#!/bin/sh
#set -xv

command="$0 $*"

# configure script for amber: creates config.h

#------------------------------------------------------------------------------
#  set up usage statement:
#------------------------------------------------------------------------------
usage(){
cat<<EOD

Usage: ./configure [flags] [compiler/architecture]

    where <compiler/architecture> is one of:

        absoft, compaqf90, efc7, hpf90, ifc7, ifort, ia64_ifort,
        pgf90, sgi_altix, sgi_mips, sparc, xlf90_aix, xlf90_suse.

    If not specified then the compiler is guessed.

    Parallel option flags:
      -lam        Use LAM/MPI (LAM_HOME must be set)
      -mpi        Use native MPI
      -mpich      Use MPICH (MPICH_HOME must be set)
      -mplite     Use MP_Lite (MPLITE_HOME must be set)
      -nopar      Explicit request of no MPI, the default
      -scali      Use SCALI (SCALI_HOME must be set)

    Platform option flags:
      -athlon     Optimize for Athlon processor (intel,pgf90).
      -gnucompat  Add a second underscore to some symbols to maintain
                    GNU compatibility (pgf90).
      -opteron    Optimize for Opteron processor (pgf90).
      -p4         Optimize for Pentium 4 processor (intel,pgf90).
      -cygwin     Add CygWin flags for Windows (absoft).

    General flags:
      -big         Big systems support, ie, 8 byte integers and pointers.
      -fpp_prefix= Define the prefix for FPP preprocessing; default is "_".
      -lmod        Request linking sander with Istvan Kolossvary's LMOD libraries.
      -mmtsb       Request building sander for MMTSB.
      -static      Static linking, i.e., prevent linking with shared libraries.
      -verbose     Add verbose compiler comment and warning flags.

    Other environment variables:
      AMBERHOME    Root directory of the Amber tree.
      MKL_HOME     Root directory of the Intel Math Kernel Library
                     (intel,sgi_altix); for example, /opt/intel/mkl61.
                     The MKL is recommended for optimal performance.

===========================================================
EOD

exit 1;
}

#------------------------------------------------------------------------------
#  Process commandline configuration options:
#------------------------------------------------------------------------------
unrequested='no'
arch='unknown'
athlon=$unrequested
big=$unrequested
bigness=''
cygwin=$unrequested
fpp_prefix='_'
gnucompat=$unrequested
lmod=$unrequested
mmtsb=$unrequested
opteron=$unrequested
parallel='none'
p4=$unrequested
sfx=''
sgimips='unknown'
static=$unrequested
verbose=$unrequested
verbosity=''

while [ $# -gt 0 ]; do
    case "$1" in
    -lam)     parallel="lam" ;;
    -mpi)     parallel="mpi" ;;
    -mpich)   parallel="mpich" ;;
    -mplite)  parallel="mplite" ;;
    -nopar)   parallel="none" ;;
    -scali)   parallel="scali" ;;

    -athlon)  athlon="yes" ;;
    -gnucompat)  gnucompat="yes" ;;
    -opteron) opteron="yes" ;;
    -p4)      p4="yes" ;;
    -cygwin)  cygwin="yes" ; sfx=".exe" ;;

    -big)     big="yes" ;;
    -fpp_prefix=*) fpp_prefix=${1#-fpp_prefix=} ;;
    -lmod)    lmod="yes" ;;
    -mmtsb)   mmtsb="yes" ;;
    -static)  static="yes" ;;
    -verbose) verbose="yes" ;;

    -*) usage ;;

    *) if [ $# -gt 1 ]; then
         usage
       fi
       arch=$1 ;;

    esac
    shift
done


if [ $arch = "unknown" ]; then
    # Guess architecture/compiler
    arch=`uname -s`
    if [ $arch = "Linux" ]; then
        arch=`uname -m`
        if [ $arch = 'ia64' ]; then
            arch=ia64_ifort
        elif [ "$IA64ROOT" != "" ]; then
            arch=ia64_ifort
        elif [ "$IA32ROOT" != "" ]; then
            arch=ifort
        elif [ "$PGI" != "" ]; then
            arch=pgf90
        else
            arch=ifc7
        fi
    fi
fi

#------------------------------------------------------------------------------
#  Set up defaults that work for most machines:
#------------------------------------------------------------------------------

if [ -z "$AMBERHOME" ]; then
    echo "Warning: the AMBERHOME environment variable is not defined !"
    echo "    It usually should be set to the path of Amber's top level directory."
    workdir=`pwd`
    AMBERHOME=`dirname $workdir`
    echo "Caution: Setting AMBERHOME to $AMBERHOME !"
    echo " "
else
    echo "AMBERHOME is set to $AMBERHOME"
fi

amber_src=$AMBERHOME/src

#  Program specific:
localflags=

# The preprocessor is always cpp even for Fortran.
fpp="cpp -traditional"
fppflags="-P -I\$(AMBER_SRC)/include"
if [ $mmtsb = "yes" ]; then
    fppflags="$fppflags -DMMTSB"
fi

