> I see. So I misremember seeing aggregate typed BIT_FIELD_REFs
> (that was probably VIEW_CONVERTs then...). Still the GIMPLE verifier
> only has
>
> else if (!INTEGRAL_TYPE_P (TREE_TYPE (expr))
> && TYPE_MODE (TREE_TYPE (expr)) != BLKmode
> && maybe_ne (GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE
> (expr))),
> size))
> {
> error ("mode size of non-integral result does not "
> "match field size of %qs",
> code_name);
> return true;
> }
>
> it doesn't verify that besides integral typed expressions only
> vector typed expressions are allowed.
I think that the !INTEGRAL_TYPE_P is simply the opposite of the first case:
if (INTEGRAL_TYPE_P (TREE_TYPE (t))
&& maybe_ne (TYPE_PRECISION (TREE_TYPE (t)), size))
{
error ("integral result type precision does not match "
"field size of BIT_FIELD_REF");
return t;
}
> Anyhow - the original patch succeeded bootstrapping and testing.
> The way I proposed it:
>
> /* For vector types, with the correct size of access, use the mode
> of
> inner type. */
> if (((TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == VECTOR_TYPE
> && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp,
> 0))))
>
> || !INTEGRAL_TYPE_P (TREE_TYPE (exp)))
>
> && tree_int_cst_equal (size_tree, TYPE_SIZE (TREE_TYPE (exp))))
> mode = TYPE_MODE (TREE_TYPE (exp));
>
> matches in sofar that we only restrict integer types (not modes) and
> for integer types allow extracts from vectors (the preexisting
> check for a matching component type is a bit too strict I guess).
IMO if the !VECTOR_TYPE case cannot be covered, changes in this delicate area
ought to be restricted to VECTOR_TYPE.
--
Eric Botcazou
