	$(MKDIR) $(REGRESS_RESULTS_DIR)
 	./tests/regression/test                         \
         --cache  tests/regression/cache             \