[0/9,middle-end] Add param to vec_perm_const hook to specify mode of input operand

  Hi,
The attached patch adds another parameter machine_mode op_mode to vec_perm_const
hook to specify mode of input operands. The motivation for doing this
is PR96463,
where we create vec_perm_expr of the form:
lhs = vec_perm_expr<rhs, mask>
where lhs and rhs have different vector types but same element type
(lhs is SVE and rhs is corresponding advsimd vector).

It seems the following targets were affected: aarch64, i386, arm, ia64,
mips, rs6000, s390, sparc, gcn.

Bootstrapped+tested on x86_64-linux-gnu, aarch64-linux-gnu.
For other targets, I did make all-gcc stage1, which seems to build OK.

Thanks,
Prathamesh
  

Hi Prathamesh,

I am just looking at this as it interacts with a change I am trying to 
make, but I'm not a reviewer so take my comments with a pinch of salt ;)

I copied in bits of your patch below to comment.

 > -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST 
(machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx 
@var{in1}, const vec_perm_indices @var{&sel})
 > +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST 
(machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, 
rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
 >  This hook is used to test whether the target can permute up to two
 >  vectors of mode @var{mode} using the permutation vector @code{sel}, and
 >  also to emit such a permutation.  In the former case @var{in0}, 
@var{in1}

Would be good to also explain what the new op_mode parameter is used for 
here.

 > @@ -6250,7 +6250,9 @@ expand_vec_perm_const (machine_mode mode, rtx 
v0, rtx v1,
 >        if (single_arg_p)
 >      v1 = v0;
 >
 > -      if (targetm.vectorize.vec_perm_const (mode, target, v0, v1, 
indices))
 > +      gcc_checking_assert (GET_MODE (v0) == GET_MODE (v1));
 > +      machine_mode op_mode = GET_MODE (v0);
 > +      if (targetm.vectorize.vec_perm_const (mode, op_mode, target, 
v0, v1, indices))
 >      return target;
 >      }

I was surprised by the assert check here. The docs seem to insinuate 
vec_perm needs both input vectors to be of the same mode, so I was 
expecting this to be checked/enforced elsewhere? But it shouldn't hurt I 
guess.

 > @@ -1894,7 +1894,7 @@ try the equivalent byte operation.  If that 
also fails, it will try forcing\n\
 >  the selector into a register and using the @var{vec_perm@var{mode}}\n\
 >  instruction pattern.  There is no need for the hook to handle these 
two\n\
 >  implementation approaches itself.",
 > - bool, (machine_mode mode, rtx output, rtx in0, rtx in1,
 > + bool, (machine_mode mode, machine_mode op_mode, rtx output, rtx 
in0, rtx in1,
 >      const vec_perm_indices &sel),
 >   NULL)

Same comment as the first, it could do with an inclusion of op_mode in 
the comments explaining the function.

On 18/05/2022 08:06, Prathamesh Kulkarni via Gcc-patches wrote:
> Hi,
> The attached patch adds another parameter machine_mode op_mode to vec_perm_const
> hook to specify mode of input operands. The motivation for doing this
> is PR96463,
> where we create vec_perm_expr of the form:
> lhs = vec_perm_expr<rhs, mask>
> where lhs and rhs have different vector types but same element type
> (lhs is SVE and rhs is corresponding advsimd vector).
>
> It seems the following targets were affected: aarch64, i386, arm, ia64,
> mips, rs6000, s390, sparc, gcn.
>
> Bootstrapped+tested on x86_64-linux-gnu, aarch64-linux-gnu.
> For other targets, I did make all-gcc stage1, which seems to build OK.
>
> Thanks,
> Prathamesh
  

Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
> Hi,
> The attached patch adds another parameter machine_mode op_mode to vec_perm_const
> hook to specify mode of input operands. The motivation for doing this
> is PR96463,
> where we create vec_perm_expr of the form:
> lhs = vec_perm_expr<rhs, mask>
> where lhs and rhs have different vector types but same element type
> (lhs is SVE and rhs is corresponding advsimd vector).
>
> It seems the following targets were affected: aarch64, i386, arm, ia64,
> mips, rs6000, s390, sparc, gcn.
>
> Bootstrapped+tested on x86_64-linux-gnu, aarch64-linux-gnu.
> For other targets, I did make all-gcc stage1, which seems to build OK.
>
> Thanks,
> Prathamesh
>
> diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> index c5006afc00d..31ff6ef3f92 100644
> --- a/gcc/doc/tm.texi
> +++ b/gcc/doc/tm.texi
> @@ -6088,7 +6088,7 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
>  access using @var{type} is known to be naturally aligned.
>  @end deftypefn
>  
> -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
>  This hook is used to test whether the target can permute up to two
>  vectors of mode @var{mode} using the permutation vector @code{sel}, and
>  also to emit such a permutation.  In the former case @var{in0}, @var{in1}

Like Andre says, the documentation should describe op_mode (and mode).

> diff --git a/gcc/optabs-query.cc b/gcc/optabs-query.cc
> index 68dc679cc6a..aef9d4c5d28 100644
> --- a/gcc/optabs-query.cc
> +++ b/gcc/optabs-query.cc
> @@ -417,8 +417,8 @@ can_vec_perm_var_p (machine_mode mode)
>     with here.  */
>  
>  bool
> -can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
> -		      bool allow_variable_p)
> +can_vec_perm_const_p (machine_mode mode, machine_mode op_mode,
> +		      const vec_perm_indices &sel, bool allow_variable_p)
>  {

The function comment should describe the new parameter.

>    /* If the target doesn't implement a vector mode for the vector type,
>       then no operations are supported.  */
> @@ -448,7 +448,7 @@ can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
>  
>    if (targetm.vectorize.vec_perm_const != NULL)
>      {
> -      if (targetm.vectorize.vec_perm_const (mode, NULL_RTX, NULL_RTX,
> +      if (targetm.vectorize.vec_perm_const (mode, op_mode, NULL_RTX, NULL_RTX,
>  					    NULL_RTX, sel))
>  	return true;
>  
> @@ -462,6 +462,13 @@ can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
>    return false;
>  }
>  
> +bool
> +can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
> +		      bool allow_variable_p)
> +{
> +  return can_vec_perm_const_p (mode, mode, sel, allow_variable_p);
> +}
> +

I can understand why you went for this, but now that we've opened
the door to mismatched modes, I think it would be better if all callers
specified the input mode explicitly.

> diff --git a/gcc/optabs.cc b/gcc/optabs.cc
> index 3d8fa3abdfe..55f10c41789 100644
> --- a/gcc/optabs.cc
> +++ b/gcc/optabs.cc
> @@ -6250,7 +6250,9 @@ expand_vec_perm_const (machine_mode mode, rtx v0, rtx v1,
>        if (single_arg_p)
>  	v1 = v0;
>  
> -      if (targetm.vectorize.vec_perm_const (mode, target, v0, v1, indices))
> +      gcc_checking_assert (GET_MODE (v0) == GET_MODE (v1));
> +      machine_mode op_mode = GET_MODE (v0);
> +      if (targetm.vectorize.vec_perm_const (mode, op_mode, target, v0, v1, indices))
>  	return target;
>      }
>  

(FWIW, I agree the assert is worth having.)

Thanks,
Richard

> @@ -6264,7 +6266,7 @@ expand_vec_perm_const (machine_mode mode, rtx v0, rtx v1,
>        v0_qi = gen_lowpart (qimode, v0);
>        v1_qi = gen_lowpart (qimode, v1);
>        if (targetm.vectorize.vec_perm_const != NULL
> -	  && targetm.vectorize.vec_perm_const (qimode, target_qi, v0_qi,
> +	  && targetm.vectorize.vec_perm_const (qimode, qimode, target_qi, v0_qi,
>  					       v1_qi, qimode_indices))
>  	return gen_lowpart (mode, target_qi);
>      }
> diff --git a/gcc/target.def b/gcc/target.def
> index d85adf36a39..2713c31dc3f 100644
> --- a/gcc/target.def
> +++ b/gcc/target.def
> @@ -1894,7 +1894,7 @@ try the equivalent byte operation.  If that also fails, it will try forcing\n\
>  the selector into a register and using the @var{vec_perm@var{mode}}\n\
>  instruction pattern.  There is no need for the hook to handle these two\n\
>  implementation approaches itself.",
> - bool, (machine_mode mode, rtx output, rtx in0, rtx in1,
> + bool, (machine_mode mode, machine_mode op_mode, rtx output, rtx in0, rtx in1,
>  	const vec_perm_indices &sel),
>   NULL)
>
  

