Another case of DCE deleting live code

[Daniel Berlin]

On Nov 9, 2004, at 6:36 PM, Diego Novillo wrote:



> On Tue, 2004-11-09 at 18:09, Daniel Berlin wrote:
>
>>>>
>>>>
>>> Yes.  The tag_set we compute in get_tmt_for must be exactly what
>>> get_alias_set returns.  We use that to determine which pointers get 
>>> the
>>> same alias set and other checks.
>>>
>>
>> Why isn't get_alias_set returning 0 for types with that flag set, 
>> which
>> would avoid anything but get_alias_set being modified?
>>
>>
> Because that bit is set on TREE_TYPE (ptr) and what we are interested 
> in
> is TREE_TYPE (TREE_TYPE (ptr)) (ie, the type of the pointed-to memory
> location).
>

Gah.
So TYPE_REF_CAN_ALIAS_ALL means that whatever it points to can alias 
anything?
That's ugly.