binutils-gdb/gdb/testsuite/gdb.xml/extra-regs.xml

<target>
  <xi:include href="core-regs.xml"/>
  <feature name="extra">
    <vector id="v4int8" type="int8" count="4"/>
    <vector id="v2int16" type="int16" count="2"/>
    <union id="vecint">
      <field name="v4" type="v4int8"/>
      <field name="v2" type="v2int16"/>
    </union>

    <reg name="extrareg" bitsize="32"/>
    <reg name="uintreg" bitsize="32" type="uint32"/>
    <reg name="vecreg" bitsize="32" type="v4int8"/>
    <reg name="unionreg" bitsize="32" type="vecint"/>
  </feature>
</target>