dnl  Process this file with autoconf to produce a configure script.


# Copyright 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
#
# This file is part of the GNU MP Library.
#
# The GNU MP Library is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation; either version 2.1 of the License, or (at
# your option) any later version.
#
# The GNU MP Library 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 Lesser General Public
# License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
# the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
# MA 02111-1307, USA.


AC_REVISION($Revision$)
AC_PREREQ(2.52)
AC_INIT(gmp-impl.h)
m4_pattern_forbid([^[ \t]*GMP_])
m4_pattern_allow(GMP_LDFLAGS)

# If --target is not used then $target_alias is empty, but if say
# "./configure athlon-pc-freebsd3.5" is used, then all three of
# $build_alias, $host_alias and $target_alias are set to
# "athlon-pc-freebsd3.5".
#
if test -n "$target_alias" && test "$target_alias" != "$host_alias"; then
  AC_MSG_ERROR([--target is not appropriate for GMP
Use --build=CPU-VENDOR-OS if you need to specify your CPU and/or system
explicitly.  Use --host if cross-compiling (see "Installing GMP" in the
manual for more on this).])
fi

GMP_INIT(config.m4)

AC_CANONICAL_HOST
tmp_host=`echo $host_cpu | sed 's/\./_/'`
AC_DEFINE_UNQUOTED(HAVE_HOST_CPU_$tmp_host)
GMP_DEFINE_RAW("define_not_for_expansion(\`HAVE_HOST_CPU_$tmp_host')", POST)

AM_INIT_AUTOMAKE(gmp, GMP_VERSION)
AM_CONFIG_HEADER(config.h:config.in)
AM_MAINTAINER_MODE


AC_ARG_ENABLE(assert,
AC_HELP_STRING([--enable-assert],[enable ASSERT checking [default=no]]),
[case $enableval in
yes|no) ;;
*) AC_MSG_ERROR([bad value $enableval for --enable-assert, need yes or no]) ;;
esac],
[enable_assert=no])

if test "$enable_assert" = "yes"; then
  AC_DEFINE(WANT_ASSERT,1,
  [./configure --enable-assert option, to enable some ASSERT()s])
fi


AC_ARG_ENABLE(alloca,
AC_HELP_STRING([--enable-alloca],[how to get temp memory [default=reentrant]]),
[case $enableval in
alloca|malloc-reentrant|malloc-notreentrant) ;;
yes|no|reentrant|notreentrant) ;;
debug) ;;
*)
  AC_MSG_ERROR([bad value $enableval for --enable-alloca, need one of:
yes no reentrant notreentrant alloca malloc-reentrant malloc-notreentrant debug]) ;;
esac],
[enable_alloca=reentrant])


# IMPROVE ME: The default for C++ is disabled.  The tests currently
# performed below for a working C++ compiler are not particularly strong,
# and in general can't be expected to get the right setup on their own.  The
# most significant problem is getting the ABI the same.  Defaulting CXXFLAGS
# to CFLAGS takes only a small step towards this.  It's also probably worth
# worrying whether the C and C++ runtimes from say gcc and a vendor C++ can
# work together.  Some rather broken C++ installations were encountered
# during testing, and though such things clearly aren't GMP's problem, if
# --enable-cxx=detect were to be the default then some careful checks of
# which, if any, C++ compiler on the system is up to scratch would be
# wanted.
#
AC_ARG_ENABLE(cxx,
AC_HELP_STRING([--enable-cxx],[enable C++ support [default=detect]]),
[case $enableval in
yes|no|detect) ;;
*) AC_MSG_ERROR([bad value $enableval for --enable-cxx, need yes/no/detect]) ;;
esac],
[enable_cxx=no])


AC_ARG_ENABLE(fft,
AC_HELP_STRING([--enable-fft],[enable FFTs for multiplication [default=yes]]),
[case $enableval in
yes|no) ;;
*) AC_MSG_ERROR([bad value $enableval for --enable-fft, need yes or no]) ;;
esac],
[enable_fft=yes])

if test "$enable_fft" = "yes"; then
  AC_DEFINE(WANT_FFT,1,
  [./configure --enable-fft option, to enable FFTs for multiplication])
fi


AC_ARG_ENABLE(mpbsd,
AC_HELP_STRING([--enable-mpbsd],
               [build Berkley MP compatibility library [default=no]]),
[case $enableval in
yes|no) ;;
*) AC_MSG_ERROR([bad value $enableval for --enable-mpbsd, need yes or no]) ;;
esac],
[enable_mpbsd=no])
AM_CONDITIONAL(WANT_MPBSD, test "$enable_mpbsd" = "yes")


AC_ARG_ENABLE(mpfr,
AC_HELP_STRING([--enable-mpfr],[build MPFR [default=no]]),
[case $enableval in
yes|no) ;;
*) AC_MSG_ERROR([bad value $enableval for --enable-mpfr, need yes or no]) ;;
esac],
[enable_mpfr=no])
AM_CONDITIONAL(WANT_MPFR, test "$enable_mpfr" = "yes")


AC_ARG_ENABLE(profiling,
AC_HELP_STRING([--enable-profiling],
               [build with profiler support [default=no]]),
[case $enableval in
no|prof|gprof) ;;
*) AC_MSG_ERROR([bad value $enableval for --enable-profiling, need no/prof/gprof]) ;;
esac],
[enable_profiling=no])

GMP_DEFINE_RAW(["define(<WANT_PROFILING>,<\`$enable_profiling'>)"])

# -fomit-frame-pointer is incompatible with -pg, on x86s at least
if test "$enable_profiling" = gprof; then
  fomit_frame_pointer=
else
  fomit_frame_pointer="-fomit-frame-pointer"
fi



# Table of compilers, options, and mpn paths.  This code has a couple of
# related purposes
#
#   - better default CC/CFLAGS selections than autoconf otherwise gives
#   - default CC/CFLAGS selections for extra CPU types specific to GMP
#   - a few tests for known bad compilers
#   - choice of ABIs on suitable systems
#   - selection of corresponding mpn search path
#
# After GMP specific searches and tests, the standard autoconf AC_PROG_CC is
# called.  User selections of CC etc are respected.
#
# Care is taken not to use macros like AC_TRY_COMPILE during the GMP
# pre-testing, since they of course depend on AC_PROG_CC, and also some of
# them cache their results, which is not wanted.
#
# The ABI selection mechanism is unique to GMP.  All that reaches autoconf
# is a different selection of CC/CFLAGS according to the best ABI the system
# supports, and/or what the user selects.  Naturally the mpn assembler code
# selected is very dependent on the ABI.
#
# The closest the standard tools come to a notion of ABI is something like
# "sparc64" which encodes a CPU and an ABI together.  This doesn't seem to
# scale well for GMP, where exact CPU types like "ultrasparc2" are wanted,
# separate from the ABI used on them.
#
#
# The variables set here are
#
#   cclist              the compiler choices
#   xx_cflags           flags for compiler xx
#   xx_cppflags         cpp flags for compiler xx
#   xx_cflags_optlist   list of sets of optional flags
#   xx_cflags_yyy       set yyy of optional flags for compiler xx
#   xx_ldflags          -Wc,-foo flags for libtool linking with compiler xx
#   ar_flags            extra flags for $AR
#   nm_flags            extra flags for $NM
#   limb                limb size, can be "longlong"
#   path                mpn search path
#   extra_functions     extra mpn functions
#
# Suppose xx_cflags_optlist="arch", then flags from $xx_cflags_arch are
# tried, and the first flag that works will be used.  An optlist like "arch
# cpu optimize" can be used to get multiple independent sets of flags tried.
# The first that works from each will be used.  If no flag in a set works
# then nothing from that set is added.
#
# For multiple ABIs, the scheme extends as follows.
#
#   abilist               set of ABI choices
#   cclist_aa             compiler choices in ABI aa
#   xx_aa_cflags          flags for xx in ABI aa
#   xx_aa_cppflags        cpp flags for xx in ABI aa
#   xx_aa_cflags_optlist  list of sets of optional flags in ABI aa
#   xx_aa_cflags_yyy      set yyy of optional flags for compiler xx in ABI aa
#   xx_aa_ldflags         -Wc,-foo flags for libtool linking
#   ar_aa_flags           extra flags for $AR in ABI aa
#   nm_aa_flags           extra flags for $NM in ABI aa
#   limb_aa               limb size in ABI aa, can be "longlong"
#   path_aa               mpn search path in ABI aa
#   extra_functions_aa    extra mpn functions in ABI aa
#
# As a convenience, the unadorned xx_cflags (etc) are used for the last ABI
# in ablist, if an xx_aa_cflags for that ABI isn't given.  For example if
# abilist="64 32" then $cc_64_cflags will be used for the 64-bit ABI, but
# for the 32-bit either $cc_32_cflags or $cc_cflags is used, whichever is
# defined.  This makes it easy to add some 64-bit compilers and flags to an
# unadorned 32-bit set.
#
# limb=longlong (or limb_aa=longlong) applies to all compilers within that
# ABI.  It won't work to have some needing long long and some not, since a
# single instantiated gmp.h will be used by both.
#
# SPEED_CYCLECOUNTER, cyclecounter_size and CALLING_CONVENTIONS_OBJS are
# also set here, with an ABI suffix.