On Wed, May 18, 2022 at 9:08 AM Prathamesh Kulkarni via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Hi,
> The attached patch adds another parameter machine_mode op_mode to vec_perm_const
> hook to specify mode of input operands. The motivation for doing this
> is PR96463,
> where we create vec_perm_expr of the form:
> lhs = vec_perm_expr<rhs, mask>
> where lhs and rhs have different vector types but same element type
> (lhs is SVE and rhs is corresponding advsimd vector).
>
> It seems the following targets were affected: aarch64, i386, arm, ia64,
> mips, rs6000, s390, sparc, gcn.
>
> Bootstrapped+tested on x86_64-linux-gnu, aarch64-linux-gnu.
> For other targets, I did make all-gcc stage1, which seems to build OK.

So it would also allow to express extract even/odd and interleave operations
with a VEC_PERM.  The interleave currently has the issue that we have
to artificially widen the inputs with "dont-care" elements. The lo/high
variants can already do with a bitfield-ref or vector-of-vector CTOR.

Richard.

>
> Thanks,
> Prathamesh
  

On Wed, 18 May 2022 at 17:27, Richard Sandiford
<richard.sandiford@arm.com> wrote:
>
> Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
> > Hi,
> > The attached patch adds another parameter machine_mode op_mode to vec_perm_const
> > hook to specify mode of input operands. The motivation for doing this
> > is PR96463,
> > where we create vec_perm_expr of the form:
> > lhs = vec_perm_expr<rhs, mask>
> > where lhs and rhs have different vector types but same element type
> > (lhs is SVE and rhs is corresponding advsimd vector).
> >
> > It seems the following targets were affected: aarch64, i386, arm, ia64,
> > mips, rs6000, s390, sparc, gcn.
> >
> > Bootstrapped+tested on x86_64-linux-gnu, aarch64-linux-gnu.
> > For other targets, I did make all-gcc stage1, which seems to build OK.
> >
> > Thanks,
> > Prathamesh
> >
> > diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> > index c5006afc00d..31ff6ef3f92 100644
> > --- a/gcc/doc/tm.texi
> > +++ b/gcc/doc/tm.texi
> > @@ -6088,7 +6088,7 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
> >  access using @var{type} is known to be naturally aligned.
> >  @end deftypefn
> >
> > -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> > +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> >  This hook is used to test whether the target can permute up to two
> >  vectors of mode @var{mode} using the permutation vector @code{sel}, and
> >  also to emit such a permutation.  In the former case @var{in0}, @var{in1}
>
> Like Andre says, the documentation should describe op_mode (and mode).
>
> > diff --git a/gcc/optabs-query.cc b/gcc/optabs-query.cc
> > index 68dc679cc6a..aef9d4c5d28 100644
> > --- a/gcc/optabs-query.cc
> > +++ b/gcc/optabs-query.cc
> > @@ -417,8 +417,8 @@ can_vec_perm_var_p (machine_mode mode)
> >     with here.  */
> >
> >  bool
> > -can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
> > -                   bool allow_variable_p)
> > +can_vec_perm_const_p (machine_mode mode, machine_mode op_mode,
> > +                   const vec_perm_indices &sel, bool allow_variable_p)
> >  {
>
> The function comment should describe the new parameter.
>
> >    /* If the target doesn't implement a vector mode for the vector type,
> >       then no operations are supported.  */
> > @@ -448,7 +448,7 @@ can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
> >
> >    if (targetm.vectorize.vec_perm_const != NULL)
> >      {
> > -      if (targetm.vectorize.vec_perm_const (mode, NULL_RTX, NULL_RTX,
> > +      if (targetm.vectorize.vec_perm_const (mode, op_mode, NULL_RTX, NULL_RTX,
> >                                           NULL_RTX, sel))
> >       return true;
> >
> > @@ -462,6 +462,13 @@ can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
> >    return false;
> >  }
> >
> > +bool
> > +can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
> > +                   bool allow_variable_p)
> > +{
> > +  return can_vec_perm_const_p (mode, mode, sel, allow_variable_p);
> > +}
> > +
>
> I can understand why you went for this, but now that we've opened
> the door to mismatched modes, I think it would be better if all callers
> specified the input mode explicitly.
>
> > diff --git a/gcc/optabs.cc b/gcc/optabs.cc
> > index 3d8fa3abdfe..55f10c41789 100644
> > --- a/gcc/optabs.cc
> > +++ b/gcc/optabs.cc
> > @@ -6250,7 +6250,9 @@ expand_vec_perm_const (machine_mode mode, rtx v0, rtx v1,
> >        if (single_arg_p)
> >       v1 = v0;
> >
> > -      if (targetm.vectorize.vec_perm_const (mode, target, v0, v1, indices))
> > +      gcc_checking_assert (GET_MODE (v0) == GET_MODE (v1));
> > +      machine_mode op_mode = GET_MODE (v0);
> > +      if (targetm.vectorize.vec_perm_const (mode, op_mode, target, v0, v1, indices))
> >       return target;
> >      }
> >
>
> (FWIW, I agree the assert is worth having.)
Hi,
I updated the patch with doc and adjusted callers to explicitly pass op_mode.
Bootstrapped + tested on x86_64-linux-gnu and aarch64-linux-gnu.
Does it look OK to commit ?

