Pengxuan Zheng <quic_pzh...@quicinc.com> writes:
> There was a bug in aarch64_evpc_reencode which could leave zero_op0_p and
> zero_op1_p of the struct "newd" uninitialized. r16-701-gd77c3bc1c35e303 fixed
> the issue by zero initializing "newd." This patch provides an alternative fix
> as suggested by Richard Sandiford based on the fact that the zeroness is
> preserved by aarch64_evpc_reencode.
>
> gcc/ChangeLog:
>
> * config/aarch64/aarch64.cc (aarch64_evpc_reencode): Copy zero_op0_p and
> zero_op1_p from d to newd.
>
> Signed-off-by: Pengxuan Zheng <quic_pzh...@quicinc.com>
OK, thanks.
Richard
> ---
> gcc/config/aarch64/aarch64.cc | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
> index 1da615c8955..2b837ec8e67 100644
> --- a/gcc/config/aarch64/aarch64.cc
> +++ b/gcc/config/aarch64/aarch64.cc
> @@ -26327,7 +26327,7 @@ aarch64_evpc_trn (struct expand_vec_perm_d *d)
> static bool
> aarch64_evpc_reencode (struct expand_vec_perm_d *d)
> {
> - expand_vec_perm_d newd = {};
> + expand_vec_perm_d newd;
>
> /* The subregs that we'd create are not supported for big-endian SVE;
> see aarch64_modes_compatible_p for details. */
> @@ -26353,6 +26353,8 @@ aarch64_evpc_reencode (struct expand_vec_perm_d *d)
> newd.op1 = d->op1 ? gen_lowpart (new_mode, d->op1) : NULL;
> newd.testing_p = d->testing_p;
> newd.one_vector_p = d->one_vector_p;
> + newd.zero_op0_p = d->zero_op0_p;
> + newd.zero_op1_p = d->zero_op1_p;
>
> newd.perm.new_vector (newpermindices.encoding (), newd.one_vector_p ? 1 :
> 2,
> newpermindices.nelts_per_input ());
