On Wed, Jun 15, 2011 at 7:46 PM, Mike Stump <mikest...@comcast.net> wrote:
> On Jun 15, 2011, at 2:04 AM, Richard Guenther wrote:
>> This VIEW_CONVERT_EXPR looks useless - in fact useless_type_conversion_p
>> will tell you that, so you can omit it.
>
> So, I tracked down who created it:
>
> tree
> convert_to_vector (tree type, tree expr)
> {
> switch (TREE_CODE (TREE_TYPE (expr)))
> {
> case INTEGER_TYPE:
> case VECTOR_TYPE:
> if (!tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (expr))))
> {
> error ("can%'t convert between vector values of different size");
> return error_mark_node;
> }
> => return build1 (VIEW_CONVERT_EXPR, type, expr);
>
> If people want to not create useless conversions in the first place, though,
> I suspect there are lots of places that create useless conversions in the
> compiler.
Yeah, the above looks it comes from the frontends - gimplification
should strip this conversion, if it doesn't that is a bug ;)
Richard.