Thanks,
Prathamesh

>
> Thanks,
> Richard
>
> > @@ -6264,7 +6266,7 @@ expand_vec_perm_const (machine_mode mode, rtx v0, rtx v1,
> >        v0_qi = gen_lowpart (qimode, v0);
> >        v1_qi = gen_lowpart (qimode, v1);
> >        if (targetm.vectorize.vec_perm_const != NULL
> > -       && targetm.vectorize.vec_perm_const (qimode, target_qi, v0_qi,
> > +       && targetm.vectorize.vec_perm_const (qimode, qimode, target_qi, v0_qi,
> >                                              v1_qi, qimode_indices))
> >       return gen_lowpart (mode, target_qi);
> >      }
> > diff --git a/gcc/target.def b/gcc/target.def
> > index d85adf36a39..2713c31dc3f 100644
> > --- a/gcc/target.def
> > +++ b/gcc/target.def
> > @@ -1894,7 +1894,7 @@ try the equivalent byte operation.  If that also fails, it will try forcing\n\
> >  the selector into a register and using the @var{vec_perm@var{mode}}\n\
> >  instruction pattern.  There is no need for the hook to handle these two\n\
> >  implementation approaches itself.",
> > - bool, (machine_mode mode, rtx output, rtx in0, rtx in1,
> > + bool, (machine_mode mode, machine_mode op_mode, rtx output, rtx in0, rtx in1,
> >       const vec_perm_indices &sel),
> >   NULL)
> >
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index c5006afc00d..f53068c5c53 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -6088,13 +6088,13 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
 access using @var{type} is known to be naturally aligned.
 @end deftypefn
 
-@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
+@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
 This hook is used to test whether the target can permute up to two
-vectors of mode @var{mode} using the permutation vector @code{sel}, and
+vectors of mode @var{op_mode} using the permutation vector @code{sel}, and
 also to emit such a permutation.  In the former case @var{in0}, @var{in1}
 and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are
-the source vectors and @var{out} is the destination vector; all three are
-operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if
+the source vectors of mode @var{op_mode} and @var{out} is the destination vector
+of mode @var{mode}.  @var{in1} is the same as @var{in0} if
 @var{sel} describes a permutation on one vector instead of two.
 
