On Fri, 9 Jan 2015 13:30:45, Jakub Jelinke wrote:
>
> On Fri, Jan 09, 2015 at 01:12:09PM +0100, Bernd Edlinger wrote:
>>>> should be equivalent to
>>>>
>>>> if (DECL_P (base) && !may_be_aliased (base))
>>>> return false;
>>>>
>>>> is that right?
>>>
>>> Yes, well, not exactly, but I wonder if its worth doing the extra check
>>> if you only check decl accesses anyway and not indirect accesses.
>>>
>>
>>
>> I think Jakub, you wrote that initially, any comments on that?
>
> I think it was still from Dmitry's code. If you can make it work by taking
> address of base and offsetting it, it works for me. Just note that I think
> base doesn't have to be always addressable, so you probably should punt if
> it is not rather than assert it is. If something is not addressable, then
> it can't be accessed by multiple threads.
>
Thanks.
FYI: the VIEW_CONVERT_EXPR did not fail in the
gcc_checking_assert (is_gimple_addressable (base))
but much later, somewhere in tree-cfg.c it dropped out.
Maybe that assert does not check exactly what is
needed for a valid argument of ADDR_EXPR ?
I mean I can somehow fold an ADDR_EXPR of a bit field member,
This won't crash at all, but I can't fold ADDR_EXPR(VIEW_CONVERT_EXPR).
Bernd.