#  C compilation:
cpp=cpp
cc=cc
cplusplus=CC
cppflags=
if [ $mmtsb = "yes" ]; then
    cppflags="$cppflags -DMMTSB"
fi
cflags=
#         (altcc is used for C codes linked to fortran main routines;
#          sometimes this is different than for C main routines....)
altcc=cc
altcflags=

#  Fortran compilation:
fc=f90
fflags="-O0 -132"
foptflags=-O2
freeformat_flag=

#  Loading:
load="$fc"
loadcc="$cc"
loadlib=
loadptraj=
if [ $static = "yes" ]; then
    static_flag='-static'
else
    static_flag=
fi

#  Libraries:
m4='m4'
sysdir='lib'
use_blas=SOURCE_COMPILED
use_lapack=SOURCE_COMPILED
if [ $lmod = "yes" ]; then
    use_lmod=LMOD_SUPPLIED
else
    use_lmod=LMOD_UNAVAILABLE
fi
xhome='/usr/X11R6'

#  Auxiliary programs:
ar='ar rv '
ranlib=ranlib

par_error () {
cat <<EOD
**********************************************************
  ERROR:  ${PAR} is not set

  set the ${PAR}_HOME environment variable to the
  location of the include/ and lib/ subdirectories
  containing $FILES
  for your $PAR distribution.

  For example, with csh/tcsh:
      setenv ${PAR}_HOME $EXAMPLE
  or with sh/bash:
      export ${PAR}_HOME=$EXAMPLE

**********************************************************
EOD
exit 1
}

echo "Setting up Amber configuration file for architecture: $arch"
echo "Using parallel communications library: $parallel"

case "$parallel" in
lam)
    if [ -z "$LAM_HOME" ]; then
        PAR="LAM"
        FILES="mpif.h and libmpi.a, liblam.a or liblamf77mpi.a"
        EXAMPLE="/usr/local/lam/intel-7.0"
        par_error
    fi
    echo "LAM_HOME is set to $LAM_HOME"
    lamlibs=`$LAM_HOME/bin/mpif77 -showme | perl -p -e 's/(-[lL]\S+\s)|\S+\s/$1/g'`
    loadlib="$loadlib $lamlibs"
    fppflags="-I$LAM_HOME/include $fppflags -DMPI "
    ;;

mpi)
    loadlib="$loadlib -lmpi"
    fppflags="$fppflags -DMPI "
    ;;

mpich)
    if [ -z "$MPICH_HOME" ]; then
        PAR="MPICH"
        FILES="mpif.h and libmpi.a or libmpich.a"
        EXAMPLE="/usr/local/src/mpich/build/LINUX/ch_pentium4"
        par_error
    fi
    echo "MPICH_HOME is set to $MPICH_HOME"
    mpichlibs=`$MPICH_HOME/bin/mpif90 -show | perl -p -e 's/(-[lL]\S+\s)|\S+\s/$1/g'`
    loadlib="$loadlib $mpichlibs"
    fppflags="-I$MPICH_HOME/include $fppflags -DMPI "
    ;;

mplite)
    if [ -z "$MPLITE_HOME" ]; then
        PAR="MPLITE"
        FILES="mpif.h and libmplite.a"
        EXAMPLE="/usr/local/mp_lite/MP_Lite_2.3"
        par_error
    fi
    echo "MPLITE_HOME is set to $MPLITE_HOME"
    loadlib="$loadlib -L$MPLITE_HOME/lib -lmplite"
    fppflags="-I$MPLITE_HOME/include $fppflags -DMPI "
    ;;

scali)
    missingfiles ()
    {
        echo " XXXXX   ERROR  XXXXX"
        echo " libs or includes are missing from \$SCALI_HOME $SCALI_HOME"
        exit 1
    }
    scali_root='/opt/scali'
    if [ -z "$SCALI_HOME" ] ; then
        if [ -d $scali_root ]; then
           echo "Warning: the SCALI_HOME environment variable is not defined !"
           SCALI_HOME="$scali_root"
           echo "Caution: Setting SCALI_HOME to $scali_root (guessed)"
        else
            PAR="SCALI"
            FILES="mpif.h and libmpi.a"
            EXAMPLE="/usr/local/scali"
            par_error
        fi
    else
        echo "SCALI_HOME is set to $SCALI_HOME"
    fi

