>>>> + if (TREE_TYPE (TREE_TYPE (src_ptr)) != src_type)
>>>
>>> This line looks unexpected, the former is type char while the latter is
>>> type __vector_pair *.
>>>
>>> I guess you meant to compare the type of pointer type like:
>>>
>>> TREE_TYPE (TREE_TYPE (src_ptr)) != TREE_TYPE (src_type)
>>
>> Maybe? However, if that is the case, how can it be working for me?
>> Let me throw this in the debugger and verify the types and I'll report
>> back with what I find.
>
> Ok, you are correct. Thanks for catching that! I don't think we need
> those matching outer TREE_TYPE() uses. I think just a simple:
>
> if (TREE_TYPE (src_ptr) != src_type)
>
> ...should suffice.
>
Yeah, it's enough for the associated test case. :)
>
>>> or even with mode like:
>>>
>>> TYPE_MODE (TREE_TYPE (TREE_TYPE (src_ptr))) != TYPE_MODE (TREE_TYPE
>>> (src_type))
>
> I'd rather not look at the mode here, since OOmode/XOmode doesn't necessarily
> mean __vector_{pair,quad}, so I'll go with the modified test above.
Good point. I thought the cv qualifier can affect the type equality check and
assumed for test case like:
void
foo (char *resp, const __vector_pair *vpp)
{
__builtin_vsx_disassemble_pair (resp, (__vector_pair *) vpp);
}
, we don't want to have the conversion there and the ICE seems related to the
underlying mode, so I thought maybe you wanted to use TYPE_MODE.
>>>> + src_ptr = build1 (VIEW_CONVERT_EXPR, src_type, src_ptr);
>>>
>>> Nit: NOP_EXPR seems to be better suited here for pointer conversion.
>
> Ok, this works too, so code changed to use it. Thanks!
>
> Question for my own education, when would you use VIEW_CONVERT_EXPR over
> NOP_EXPR?
tree.def has some note about VIEW_CONVERT_EXPR, it quite matches what Segher
replied.
In my experience, VIEW_CONVERT_EXPR are used a lot for vector type conversion.
BR,
Kewen
