The thinking here is that using the largest possible LMUL when we know the
operation will fit in fewer registers potentially leaves performance on the
table - indirectly, due to the unnecessarily increased register pressure,
and also directly, depending on the implementation.
On Mon, Dec 11, 2023 at 10:05 AM juzhe.zh...@rivai.ai <juzhe.zh...@rivai.ai>
wrote:
> Hi, Thanks for contributing this.
>
> +/* Select appropriate LMUL for a single vector operation based on
> + byte size of data to be processed.
> + On success, return true and populate lmul_out.
> + If length_in is too wide for a single vector operation, return false
> + and leave lmul_out unchanged. */
> +
> +static bool
> +select_appropriate_lmul (HOST_WIDE_INT length_in,
> + HOST_WIDE_INT &lmul_out)
> +{
>
> I don't think we need this, you only need to use TARGET_MAX_LMUL
>
>
> ------------------------------
> juzhe.zh...@rivai.ai
>
