Hi Victor,
> - if ((vf.is_constant () && pow2p_hwi (new_alignment.to_constant ()))
> - || (!vf.is_constant () && pow2p_hwi (align_factor_c)))
> + if ((vf.is_constant () && !pow2p_hwi (new_alignment.to_constant ()))
> + || (!vf.is_constant () && !pow2p_hwi (align_factor_c)))
> + new_alignment
> + = HOST_WIDE_INT_1U << ceil_log2 (new_alignment.to_constant ());
Is this safe when !vf.is_constant ()? I.e. with new_alignment = vf * ... won't
to_constant () fail?
> - if (*memory_access_type == VMAT_ELEMENTWISE
> - || *memory_access_type == VMAT_GATHER_SCATTER_LEGACY
> + if (*memory_access_type == VMAT_ELEMENTWISE)
> + {
> + if (dr_safe_speculative_read_required (stmt_info)
> + && !STMT_VINFO_GATHER_SCATTER_P (stmt_info)
> + && !DR_SCALAR_KNOWN_BOUNDS (STMT_VINFO_DR_INFO (stmt_info)))
> + *alignment_support_scheme = dr_unaligned_unsupported;
> + else
> + *alignment_support_scheme = dr_unaligned_supported;
> + *misalignment = DR_MISALIGNMENT_UNKNOWN;
> + }
> +
> + else if (*memory_access_type == VMAT_GATHER_SCATTER_LEGACY
> || *memory_access_type == VMAT_STRIDED_SLP
> || *memory_access_type == VMAT_INVARIANT)
> {
Not being fully acquainted with the early-break flow, I'm not exactly sure
what's happening here. Won't setting the alignment to dr_unaligned_unsupported
just going to cause a "return false" soon after? If so, can't we fold the
check into the early-break checks we already have (around line 2564), thus
making it slightly more explicit?
BTW not related to your patch at all but I noticed that we have
/* Scatter-gather and invariant accesses continue to address individual
scalars, so vector-level alignment is irrelevant. */
if (STMT_VINFO_GATHER_SCATTER_P (stmt_info)
|| integer_zerop (DR_STEP (dr_info->dr)))
return false;
in vect_relevant_for_alignment_p and that's not universally true anymore :/
--
Regards
Robin
