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

[Richard Biener <rguenther@suse.de>]

On Mon, 26 Jun 2023, juzhe.zhong@rivai.ai wrote:

> Hi, Richi. I am wondering whether it is true that :?
> 
> TYPE_VECTOR_SUBPARTS (vectype).to_constant ()

Not necessarily.

> 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;
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