AC_ARG_VAR(ABI,[intended ABI (for processors supporting more than one ABI)])

# abilist needs to be non-empty, "standard" is just a generic name here
abilist="standard"

# FIXME: Prefer c89 to cc.
cclist="gcc cc"

gcc_cflags="-g -O2"
gcc_64_cflags="-g -O2"
cc_cflags="-O"
cc_64_cflags="-O"

SPEED_CYCLECOUNTER_OBJ=
cyclecounter_size=2

AC_SUBST(__GMP_HAVE_HOST_CPU_FAMILY_power,  0)
AC_SUBST(__GMP_HAVE_HOST_CPU_FAMILY_powerpc,0)

case $host in

  a29k*-*-*)
    path="a29k"
    ;;


  alpha*-*-*)
    path="alpha"
    extra_functions="cntlz"
    case $host in
      alphaev5*-*-* | alphapca56*-*-*) path="alpha/ev5 alpha" ;;
      alphaev6*-*-*)                   path="alpha/ev6 alpha/ev5 alpha" ;;
    esac

    SPEED_CYCLECOUNTER_OBJ=alpha.lo
    cyclecounter_size=1

    flavour=`echo $host_cpu | sed 's/^alpha//g'`
    case "$flavour" in
      # compilers don't seem to understand `ev67' and such.
      ev6? | ev7*)  flavour=ev6 ;;
      ev* | pca*) ;;
      *) flavour=ev4 ;;
    esac

    # FIXME: Maybe a feature test should find out whether -Wa,arch is
    # necessary.
    if test -n "$flavour"; then
      gcc_cflags_optlist="cpu arch"
      gcc_cflags_cpu="-mcpu=$flavour"
      gcc_cflags_arch="-Wa,-arch,$flavour -Wa,-m$flavour"
    fi

    case $host in
      *-cray-unicos*)
        # FIXME: Is GCC available for these systems? Hopefully it doesn't
        # hurt to check for it anyway.
        cc_cflags="-O"		# no -g, it silently disables all optimizations
        GMP_INCLUDE_MPN(alpha/unicos.m4)
        # Don't perform any assembly syntax tests on this beast.
        gmp_asm_syntax_testing=no
        # tune/alpha.asm assumes int==4bytes but unicos uses int=8bytes
        SPEED_CYCLECOUNTER_OBJ=
        ;;
      *-*-osf*)
        cc_cflags_optlist="cpu"
        cc_cflags="-arch $flavour -tune $flavour"
        GMP_INCLUDE_MPN(alpha/default.m4)
        ;;
      *)
        GMP_INCLUDE_MPN(alpha/default.m4)
        ;;
    esac
    ;;


  # Cray vector machines.
  # This must come after alpha* so that we can recognize present and future
  # vector processors with a wildcard.
  *-cray-unicos*)
    gmp_asm_syntax_testing=no
    cclist="cc"
    cc_cflags="-O3 -htask0 -Wa,-B"
    path="cray"
    ;;


  arm*-*-*)
    path="arm"
    gcc_cflags="$gcc_cflags $fomit_frame_pointer"
    gcc_testlist="gcc-arm-umodsi"
    extra_functions="udiv"
    GMP_INCLUDE_MPN(arm/arm-defs.m4)
    ;;


  clipper*-*-*)
    path="clipper"
    ;;


  # Fujitsu
  [f30[01]-fujitsu-sysv*])
    cclist="gcc vcc"
    # FIXME: flags for vcc?
    vcc_cflags="-g"
    path="fujitsu"
    ;;


  hppa*-*-*)
    # HP cc is K&R by default, but AM_C_PROTOTYPES will add "-Ae", or "-Aa
    # -D_HPUX_SOURCE", to put it into ansi mode, if possible.

    # default to pa7100
    gcc_cflags="-g -O2"
    gcc_cflags_optlist="arch"
    gcc_cflags_arch="-mpa-risc-1-1"
    cc_cflags="+DA1.1 +O2"
    path="hppa/hppa1_1/pa7100 hppa/hppa1_1 hppa"
    extra_functions="udiv_qrnnd"

    SPEED_CYCLECOUNTER_OBJ=hppa.lo
    cyclecounter_size=1

    case $host in
      hppa1.0*-*-*)
        # override back to plain 1.0
        gcc_cflags_optlist=
        cc_cflags="+O2"
        path="hppa"
        ;;
      hppa7000*-*-*)
        path="hppa/hppa1_1 hppa"
        ;;

      hppa2.0*-*-*)
        abilist="2.0n 1.0"

        # FIXME: It's suspected that an assembler feature test might be
        # necessary before -mpa-risc-2-0 can be enabled, since it's not
        # clear (as of gcc 2.95.2) whether that option always gives an
        # explicit ".level 2.0" or whatever to the assembler.  In any case,
        # under gcc 2.95.2 it only enables a few extra floating point insns,
        # so it's not very important.
        #
        # gmp_cflags_arch="-mpa-risc-2-0 -mpa-risc-1-1"

        # FIXME: path should be "hppa/hppa2_0 hppa/hppa1_1 hppa"
        path="hppa/hppa2_0 hppa/hppa1_1/pa7100 hppa/hppa1_1 hppa"

        # no gcc support for long long in 2.0n
	cclist_20n="cc"
        # +O2 to cc triggers bug in mpz/powm.c (cvs version 1.4)
        cc_20n_cflags="+DA2.0 +e +O3"
        cc_20n_testlist="hpc-hppa-2-0"
        path_20n="pa64"
	limb_20n=longlong
        extra_functions_20n="umul_ppmm udiv_qrnnd"
        SPEED_CYCLECOUNTER_OBJ_20n=hppa2.lo
        cyclecounter_size_20n=2

	# ABI=2.0w is available for hppa2.0w and hppa2.0, but not for hppa2.0n.
	case $host in
        hppa2.0n-*-*) ;;
        *)
          # HPUX 11 or up is required to run 2.0w.  Not sure about other
          # systems (GNU/Linux for instance), but lets assume they're ok.
          case $host in
          [*-*-hpux1[1-9]*]) abilist="2.0w $abilist" ;;
	  *-*-hpux*)                                 ;;
          *)                 abilist="2.0w $abilist" ;;
          esac

          # gcc support for 2.0w is in progress
          cclist_20w="cc"
          cc_20w_cflags="+DD64 +O3"
          cc_20w_testlist="hpc-hppa-2-0"
          path_20w="pa64w"
          extra_functions_20w="umul_ppmm udiv_qrnnd"
          SPEED_CYCLECOUNTER_OBJ_20w=hppa2w.lo
          cyclecounter_size_20w=2
	  ;;
        esac
        ;;
    esac
    ;;


  i960*-*-*)
    path="i960"
    ;;


  ia64*-*-*)
    path="ia64"
    GMP_INCLUDE_MPN(ia64/default.m4)
    SPEED_CYCLECOUNTER_OBJ=ia64.lo
    ;;


  # Motorola 68k
  #
  m68*-*-*)
    GMP_INCLUDE_MPN(m68k/m68k-defs.m4)
    gcc_cflags="-g $fomit_frame_pointer"
    gcc_cflags_optlist="optimize arch"
    gcc_cflags_optimize="-O2"   # munged below on gcc 2.95.x

    # gcc 2.7.2 doesn't know -m68060 or -mcpu32, so let them fall back
    # appropriately.
    # FIXME: Maybe "-m68020 -mnobitfield" would suit cpu32 on 2.7.2.
    #
    case $host in
    m68020-*-*)  gcc_cflags_arch="-m68020" ;;
    m68030-*-*)  gcc_cflags_arch="-m68030" ;;
    m68040-*-*)  gcc_cflags_arch="-m68040" ;;
    m68060-*-*)  gcc_cflags_arch="-m68060 -m68040" ;;
    m68360-*-*)  gcc_cflags_arch="-mcpu32 -m68000" ;;
    *)           gcc_cflags_arch="-m68000" ;;
    esac