    if [ ! -d $SCALI_HOME/lib ] || [ ! -d $SCALI_HOME/include ]
        then echo " missing dirs"; missingfiles ; fi
    if [ ! -f $SCALI_HOME/include/mpif.h ] ;
        then echo " missing include"; missingfiles ; fi
    for lib in mpi scasci scirtl ; do
        if  [ ! -f $scali_root/lib/lib$lib.so ]  && \
        [ ! -f $scali_root/lib/lib$lib.a ]
            then echo " missing libs"; missingfiles; fi
    done

    if [ $static = "yes" ]; then
        # scali/doc/ScaMPI/FAQ item 20 (Version: 1.20 Date: Oct 15th 2001):
        #loadlib="$loadlib -L$SCALI_HOME/lib -lfmpi -lmpi -Wl,-Bdynamic -lpthread -ldl -Wl,-Bstatic"
        # builds but does not execute. 
        # Neither does static linking of -lpthread -ldl.
        echo "Error: static linking with SCALI is not supported !"
        exit 1
    else
        loadlib="$loadlib -L$SCALI_HOME/lib -lfmpi -lmpi"
    fi
    fppflags="-I$SCALI_HOME/include $fppflags -DMPI"
    ;;

none) # Nothing to do
    ;;

*)
    echo "FIXME: add support for parallel flag $parallel"
    exit 1
    ;;

esac

#------------------------------------------------------------------------------
#  Case statement identifying the architecture/compilers:
#------------------------------------------------------------------------------

case "$arch" in

############ IA64 Intel compilers ################
efc7|ia64_ifort|sgi_altix)
    fppflags="$fppflags "
    freeformat_flag='-FR'
    fflags=" -w95 -ftz "
    if [ $big = "yes" ]; then
        echo '32 bit architecture - pointers remain 4 bytes; integers 8 bytes.'
        if [ $lmod = "yes" ]; then
            echo "Warning: the big flag is incompatible with LMOD."
        fi
        bigness='-i8'
    fi
    if [ $verbose = "yes" ]; then
        verbosity='-vec_report3 -opt_report -opt_report_level max -opt_report_phase all -V -v'
    fi
    fflags="$fflags $bigness $verbosity"

    #   check for installation of the Intel Math Kernel library:
    mkll=$unrequested
    if [ -z "$MKL_HOME" ]; then
        echo "The MKL_HOME environment variable is not defined."
        echo "    The MKL is recommended for optimal performance."
    else
        echo "MKL_HOME is set to $MKL_HOME"
        if [ -d $MKL_HOME/lib/64 ]; then
            mkll=$MKL_HOME/lib/64
            echo "Using MKL libraries from $mkll"
        else
            echo "MKL libraries were not found !"
        fi
    fi
    if [ $mkll != $unrequested ]; then
        use_lapack=VENDOR_SUPPLIED
        use_blas=VENDOR_SUPPLIED
        # MKL Technical Notes: Itanium static linking of LAPACK and kernels
        loadlib="$loadlib $mkll/libmkl_lapack.a $mkll/libmkl_ipf.a -L$mkll -lguide -lpthread -ldl"
        # dynamic linking fails on our altix for parallel execution, Nov 17, 2003:
        # ERROR: dlerror called but not available on linux
        # Furthermore, -static does not help since libmpi.a does not exist.
        # MKL Technical Notes: Itanium dynamic linking of LAPACK and kernels
        #loadlib="$loadlib -L$mkll -lmkl_lapack -lmkl -lvml -lguide -lpthread -ldl"
        fppflags="$fppflags -DMKL"
    else
        usrlib=/usr/lib
        if [ -e $usrlib/libscs.so ]; then
            # Assume that .a's also exist if static has been requested.
            use_lapack=VENDOR_SUPPLIED
            use_blas=VENDOR_SUPPLIED
            loadlib="$loadlib -lscs"
            fppflags="$fppflags -DSGIFFT"
            echo "Using LAPACK and BLAS from SCSL."
        fi
    fi

    if [ $arch = 'sgi_altix' -o $arch = 'ia64_ifort' ]; then
        fc=ifort
        load="$fc $static_flag"
        foptflags="$fflags -O3 -IPF_fma -ip"
        cc=icc
        altcc=icc
        cplusplus=icpc
    else
        fc=efc
        load="$fc $static_flag -Vaxlib"
        foptflags="$fflags -O2 -IPF_fma -ip"
        cc=ecc
        altcc=ecc
        cplusplus=ecc
    fi
    fflags="$fflags -O2"
    cflags=-O2
    loadcc="$cc $static_flag"

