__builtin_eh_return_data_regno

[Mark Mitchell]

I started trying to track this down.  It doesn't look like
EH_RETURN_DATA_REGNO is defined for MIPS.  Can I pick any four
call-clobberred registers for this purpose?  (That's what the
documentation seems to say, but I just wanted to check.)

Also, isn't this:

#ifdef EH_RETURN_DATA_REGNO
  builtin_function ("__builtin_eh_return_data_regno", int_ftype_int,
		    BUILT_IN_EH_RETURN_DATA_REGNO, BUILT_IN_NORMAL, NULL_PTR);
#endif

suboptimal?  From looking at the switch statement in builtins.c, it
seems that we are meant always define the function, and then issue an
error indicating that the builtin function is not supported on a
particular target.

Thanks,

--
Mark Mitchell                   mark@codesourcery.com
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