dnl AG_GST_ARCH
dnl sets up defines and automake conditionals for host architecture
dnl checks endianness
dnl defines HOST_CPU

AC_DEFUN([AG_GST_ARCH],
[
  AC_REQUIRE([AC_CANONICAL_HOST]) dnl we use host_ variables

  dnl Determine CPU
  case "x${host_cpu}" in
    xi?86 | xk? | xi?86_64)
      HAVE_CPU_I386=yes
      AC_DEFINE(HAVE_CPU_I386, 1, [Define if the host CPU is an x86])
  
      dnl FIXME could use some better detection
      dnl (ie CPUID)
      case "x${host_cpu}" in
        xi386 | xi486) ;;
        *)
          AC_DEFINE(HAVE_RDTSC, 1, [Define if RDTSC is available]) ;;
      esac ;;
    xpowerpc)
      HAVE_CPU_PPC=yes
      AC_DEFINE(HAVE_CPU_PPC, 1, [Define if the host CPU is a PowerPC]) ;;
    xpowerpc64)
      HAVE_CPU_PPC64=yes
      AC_DEFINE(HAVE_CPU_PPC64, 1, [Define if the host CPU is a 64 bit PowerPC]) ;;
    xalpha*)
      HAVE_CPU_ALPHA=yes
      AC_DEFINE(HAVE_CPU_ALPHA, 1, [Define if the host CPU is an Alpha]) ;;
    xarm*)
      HAVE_CPU_ARM=yes
      AC_DEFINE(HAVE_CPU_ARM, 1, [Define if the host CPU is an ARM]) ;;
    xsparc*)
      HAVE_CPU_SPARC=yes
      AC_DEFINE(HAVE_CPU_SPARC, 1, [Define if the host CPU is a SPARC]) ;;
    xmips*)
      HAVE_CPU_MIPS=yes
      AC_DEFINE(HAVE_CPU_MIPS, 1, [Define if the host CPU is a MIPS]) ;;
    xhppa*)
      HAVE_CPU_HPPA=yes
      AC_DEFINE(HAVE_CPU_HPPA, 1, [Define if the host CPU is a HPPA]) ;;
    xs390*)
      HAVE_CPU_S390=yes
      AC_DEFINE(HAVE_CPU_S390, 1, [Define if the host CPU is a S390]) ;;
    xia64*)
      HAVE_CPU_IA64=yes
      AC_DEFINE(HAVE_CPU_IA64, 1, [Define if the host CPU is a IA64]) ;;
    xm68k*)
      HAVE_CPU_M68K=yes
      AC_DEFINE(HAVE_CPU_M68K, 1, [Define if the host CPU is a M68K]) ;;
    xx86_64)
      HAVE_CPU_X86_64=yes
      AC_DEFINE(HAVE_CPU_X86_64, 1, [Define if the host CPU is a x86_64]) ;;
    xcris)
      HAVE_CPU_CRIS=yes
      AC_DEFINE(HAVE_CPU_CRIS, 1, [Define if the host CPU is a CRIS]) ;;
    xcrisv32)
      HAVE_CPU_CRISV32=yes
      AC_DEFINE(HAVE_CPU_CRISV32, 1, [Define if the host CPU is a CRISv32]) ;;
  esac
  
  dnl Determine endianness
  AC_C_BIGENDIAN
  
  AM_CONDITIONAL(HAVE_CPU_I386,       test "x$HAVE_CPU_I386" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_PPC,        test "x$HAVE_CPU_PPC" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_PPC64,      test "x$HAVE_CPU_PPC64" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_ALPHA,      test "x$HAVE_CPU_ALPHA" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_ARM,        test "x$HAVE_CPU_ARM" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_SPARC,      test "x$HAVE_CPU_SPARC" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_HPPA,       test "x$HAVE_CPU_HPPA" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_MIPS,       test "x$HAVE_CPU_MIPS" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_S390,       test "x$HAVE_CPU_S390" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_IA64,       test "x$HAVE_CPU_IA64" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_M68K,       test "x$HAVE_CPU_M68K" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_X86_64,     test "x$HAVE_CPU_X86_64" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_CRIS,       test "x$HAVE_CPU_CRIS" = "xyes")
  AM_CONDITIONAL(HAVE_CPU_CRISV32,    test "x$HAVE_CPU_CRISV32" = "xyes")

  AC_DEFINE_UNQUOTED(HOST_CPU, "$host_cpu", [the host CPU])
])

dnl check if unaligned memory access works correctly
AC_DEFUN([AG_GST_UNALIGNED_ACCESS], [
  AC_MSG_CHECKING([if unaligned memory access works correctly])
  if test x"$as_cv_unaligned_access" = x ; then
    case $host in
      alpha*|arm*|hp*|mips*|sh*|sparc*|ia64*)
        _AS_ECHO_N([(blacklisted) ])
        as_cv_unaligned_access=no
	;;
      i?86*|powerpc*|m68k*|cris*)
        _AS_ECHO_N([(whitelisted) ])
        as_cv_unaligned_access=yes
	;;
    esac
  else
    _AS_ECHO_N([(cached) ])
  fi
  if test x"$as_cv_unaligned_access" = x ; then
    AC_TRY_RUN([
int main(int argc, char **argv)
{
  char array[] = "ABCDEFGH";
  unsigned int iarray[2];
  memcpy(iarray,array,8);
#define GET(x) (*(unsigned int *)((char *)iarray + (x)))
  if(GET(0) != 0x41424344 && GET(0) != 0x44434241) return 1;
  if(GET(1) != 0x42434445 && GET(1) != 0x45444342) return 1;
  if(GET(2) != 0x43444546 && GET(2) != 0x46454443) return 1;
  if(GET(3) != 0x44454647 && GET(3) != 0x47464544) return 1;
  return 0;
}
    ], as_cv_unaligned_access="yes", as_cv_unaligned_access="no")
  fi
  AC_MSG_RESULT($as_cv_unaligned_access)
  if test "$as_cv_unaligned_access" = "yes"; then
    AC_DEFINE_UNQUOTED(HAVE_UNALIGNED_ACCESS, 1,
      [defined if unaligned memory access works correctly])
  fi
])