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Re: [PATCH] Fix PR middle-end/17793


On Tue, 19 Oct 04 19:17:15 EDT, kenner@vlsi1.ultra.nyu.edu (Richard Kenner) wrote:

>     VIEW_CONVERT_EXPR operates on the reference, NOP_EXPR on the value.
>
> No.  VIEW_CONVERT_EXPR conceptually operates on a *value*.  In Ada, it's
> the equivalent of an unchecked conversion, which is semantically a
> *function*.  In C, it's the equivalent of a conversion of a value into
> a union and then an extraction of another field of that union, which
> is also a value.

That would seem to imply making a copy of the (possibly aggregate) value,
which I thought we were trying to avoid.  If we're using a
VIEW_CONVERT_EXPR on the lhs of a COMPONENT_REF, where does the extraction
come in?

Jason


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