 Return true if the operation is possible, emitting instructions for it
diff --git a/gcc/match.pd b/gcc/match.pd
index f5efa77560c..b06d7013603 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -7703,12 +7703,14 @@ and,
 	       2-argument version.  */
 	    tree oldop2 = op2;
 	    if (sel.ninputs () == 2
-	       || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
+	       || can_vec_perm_const_p (TYPE_MODE (type), TYPE_MODE (type),
+					sel, false))
 	      op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel);
 	    else
 	      {
 	        vec_perm_indices sel2 (builder, 2, nelts);
-	        if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
+		if (can_vec_perm_const_p (TYPE_MODE (type), TYPE_MODE (type),
+					  sel2, false))
 	          op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel2);
 	        else
 	          /* Not directly supported with either encoding,
diff --git a/gcc/optabs-query.cc b/gcc/optabs-query.cc
index 68dc679cc6a..809482b8092 100644
--- a/gcc/optabs-query.cc
+++ b/gcc/optabs-query.cc
@@ -407,9 +407,9 @@ can_vec_perm_var_p (machine_mode mode)
 }
 
 /* Return true if the target directly supports VEC_PERM_EXPRs on vectors
-   of mode MODE using the selector SEL.  ALLOW_VARIABLE_P is true if it
-   is acceptable to force the selector into a register and use a variable
-   permute (if the target supports that).
+   of mode OP_MODE and result vector of mode MODE using the selector SEL.
+   ALLOW_VARIABLE_P is true if it is acceptable to force the selector into a
+   register and use a variable permute (if the target supports that).
 
    Note that additional permutations representing whole-vector shifts may
    also be handled via the vec_shr or vec_shl optab, but only where the
@@ -417,8 +417,8 @@ can_vec_perm_var_p (machine_mode mode)
    with here.  */
 
 bool
-can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
-		      bool allow_variable_p)
+can_vec_perm_const_p (machine_mode mode, machine_mode op_mode,
+		      const vec_perm_indices &sel, bool allow_variable_p)
 {
   /* If the target doesn't implement a vector mode for the vector type,
      then no operations are supported.  */
@@ -448,7 +448,7 @@ can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
 
   if (targetm.vectorize.vec_perm_const != NULL)
     {
-      if (targetm.vectorize.vec_perm_const (mode, NULL_RTX, NULL_RTX,
+      if (targetm.vectorize.vec_perm_const (mode, op_mode, NULL_RTX, NULL_RTX,
 					    NULL_RTX, sel))
 	return true;
 
@@ -534,7 +534,7 @@ can_mult_highpart_p (machine_mode mode, bool uns_p)
 			    + (i & ~1)
 			    + ((i & 1) ? nunits : 0));
 	  vec_perm_indices indices (sel, 2, nunits);
-	  if (can_vec_perm_const_p (mode, indices))
+	  if (can_vec_perm_const_p (mode, mode, indices))
 	    return 2;
 	}
     }
@@ -550,7 +550,7 @@ can_mult_highpart_p (machine_mode mode, bool uns_p)
 	  for (unsigned int i = 0; i < 3; ++i)
 	    sel.quick_push (2 * i + (BYTES_BIG_ENDIAN ? 0 : 1));
 	  vec_perm_indices indices (sel, 2, nunits);
-	  if (can_vec_perm_const_p (mode, indices))
+	  if (can_vec_perm_const_p (mode, mode, indices))
 	    return 3;
 	}
     }
diff --git a/gcc/optabs-query.h b/gcc/optabs-query.h
index b9c9fd6f64d..32e52b20109 100644
--- a/gcc/optabs-query.h
+++ b/gcc/optabs-query.h
@@ -178,7 +178,7 @@ bool can_conditionally_move_p (machine_mode mode);
 opt_machine_mode qimode_for_vec_perm (machine_mode);
 bool selector_fits_mode_p (machine_mode, const vec_perm_indices &);
 bool can_vec_perm_var_p (machine_mode);
-bool can_vec_perm_const_p (machine_mode, const vec_perm_indices &,
+bool can_vec_perm_const_p (machine_mode, machine_mode, const vec_perm_indices &,
 			   bool = true);
 /* Find a widening optab even if it doesn't widen as much as we want.  */
 #define find_widening_optab_handler(A, B, C) \
diff --git a/gcc/optabs.cc b/gcc/optabs.cc
index 3d8fa3abdfe..c0a68471d2d 100644
--- a/gcc/optabs.cc
+++ b/gcc/optabs.cc
@@ -6250,7 +6250,10 @@ expand_vec_perm_const (machine_mode mode, rtx v0, rtx v1,
       if (single_arg_p)
 	v1 = v0;
 
