On Thu, Oct 10, 2024 at 5:25 PM Victor Do Nascimento
<victor.donascime...@arm.com> wrote:
>
> The recent refactoring of the dot_prod optab to convert-type exposed a
> limitation in how `find_widening_optab_handler_and_mode' is currently
> implemented, owing to the fact that, while the function expects the
>
> GET_MODE_CLASS (from_mode) == GET_MODE_CLASS (to_mode)
>
> condition to hold, the c6x backend implements a dot product from V2HI
> to SI, which triggers an ICE.
>
> Consequently, this patch adds some logic to allow widening optabs
> which accumulate vector elements to a single scalar.
>
> Regression tested on x86_64 and aarch64 with no new regressions.
> Fixes failing unit tests on c6x, as validated for the tic6x-unknown-elf
> target.
>
> Ok for master?
>
> gcc/ChangeLog:
>
> PR middle-end/116926
> * optabs-query.cc (find_widening_optab_handler_and_mode): Add
> handling of vector -> scalar optab handling.
> ---
> gcc/optabs-query.cc | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/gcc/optabs-query.cc b/gcc/optabs-query.cc
> index c3134d6a2ce..8a9092ffec7 100644
> --- a/gcc/optabs-query.cc
> +++ b/gcc/optabs-query.cc
> @@ -485,6 +485,19 @@ find_widening_optab_handler_and_mode (optab op,
> machine_mode to_mode,
> if (GET_MODE_CLASS (limit_mode) == MODE_PARTIAL_INT)
> limit_mode = GET_MODE_WIDER_MODE (limit_mode).require ();
> }
> + else if (GET_MODE_CLASS (from_mode) != GET_MODE_CLASS (to_mode))
> + {
> + gcc_checking_assert (VECTOR_MODE_P (from_mode)
> + && !VECTOR_MODE_P (to_mode)
> + && GET_MODE_INNER (from_mode) < to_mode);
> + enum insn_code handler = convert_optab_handler (op, to_mode,
> from_mode);
> + if (handler != CODE_FOR_nothing)
> + {
> + if (found_mode)
> + *found_mode = from_mode;
> + return handler;
> + }
else if (is_a <scalar_int_mode> (to_mode))
{
gcc_checking_assert (VECTOR_MODE_P (from_mode)
&& GET_MODE_INNER
(from_mode) < to_mode);
limit_mode = from_mode;
}
else
...
would also work?
Thanks,
Richard.
> + }
> else
> gcc_checking_assert (GET_MODE_CLASS (from_mode) == GET_MODE_CLASS
> (to_mode)
> && from_mode < to_mode);
> --
> 2.34.1
>
