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Re: [PATCH] Introduce abi_word_mode
Ian Lance Taylor <iant@google.com> writes:
> "Ulrich Weigand" <uweigand@de.ibm.com> writes:
>> - Define a new abi_word_mode (from the target's UNITS_PER_ABI_WORD)
>> that is to represent the mode of attibute ((mode (word))).
>>
>> - Do not change unwind-generic.h -- its data structures will now
>> automatically correspond to the abi_word_mode.
>>
>> - Explicitly use abi_word_mode in except.c when refering to data
>> structures also manipulated by libgcc_eh code.
>>
>> - This obsoletes TARGET_EH_RETURN_FILTER_MODE.
>>
>> > I'm willing to look at a patch which fixes those cases only.
>>
>> Just to clarify, is the solution outlined above what you
>> intended, or did I misunderstand?
>
> That is what I intended (plus also use abi_word_mode in a couple of
> places in optabs.c, of course). Sorry for being confusing.
Sorry to hammer on about this -- I'm probably just being dense -- but
defining the ABI word mode to be "the mode of attribute ((mode (word)))"
seems inherently cyclic. attribute ((mode (...))) is just a way of
exposing gcc's internal modes to users. The documentation of the
attribute doesn't seem to anchor it to externals much:
You may also specify a mode of @samp{byte} or @samp{__byte__} to
indicate the mode corresponding to a one-byte integer, @samp{word} or
@samp{__word__} for the mode of a one-word integer, [...]
If we have two different concepts of "word" in play, this documentation
doesn't really help either.
Richard