    # nofor_main prevents linking of the fortran main routine.
    loadptraj="$load -nofor_main"
    ;;

############ IA32 Intel compilers;  ################
ifc7|ifort|ia32_ifort)
    cc=gcc
    altcc=gcc
    cplusplus=g++
    cflags=-O2
    loadcc="$cc $static_flag"
    fppflags="$fppflags"
    freeformat_flag='-FR'
    fflags=" -w95 "
    if [ $big = "yes" ]; then
        echo '32 bit architecture - pointers remain 4 bytes; integers 8 bytes.'
        if [ $lmod = "yes" ]; then
            echo "Warning: the big flag is incompatible with LMOD."
        fi
        bigness='-i8'
    fi
    if [ $verbose = "yes" ]; then
        verbosity='-sox -vec_report3 -opt_report -opt_report_level max -opt_report_phase all -V -v -Wl,-verbose,-M'
    fi
    fflags="$fflags $bigness $verbosity"

    if [ $athlon = "yes" ]; then
        fflags="$fflags -tpp6 "
#       cflags="$cflags -march=athlon"
    elif [ $p4 = "yes" ]; then
        fflags="$fflags -tpp7 "
#       cflags="$cflags -march=pentium4"
        loadlib="$loadlib -lsvml"
    fi

    #   check for installation of the Intel Math Kernel library:

    mkll=$unrequested
    if [ $big = "yes" ]; then
        echo "Warning: the big flag is incompatible with the MKL."
        echo "    The MKL_HOME environment variable is not ignored."
    else
        if [ -z "$MKL_HOME" ]; then
            echo "The MKL_HOME environment variable is not defined."
            echo "    The MKL is recommended for optimal performance."
        else
            echo "MKL_HOME is set to $MKL_HOME"
            if [ -d $MKL_HOME/lib/32 ]; then
                mkll=$MKL_HOME/lib/32
                echo "Using MKL libraries from $mkll"
            else
                echo "MKL libraries were not found !"
            fi
        fi
    fi
    if [ $mkll != $unrequested ]; then
        use_lapack=VENDOR_SUPPLIED
        use_blas=VENDOR_SUPPLIED
        if [ $static = "yes" ]; then
            # Intel� Math Kernel Library 6.1 for Linux Technical User Notes
            #  IA-32 static linking of LAPACK and kernels
            loadlib="$loadlib $mkll/libmkl_lapack.a $mkll/libmkl_ia32.a -L$mkll -lguide -lpthread"
        else
            # Intel� Math Kernel Library 6.1 for Linux Technical User Notes
            #  IA-32 dynamic linking of double-precision-LAPACK and kernels
            loadlib="$loadlib -L$mkll -lvml -lmkl_lapack64 -lmkl -lguide -lpthread"
        fi
        fppflags="$fppflags -DMKL"
    fi

    if [ $arch = 'ifort' -o $arch = 'ia32_ifort' ]; then
        fc=ifort
        load="$fc $static_flag "
    else
        fc=ifc
        load="$fc $static_flag -Vaxlib"
    fi
    foptflags="$fflags -mp1 -ip -O3"
    fflags="$fflags -mp1 -O0"

    # nofor_main prevents linking of the fortran main routine.
    loadptraj="$load -nofor_main"
    ;;

#################### Portland Compiler #####################
pgf90)
    cc=pgcc
    altcc=pgcc
    cplusplus=pgCC
    fc=pgf90
    if [ $static = "yes" ]; then
        static_flag='-Bstatic'
    fi
    load="$fc $static_flag"
    loadcc="$cc $static_flag"
    if [ -e /usr/pgi/linux86/lib/liblapack.a ]; then
        use_lapack=VENDOR_SUPPLIED
        use_blas=VENDOR_SUPPLIED
        loadlib="$loadlib -llapack -lblas"
        echo "Using Portland Group LAPACK and BLAS."
    fi
    cflags='-O2'
    if [ $athlon = "yes" ]; then
        cflags="$cflags -tp athlon"
        fflags="-tp athlon -O"
        foptflags="-tp athlon -fast"
    elif [ $opteron = "yes" ]; then
        # In August 2003 static builds on opterons did not work.
        if [ $big = "yes" ]; then
            fflags=" -O"
            foptflags=" -fast"
            load="pgf90"
        else
            cflags="$cflags -tp k8-32"
            fflags="-tp k8-32 -O"
            foptflags="-tp k8-32 -fastsse"
            load="pgf90 -tp k8-32 -fastsse"
        fi
    elif [ $p4 = "yes" ]; then
        cflags="$cflags -tp p7"
        fflags="-tp p7 -O"
        # -fastsse is -Mscalarsse -Mvect=sse -Mcache_align -Mflushz -fast
        # but -Mcache_align causes sander to segmentation fault; SRB March 2004
        foptflags="-tp p7 -Mscalarsse -Mvect=sse -Mflushz -fast -O3"
        load="$load -tp p7 -fastsse -O3"
    else
        cflags="$cflags -tp px"
        fflags="-tp px -O"
        foptflags="-tp px -fast"
    fi
    if [ $gnucompat = "yes" ]; then
        gnucompatibility='-Msecond_underscore'
        cflags="$cflags $gnucompatibility"
        fflags="$fflags $gnucompatibility"
        foptflags="$foptflags $gnucompatibility"
    fi
    if [ $big = "yes" ]; then
        echo '32 bit architecture - pointers remain 4 bytes; integers 8 bytes.'
        if [ $lmod = "yes" ]; then
            echo "Warning: the big flag may be incompatible with LMOD."
        fi
        bigness='-i8 -i8storage'
    fi
    if [ $verbose = "yes" ]; then
        verbosity='-v -V -Minfo=all -Minform=inform -Mneginfo'
    fi
    fflags="$fflags $bigness $verbosity"
    foptflags="$foptflags $bigness $verbosity"
    freeformat_flag='-Mfree'
    loadptraj="$load -Mnomain"
    ;;