    # FIXME: m68k/mc68020 looks like it's ok for cpu32, but this wants to be
    # tested.  Will need to introduce an m68k/cpu32 if m68k/mc62020 ever uses
    # the bitfield instructions.
    case $host in
    [m680[2346]0-*-* | m68360-*-*])  path="m68k/mc68020 m68k"
                                     extra_functions="udiv umul" ;;
    *)                               path="m68k" ;; 
    esac
    ;;


  # Motorola 88k
  m88k*-*-*)
    path="m88k"
    ;;
  m88110*-*-*)
    # FIXME: Use `-O2'?
    gcc_cflags="-g -O -m88110"
    path="m88k/mc88110 m88k"
    ;;


  # National Semiconductor 32k
  ns32k*-*-*)
    path="ns32k"
    ;;


  # IRIX 5 and earlier can only run 32-bit o32.
  #
  # IRIX 6 and up can run n32 or 64, and GMP uses a 64-bit limb on both.  It
  # could run the mips2 code in n32 with a 32-bit limb, which we could
  # perhaps call 32, but since that would just create a slower library, we
  # don't give that option.
  #
  # Linux kernel 2.2.13 arch/mips/kernel/irixelf.c has a comment about not
  # supporting n32 or 64.
  #
  # We here use ldflags for passing options with libtool to the compiler
  # when generating the shared library.

  [mips*-*-irix[6789]*])
    abilist="n32 64"

    # let the $found_compiler test below know that the cpu is recognised
    path=dummy

    cclist_n32="gcc cc"
    gcc_n32_cflags="-g -O2 -mabi=n32"
    gcc_n32_ldflags="-Wc,-mabi=n32"
    cc_n32_cflags="-O2 -n32"		# no -g, it disables all optimizations
    cc_n32_ldflags="-Wc,-n32"
    limb_n32=longlong
    path_n32="mips3"

    cclist_64="gcc cc"
    gcc_64_cflags="-g -O2 -mabi=64"
    gcc_64_ldflags="-Wc,-mabi=64"
    cc_64_cflags="-O2 -64"		# no -g, it disables all optimizations
    cc_64_ldflags="-Wc,-64"
    path_64="mips3"

    GMP_INCLUDE_MPN(mips3/mips.m4)
    ;;

  mips*-*-*)
    path="mips2"
    ;;


  # Darwin (powerpc-apple-darwin1.3) has gcc installed as cc.
  #
  # The darwin assembler doesn't accept "-mppc", so gcc_cflags_asm is
  # optional.  The right flag would be "-arch ppc" or some such, but that's
  # already the default.
  #
  # The darwin pre-compiling preprocessor is disabled with -no-cpp-precomp
  # since it doesn't like "__attribute__ ((mode (SI)))" etc in gmp-impl.h,
  # and so always ends up running the plain preprocessor anyway.  This could
  # be done in CPPFLAGS rather than CFLAGS, but there's not many places
  # preprocessing is done separately, and this is only a speedup, the normal
  # preprocessor gets run if there's any problems.
  #
  powerpc*-*-*)
    AC_DEFINE(HAVE_HOST_CPU_FAMILY_powerpc)
    __GMP_HAVE_HOST_CPU_FAMILY_powerpc=1
    cclist="gcc cc"
    cc_cflags="-g -O2"
    gcc_cflags="-g -O2 -mpowerpc"
    gcc_cflags_optlist="asm precomp"
    gcc_cflags_asm="-Wa,-mppc"
    gcc_cflags_precomp="-no-cpp-precomp"
    path="powerpc32"
    extra_functions="umul"
    case $host in
      *-*-aix*) cclist="gcc xlc cc"
                xlc_cflags="-g -O2 -qarch=ppc -qmaxmem=20000" ;;
    esac

    case $host in
      powerpc64*-*-*)
        # CPU type powerpc64 forces to a 64-bit limb
        case $host in
          powerpc64-*-*) abilist="32L" ;;
          *)             abilist="32L 32" ;;
        esac
        cclist_32L="gcc"
        gcc_32L_cflags="-g -O2 -mpowerpc64"
        limb_32L=longlong
        path_32L="powerpc64"

        # On AIX a true 64-bit ABI is available.
        case $host in
          *-*-aix*)
            # Need -Wc to pass object type flags through to the linker.
            abilist="aix64 $abilist"
            cclist_aix64="gcc xlc"
            gcc_aix64_cflags="-g -O2 -maix64 -mpowerpc64"
	    gcc_aix64_ldflags="-Wc,-maix64"
            xlc_aix64_cflags="-g -O2 -q64 -qtune=pwr3 -qmaxmem=20000"
	    xlc_aix64_ldflags="-Wc,-q64"
            # Must indicate object type to ar and nm
	    ar_aix64_flags="-X64"
	    nm_aix64_flags="-X64"
            path_aix64="powerpc64"
            ;;
        esac
        ;;
    esac
    ;;


  # POWER
  [power-*-* | power[12]-*-* | power2sc-*-*])
    AC_DEFINE(HAVE_HOST_CPU_FAMILY_power)
    __GMP_HAVE_HOST_CPU_FAMILY_power=1
    cclist="gcc"
    extra_functions="udiv_w_sdiv"
    path="power"

    gcc_cflags_optlist="cpu"
    case $host in
      power-*-*)    gcc_cflags_cpu="-mcpu=power -mpower" ;;
      power1-*-*)   gcc_cflags_cpu="-mcpu=rios1 -mpower" ;;
      power2-*-*)   gcc_cflags_cpu="-mcpu=rios2 -mpower" ;;
      power2sc-*-*) gcc_cflags_cpu="-mcpu=rsc   -mpower" ;;
    esac
    case $host in
    *-*-aix*)
      cclist="gcc xlc"
      xlc_cflags="-g -O2 -qarch=pwr -qmaxmem=20000"
      ;;
    esac
    ;;


  # FIXME: ppc601 isn't accepted by config.sub.
  ppc601-*-*)
    path="power powerpc32"
    ;;


  pyramid-*-*)
    path="pyr"
    ;;


  # IBM s/370 and similar
  [s3[6-9]0*-*-*])
    gcc_cflags="-g -O2 $fomit_frame_pointer"
    path="s390"
    extra_functions="udiv_w_sdiv"
    ;;


  sh-*-*)   path="sh" ;;
  sh2-*-*)  path="sh/sh2 sh" ;;


  *sparc*-*-*)
    # For cc and acc, -g disables -O, so it's not used
    cclist="gcc acc cc"
    path="sparc32"
    gcc_cflags="-g -O2"
    gcc_cflags_optlist="cpu"
    gcc_cflags_cpu=
    acc_cflags="-O2"
    cc_cflags="-O2"

    # FIXME: This should be selected according to the CPU
    if test x${floating_point} = xno
    then extra_functions="udiv_nfp"
    else extra_functions="udiv_fp"
    fi

    case $host in
      sparcv8*-*-* | supersparc*-*-* | microsparc*-*-*)
        gcc_cflags_cpu="-mcpu=v8 -mv8"
        acc_cflags="-O2 -cg92"
        path="sparc32/v8 sparc32"

        case $host in
          *-*-solaris2.*)  cc_cflags="-xtarget=native -xarch=v8 -xO4" ;;
        esac
        case $host in
          supersparc*-*-*) path="sparc32/v8/supersparc sparc32/v8 sparc32"
                           extra_functions="udiv" ;;
        esac
        ;;

      # sparc64-*-linux-gnu is a misnomer, since there's no support for any
      # 64-bit operations in user mode.  We assume that a future release
      # will have some 64-bit support and that the gcc options will be the
      # same as on solaris.
      #
      # cc -xarch actually controls the ABI, hence it must be v8 for 32-bit,
      # even though the chip is v9.
      #
      sparcv9*-*-* | ultrasparc*-*-* | sparc64-*-*)
        path="sparc32/v9 sparc32/v8 sparc32"
        extra_functions="udiv_fp"

