AC_INIT(src/swap_bytes.h.in)
AC_CONFIG_HEADER(src/swap_bytes.h)
: ${R_HOME=`R RHOME`}
if test -z "${R_HOME}"; then
  echo "could not determine R_HOME"
  exit 1
fi
CC=`grep "^CC" ${R_HOME}/etc/Makeconf | sed "s/^CC *= *//"`
AC_PROG_CC
### check if system has a byteswap.h file defining bswap_n for n = 16, 32 and 64
AC_CHECK_HEADER(byteswap.h,
    AC_TRY_LINK([#include <byteswap.h>],
    [
    unsigned short s = 1;
    unsigned int i = 1;
    s = bswap_16(s);
    i = bswap_32(i);
    ], [AC_DEFINE(HAVE_GLIBC_BSWAP)]))
AC_CHECK_SIZEOF(double, 8)
AC_CHECK_SIZEOF(int, 4)
AC_CHECK_SIZEOF(long, 4)
AC_SUBST(SIZEOF_DOUBLE)
AC_SUBST(SIZEOF_LONG)
AC_SUBST(HAVE_GLIBC_BSWAP)
AC_OUTPUT(src/var.h)