#################### Absoft Windows #####################
absoft)
    if [ $cygwin = "yes" ]; then
#
#       ---note that altcflags, loadlib, and fc definitions are specific
#          to the Absoft version (8.2 here) and the installation location
#
        cc=gcc
        altcc=acc
        altcflags=" -DABSOFT_WINDOWS -Ic:/Absoft82/CINCLUDE -DCLINK_CAPS"
        cplusplus='g++'
        cflags="-DCLINK_CAPS"
        fc="f90.exe -Z1643 -Z1644"
        fppflags="$fppflags -DABSOFT_WINDOWS "
        load=$fc
        loadcc=$cc
        loadlib=" -aliases:unicode.als c:/Absoft82/LIB/unix.lib"
        fflags="-O1"
        foptflags="-O2"
        if [ $verbose = "yes" ]; then
            echo "verbose option is not implemented yet."
        fi
        fflags="$fflags $bigness $verbosity"
        foptflags="$foptflags $bigness $verbosity"
        freeformat_flag='-f free'
        ar="lb.exe /out:"
        ranlib=/bin/true
#       use_lapack=VENDOR_SUPPLIED
#       use_blas=VENDOR_SUPPLIED
    else
#                   (absoft-Linux, not yet tested!)
        cc=gcc
        altcc=acc
        altcflags="-DCLINK_CAPS"
        cplusplus='g++'
        cflags="-DCLINK_CAPS"
        fc=f90
        load=$fc
        loadcc=$cc
        loadlib=" -lm"
        fflags="-O1"
        foptflags="-O2"
        if [ $big = "yes" ]; then
            echo "big option is not implemented yet."
        fi
        if [ $verbose = "yes" ]; then
            echo "verbose option is not implemented yet."
        fi
        fflags="$fflags $bigness $verbosity"
        foptflags="$foptflags $bigness $verbosity"
        freeformat_flag='-f free'
#       use_lapack=VENDOR_SUPPLIED
#       use_blas=VENDOR_SUPPLIED
    fi
    loadptraj="$load"
    ;;

##################### SGI IRIX 32-bit ###############
sgi_mips|IRIX64)

    sgi_abi='-n32'
    fpp='/lib/cpp'
    fppflags="$fppflags -DSGI -DnoVDINVSQRT"
    if [ -e /usr/lib32/mips4/libscs.so ]; then
        use_lapack=VENDOR_SUPPLIED
        use_blas=VENDOR_SUPPLIED
        loadlib="$loadlib -lscs"
        fppflags="$fppflags -DSGIFFT"
    fi

    sgi_cpuarch=` hinv -t cpu | awk ' { print $3 }  ' | head -1 `
    sgi_Rdigit=` echo $sgi_cpuarch | sed s/R// `
    if [ $sgi_Rdigit -lt 4000 ]; then
        # R3k machines, those less than R4000 are not supported.
        echo "The $sgi_cpuarch Processor is no longer supported."
    elif [ $sgi_Rdigit -lt 5000 ]; then
        # R4k machines: only ones with -mips3
        sgi_mips='-mips3'
    else
        # All others are now -mips4
        sgi_mips="-mips4 -r$sgi_Rdigit"
    fi
    if [ $sgi_cpuarch = R5000 ]; then
        # R5k machines
        sgi_options='-OPT:roundoff=3:IEEE_arithmetic=3 -TENV:X=1 -SWP:strict_ivdep=OFF:if_conversion=OFF -WK,-dr=ACK,-o=1,-so=1,-r=3'
        # -WK options should be removed in a year; SRB Apr 2003.
        loadlib="$loadlib -lm"
    elif [ $sgi_cpuarch = R8000 ]; then
        # R8k machines
        sgi_options='-OPT:cis=off:roundoff=3:IEEE_arithmetic=3 -TENV:X=3 -SWP:strict_ivdep=OFF -WK,-dr=AKC'
        # -WK options should be removed in a year; SRB Apr 2003.
        loadlib="$loadlib -lfastm"
    else
        sgi_options='-OPT:roundoff=3:IEEE_arithmetic=3 -TENV:X=1'
        loadlib="$loadlib -lfastm"
    fi

