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Re: [PATCH; RFC] Alignment of component_ref's.
Maxim Kuvyrkov writes:
> Adam Nemet wrote:
> > Maxim Kuvyrkov <maxim@codesourcery.com> writes:
> >> + /* If the reference is with offset outstanding on T,
> >> + use alignment of the field. This is used to avoid
> >> + suboptimal field references via referencing a larger value
> >> + and then extracting pieces of it. Instead, we prefer to
> >> + generate several smaller references.
> >
> > I don't think this is true for loads.
>
> What part of it is not true for loads?
That multiple smaller loads are better that one aligned load and an
extraction.
> > Is this code used for loads as well?
>
> No, set_mem_attributes_minus_bitpos(..., bitpos != 0) is only used for
> storing to bitfields.
Then maybe the comment should say that we are trying to avoid a
read-modify-write sequence here and do multiple smaller stores instead. Am I
misunderstanding your patch?
Adam