On Tue, Jun 20, 2023 at 6:11 PM liuhongt via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> I notice there's some refactor in vectorizable_conversion
> for code_helper,so I've adjusted my patch to that.
> Here's the patch I'm going to commit.
>
> We have already use intermidate type in case WIDEN, but not for NONE,
> this patch extended that.
>
> gcc/ChangeLog:
>
>         PR target/110018
>         * tree-vect-stmts.cc (vectorizable_conversion): Use
>         intermiediate integer type for float_expr/fix_trunc_expr when
>         direct optab is not existed.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.target/i386/pr110018-1.c: New test.

> +
> +      /* For conversions between float and smaller integer types try whether we
> +        can use intermediate signed integer types to support the
> +        conversion.  */

I'm trying to enhance testcase coverage with explicit signed/unsigned
types (patch attached), and I have noticed that zero-extension is used
for unsigned types. So, the above comment that mentions only signed
integer types is not entirely correct.

Uros.