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Re: Proposal: changing representation of memory references
- From: Ian Lance Taylor <iant at google dot com>
- To: Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>
- Cc: gcc at gcc dot gnu dot org
- Date: 04 Apr 2007 18:00:48 -0700
- Subject: Re: Proposal: changing representation of memory references
- References: <20070404143508.GA461@atrey.karlin.mff.cuni.cz>
Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz> writes:
> Proposal:
>
> For each memory reference, we remember the following information:
>
> -- base of the reference
> -- constant offset
> -- vector of indices
> -- type of the accessed location
> -- original tree of the memory reference (or another summary of the
> structure of the access, for aliasing purposes)
> -- flags
>
> for each index, we remeber
> -- lower and upper bound
> -- step
> -- value of the index
Sounds promising but I'm concerned about additional memory overhead in
the data structures for the common case of pointer dereference when we
don't know what the pointer points to. Would it make sense to keep
INDIRECT_REF, essentially as a specific space optimization?
Ian