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Re: a question about IVOPTS: find_interesting_uses_address
On Wed, Nov 16, 2011 at 12:28 PM, Eric Botcazou <ebotcazou@adacore.com> wrote:
>> Huh, IVOPTs should never cause a different size memory read. ?I wonder
>> if the original issue would still reproduce with the fix reverted.
>
> The original issue was unaligned arrays in packed structures. ?I don't see what
> could have changed since then.
Ah, so it was expand being confused about the constructed access (not seeing
a component-ref), thus the usual old issue we have there. There's indeed no
trivial fix for this but to create the [TARGET_]MEM_REF with an explicitely
unaligned type and hope that the target implements the movmisalign optab
(the only case this explicit alignment is honored). And double-check the
TARGET_MEM_REF expansion code properly duplicates the movmisalign
path from the MEM_REF expander.
I'd wish somebody fixed this path for non-movmisalign strict-align targets.
Richard.
> --
> Eric Botcazou
>