On Mon, 26 Jun 2023, juzhe.zh...@rivai.ai wrote:
> From: Ju-Zhe Zhong <juzhe.zh...@rivai.ai>
>
> Hi, this patch is to add LEN_MASK_STORE into SCCVN.
>
> LEN_MASK_STORE is predicated by both len and mask together.
> My understanding is that LEN_MASK_STORE has same rhs_off and offset as
> MASK_STORE.
> The size = MIN (length (deduced from mask), (len + bias)).
>
> Not sure my understanding it correct or no.
> Hope experts (both Richard && Richi) can correct me if I am wrong.
>
> Thanks.
>
> gcc/ChangeLog:
>
> * tree-ssa-sccvn.cc (vn_reference_lookup_3): Add LEN_MASK_STORE.
>
> ---
> gcc/tree-ssa-sccvn.cc | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc
> index 11061a374a2..d1629800705 100644
> --- a/gcc/tree-ssa-sccvn.cc
> +++ b/gcc/tree-ssa-sccvn.cc
> @@ -3304,6 +3304,16 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void
> *data_,
> if (!tree_fits_uhwi_p (len) || !tree_fits_shwi_p (bias))
> return (void *)-1;
> break;
> + case IFN_LEN_MASK_STORE:
> + len = gimple_call_arg (call, 2);
> + bias = gimple_call_arg (call, 5);
> + if (!tree_fits_uhwi_p (len) || !tree_fits_shwi_p (bias))
> + return (void *)-1;
> + mask = gimple_call_arg (call, internal_fn_mask_index (fn));
> + mask = vn_valueize (mask);
> + if (TREE_CODE (mask) != VECTOR_CST)
> + return (void *)-1;
> + break;
> default:
> return (void *)-1;
> }
> @@ -3379,6 +3389,13 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void
> *data_,
> pd.rhs_off = start;
> pd.offset = offset2i + start;
> pd.size = length;
> + if (fn == IFN_LEN_MASK_STORE)
can you use if (len != 0) here?
> + {
> + HOST_WIDE_INT len_bitsize
> + = (tree_to_uhwi (len) + tree_to_shwi (bias))
> + * BITS_PER_UNIT;
> + pd.size = length > len_bitsize ? length : len_bitsize;
> + }
> if (ranges_known_overlap_p (offset, maxsize,
> pd.offset, pd.size))
> return data->push_partial_def (pd, set, set,
the code continues with
mask_idx++;
}
while (known_lt (mask_idx, TYPE_VECTOR_SUBPARTS
(vectype)));
it might be nicer to store TYPE_VECTOR_SUBPARTS in a variable and
trim that on 'len' instead?
Thanks,
Richard.