        SPEED_CYCLECOUNTER_OBJ=sparcv9.lo

        gcc_cflags="-g -O2 -Wa,-xarch=v8plus"
        gcc_cflags_cpu="-mcpu=ultrasparc -mcpu=v9 -mcpu=v8 -mv8"

        cc_cflags="-xtarget=native -xarch=v8 -xO4"

        case $host in
          [*-*-solaris2.[7-9]])
            # solaris prior to 2.6 doesn't save registers properly, so the
            # 64-bit ABI is only available for 2.7 up
            abilist="64 32"
            path_64="sparc64"
            cclist_64="gcc cc"
            gcc_64_cflags="-g -O2 -m64 -mptr64 -Wa,-xarch=v9 -mcpu=v9"
            cc_64_cflags="-xtarget=native -xarch=v9 -xO4"
            ;;
        esac
      ;;
    esac
    ;;


  # VAX
  vax*-*-*)
    # Currently (version 3.0) gcc on vax always uses a frame pointer
    # (config/vax/vax.h FRAME_POINTER_REQUIRED=1), so -fomit-frame-pointer
    # will be ignored.
    #
    gcc_cflags="-g -O2 $fomit_frame_pointer"
    path="vax"
    extra_functions="udiv_w_sdiv"
    ;;


  # AMD and Intel x86 configurations
  X86_PATTERN)
    AC_DEFINE(HAVE_HOST_CPU_FAMILY_x86)
    # Rumour has it gcc -O2 used to give worse register allocation than just
    # -O, but lets assume that's no longer true.
    gcc_cflags="-g -O2 $fomit_frame_pointer"
    GMP_INCLUDE_MPN(x86/x86-defs.m4)
    extra_functions="udiv umul"
    CALLING_CONVENTIONS_OBJS='x86call.lo x86check$U.lo'

    # Availability of rdtsc is checked at run-time.
    SPEED_CYCLECOUNTER_OBJ=pentium.lo

    # gcc 2.7.2 only knows i386 and i486, using -m386 or -m486.  These
    # represent -mcpu= since -m486 doesn't generate 486 specific insns.  The
    # -mcpu= and -march= options will fail, leaving just -m486.
    #
    # gcc 2.95.2 adds k6, pentium and pentiumpro, and allows -march= and
    # -mcpu=.
    #
    # gcc 3.0 adds athlon.
    #
    # gcc 3.1 adds pentium4.

    # Defaults for anything not otherwise mentioned.
    path="x86"
    gcc_cflags_optlist="cpu arch"
    gcc_cflags_cpu="-mcpu=i486 -m486"
    gcc_cflags_arch="-march=i486"

    case $host in
      i386*-*-*)
        # Because i386 means generic x86, -mcpu=i486 is used since that
        # should better suit newer processors.
        # FIXME: How would a user ask for an actual 80386? Currently only by
        # using CFLAGS="-mcpu=386" or whatever.
        gcc_cflags_cpu="-mcpu=i486 -m486"
        gcc_cflags_arch="-march=i386"
        ;;
      i586*-*-* | pentium-*-* | pentiummmx-*-*)
        gcc_cflags_cpu="-mcpu=pentium -m486"
        gcc_cflags_arch="-march=pentium"
        ;;
      [i686*-*-* | pentiumpro-*-* | pentium[23]-*-*])
        gcc_cflags_cpu="-mcpu=pentiumpro -mcpu=i486 -m486"
        gcc_cflags_arch="-march=pentiumpro -march=i486"
        ;;
      k6*-*-*)
        gcc_cflags_cpu="-mcpu=k6 -mcpu=i486 -m486"
        gcc_cflags_arch="-march=k6 -march=i486"
        ;;
      athlon-*-*)
        # Athlon instruction costs are close to P6 (3 cycle load latency,
        # 4-6 cycle mul, 40 cycle div, pairable adc, etc) so if gcc doesn't
        # know athlon (eg. 2.95.2 doesn't) then fall back on pentiumpro.
        gcc_cflags_cpu="-mcpu=athlon -mcpu=pentiumpro -mcpu=i486 -m486"
        gcc_cflags_arch="-march=athlon -march=pentiumpro -march=i486"
        ;;
      pentium4-*-*)
        # pentium4 is known to gcc 3.1 and up, not sure what cpu choice
        # would best suit previous versions, pentiumpro will get us cmov
        # from gcc 2.95.4 up, otherwise let's just try i486.
        gcc_cflags_cpu="-mcpu=pentium4 -mcpu=pentiumpro -mcpu=i486 -m486"
        gcc_cflags_arch="-march=pentium4 -march=pentiumpro -march=i486"
        ;;
    esac

    case $host in
      i486*-*-*)                  path="x86/i486 x86" ;;
      i586*-*-* | pentium-*-*)    path="x86/pentium x86" ;;
      pentiummmx-*-*)             path="x86/pentium/mmx x86/pentium x86" ;;
      i686*-*-* | pentiumpro-*-*) path="x86/p6 x86" ;;
      pentium2-*-*)   path="x86/p6/mmx x86/p6 x86" ;;
      pentium3-*-*)   path="x86/p6/p3mmx x86/p6/mmx x86/p6 x86";;
      [k6[23]*-*-*])  path="x86/k6/k62mmx x86/k6/mmx x86/k6 x86" ;;
      k6*-*-*)        path="x86/k6/mmx x86/k6 x86" ;;
      athlon-*-*)     path="x86/k7/mmx x86/k7 x86" ;;
      pentium4-*-*)   path="x86/pentium4/sse2 x86/pentium4/mmx x86/pentium4 x86" ;;
    esac
    ;;


  # FIXME: z8kx won't get through config.sub.  Could make 16 versus 32 bit
  # limb an ABI option perhaps.
  z8kx*-*-*)
    path="z8000x"
    extra_functions="udiv_w_sdiv"
    ;;
  z8k*-*-*)
    path="z8000"
    extra_functions="udiv_w_sdiv"
    ;;


  # Special CPU "none" selects generic C.  -DNO_ASM is used to disable gcc
  # asm blocks in longlong.h (since they're driven by cpp pre-defined
  # symbols like __alpha rather than the configured $host_cpu).
  #
  none-*-*)
    abilist="long longlong"
    cclist_long=$cclist
    gcc_long_cflags=$gcc_cflags
    gcc_long_cppflags="-DNO_ASM"
    cc_long_cflags=$cc_cflags
    cclist_longlong=$cclist
    gcc_longlong_cflags=$gcc_cflags
    gcc_longlong_cppflags="-DNO_ASM"
    cc_longlong_cflags=$cc_cflags
    limb_longlong=longlong
    ;;

esac


CFLAGS_or_unset=${CFLAGS-'(unset)'}
CPPFLAGS_or_unset=${CPPFLAGS-'(unset)'}

cat >&AC_FD_CC <<EOF
configure:__line__: User:
ABI=$ABI
CC=$CC
CFLAGS=$CFLAGS_or_unset
CPPFLAGS=$CPPFLAGS_or_unset
MPN_PATH=$MPN_PATH
configure:__line__: GMP:
abilist=$abilist
cclist=$cclist
EOF


test_CFLAGS=${CFLAGS+set}
test_CPPFLAGS=${CPPFLAGS+set}

for abi in $abilist; do
  abi_last="$abi"
done

# If the user specifies an ABI then it must be in $abilist, after that
# $abilist is restricted to just that choice.
#
if test -n "$ABI"; then
  found=no
  for abi in $abilist; do
    if test $abi = "$ABI"; then found=yes; break; fi
  done
  if test $found = no; then
    AC_MSG_ERROR([ABI=$ABI is not among the following valid choices: $abilist])
  fi
  abilist="$ABI"
fi

found_compiler=no

for abi in $abilist; do

  # Suppose abilist="64 32", then for abi=64, will have abi1="_64" and
  # abi2="_64".  For abi=32, will have abi1="_32" and abi2="".  This is how
  # $gcc_cflags becomes a fallback for $gcc_32_cflags (the last in the
  # abilist), but there's no fallback for $gcc_64_cflags.
  #
  abi1=[`echo _$abi | sed 's/[.]//g'`]
  if test $abi = $abi_last; then abi2=; else abi2="$abi1"; fi

  # Compiler choices under this ABI
                              eval cclist_chosen=\"\$cclist$abi1\"
  test -n "$cclist_chosen" || eval cclist_chosen=\"\$cclist$abi2\"

  # If there's a user specified $CC then don't use a list for
  # $cclist_chosen, just a single value for $ccbase.
  #
  if test -n "$CC"; then

