Add COMPILER option to OpenCL Makefile

OpenCL.make

@@ -1,4 +1,17 @@
 
+ifndef COMPILER
+$(info Define a compiler to set common defaults, i.e make COMPILER=GNU)
+endif
+
+COMPILER_ = $(CXX)
+COMPILER_GNU = g++
+COMPILER_CRAY = CC
+
+FLAGS_ = -O3
+FLAGS_GNU = -O3 -std=c++11
+FLAGS_CRAY = -O3 -hstd=c++11
+CFLAGS=$(FLAGS_$(COMPILER))
+
 ocl-stream: main.cpp OCLStream.cpp
-	$(CXX) -O3 -std=c++11 -DOCL $^ $(EXTRA_FLAGS) -lOpenCL -o $@
+	$(COMPILER_$(COMPILER)) $(CFLAGS) -DOCL $^ $(EXTRA_FLAGS) -lOpenCL -o $@