O2 optimization makefiles.

diff --git a/lib/Makefile b/lib/Makefile
index e95d160..d1adfdf 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -1,6 +1,6 @@
 FC      = xlf_r -c
 #FC      = ifort -c
-FCFLAGS = -O3 -g -q64 -qarch=pwr7 -qtune=pwr7
+FCFLAGS = -O2 -g -q64 -qarch=pwr7 -qtune=pwr7

 SHRLD    = xlf_r
 SHRFLAGS = -qpic
diff --git a/lib/Makefile.xlf_O2 b/lib/Makefile.xlf_O2
new file mode 100644
index 0000000..d1adfdf
--- /dev/null
+++ b/lib/Makefile.xlf_O2
@@ -0,0 +1,66 @@
+FC      = xlf_r -c
+#FC      = ifort -c
+FCFLAGS = -O2 -g -q64 -qarch=pwr7 -qtune=pwr7
+
+SHRLD    = xlf_r
+SHRFLAGS = -qpic
+SHARED   = -qmkshrobj
+SHRLIB   =
+
+TAR       = tar
+AR        = ar
+ARFLAGS   = -crusv
+
+#------------------------------ L-BFGS-B ------------------------------#
+
+LBFGSB = Lbfgsb.3.0
+
+OBJLBFGSB = $(LBFGSB)/blas.o    $(LBFGSB)/lbfgsb.o \
+            $(LBFGSB)/linpack.o $(LBFGSB)/timer.o
+
+PICLBFGSB = $(LBFGSB)/blas_pic.o    $(LBFGSB)/lbfgsb_pic.o \
+            $(LBFGSB)/linpack_pic.o $(LBFGSB)/timer_pic.o
+
+TRGLBFGSB = liblbfgsb.a
+SHRLBFGSB = liblbfgsb.so
+
+#----------------------------------------------------------------------#
+#                                Rules                                 #
+#----------------------------------------------------------------------#
+
+.SUFFIXES: .o .f $(SUFFIXES)
+.PHONY : all static shared clean veryclean
+
+all    : $(LBFGSB) $(TRGLBFGSB) $(SHRLBFGSB)
+static : $(LBFGSB) $(TRGLBFGSB)
+shared : $(LBFGSB) $(SHRLBFGSB)
+lbfgsb : $(LBFGSB) $(TRGLBFGSB) $(SHRLBFGSB)
+
+%.o : %.f Makefile
+	$(FC) $(FCFLAGS) $< -o $*.o
+
+%_pic.o : %.f
+	$(FC) $(FCFLAGS) $(SHRFLAGS) -o $@ $<
+
+$(LBFGSB) : $(LBFGSB).tar.gz
+	$(TAR) xfvz $<
+
+$(TRGLBFGSB) : $(OBJLBFGSB) Makefile
+	$(AR) $(ARFLAGS) $@ $(OBJLBFGSB)
+
+$(SHRLBFGSB) : $(PICLBFGSB) Makefile
+	$(SHRLD) $(SHARED) $(PICLBFGSB) $(SHRLIB) -o $@
+
+clean :
+	if [ -d $(LBFGSB) ]; then rm -rf $(LBFGSB); fi
+	for f in $(OBJLBFGSB); do if [ -e $$f ]; then rm -f $$f; fi; done
+	for f in $(PICLBFGSB); do if [ -e $$f ]; then rm -f $$f; fi; done
+	for f in *~; do rm -f $$f; done
+
+veryclean:
+	if [ -d $(LBFGSB) ]; then rm -rf $(LBFGSB); fi
+	if [ -e $(TRGLBFGSB) ]; then rm -f $(TRGLBFGSB); fi
+	if [ -e $(SHRLBFGSB) ]; then rm -f $(SHRLBFGSB); fi
+	for f in $(OBJLBFGSB); do if [ -e $$f ]; then rm -f $$f; fi; done
+	for f in $(PICLBFGSB); do if [ -e $$f ]; then rm -f $$f; fi; done
+	for f in *~; do rm -f $$f; done
diff --git a/src/makefiles/Makefile.xlf2003_serial_O2 b/src/makefiles/Makefile.xlf2003_serial_O2
new file mode 100644
index 0000000..424f7c4
--- /dev/null
+++ b/src/makefiles/Makefile.xlf2003_serial_O2
@@ -0,0 +1,45 @@
+#-*- mode: makefile -*-
+#-----------------------------------------------------------------------
+#                  IBM Fortran Compiler (serial)
+#-----------------------------------------------------------------------
+#+ This file is part of the AENET package.
+#+
+#+ Copyright (C) 2012-2016 Nongnuch Artrith and Alexander Urban
+#+
+#+ This program is free software: you can redistribute it and/or modify
+#+ it under the terms of the GNU General Public License as published by
+#+ the Free Software Foundation, either version 3 of the License, or
+#+ (at your option) any later version.
+#+
+#+ This program is distributed in the hope that it will be useful, but
+#+ WITHOUT ANY WARRANTY; without even the implied warranty of
+#+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#+ General Public License for more details.
+#+
+#+ You should have received a copy of the GNU General Public License
+#+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#-----------------------------------------------------------------------
+# 2015-05-26 Alexander Urban (AU) and Nongnuch Artrith (NA)
+#-----------------------------------------------------------------------
+
+SUFFIX   = xlf2003_serial_O2
+
+FC       = xlf2003_r -c
+LD       = xlf2003_r
+DEBUG    = # -g -warn all -check bounds
+FCFLAGS  = -O2 -g -q64 -qarch=pwr7 -qtune=pwr7 $(DEBUG)
+LDFLAGS  = $(DEBUG)
+NUMLIB   = -L$(SCINET_LAPACK_LIB) -q64 -lessl -llapack -lrefblas
+
+CC       = xlc_r -c
+CCFLAGS  =
+
+# linker for C-interoperable library (gcc & gfortran)
+LIBLD    = xlc_r
+LIBFLAGS = -qmkshrobj
+LIBLIB   =
+
+AR       = ar
+ARFLAGS  = -crusv
+
+include ./Makefile.inc