    # The first word of $CC, stripped of any directory.  For instance
    # CC="/usr/local/bin/gcc -pipe" will give "gcc".
    #
    for ccbase in $CC; do break; done
    ccbase=`echo $ccbase | sed 's:.*/::'`

    # If this $ccbase is in $cclist_chosen then it's a compiler we know and
    # we can do flags defaulting with it.  If not, then $cclist_chosen is
    # set to "unrecognised" so no default flags are used.
    #
    # "unrecognised" is used to avoid bad effects with eval if $ccbase has
    # non-symbol characters.  For instance ccbase=my+cc would end up with
    # something like cflags="$my+cc_cflags" which would give
    # cflags="+cc_cflags" rather than the intended empty string for an
    # unknown compiler.
    #
    found=unrecognised
    for i in $cclist_chosen; do
      if test "$ccbase" = $i; then
        found=$ccbase
        break
      fi
    done
    cclist_chosen=$found
  fi  

  for ccbase in $cclist_chosen; do

    # When cross compiling, look for a compiler with the $host_alias as a
    # prefix, the same way that AC_CHECK_TOOL does.  But don't do this to a
    # user-selected $CC.
    #
    # $cross_compiling will be yes/no/maybe at this point.  Do the host
    # prefixing for "maybe" as well as "yes".
    #
    if test "$cross_compiling" != no && test -z "$CC"; then
      cross_compiling_prefix="${host_alias}-"
    fi

    for ccprefix in $cross_compiling_prefix ""; do

      cc="$CC"
      test -n "$cc" || cc="$ccprefix$ccbase"

      # If the compiler is gcc but installed under another name, then change
      # $ccbase so as to use the flags we know for gcc.  This helps for
      # instance when specifying CC=gcc272 on Debian GNU/Linux, or the
      # native cc which is really gcc on NeXT or MacOS-X.
      #
      # FIXME: There's a slight misfeature here.  If cc is actually gcc but
      # gcc is not a known compiler under this $abi then we'll end up
      # testing it with no flags and it'll work, but chances are it won't be
      # in the right mode for the ABI we desire.  Let's quietly hope this
      # doesn't happen.
      #
      if test $ccbase != gcc; then
        GMP_PROG_CC_IS_GNU($cc,ccbase=gcc)
      fi

      # Similarly if the compiler is IBM xlc but invoked as cc or whatever
      # then change $ccbase and make the default xlc flags available.
      if test $ccbase != xlc; then
        GMP_PROG_CC_IS_XLC($cc,ccbase=xlc)
      fi

      # Any user CFLAGS, even an empty string, takes precendence
                           eval cflags=\"\$${ccbase}${abi1}_cflags\"
      test -n "$cflags" || eval cflags=\"\$${ccbase}${abi2}_cflags\"
      if test "$test_CFLAGS" = set; then cflags=$CFLAGS; fi

      # Any user CPPFLAGS, even an empty string, takes precendence
                             eval cppflags=\"\$${ccbase}${abi1}_cppflags\"
      test -n "$cppflags" || eval cppflags=\"\$${ccbase}${abi2}_cppflags\"
      if test "$test_CPPFLAGS" = set; then cppflags=$CPPFLAGS; fi

      # --enable-profiling adds -p/-pg even to user-specified CFLAGS.
      # This is convenient, but it's perhaps a bit naughty to modify user
      # CFLAGS.
      case "$enable_profiling" in
      prof)  cflags="$cflags -p" ;;
      gprof) cflags="$cflags -pg" ;;
      esac

      GMP_PROG_CC_WORKS($cc $cflags $cppflags,,continue)

      # The tests to perform on this $cc, if any
                             eval testlist=\"\$${ccbase}${abi1}_testlist\"
      test -n "$testlist" || eval testlist=\"\$${ccbase}${abi2}_testlist\"

      testlist_pass=yes
      for tst in $testlist; do
        case $tst in
        hpc-hppa-2-0)   GMP_HPC_HPPA_2_0($cc,,testlist_pass=no) ;;
        gcc-arm-umodsi) GMP_GCC_ARM_UMODSI($cc,,testlist_pass=no) ;;
        esac
        if test $testlist_pass = no; then break; fi
      done

      if test $testlist_pass = yes; then
        found_compiler=yes
        break
      fi
    done

    if test $found_compiler = yes; then break; fi
  done

  if test $found_compiler = yes; then break; fi
done


# If we recognised the CPU, as indicated by $path being set, then insist
# that we have a working compiler, either from our $cclist choices or from
# $CC.  We can't let AC_PROG_CC look around for a compiler because it might
# find one that we've rejected (for not supporting the modes our asm code
# demands, etc).
#
# If we didn't recognise the CPU (and this includes host_cpu=none), then
# fall through and let AC_PROG_CC look around for a compiler too.  This is
# mostly in the interests of following a standard autoconf setup, after all
# we've already tested cc and gcc adequately (hopefully).  As of autoconf
# 2.50 the only thing AC_PROG_CC really adds is a check for "cl" (Microsoft
# C on MS-DOS systems).
#
if test $found_compiler = no && test -n "$path"; then
  AC_MSG_ERROR([could not find a working compiler])
fi


if test $found_compiler = yes; then

  # If we're creating CFLAGS, then look for optional additions.  If the user
  # set CFLAGS then leave it alone.
  #
  if test "$test_CFLAGS" != set; then
                          eval optlist=\"\$${ccbase}${abi1}_cflags_optlist\"
    test -n "$optlist" || eval optlist=\"\$${ccbase}${abi2}_cflags_optlist\"

    for opt in $optlist; do
                             eval optflags=\"\$${ccbase}${abi1}_cflags_${opt}\"
      test -n "$optflags" || eval optflags=\"\$${ccbase}${abi2}_cflags_${opt}\"

      for flag in $optflags; do

        case $flag in
          -march=pentiumpro)
            # tickles stack slot bugs on some gcc, exclude as necessary
            GMP_GCC_MARCH_PENTIUMPRO($cc,,continue)
            ;;
          -O*)
            # ease back to just -O on m68k gcc 2.95.x
            GMP_GCC_M68K_OPTIMIZE($ccbase,$cc,flag)
            ;;
          -no-cpp-precomp)
            # special check, avoiding a warning
            GMP_GCC_NO_CPP_PRECOMP($ccbase,$cc,$cflags,
                                   [cflags="$cflags $flag"
                                   break],
                                   [continue])
            ;;
        esac

        GMP_PROG_CC_WORKS($cc $cflags $cppflags $flag,
          [cflags="$cflags $flag"
          break])
      done
    done
  fi

  ABI="$abi"
  CC="$cc"
  CFLAGS="$cflags"
  CPPFLAGS="$cppflags"


  # Could easily have this in config.h too, if desired.
  ABI_nodots=`echo $ABI | sed 's/\./_/'`
  GMP_DEFINE_RAW("define_not_for_expansion(\`HAVE_ABI_$ABI_nodots')", POST)


  # GMP_LDFLAGS substitution, selected according to ABI.
  # These are needed on libgmp.la and libmp.la, but currently not on
  # convenience libraries like tune/libspeed.la or mpz/libmpz.la.
  #
                            eval GMP_LDFLAGS=\"\$${ccbase}${abi1}_ldflags\"
  test -n "$GMP_LDFLAGS" || eval GMP_LDFLAGS=\"\$${ccbase}${abi1}_ldflags\"
  AC_SUBST(GMP_LDFLAGS)

  # extra_functions, selected according to ABI
                    eval tmp=\"\$extra_functions$abi1\"
  test -n "$tmp" || eval tmp=\"\$extra_functions$abi2\"
  extra_functions="$tmp"


  # Cycle counter, selected according to ABI.
  #
                    eval tmp=\"\$SPEED_CYCLECOUNTER_OBJ$abi1\"
  test -n "$tmp" || eval tmp=\"\$SPEED_CYCLECOUNTER_OBJ$abi2\"
  SPEED_CYCLECOUNTER_OBJ="$tmp"
                    eval tmp=\"\$cyclecounter_size$abi1\"
  test -n "$tmp" || eval tmp=\"\$cyclecounter_size$abi2\"
  cyclecounter_size="$tmp"

  if test -n "$SPEED_CYCLECOUNTER_OBJ"; then
    AC_DEFINE_UNQUOTED(HAVE_SPEED_CYCLECOUNTER, $cyclecounter_size,
    [Tune directory speed_cyclecounter, undef=none, 1=32bits, 2=64bits)])
  fi
  AC_SUBST(SPEED_CYCLECOUNTER_OBJ)


