diff --git a/Make.inc b/Make.inc
index f015fd8..35c6ace 100644
--- a/Make.inc
+++ b/Make.inc
@@ -1,7 +1,19 @@
-CC=gcc
 OS = $(shell uname)
 ARCH = $(shell uname -m)
-CFLAGS= -std=c99 -Wall -O2 -I$(OPENLIBM_HOME) -I$(OPENLIBM_HOME)/include -I$(OPENLIBM_HOME)/ld80 -I$(OPENLIBM_HOME)/$(ARCH) -I$(OPENLIBM_HOME)/src -DASSEMBLER -D__BSD_VISIBLE -Wno-implicit-function-declaration
+
+USEGCC = 1
+USECLANG = 0
+
+ifeq ($(USECLANG),1)
+USEGCC = 0
+CC = clang
+CFLAGS= -std=c99 -Wall -O4 -I$(OPENLIBM_HOME) -I$(OPENLIBM_HOME)/include -I$(OPENLIBM_HOME)/ld80 -I$(OPENLIBM_HOME)/$(ARCH) -I$(OPENLIBM_HOME)/src -DASSEMBLER -D__BSD_VISIBLE -Wno-implicit-function-declaration
+endif
+
+ifeq ($(USEGCC),1)
+CC = gcc
+CFLAGS= -std=c99 -Wall -O3 -I$(OPENLIBM_HOME) -I$(OPENLIBM_HOME)/include -I$(OPENLIBM_HOME)/ld80 -I$(OPENLIBM_HOME)/$(ARCH) -I$(OPENLIBM_HOME)/src -DASSEMBLER -D__BSD_VISIBLE -Wno-implicit-function-declaration
+endif
 
 default: all
 
diff --git a/Makefile b/Makefile
index d1b3c1a..b7cd5f9 100644
--- a/Makefile
+++ b/Makefile
@@ -19,7 +19,9 @@ DUPLICATE_SRCS = $(addsuffix .c,$(DUPLICATE_NAMES))
 
 OBJS = $(patsubst %.S,%.S.o,\
 	$(patsubst %.c,%.c.o,$(filter-out $(addprefix src/,$(DUPLICATE_SRCS)),$(SRCS))))
+
 all: libopenlibm.a libopenlibm.$(SHLIB_EXT) 
+	$(MAKE) -C test
 libopenlibm.a: $(OBJS)  
 	$(QUIET_LINK)ar -rcs libopenlibm.a $(OBJS)
 libopenlibm.$(SHLIB_EXT): $(OBJS)
@@ -27,3 +29,4 @@ libopenlibm.$(SHLIB_EXT): $(OBJS)
 
 cleanall:
 	rm -f $(OBJS) *.a *.$(SHLIB_EXT)
+	$(MAKE) -C test clean