On Fri, Nov 03, 2023 at 04:20:57PM +0000, Qing Zhao wrote:
> So, based on the discussion so far, We will define the .ACCESS_WITH_SIZE as
> following:
>
> .ACCESS_WITH_SIZE (REF_TO_OBJ, REF_TO_SIZE, ACCESS_MODE)
>
> INTERNAL_FN (ACCESS_WITH_SIZE, ECF_LEAF | ECF_NOTHROW, NULL)
>
> which returns the “REF_TO_OBJ" same as the 1st argument;
>
> 1st argument “REF_TO_OBJ": Reference to the object;
> 2nd argument “REF_TO_SIZE”: Reference to size of the object referenced by
> the 1st argument,
> if the object that the “REF_TO_OBJ” refered has a
> * real type, the SIZE that the “REF_TO_SIZE” referred is the number of the
> elements of the type;
> * void type, the SIZE that the “REF_TO_SIZE” referred is number of bytes;
No, you can't do this. Conversions between pointers are mostly useless in
GIMPLE, , so you can't make decisions based on TREE_TYPE (TREE_TYPE (fnarg))
as it could have some random completely unrelated type.
So, the multiplication factor needs to be encoded in the arguments rather
than derived from REF_TO_OBJ's type, and similarly the size of what
REF_TO_SIZE points to needs to be encoded somewhere.
> 3rd argument "ACCESS_MODE":
> -1: Unknown access semantics
> 0: none
> 1: read_only
> 2: write_only
> 3: read_write
Jakub
