On Sun, Aug 29, 2021 at 12:11:23PM -0700, H.J. Lu wrote:
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -1840,6 +1840,54 @@ init_cumulative_args (CUMULATIVE_ARGS *cum, /*
> Argument info to initialize */
> cfun->machine->arg_reg_available = (cum->nregs > 0);
> }
>
> +/* Return the single 64-bit vector type of TYPE. */
> +
> +static const_tree
> +single_m64_base_type (const_tree type)
> +{
> + if ((TREE_CODE (type) == RECORD_TYPE
> + || TREE_CODE (type) == UNION_TYPE
> + || TREE_CODE (type) == QUAL_UNION_TYPE)
> + && int_size_in_bytes (type) == 8)
> + {
> + const_tree field;
> + const_tree first_field = nullptr;
> +
> + for (field = TYPE_FIELDS (type);
> + field;
> + field = DECL_CHAIN (field))
> + if (TREE_CODE (field) == FIELD_DECL)
> + {
> + if (TREE_TYPE (field) == error_mark_node)
> + continue;
> +
> + /* Skip if structure has more than one field. */
> + if (first_field)
> + return nullptr;
> +
> + first_field = field;
> + }
> +
> + /* Skip if structure doesn't have any fields. */
> + if (!first_field)
> + return nullptr;
Is this an attempt to emulate compute_record_mode or something else?
How should it treat zero-width bitfields (either the C ones kept
in the structures or C++ ones formerly removed from them and now no longer)?
compute_record_mode actually has more complicated details...
Jakub
