Re: Re: [PATCH V2] SCCVN: Add LEN_MASK_STORE and fix LEN_STORE

["juzhe.zhong@rivai.ai" <juzhe.zhong@rivai.ai>]

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Hi, Richi. I am wondering whether it is true that :?

TYPE_VECTOR_SUBPARTS (vectype).to_constant ()

Thanks.


juzhe.zhong@rivai.ai
 
From: Richard Biener
Date: 2023-06-26 19:18
To: Ju-Zhe Zhong
CC: gcc-patches; richard.sandiford
Subject: Re: [PATCH V2] SCCVN: Add LEN_MASK_STORE and fix LEN_STORE
On Mon, 26 Jun 2023, juzhe.zhong@rivai.ai wrote:
 
> From: Ju-Zhe Zhong <juzhe.zhong@rivai.ai>
> 
> Hi, Richi. It seems that we use nunits which is len + bias to iterate then we can
> simplify the codes.
> 
> Also, I fixed behavior of len_store,
> 
> Before this patch:
>    (len - bias) * BITS_PER_UNIT
> After this patch:
>    (len + bias) * BITS_PER_UNIT
>    
> gcc/ChangeLog:
> 
>         * tree-ssa-sccvn.cc (vn_reference_lookup_3): Add LEN_MAS_STORE and fix LEN_STORE.
> 
> ---
>  gcc/tree-ssa-sccvn.cc | 19 +++++++++++++++++--
>  1 file changed, 17 insertions(+), 2 deletions(-)
> 
> diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc
> index 11061a374a2..228ec117ff3 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;
>  }
> @@ -3344,6 +3354,11 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
>        tree vectype = TREE_TYPE (def_rhs);
>        unsigned HOST_WIDE_INT elsz
>  = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (vectype)));
> +       poly_uint64 nunits;
> +       if (len)
> + nunits = tree_to_uhwi (len) + tree_to_shwi (bias);
> +       else
> + nunits = TYPE_VECTOR_SUBPARTS (vectype);
 
Are the _LEN ifns accessible via intrinsics as well?  If so I think
we should use MIN (nunits, len + bias) here as otherwise we risk
out-of bound accesses.
 
Otherwise looks good to me.
 
Thanks,
Richard.
 
>        if (mask)
>  {
>    HOST_WIDE_INT start = 0, length = 0;
> @@ -3373,7 +3388,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
>  length += elsz;
>        mask_idx++;
>      }
> -   while (known_lt (mask_idx, TYPE_VECTOR_SUBPARTS (vectype)));
> +   while (known_lt (mask_idx, nunits));
>    if (length != 0)
>      {
>        pd.rhs_off = start;
> @@ -3389,7 +3404,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
>  {
>    pd.offset = offset2i;
>    pd.size = (tree_to_uhwi (len)
> -      + -tree_to_shwi (bias)) * BITS_PER_UNIT;
> +      + tree_to_shwi (bias)) * BITS_PER_UNIT;
>    if (BYTES_BIG_ENDIAN)
>      pd.rhs_off = pd.size - tree_to_uhwi (TYPE_SIZE (vectype));
>    else
> 
 
-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
HRB 36809 (AG Nuernberg)