    cflags="$sgi_abi $sgi_mips $sgi_options -O2 -DSYSV"
    fflags="$sgi_abi $sgi_mips $sgi_options -O0"
    foptflags="$sgi_abi $sgi_mips $sgi_options -O3"
    if [ $big = "yes" ]; then
        bigness='-64 -i8'
    fi
    if [ $verbose = "yes" ]; then
        # include -S to get a software pipelining report,
        # delete the .s files later else the build will not be up to date.
        verbosity="-LIST:notes=ON:software_names=ON -LIST:all_options=ON:cite=ON:symbols=ON"
    fi
    cflags="$cflags $bigness"
    fflags="$fflags $bigness $verbosity"
    foptflags="$foptflags $bigness $verbosity"
    load="$fc $sgi_abi $sgi_mips"
    loadcc="$cc $sgi_abi $sgi_mips"
    if [ $static = "yes" ]; then
        echo "Warning: static linking is not supported; option ignored."
    fi
    freeformat_flag='-freeform'
    ar='ar rvs '
    ranlib=/bin/true
    m4='m4 -B50000'
    loadptraj="$load"
    ;;

####################### HP ############################
hpf90|HP-UX)
    fpp='/lib/cpp'
    if [ $parallel = "mpi" ]; then
        fppflags="$fppflags -I/opt/mpi/include"
        fc='mpif90'
    else
        fc=f90
    fi
    cplusplus=aCC
    use_lapack=VENDOR_SUPPLIED
    use_blas=VENDOR_SUPPLIED
    loadlib="$loadlib -lveclib -llapack -lm "
    if [ $static = "yes" ]; then
        # +noshared is preferred over -N which is ignored by ld.
        # But it is not clear that +noshared is working; so use archive_shared.
        static_flag='+noshared -Wl,-aarchive_shared'
    fi
    load="$fc $static_flag"
    loadcc="$cc $static_flag"

    fppflags="$fppflags -DHP "
    cppflags="-DCLINK_PLAIN"
    cflags="-Ae -DSYSV"
    # no postpending underscores (ppu) to link Fortran and C.
    # U77 library contains: etime, getarg, iargc.
    fflags='+noppu +U77 +Ofast'
    # +Ofaster is ~10% faster (JAC) but build is very slow
    # and in Sep 2003 for unknown reasons suddenly produces link errors
    foptflags='+noppu +U77 +Ofast'
    if [ $big = "yes" ]; then
        if [ $lmod = "yes" ]; then
            echo "Warning: the big flag is incompatible with LMOD."
        fi
        bigness='+DD64 +i8'
    fi
    if [ $verbose = "yes" ]; then
        verbosity='-v +Oinfo -Wl,-v,-m'
    fi
    cflags="$cflags $bigness"
    fflags="$fflags $bigness $verbosity"
    foptflags="$foptflags $bigness $verbosity"
    load="$load $foptflags"
    freeformat_flag='+source=free'
    ar='ar rvs '
    ranlib=/bin/true
    m4='m4 -B50000'
    loadptraj="$load"
    ;;

####################### IBM AIX ############################
xlf90_aix|AIX)

    libpath=/usr/lib
    if [ -e $libpath/libmass.a ]; then
        loadlib="$loadlib -L$libpath -lmass"
        fppflags="$fppflags -DMASSLIB"
    fi
    if [ -e $libpath/libblas.a ]; then
        loadlib="$loadlib -L$libpath -lblas"
        use_blas=VENDOR_SUPPLIED
    fi
    if [ -e $libpath/libessl.a ]; then
        loadlib="$loadlib -L$libpath -lessl"
        use_lapack=SOURCE_COMPILED
        fppflags="$fppflags -DESSL"
    fi
    sysdir='Machines/ibm_aix'
    fppflags="$fppflags -DNMLEQ -DCLINK_PLAIN -Drs6000"
    fpp='/lib/cpp -traditional'
    if [ $parallel = "mpi" ]; then
        fppflags="$fppflags -DPOE"
        fpp="$fpp -I/usr/lpp/ppe.poe/include"
        fc='mpxlf90_r -bmaxdata:0x80000000'
    else
        fc=xlf90
    fi
    cc=xlc
    altcc=xlc
    cppflags="-DCLINK_PLAIN"
    cflags="-O2"
    cplusplus=xlC
    if [ $static = "yes" ]; then
        static_flag='-bstatic'
    fi
    load="$fc $static_flag "
    loadcc="$cc $static_flag"
    fflags="-qfixed -c"
    foptflags="-qfixed -O3 -qmaxmem=-1 -qarch=auto -qtune=auto -c"
    if [ $big = "yes" ]; then
        echo "big option is not implemented yet."
    fi
    if [ $verbose = "yes" ]; then
        verbosity='-qsource -qreport=hotlist'
    fi
    fflags="$fflags $bigness $verbosity"
    foptflags="$foptflags $bigness $verbosity"
    freeformat_flag='-qfree'
    ar='ar rvs '
    ranlib=/bin/true
    loadptraj="$load"
    m4='m4 -B50000'
    ;;