-      if (targetm.vectorize.vec_perm_const (mode, target, v0, v1, indices))
+      gcc_checking_assert (GET_MODE (v0) == GET_MODE (v1));
+      machine_mode op_mode = GET_MODE (v0);
+      if (targetm.vectorize.vec_perm_const (mode, op_mode, target, v0, v1,
+					    indices))
 	return target;
     }
 
@@ -6264,7 +6267,7 @@ expand_vec_perm_const (machine_mode mode, rtx v0, rtx v1,
       v0_qi = gen_lowpart (qimode, v0);
       v1_qi = gen_lowpart (qimode, v1);
       if (targetm.vectorize.vec_perm_const != NULL
-	  && targetm.vectorize.vec_perm_const (qimode, target_qi, v0_qi,
+	  && targetm.vectorize.vec_perm_const (qimode, qimode, target_qi, v0_qi,
 					       v1_qi, qimode_indices))
 	return gen_lowpart (mode, target_qi);
     }
diff --git a/gcc/target.def b/gcc/target.def
index d85adf36a39..e8537b3eaf4 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -1878,11 +1878,11 @@ access using @var{type} is known to be naturally aligned.",
 DEFHOOK
 (vec_perm_const,
  "This hook is used to test whether the target can permute up to two\n\
-vectors of mode @var{mode} using the permutation vector @code{sel}, and\n\
+vectors of mode @var{op_mode} using the permutation vector @code{sel}, and\n\
 also to emit such a permutation.  In the former case @var{in0}, @var{in1}\n\
 and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are\n\
-the source vectors and @var{out} is the destination vector; all three are\n\
-operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if\n\
+the source vectors of mode @var{op_mode} and @var{out} is the destination vector\n\
+of mode @var{mode}.  @var{in1} is the same as @var{in0} if\n\
 @var{sel} describes a permutation on one vector instead of two.\n\
 \n\
 Return true if the operation is possible, emitting instructions for it\n\
@@ -1894,7 +1894,7 @@ try the equivalent byte operation.  If that also fails, it will try forcing\n\
 the selector into a register and using the @var{vec_perm@var{mode}}\n\
 instruction pattern.  There is no need for the hook to handle these two\n\
 implementation approaches itself.",
- bool, (machine_mode mode, rtx output, rtx in0, rtx in1,
+ bool, (machine_mode mode, machine_mode op_mode, rtx output, rtx in0, rtx in1,
 	const vec_perm_indices &sel),
  NULL)
 
