diff mbox series

[v2] middle-end: [PR middle-end/116926] Allow widening optabs for vec-mode -> scalar-mode

Message ID 20241011155428.1615480-1-victor.donascimento@arm.com
State New
Headers show
Series [v2] middle-end: [PR middle-end/116926] Allow widening optabs for vec-mode -> scalar-mode | expand

Commit Message

Victor Do Nascimento Oct. 11, 2024, 3:54 p.m. UTC 
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 | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Richard Biener Oct. 12, 2024, 12:06 p.m. UTC | #1 
On Fri, Oct 11, 2024 at 8:37 PM Victor Do Nascimento
<victor.donascimento@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?

OK.

Richard.

> 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 | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/gcc/optabs-query.cc b/gcc/optabs-query.cc
> index c3134d6a2ce..cc52bc0f5ea 100644
> --- a/gcc/optabs-query.cc
> +++ b/gcc/optabs-query.cc
> @@ -485,6 +485,12 @@ 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 (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
>      gcc_checking_assert (GET_MODE_CLASS (from_mode) == GET_MODE_CLASS (to_mode)
>                          && from_mode < to_mode);
> --
> 2.34.1
>
diff mbox series

Patch

diff --git a/gcc/optabs-query.cc b/gcc/optabs-query.cc
index c3134d6a2ce..cc52bc0f5ea 100644
--- a/gcc/optabs-query.cc
+++ b/gcc/optabs-query.cc
@@ -485,6 +485,12 @@  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 (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
     gcc_checking_assert (GET_MODE_CLASS (from_mode) == GET_MODE_CLASS (to_mode)
 			 && from_mode < to_mode);