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Re: Alias analysis or DSE problem?
On Tue, Oct 20, 2009 at 1:34 AM, Justin Seyster <jrseys@gmail.com> wrote:
> Thanks a lot for the help! ?It looks like creating a temporary
> took care of it.
>
> On Sat, Oct 17, 2009 at 7:41 AM, Richard Guenther
> <richard.guenther@gmail.com> wrote:
>> I think the call you insert is not of valid gimple form - an address
>> argument has to fulfill the is_gimple_min_invariant() predicate.
>> Thus I suspect you have something like &ptr->field in there which
>> needs a temporary.
>
> That was it. ?Actually, the TREE was of the form
> ADDR_EXPR(ARRAY_REF(STRING_CST)), which does not satisfy
> is_gimple_min_invariant().
>
> The strange thing is, I copied that structure verbatim from
> unmodified GCC. ?I'm trying to insert a call that looks like:
>
> foo("some string constant");
>
> If I put that function call in a simple C program and dump out
> the resulting GIMPLE, it gives me the ADDR_EXPR that was causing
> problems in refs_may_alias_p_1().
>
> Does anyone know why that structure is ok in the contexts that
> GCC is using it but not in the context that my plug-in uses it
> in?
If your "string" does not satisfy is_gimple_min_invariant then
it is not of the form you mentioned above. A wild guess would
be that you have the 2nd or 3rd operand of the ARRAY_REF set.
Richard.
> ? ? ? ?--Justin
>