####################### PowerPC SUSE Linux ############################
xlf90_suse)

    libpath=/usr/lib
    if [ -e $libpath/libmass.a ]; then
        loadlib="$loadlib -L$libpath "
        fppflags="$fppflags"
    fi
    if [ -e $libpath/libblas.a ]; then
        loadlib="$loadlib -L$libpath -lblas"
        use_blas=VENDOR_SUPPLIED
    fi
    if [ -e $libpath/libessl.a ]; then
        loadlib="$loadlib -L$libpath -lessl"
        use_lapack=VENDOR_SUPPLIED
    fi

    fppflags="$fppflags -DCLINK_PLAIN -Drs6000"
    fpp='/opt/ibmcmp/xlf/8.1/exe/cpp '
    if [ $parallel = "mpich" ]; then
        fpp="$fpp -I$MPICH_HOME/include"
        fc='mpif90'
    else
        echo "ONLY HAVE MPICH for parallel"
        exit 1
    fi
    cc=cc
    cppflags="-DCLINK_PLAIN"
    cflags="-O2"
    cplusplus=xlC
    if [ $static = "yes" ]; then
        static_flag='-bstatic'
    fi
    load="$fc $static_flag "
    loadcc="$cc $static_flag"
    fflags="-qfixed -c"
    foptflags="-qfixed -O3 -qmaxmem=-1 -qarch=auto -qtune=auto -c"
    if [ $big = "yes" ]; then
        echo "big option is not implemented yet."
    fi
    if [ $verbose = "yes" ]; then
        verbosity='-qsource -qreport=hotlist'
    fi
    fflags="$fflags $bigness $verbosity"
    foptflags="$foptflags $bigness $verbosity"
    freeformat_flag='-qfree'
    ar='ar rvs '
    ranlib=/bin/true
    loadptraj="$load"
    ;;

####################### Compaq DEC Alpha OSF1 ##########################
compaqf90|OSF1)

    use_lapack=VENDOR_SUPPLIED
    use_blas=VENDOR_SUPPLIED

    # -C prevents striping of C-style AND C++-style comments;
    # some format statements contain //
    fppflags="-C $fppflags"
    fpp='/lib/cpp -traditional'

    fflags="-tune host -arch host"
    foptflags="-fast -O3 -tune host -arch host"
    cplusplus=cxx
    cflags="-O -std1"
    if [ $big = "yes" ]; then
        # pointers are always 64 bits
        # but see -taso
        if [ $lmod = "yes" ]; then
            echo "Warning: the big flag is incompatible with LMOD."
        fi
        bigness='-i8'
    fi
    if [ $verbose = "yes" ]; then
        verbosity='-source_listing -annotations all -Wl,-v,-m,-M'
    fi
    fflags="$fflags $bigness $verbosity"
    foptflags="$foptflags $bigness $verbosity"

    if [ $static = "yes" ]; then
        static_flag='-non_shared'
    fi
    load="$fc $static_flag $verbosity"
    loadcc="$cc $static_flag"
    loadlib="$loadlib -ldxml -lm"
    freeformat_flag='-free'
    ranlib=/bin/true
    m4='m4 -B50000'
    # nofor_main prevents linking of the fortran main routine.
    loadptraj="$load -nofor_main"
    ;;