  # Calling conventions checking, selected according to ABI.
  #
                    eval tmp=\"\$CALLING_CONVENTIONS_OBJS$abi1\"
  test -n "$tmp" || eval tmp=\"\$CALLING_CONVENTIONS_OBJS$abi2\"
  CALLING_CONVENTIONS_OBJS="$tmp"

  if test -n "$CALLING_CONVENTIONS_OBJS"; then
    AC_DEFINE(HAVE_CALLING_CONVENTIONS,1,
    [Define if tests/libtests has calling conventions checking for the CPU])
  fi
  AC_SUBST(CALLING_CONVENTIONS_OBJS)

fi


# If the user gave an MPN_PATH, use that verbatim, otherwise choose
# according to the ABI and add "generic".
#
if test -n "$MPN_PATH"; then
  path="$MPN_PATH"
else
                    eval tmp=\"\$path$abi1\"
  test -n "$tmp" || eval tmp=\"\$path$abi2\"
  path="$tmp generic"
fi


# Whether using a long long limb in this ABI.
                          eval limb_chosen=\"\$limb$abi1\"
test -n "$limb_chosen" || eval limb_chosen=\"\$limb$abi2\"
case $limb_chosen in
longlong) DEFN_LONG_LONG_LIMB="#define _LONG_LONG_LIMB 1"    ;;
*)        DEFN_LONG_LONG_LIMB="/* #undef _LONG_LONG_LIMB */" ;;
esac
AC_SUBST(DEFN_LONG_LONG_LIMB)


# The C compiler and preprocessor, put into ANSI mode if possible.
AC_PROG_CC
AC_PROG_CC_STDC
AC_PROG_CPP
GMP_H_ANSI


# The C++ compiler, if desired.
want_cxx=no
if test $enable_cxx != no; then
  test_CXXFLAGS=${CXXFLAGS+set}
  AC_PROG_CXX

  echo "CXXFLAGS chosen by autoconf: $CXXFLAGS" >&AC_FD_CC
  cxxflags_ac_prog_cxx=$CXXFLAGS
  cxxflags_list=ac_prog_cxx

  # If the user didn't specify $CXXFLAGS, then try $CFLAGS, with -g removed
  # if AC_PROG_CXX thinks that doesn't work.  $CFLAGS stands a good chance
  # of working, eg. on a GNU system where CC=gcc and CXX=g++.
  #
  if test "$test_CXXFLAGS" != set; then
    cxxflags_cflags=$CFLAGS
    cxxflags_list="cflags $cxxflags_list"
    if test "$ac_prog_cxx_g" = no; then
      cxxflags_cflags=`echo "$cxxflags_cflags" | sed -e 's/ -g //' -e 's/^-g //' -e 's/ -g$//'`
    fi
  fi

  # See if the C++ compiler works.  If the user specified CXXFLAGS then all
  # we're doing is checking whether AC_PROG_CXX succeeded, since it doesn't
  # give a fatal error, just leaves CXX set to a default g++.  If on the
  # other hand the user didn't specify CXXFLAGS then we get to try here our
  # $cxxflags_list alternatives.
  #
  for cxxflags_choice in $cxxflags_list; do
    eval CXXFLAGS=\"\$cxxflags_$cxxflags_choice\"
    GMP_PROG_CXX_WORKS($CXX $CXXFLAGS,
      [want_cxx=yes
      break])
  done

  # If --enable-cxx=yes but a C++ compiler can't be found, then abort.
  if test $want_cxx = no && test $enable_cxx = yes; then
    AC_MSG_ERROR([C++ compiler not available])
  fi
fi

AM_CONDITIONAL(WANT_CXX, test $want_cxx = yes)

# FIXME: We're not interested in CXXCPP for ourselves, but if we don't call
# it here then AC_PROG_LIBTOOL (via _LT_AC_TAGCONFIG) will do so
# unconditionally, and that will fail if there's no C++ compiler (and no
# generic /lib/cpp).
#
if test $want_cxx = yes; then
  AC_PROG_CXXCPP
fi

cat >&AC_FD_CC <<EOF
configure:__line__: Decided:
ABI=$ABI
CC=$CC
CFLAGS=$CFLAGS
CPPFLAGS=$CPPFLAGS
GMP_LDFLAGS=$GMP_LDFLAGS
CXX=$CXX
CXXFLAGS=$CXXFLAGS
path=$path
EOF
echo "using ABI=\"$ABI\""
echo "      CC=\"$CC\""
echo "      CFLAGS=\"$CFLAGS\""
echo "      CPPFLAGS=\"$CPPFLAGS\""
if test $want_cxx = yes; then
  echo "      CXX=\"$CXX\""
  echo "      CXXFLAGS=\"$CXXFLAGS\""
fi

case $host_cpu in
  c90 | t90)
    AC_EGREP_CPP(yes,
[#ifdef _CRAYIEEE
yes
#endif],
    [add_path="cray/ieee"],
    [add_path="cray/cfp"; extra_functions="mulwwc90"]) ;;
  j90 | sv1)
    extra_functions="mulwwj90"
    add_path="cray/cfp" ;;
esac

if test -z "$MPN_PATH"; then
  path="$add_path $path"
fi


# Automake ansi2knr support.
AM_C_PROTOTYPES

GMP_PROG_AR
GMP_PROG_NM

case $host in
  # FIXME: On AIX 3 and 4, $libname.a is included in libtool
  # $library_names_spec, so libgmp.a becomes a symlink to libgmp.so, making
  # it impossible to build shared and static libraries simultaneously.
  # Disable shared libraries by default, but let the user override with
  # --enable-shared --disable-static.
  #
  # FIXME: This $libname.a problem looks like it might apply to *-*-amigaos*
  # and *-*-os2* too, but wait for someone to test this before worrying
  # about it.  If there is a problem then of course libtool is the right
  # place to fix it.
  #
  [*-*-aix[34]*])
    if test -z "$enable_shared"; then enable_shared=no; fi ;;

  # On Windows, build only static by default, and don't allow both static
  # and DLL.  libtool -no-undefined is needed for a DLL, as per the
  # AC_LIBTOOL_WIN32_DLL doco.
  #
  *-*-cygwin* | *-*-mingw* | *-*-pw32* | *-*-os2*)
    if test -z "$enable_shared"; then
      enable_shared=no
    fi
    if test "$enable_shared" != no && test "$enable_static" != no; then
      AC_MSG_ERROR([cannot build both static and DLL, since gmp.h is different for each.
Use "--disable-static --enable-shared" to build just a DLL.])
    fi
    if test "$enable_shared" = yes; then
      GMP_LDFLAGS="$GMP_LDFLAGS -no-undefined"
    fi
    ;;

  # FIXME: Libtool recognises djgpp can't build shared libraries, but still
  # makes tests/.libs/libtests.al out of PIC objects, which then fail to
  # link into the test programs.  Forcibly disable shared stuff until
  # libtool gets it right,
  #
  *-*-msdosdjgpp*)
    enable_shared=no ;;

  # FIXME: On SCO 5, an explicit -lc is not wanted when making shared
  # libraries.  Giving it makes strange things happen, like ctype.h macros
  # not working and profiler mcount calls segfaulting.  Libtool ought to
  # know about this, but as of Dec 2000 it doesn't, so forcibly disable -lc
  # on relevant systems.
  #
  *-*-sco3.2v5*)
    lt_cv_archive_cmds_need_lc=no ;;

  # FIXME: Shared libraries aren't supported on unicos, but as of Dec 2000
  # libtool doesn't seem to detect this correctly, so forcibly disable them.
  #
  *-*-unicos*)
    enable_shared=no ;;

  # It seems there are no shared libs on ultrix, and it is not very important
  # to work on this.  Just disable for now.
  *-*-ultrix*)
    enable_shared=no ;;
esac

# Libtool runs an impgen.c program on the build system when making windows
# DLLs.  If we're cross compiling then look for a suitable build system
# compiler, since $CC can't be expected to work.
# FIXME: Libtool ought to do this itself.
#
if test "$cross_compiling" != no && test "$enable_shared" != no; then
  case $host in
    *-*-cygwin* | *-*-mingw* | *-*-pw32*)
      GMP_PROG_HOST_CC
      ;;
  esac
fi

