if [ "$CARCH" = 'i486' ]; then
  # these atomics are unavailable on i486, but that is not detected (?)
  eval "$(
    declare -f prepare | \
      sed '
        /^}$/ i \
          sed -i '"'"' \
            /#define BROKEN_64BIT_ATOMICS_INTRINSIC 1/ i \\\
            #endif \\\
            #if true \
          '"'"' mono/utils/atomic.h 
      '
  )"
fi