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 48cab5844e0..e253e848796 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -3016,7 +3016,8 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
 			: (elts[0].second == 0 && elts[0].first == 0
 			   ? 0 : refnelts) + i);
       vec_perm_indices indices (sel, orig[1] ? 2 : 1, refnelts);
-      if (!can_vec_perm_const_p (TYPE_MODE (perm_type), indices))
+      machine_mode vmode = TYPE_MODE (perm_type);
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	return false;
       mask_type
 	= build_vector_type (build_nonstandard_integer_type (elem_size, 1),
@@ -3065,7 +3066,8 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
 	    sel.quick_push (elts[i].first
 			    ? elts[i].second + nelts : i);
 	  vec_perm_indices indices (sel, 2, nelts);
-	  if (!can_vec_perm_const_p (TYPE_MODE (type), indices))
+	  machine_mode vmode = TYPE_MODE (type);
+	  if (!can_vec_perm_const_p (vmode, vmode, indices))
 	    return false;
 	  mask_type
 	    = build_vector_type (build_nonstandard_integer_type (elem_size, 1),
diff --git a/gcc/tree-vect-data-refs.cc b/gcc/tree-vect-data-refs.cc
index 09223baf718..d20a10a1524 100644
--- a/gcc/tree-vect-data-refs.cc
+++ b/gcc/tree-vect-data-refs.cc
@@ -5347,7 +5347,7 @@ vect_grouped_store_supported (tree vectype, unsigned HOST_WIDE_INT count)
 		    sel[3 * i + nelt2] = 0;
 		}
 	      indices.new_vector (sel, 2, nelt);
-	      if (!can_vec_perm_const_p (mode, indices))
+	      if (!can_vec_perm_const_p (mode, mode, indices))
 		{
 		  if (dump_enabled_p ())
 		    dump_printf (MSG_MISSED_OPTIMIZATION,
@@ -5365,7 +5365,7 @@ vect_grouped_store_supported (tree vectype, unsigned HOST_WIDE_INT count)
 		    sel[3 * i + nelt2] = nelt + j2++;
 		}
 	      indices.new_vector (sel, 2, nelt);
-	      if (!can_vec_perm_const_p (mode, indices))
+	      if (!can_vec_perm_const_p (mode, mode, indices))
 		{
 		  if (dump_enabled_p ())
 		    dump_printf (MSG_MISSED_OPTIMIZATION,
@@ -5390,12 +5390,12 @@ vect_grouped_store_supported (tree vectype, unsigned HOST_WIDE_INT count)
 	      sel[i * 2 + 1] = i + nelt;
 	    }
 	  vec_perm_indices indices (sel, 2, nelt);
-	  if (can_vec_perm_const_p (mode, indices))
+	  if (can_vec_perm_const_p (mode, mode, indices))
 	    {
 	      for (i = 0; i < 6; i++)
 		sel[i] += exact_div (nelt, 2);
 	      indices.new_vector (sel, 2, nelt);
-	      if (can_vec_perm_const_p (mode, indices))
+	      if (can_vec_perm_const_p (mode, mode, indices))
 		return true;
 	    }
 	}
@@ -5963,7 +5963,7 @@ vect_grouped_load_supported (tree vectype, bool single_element_p,
 		else
 		  sel[i] = 0;
 	      indices.new_vector (sel, 2, nelt);
-	      if (!can_vec_perm_const_p (mode, indices))
+	      if (!can_vec_perm_const_p (mode, mode, indices))
 		{
 		  if (dump_enabled_p ())
 		    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -5977,7 +5977,7 @@ vect_grouped_load_supported (tree vectype, bool single_element_p,
 		else
 		  sel[i] = nelt + ((nelt + k) % 3) + 3 * (j++);
 	      indices.new_vector (sel, 2, nelt);
-	      if (!can_vec_perm_const_p (mode, indices))
+	      if (!can_vec_perm_const_p (mode, mode, indices))
 		{
 		  if (dump_enabled_p ())
 		    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6000,12 +6000,12 @@ vect_grouped_load_supported (tree vectype, bool single_element_p,
 	  for (i = 0; i < 3; i++)
 	    sel[i] = i * 2;
 	  vec_perm_indices indices (sel, 2, nelt);
-	  if (can_vec_perm_const_p (mode, indices))
+	  if (can_vec_perm_const_p (mode, mode, indices))
 	    {
 	      for (i = 0; i < 3; i++)
 		sel[i] = i * 2 + 1;
 	      indices.new_vector (sel, 2, nelt);
-	      if (can_vec_perm_const_p (mode, indices))
+	      if (can_vec_perm_const_p (mode, mode, indices))
 		return true;
 	    }
         }
@@ -6327,6 +6327,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
   gimple *perm_stmt;
 
   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+  machine_mode vmode = TYPE_MODE (vectype);
   unsigned int i;
   loop_vec_info loop_vinfo = dyn_cast <loop_vec_info> (vinfo);
 