# Enable CXX in libtool only if we want it, and never enable GCJ, nor RC on
# mingw and cygwin.  Under --disable-cxx this avoids some error messages
# from libtool arising from the fact we didn't actually run AC_PROG_CXX.
# Notice that any user-supplied --with-tags setting takes precedence.
#
# FIXME: Is this the right way to get this effect?  Very possibly not, but
# the current _LT_AC_TAGCONFIG doesn't really suggest an alternative.
#
if test "${with_tags+set}" != set; then
  if test $want_cxx = yes; then
    with_tags=CXX
  else
    with_tags=
  fi
fi

AC_LIBTOOL_WIN32_DLL
AC_PROG_LIBTOOL

# Generate an error here if attempting to build both shared and static when
# $libname.a is in $library_names_spec (as mentioned above), rather than
# wait for ar or ld to fail.
#
if test "$enable_shared" = yes && test "$enable_static" = yes; then
  case $library_names_spec in
    *libname.a*)
      AC_MSG_ERROR([cannot create both shared and static libraries on this system, --disable one of the two])
      ;;
  esac
fi

# Encode in gmp.h whether a shared or static library is available.
# Currently only used for the windows DLL stuff.
#
case $enable_shared in
yes) __GMP_LIBGMP_SHARED=1 ;;
no)  __GMP_LIBGMP_SHARED=0 ;;
esac
AC_SUBST(__GMP_LIBGMP_SHARED)

case $enable_static in
yes) __GMP_LIBGMP_STATIC=1 ;;
no)  __GMP_LIBGMP_STATIC=0 ;;
esac
AC_SUBST(__GMP_LIBGMP_STATIC)


# How to assemble, used with CFLAGS etc, see mpn/Makeasm.am.
# Using the compiler is a lot easier than figuring out how to invoke the
# assembler directly.
#
test -n "$CCAS" || CCAS="$CC -c"
AC_SUBST(CCAS)

case $host in
  X86_PATTERN)
    # If there's any sse2 or mmx in the path, check whether the assembler
    # supports it, and remove if not.
    case "$path" in
      *mmx*)   GMP_ASM_X86_MMX( , [GMP_STRIP_PATH(*mmx*)]) ;;
    esac
    case "$path" in
      *sse2*)  GMP_ASM_X86_SSE2( , [GMP_STRIP_PATH(sse2)]) ;;
    esac
  ;;
esac


# The library and header checks are mostly for the benefit of supplementary
# programs.  libgmp doesn't use anything too weird.

AC_HEADER_STDC
AC_HEADER_TIME

# stdint.h, unistd.h and sys/types.h are already in the autoconf default
# tests
AC_CHECK_HEADERS(locale.h sys/mman.h sys/param.h sys/processor.h sys/resource.h sys/sysctl.h sys/systemcfg.h sys/time.h sys/times.h)

# optarg should be in unistd.h, which is already in the default includes
AC_CHECK_DECLS([fgetc, fscanf, optarg, ungetc, vfprintf])

AC_TYPE_SIGNAL

# the default includes are sufficient for all these types
AC_CHECK_TYPES([intmax_t, long double, long long, ptrdiff_t, quad_t])

AC_C_STRINGIZE
GMP_C_STDARG
GMP_C_ATTRIBUTE_CONST
GMP_C_ATTRIBUTE_MALLOC
GMP_C_ATTRIBUTE_MODE
GMP_C_ATTRIBUTE_NORETURN

AC_C_INLINE
GMP_H_EXTERN_INLINE

# from libtool
AC_CHECK_LIBM
AC_SUBST(LIBM)

GMP_FUNC_ALLOCA
GMP_OPTION_ALLOCA

GMP_H_HAVE_FILE
GMP_IMPL_H_IEEE_FLOATS


# On m68k NetBSD 1.4.1 getrusage() is doubtful.  ru_utime looks microsecond
# accurate but has been seen remaining unchanged after many microseconds
# have elapsed.  This upsets the tune and speed programs, so pretend it
# doesn't exist.
#
# FIXME: Would prefer tune/time.c to do a run-time test for this rather than
# driving it from the system name.
#
case $host in
  m68*-*-netbsd1.4*) ac_cv_func_getrusage=no ;;
esac

AC_CHECK_FUNCS(alarm getpagesize getrusage gettimeofday localeconv memset mmap mprotect obstack_vprintf popen processor_info read_real_time strchr strnlen strtoul sysconf sysctl sysctlbyname times)

# FIXME: Would have done this with an AM_CONDITIONAL, but automake 1.5
# doesn't like that under libgmp_la_DEPENDENCIES.
GMP_FUNC_VSNPRINTF
if test "$gmp_cv_func_vsnprintf" = no; then
  AC_SUBST(REPL_VSNPRINTF_PRINTF_OBJ, 'printf/repl-vsnprintf$U.lo')
  AC_SUBST(REPL_VSNPRINTF_OBJ,        'repl-vsnprintf$U.lo')
fi

GMP_FUNC_SSCANF_WRITABLE_INPUT


# Pick the correct source files in $path and link them to mpn/.
# $gmp_mpn_functions lists all functions we need.
#
# The rule is to find a file with the function name and a .asm, .S,
# .s, or .c extension.  Certain multi-function files with special names
# can provide some functions too.  (mpn/Makefile.am passes
# -DOPERATION_<func> to get them to generate the right code.)

# FIXME: udiv and umul aren't in $gmp_mpn_functions_optional yet since
# there's some versions of those files which should be checked for bit
# rot first.  Put them in $extra_functions for each host for now,
# change to standard optionals when all are ready.

# Note: The following lines defining $gmp_mpn_functions_optional
#       and $gmp_mpn_functions are parsed by the "macos/configure"
#       Perl script. So if you change the lines in a major way
#       make sure to run and examine the output from
#       
#           % (cd macos; perl configure)
#
# Note: $gmp_mpn_functions must have mod_1 before pre_mod_1 so the former
#       can optionally provide the latter as an extra entrypoint.

gmp_mpn_functions_optional="copyi copyd com_n		\
  and_n andn_n nand_n ior_n iorn_n nior_n xor_n xnor_n	\
  gcd_finda invert_limb sqr_diagonal"

gmp_mpn_functions="$extra_functions					   \
  add add_1 add_n sub sub_1 sub_n mul_1 addmul_1			   \
  submul_1 lshift rshift dive_1 diveby3 divis divrem divrem_1 divrem_2     \
  fib2_ui mod_1 mod_34lsub1 mode1o pre_mod_1 dump                          \
  mul mul_fft mul_n mul_basecase sqr_basecase random                       \
  random2 sqrtrem get_str set_str scan0 scan1 popcount hamdist cmp perfsqr \
  bdivmod gcd_1 gcd gcdext tdiv_qr dc_divrem_n sb_divrem_mn jacbase        \
  $gmp_mpn_functions_optional"

# the list of all object files used by mpn/Makefile.in and the
# top-level Makefile.in, respectively
mpn_objects=
mpn_objs_in_libgmp="mpn/mp_bases.lo"

# links from the sources, to be removed by "make distclean"
gmp_srclinks=

define(MPN_SUFFIXES,[asm S s c])

for tmp_ext in MPN_SUFFIXES; do
  eval found_$tmp_ext=no
done

for tmp_fn in $gmp_mpn_functions; do
  for tmp_ext in MPN_SUFFIXES; do
    test "$no_create" = yes || rm -f mpn/$tmp_fn.$tmp_ext
  done

  # Don't need pre_mod_1 if it's already been provided (by an asm mod_1).
  case $tmp_fn in
  pre_mod_1)
    if test "$HAVE_NATIVE_mpn_preinv_mod_1" = yes; then continue; fi ;;
  esac

  # functions that can be provided by multi-function files
  tmp_mulfunc=
  case $tmp_fn in
  add_n|sub_n)       tmp_mulfunc="aors_n"    ;;
  addmul_1|submul_1) tmp_mulfunc="aorsmul_1" ;;
  popcount|hamdist)  tmp_mulfunc="popham"    ;;
  and_n|andn_n|nand_n | ior_n|iorn_n|nior_n | xor_n|xnor_n)
                     tmp_mulfunc="logops_n"  ;;
  lshift|rshift)     tmp_mulfunc="lorrshift";;
  esac

  found=no
  for tmp_dir in $path; do
    for tmp_base in $tmp_fn $tmp_mulfunc; do
      for tmp_ext in MPN_SUFFIXES; do
        tmp_file=$srcdir/mpn/$tmp_dir/$tmp_base.$tmp_ext
        if test -f $tmp_file; then
          found=yes
          eval found_$tmp_ext=yes

          if test $tmp_ext = c; then
            tmp_u='$U'
          else
            tmp_u=
          fi

          mpn_objects="$mpn_objects $tmp_fn$tmp_u.lo"
          mpn_objs_in_libgmp="$mpn_objs_in_libgmp mpn/$tmp_fn$tmp_u.lo"
          AC_CONFIG_LINKS(mpn/$tmp_fn.$tmp_ext:mpn/$tmp_dir/$tmp_base.$tmp_ext)
          gmp_srclinks="$gmp_srclinks mpn/$tmp_fn.$tmp_ext"

