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Re: [google]: initialize language field for clone function struct
On Wed, May 4, 2011 at 7:14 PM, Eric Botcazou <ebotcazou@adacore.com> wrote:
>> Actually it turns out that it doesn't matter. ?If we arrive here with
>> something that needs a SAVE_EXPR we have to be able to generate code
>> for it somewhere, where there would be obviously the possibility to
>> also generate code for a SAVE_EXPR.
>
> The transformations done in fold are optimizations that duplicate things,
> hence the need to protect them from multiple evaluations. ?If you cannot
> easily do so (e.g. at global level), you just don't do the optimizations.
>
> But, yes, there is something true. ?If you have variable sizes at the global
> level, they need to be evaluated once for all (unless self-referential, but
> this is another subject) so you need to do it somewhere. ?But you cannot do
> it with SAVE_EXPRs since they would end up being shared across functions.
Sure, but that's a limitation of out SAVE_EXPR handling (given that it would
be ok to expand the SAVE_EXPR multiple times - once per "instantiation
context").
Richard.
> --
> Eric Botcazou
>