Tamar Christina <tamar.christ...@arm.com> writes:
> Hi All,
>
> For historical reasons AArch64 has TI mode vector types but does not consider
> TImode a vector mode.
>
> What's happening in the PR is that get_vectype_for_scalar_type is returning
> vector(1) TImode for a TImode scalar. This then fails when we call
> targetm.vectorize.get_mask_mode (vecmode).exists (&) on the TYPE_MODE.
>
> I've checked other usages of get_mask_mode and none of them have anything that
> would prevent this same issue from happening. It only happens that normally
> the vectorizer rejects the vector(1) type early, but in this case we get
> further because the COND_EXPR hasn't been analyzed yet for a type.
>
> I believe get_mask_mode shouldn't fault, and so this adds the check for vector
> mode in the hook and returns nothing if it's not. I did not add this to the
> generic function because I believe this is an AArch64 quirk.
Feels to me like the problem is higher up. The hook says:
Return the mode to use for a vector mask that holds one boolean
result for each element of vector mode @var{mode}. ...
So the caller is breaking the interface if it is passing a non-vector mode.
Thanks,
Richard
>
> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
>
> Ok for master?
>
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> PR target/116074
> * config/aarch64/aarch64.cc (aarch64_get_mask_mode): Check vector mode.
>
> gcc/testsuite/ChangeLog:
>
> PR target/116074
> * g++.target/aarch64/pr116074.C: New test.
>
> ---
>
> diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
> index
> 355ab97891cf0a7d487fa4c69ae23a5f75897851..045ac0e09b0eaa14935db3924798402c9dd1947c
> 100644
> --- a/gcc/config/aarch64/aarch64.cc
> +++ b/gcc/config/aarch64/aarch64.cc
> @@ -1870,6 +1870,9 @@ aarch64_sve_pred_mode (machine_mode mode)
> static opt_machine_mode
> aarch64_get_mask_mode (machine_mode mode)
> {
> + if (!VECTOR_MODE_P (mode))
> + return opt_machine_mode ();
> +
> unsigned int vec_flags = aarch64_classify_vector_mode (mode);
> if (vec_flags & VEC_SVE_DATA)
> return aarch64_sve_pred_mode (mode);
> diff --git a/gcc/testsuite/g++.target/aarch64/pr116074.C
> b/gcc/testsuite/g++.target/aarch64/pr116074.C
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..54cf561510c460499a816ab6a84603fc20a5f1e5
> --- /dev/null
> +++ b/gcc/testsuite/g++.target/aarch64/pr116074.C
> @@ -0,0 +1,24 @@
> +/* { dg-do compile } */
> +/* { dg-additional-options "-O3" } */
> +
> +int m[40];
> +
> +template <typename k> struct j {
> + int length;
> + k *e;
> + void operator[](int) {
> + if (length)
> + __builtin___memcpy_chk(m, m+3, sizeof (k), -1);
> + }
> +};
> +
> +j<j<int>> o;
> +
> +int *q;
> +
> +void ao(int i) {
> + for (; i > 0; i--) {
> + o[1];
> + *q = 1;
> + }
> +}