####################### Sun ############################
sparc|SunOS)

    xhome='/usr/openwin'
    fpp='/lib/cpp'
    fppflags="$fppflags"
    if [ -f /opt/SUNWspro/lib/libsunperf.so ]; then
        use_lapack=VENDOR_SUPPLIED
        use_blas=VENDOR_SUPPLIED
        loadlib="$loadlib -xlic_lib=sunperf"
        # Note that the Sun Performance Library has FFT routines.
        # Sun Performance Library User's Guide,
        # http://docs.sun.com/source/806-3566/index.html
    fi
    loadlib="$loadlib -lm"

    fflags='-O1'
    foptflags='-O2'
    if [ $big = "yes" ]; then
        #in fact f90 -xhelp=readme suggests that integer sizes cannot be controlled with compiler options.
        echo "big option is not implemented yet."
    fi
    if [ $verbose = "yes" ]; then
        echo "verbose option is not implemented yet."
    fi
    fflags="$fflags $bigness $verbosity"
    foptflags="$foptflags $bigness $verbosity"
    if [ $static = "yes" ]; then
        static_flag='-Bstatic'
    fi
    load="$fc $static_flag "
    loadcc="$cc $static_flag"
    cflags="$cflags -DSYSV "
    freeformat_flag='-free'
    m4='m4 -B50000'
    loadptraj="$load"
    ;;

*)
    echo "Architecture/compiler $arch is not supported (?)" 1>&2
    usage
    ;;


esac

#------------------------------------------------------------------------------
#  Finally, write out the config.h file:
#------------------------------------------------------------------------------

cat <<EOD > config.h
#==============================================================================
# AMBER Makefile configuration for compiler/architecture: $arch
# Generated via command: $command
#
# Configuration script written mainly by Joe Krahn, Scott Brozell, and
# Dave Case, with contributions from lots of people.
#==============================================================================

#------------------------------------------------------------------------------
# Main AMBER source root directory
#------------------------------------------------------------------------------
AMBER_SRC=$amber_src

#------------------------------------------------------------------------------
# AMBERBUILDFLAGS provides a hook into the build process for installers;
# for example, to build debug versions of the amber programs
# make -e AMBERBUILDFLAGS="-DDEBUG -g"
#------------------------------------------------------------------------------
AMBERBUILDFLAGS=

#------------------------------------------------------------------------------
# LOCALFLAGS is intended for program specific modifications to the
# Fortran build process and may be modified by the program's local makefile
#------------------------------------------------------------------------------
LOCALFLAGS=$localflags

#------------------------------------------------------------------------------
# Availability and method of delivery of math and optional libraries
#------------------------------------------------------------------------------
USE_BLASLIB=\$($use_blas)
USE_LAPACKLIB=\$($use_lapack)
USE_LMODLIB=\$($use_lmod)

#------------------------------------------------------------------------------
# C compiler
#------------------------------------------------------------------------------
CC= $cc
CPLUSPLUS=$cplusplus
ALTCC=$altcc
CFLAGS=$cflags \$(AMBERBUILDFLAGS)
ALTCFLAGS=$altcflags \$(AMBERBUILDFLAGS)
CPPFLAGS=$cppflags \$(AMBERBUILDFLAGS)

#------------------------------------------------------------------------------
# Fortran preprocessing and compiler.
# FPPFLAGS holds the main Fortran options, such as whether MPI is used.
#------------------------------------------------------------------------------
FPPFLAGS= $fppflags \$(AMBERBUILDFLAGS)
FPP= $fpp \$(FPPFLAGS)
FC= $fc
FFLAGS= $fflags \$(LOCALFLAGS) \$(AMBERBUILDFLAGS)
FOPTFLAGS= $foptflags \$(LOCALFLAGS) \$(AMBERBUILDFLAGS)
FPP_PREFIX= $fpp_prefix
FREEFORMAT_FLAG= $freeformat_flag

#------------------------------------------------------------------------------
# Loader:
#------------------------------------------------------------------------------
LOAD= $load \$(LOCALFLAGS) \$(AMBERBUILDFLAGS)
LOADCC= $loadcc \$(LOCALFLAGS) \$(AMBERBUILDFLAGS)
LOADLIB= $loadlib
LOADPTRAJ= $loadptraj \$(LOCALFLAGS) \$(AMBERBUILDFLAGS)
XHOME= $xhome

#------------------------------------------------------------------------------
#  Other stuff:
#------------------------------------------------------------------------------
.SUFFIXES:  .f90
SYSDIR=$sysdir
AR=$ar
M4=$m4
RANLIB=$ranlib
SFX=$sfx
MAKEDEPEND=\$(AMBER_SRC)/../bin/amber_makedepend

#  default rules for Fortran and C compilation:

.f.o:   \$<
	\$(FPP) \$< > \$(FPP_PREFIX)\$<
	\$(FC) -c \$(FFLAGS) -o \$@ \$(FPP_PREFIX)\$<

.f90.o:   $<
	\$(FPP) \$< > \$(FPP_PREFIX)\$<
	\$(FC) -c \$(FFLAGS) -o \$@ \$(FPP_PREFIX)\$<

.c.o:
	\$(CC) -c \$(CFLAGS) \$(CPPFLAGS) -o \$@ \$<

EOD

echo " "
echo "The configuration file, config.h, was successfully created."
echo " "
exit