          # Duplicate AC_DEFINEs are harmless, so it doesn't matter
          # that multi-function files get grepped here repeatedly.
	  # The PROLOGUE pattern has ".*" so that alpha PROLOGUE_GP matches.
          gmp_ep=[`
            sed -n 's/^[ 	]*MULFUNC_PROLOGUE(\(.*\))/\1/p' $tmp_file ;
            sed -n 's/^[ 	]*PROLOGUE.*(\(.*\))/\1/p' $tmp_file
          `]
          for gmp_tmp in $gmp_ep; do
            AC_DEFINE_UNQUOTED(HAVE_NATIVE_$gmp_tmp)
            eval HAVE_NATIVE_$gmp_tmp=yes
          done

          case $tmp_fn in
          sqr_basecase) sqr_basecase_source=$tmp_file ;;
          esac

          break
        fi
      done
      if test $found = yes; then break ; fi
    done
    if test $found = yes; then break ; fi
  done

  if test $found = no; then
    for tmp_optional in $gmp_mpn_functions_optional; do
      if test $tmp_optional = $tmp_fn; then
        found=yes
      fi
    done
    if test $found = no; then
      AC_MSG_ERROR([no version of $tmp_fn found in path: $path])
    fi
  fi
done

# All cycle counters are .asm files currently
if test -n "$SPEED_CYCLECOUNTER_OBJ"; then
  found_asm=yes
fi


# Don't demand an m4 unless it's actually needed.
if test $found_asm = yes; then
  GMP_PROG_M4
  GMP_M4_M4WRAP_SPURIOUS
else
  M4=m4-not-needed
fi

# Only do the GMP_ASM checks if there's a .S or .asm wanting them.
if test $found_asm = no && test $found_S = no; then
  gmp_asm_syntax_testing=no
fi

if test "$gmp_asm_syntax_testing" != no; then
  GMP_ASM_TEXT
  GMP_ASM_DATA
  GMP_ASM_LABEL_SUFFIX
  GMP_ASM_GLOBL
  GMP_ASM_UNDERSCORE
  GMP_ASM_RODATA
  GMP_ASM_GLOBL_ATTR
  GMP_ASM_TYPE
  GMP_ASM_SIZE
  GMP_ASM_LSYM_PREFIX
  GMP_ASM_W32
  GMP_ASM_ALIGN_LOG

  case $host in
    m68*-*-*)
      GMP_ASM_M68K_INSTRUCTION
      GMP_ASM_M68K_ADDRESSING
      GMP_ASM_M68K_BRANCHES
      ;;
    power*-*-*)
      GMP_ASM_POWERPC_R_REGISTERS
      GMP_INCLUDE_MPN(powerpc32/powerpc-defs.m4)
      case $host in
      powerpc64*-*-aix*) GMP_INCLUDE_MPN(powerpc64/aix.m4) ;;
      *-*-aix*)          GMP_INCLUDE_MPN(powerpc32/aix.m4) ;;
      esac
      ;;

    X86_PATTERN)
      GMP_ASM_ALIGN_FILL_0x90
      GMP_ASM_X86_SHLDL_CL
      if test "$enable_profiling" != no; then
        GMP_ASM_X86_MCOUNT
      fi
      ;;
  esac
fi


# Create link for gmp-mparam.h.
gmp_mparam_source=
for tmp_dir in $path; do
  test "$no_create" = yes || rm -f gmp-mparam.h
  tmp_file=$srcdir/mpn/$tmp_dir/gmp-mparam.h
  if test -f $tmp_file; then
    AC_CONFIG_LINKS(gmp-mparam.h:mpn/$tmp_dir/gmp-mparam.h)
    gmp_srclinks="$gmp_srclinks gmp-mparam.h"
    gmp_mparam_source=$tmp_file
    break
  fi
done
if test -z "$gmp_mparam_source"; then
  AC_MSG_ERROR([no version of gmp-mparam.h found in path: $path])
fi

# Copy any KARATSUBA_SQR_THRESHOLD from gmp-mparam.h to config.m4.
# Some versions of sqr_basecase.asm use this.
tmp_gmp_karatsuba_sqr_threshold=`sed -n 's/^#define KARATSUBA_SQR_THRESHOLD[ 	]*\([0-9][0-9]*\).*$/\1/p' $gmp_mparam_source`
if test -n "$tmp_gmp_karatsuba_sqr_threshold"; then
  GMP_DEFINE_RAW(["define(<KARATSUBA_SQR_THRESHOLD>,<$tmp_gmp_karatsuba_sqr_threshold>)"])
fi

# This must come after gmp-mparam.h has been chosen.
GMP_C_SIZES


# Exclude the mpn random functions from mpbsd since that would drag in the
# top-level rand things, all of which are unnecessary for libmp.  There's
# other unnecessary objects too actually, if we could be bothered figuring
# out exactly which they are.
#
mpn_objs_in_libmp=
for i in $mpn_objs_in_libgmp; do
  case $i in
  *random*) ;;
  *) mpn_objs_in_libmp="$mpn_objs_in_libmp $i" ;;
  esac
done
AC_SUBST(mpn_objs_in_libmp)

AC_SUBST(mpn_objects)
AC_SUBST(mpn_objs_in_libgmp)
AC_SUBST(gmp_srclinks)


# A recompiled sqr_basecase for use in the tune program, if necessary.
TUNE_SQR_OBJ=
test -d tune || mkdir tune
case $sqr_basecase_source in
  *.asm)
    sqr_max=[`sed -n 's/^def...(KARATSUBA_SQR_THRESHOLD_MAX, *\([0-9]*\))/\1/p' $sqr_basecase_source`]
    if test -n "$sqr_max"; then
      TUNE_SQR_OBJ=sqr_asm.o
      AC_DEFINE_UNQUOTED(TUNE_KARATSUBA_SQR_MAX,$sqr_max,
      [Maximum size the tune program can test for KARATSUBA_SQR_THRESHOLD])
    fi
    cat >tune/sqr_basecase.c <<EOF
/* not sure that an empty file can compile, so put in a dummy */
int sqr_basecase_dummy;
EOF
    ;;
  *.c)
    TUNE_SQR_OBJ=
    AC_DEFINE(TUNE_KARATSUBA_SQR_MAX,KARATSUBA_SQR_MAX_GENERIC)
    cat >tune/sqr_basecase.c <<EOF
#define TUNE_PROGRAM_BUILD 1
#define TUNE_PROGRAM_BUILD_SQR 1
#include "mpn/sqr_basecase.c"
EOF
    ;;
esac
AC_SUBST(TUNE_SQR_OBJ)


# Configs for demos/expr directory
if test $enable_mpfr = yes; then
  HAVE_MPFR=1
else
  HAVE_MPFR=0
fi
AC_SUBST(HAVE_MPFR)


# Create config.m4.
GMP_FINISH

# Create Makefiles
# FIXME: Upcoming version of autoconf/automake may not like broken lines.
#        Right now automake isn't accepting the new AC_CONFIG_FILES scheme.

AC_OUTPUT(Makefile							\
  mpbsd/Makefile mpf/Makefile mpn/Makefile mpq/Makefile	\
  mpz/Makefile printf/Makefile scanf/Makefile cxx/Makefile		\
  tests/Makefile tests/devel/Makefile tests/mpbsd/Makefile		\
  tests/mpf/Makefile tests/mpn/Makefile tests/mpq/Makefile		\
  tests/mpz/Makefile tests/rand/Makefile tests/misc/Makefile		\
  tests/cxx/Makefile							\
  tune/Makefile								\
  demos/Makefile demos/calc/Makefile demos/expr/Makefile		\
  gmp.h:gmp-h.in mp.h:mp-h.in						\
  demos/expr/expr-impl.h:demos/expr/expr-impl-h.in)

dnl  mpfr temporarily removed from the distribution
dnl  mpfr/Makefile mpfr/tests/Makefile