[Bug target/107515] MVE: Generic functions do not accept _Float16 scalars

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107515

--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by Stam Markianos-Wright
<stammark@gcc.gnu.org>:

https://gcc.gnu.org/g:c7c4dfb5989e80ffc8e8439a8d9a9ed654612b90

commit r12-9608-gc7c4dfb5989e80ffc8e8439a8d9a9ed654612b90
Author: Stam Markianos-Wright <stam.markianos-wright@arm.com>
Date:   Mon Jan 16 11:40:40 2023 +0000

    arm: Split up MVE _Generic associations to prevent type clashes [PR107515]

    With these previous patches:
    https://gcc.gnu.org/pipermail/gcc-patches/2022-November/606586.html
    https://gcc.gnu.org/pipermail/gcc-patches/2022-November/606587.html
    we enabled the MVE overloaded _Generic associations to handle more
    scalar types, however at PR 107515 we found a new regression that
    wasn't detected in our testing:

    With glibc's posix/types.h:
    ```
    typedef signed int __int32_t;
    ...
    typedef __int32_t int32_t;
    ```
    We would get a `error: '_Generic' specifies two compatible types`
    from `__ARM_mve_coerce3` because of `type: param`, when `type` is
    `int` and `int32_t: param` both being the same under the hood.

    The same did not happen with Newlib's header sys/_stdint.h:
    ```
    typedef long int __int32_t;
    ...
    typedef __int32_t int32_t ;
    ```
    which worked fine, because it uses `long int`.

    The same could feasibly happen in `__ARM_mve_coerce2` between
    `__fp16` and `float16_t`.

    The solution here is to break the _Generic down so that the similar
    types don't appear at the same level, as is done in `__ARM_mve_typeid`

    gcc/ChangeLog:
            PR target/96795
            PR target/107515
            * config/arm/arm_mve.h (__ARM_mve_coerce2): Split types.
            (__ARM_mve_coerce3): Likewise.

    gcc/testsuite/ChangeLog:
            PR target/96795
            PR target/107515
            * gcc.target/arm/mve/intrinsics/mve_intrinsic_type_overloads-fp.c:
New test.
            * gcc.target/arm/mve/intrinsics/mve_intrinsic_type_overloads-int.c:
New test.

    (cherry picked from commit 8a1360e72d6c6056606aa5edd8c906c50f26de59)