Hi Eric,
On Tue, Nov 20, 2018 at 10:05:21AM +0100, Eric Botcazou wrote:
> +/* Return true if X is an operation that always operates on the full
> + registers for WORD_REGISTER_OPERATIONS architectures. */
> +
> +inline bool
> +word_register_operation_p (const_rtx x)
> +{
> + switch (GET_CODE (x))
> + {
> + case ROTATE:
> + case ROTATERT:
> + case SIGN_EXTRACT:
> + case ZERO_EXTRACT:
> + return false;
> +
> + default:
> + return true;
> + }
> +}
This is saying that *every* op except those very few works on the full
register. And that for every architecture that has W_R_O.
It also only looks at the top code in the RTL, so it will say for example
a rotate-and-mask is just fine, while that isn't true.
Segher
