On Thu, Jul 30, 2026 at 12:03:27PM +0200, Robin Dapp wrote:
> Hi Souradipto,
>
> Thanks for your patch.
>
> Given its size I think it can be considered legally insignificant so we
> won't be needing a DCO signoff or copyright assignment for now. We will
> be needing one in the future as you contribute more.
Thank you so much for taking a look at my patch.
I do want to contribute more can you please tell me what else do i need to
include
in the future along with the "signed off by" tag?
>
> For the record and in accordance with out AI policy, would you please
> specify whether any LLM assistance was used for this patch?
I used claude to set up the local qemu-user and board files to test this patch
because this was not part of the gcc repository i didnt mention this on this
patch.
>
> > + /* Check if the beginning and end of the sequence corresponds to OP0
> > and OP1 respectively */
> > + if (!(known_eq (d->perm[0], vlen - slideup_cnt) && known_eq
> > (d->perm[vlen - 1], 2 * vlen - 1 - slideup_cnt)))
> > + return false;
> > +
> > }
> >
> > /* Check for a monotonic sequence with one or two pivots. */
> > @@ -3842,7 +3847,7 @@ shuffle_slide_patterns (struct expand_vec_perm_d *d)
> > && maybe_ne (d->perm[i], d->perm[i - 1] + 1))
> > {
> > /* A second pivot would indicate the vector length and is in OP0. */
> > - if (known_ge (d->perm[i], vec_len) || pivot == -1 || len != 0)
> > + if (known_ge (d->perm[i], vec_len) || pivot == -1 || len != 0 ||
> > need_slideup_p)
> > return false;
> > len = i;
>
> The conditions aren't getting any more intuitive :) but the change looks
> correct to me.
Should I include a comment here?
>
> > diff --git a/gcc/testsuite/gcc.target/riscv/rvv/base/bug126411.c
> > b/gcc/testsuite/gcc.target/riscv/rvv/base/bug126411.c
> > new file mode 100644
> > index 00000000000..738d9247cab
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/riscv/rvv/base/bug126411.c
> > @@ -0,0 +1,15 @@
> > +/* { dg-do run { target { riscv_v } } } */
> > +/* { dg-options "-march=rv64gcv -O0" } */
>
> For a run test we need an effective-target check and riscv_v_ok. A
> compile check might be a slightly more involved because we would need to
> check for RTL but could work as well.
Sorry I missed that, I will send a V2 with the corrected test file.
>
> --
> Regards
> Robin
>
Thanks again
Souradipto
