Added comments for GPU, PSB-EXT, GPGPU adds

examples/gpu/Makefile

@@ -4,8 +4,18 @@ include $(AMGINCDIR)/Make.inc.amg4psblas
 AMGMODDIR=$(AMGDIR)/modules
 AMGLIBDIR=$(AMGDIR)/lib
 AMG_LIBS=-L$(AMGLIBDIR) -lpsb_krylov -lamg_prec -lpsb_prec
-FINCLUDES=$(FMFLAG). $(FMFLAG)$(AMGMODDIR) $(FMFLAG)$(AMGINCDIR) $(PSBLAS_INCLUDES) $(FIFLAG).
-LINKOPT=
+# To compile these example you need to have also installed PSBLAS-EXT, SPGPU and
+# CUDA. Please refer to the documentation of AMG4PSBLAS and PSBLAX-EXT for the
+# full details.
+# This define the variables : PSBGPULDLIBS, LIBRSB_INCLUDES, and CUDA_INCLUDES
+PSBEXT_DIR= #< FILL-ME >
+include $(PSBEXT_DIR)/include/Make.inc.ext
+
+FINCLUDES=$(FMFLAG). $(FMFLAG)$(AMGMODDIR) $(FMFLAG)$(AMGINCDIR) \
+$(PSBLAS_INCLUDES) $(FIFLAG). $(FMFLAG)$(SPGPU_INCDIR) \
+$(FMFLAG)$(LIBRSB_INCLUDES) $(FMFLAG)$(CUDA_INCLUDES) \
+
+LINKOPT=$(CINCLUDES) $(CDEFINES) $(CUDEFINES) 
 
 DGOBJS=amg_dexample_gpu.o data_input.o amg_dpde_mod.o
 
@@ -16,7 +26,7 @@ all: amg_dexample_gpu
 
 amg_dexample_gpu: $(DGOBJS)
 	$(FLINK) $(LINKOPT) $(DGOBJS) -o amg_dexample_gpu \
-	$(AMG_LIBS) $(PSBLAS_LIBS)  $(LDLIBS)
+	$(AMG_LIBS) $(PSBLAS_LIBS) $(PSBGPULDLIBS) $(LDLIBS)
 	/bin/mv amg_dexample_gpu $(EXEDIR)
 
 amg_dexample_gpu.o: data_input.o amg_dpde_mod.o
@@ -28,4 +38,3 @@ lib:
 	(cd ../../; make library)
 verycleanlib:
 	(cd ../../; make veryclean)
-