@@ -6351,7 +6352,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt / 2; ++i)
 	sel[nelt / 2 + i] = i * 2 + 1;
       vec_perm_indices indices (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6366,7 +6367,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt / 2; ++i)
 	sel[nelt / 2 + i] = i * 2;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6381,7 +6382,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt; i++)
 	sel[i] = nelt / 2 + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6397,7 +6398,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = nelt / 2; i < nelt; i++)
 	sel[i] = nelt + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6461,7 +6462,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
 	  k++;
 	}
       vec_perm_indices indices (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6476,7 +6477,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt; i++)
 	sel[i] = 2 * (nelt / 3) + (nelt % 3) + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6490,7 +6491,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt; i++)
 	sel[i] = 2 * (nelt / 3) + 1 + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6504,7 +6505,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt; i++)
 	sel[i] = (nelt / 3) + (nelt % 3) / 2 + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6518,7 +6519,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt; i++)
 	sel[i] = 2 * (nelt / 3) + (nelt % 3) / 2 + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
diff --git a/gcc/tree-vect-generic.cc b/gcc/tree-vect-generic.cc
index d99e3207fbe..17de3375127 100644
--- a/gcc/tree-vect-generic.cc
+++ b/gcc/tree-vect-generic.cc
@@ -1527,7 +1527,8 @@ lower_vec_perm (gimple_stmt_iterator *gsi)
       && tree_to_vec_perm_builder (&sel_int, mask))
     {
       vec_perm_indices indices (sel_int, 2, elements);
-      if (can_vec_perm_const_p (TYPE_MODE (vect_type), indices))
+      machine_mode vmode = TYPE_MODE (vect_type);
+      if (can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  gimple_assign_set_rhs3 (stmt, mask);
 	  update_stmt (stmt);
diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
index 1d4337eb261..11dc6cbf576 100644
--- a/gcc/tree-vect-loop-manip.cc
+++ b/gcc/tree-vect-loop-manip.cc
@@ -312,7 +312,8 @@ interleave_supported_p (vec_perm_indices *indices, tree vectype,
       sel.quick_push (base + i + nelts);
     }
   indices->new_vector (sel, 2, nelts);
-  return can_vec_perm_const_p (TYPE_MODE (vectype), *indices);
+  return can_vec_perm_const_p (TYPE_MODE (vectype), TYPE_MODE (vectype),
+			       *indices);
 }
 
 /* Try to use permutes to define the masks in DEST_RGM using the masks
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index ab7dade1c74..7ac938b3c7b 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -4527,7 +4527,7 @@ have_whole_vector_shift (machine_mode mode)
     {
       calc_vec_perm_mask_for_shift (i, nelt, &sel);
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (mode, indices, false))
+      if (!can_vec_perm_const_p (mode, mode, indices, false))
 	return false;
     }
   return true;
diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index 8c61eb965a6..51803ec97c2 100644
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -2643,7 +2643,8 @@ vect_recog_rotate_pattern (vec_info *vinfo,
 
 	  vec_perm_indices indices (elts, 1,
 				    TYPE_VECTOR_SUBPARTS (char_vectype));
-	  if (can_vec_perm_const_p (TYPE_MODE (char_vectype), indices))
+	  machine_mode vmode = TYPE_MODE (char_vectype);
+	  if (can_vec_perm_const_p (vmode, vmode, indices))
 	    {
 	      /* vectorizable_bswap can handle the __builtin_bswap16 if we
 		 undo the argument promotion.  */
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index cdfff1ab9f6..fe9361c338e 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -420,8 +420,9 @@ can_duplicate_and_interleave_p (vec_info *vinfo, unsigned int count,
 		}
 	      vec_perm_indices indices1 (sel1, 2, nelts);
 	      vec_perm_indices indices2 (sel2, 2, nelts);
-	      if (can_vec_perm_const_p (TYPE_MODE (vector_type), indices1)
-		  && can_vec_perm_const_p (TYPE_MODE (vector_type), indices2))
+	      machine_mode vmode = TYPE_MODE (vector_type);
+	      if (can_vec_perm_const_p (vmode, vmode, indices1)
+		  && can_vec_perm_const_p (vmode, vmode, indices2))
 		{
 		  if (nvectors_out)
 		    *nvectors_out = nvectors;
@@ -6762,7 +6763,7 @@ vect_transform_slp_perm_load (vec_info *vinfo,
       if (index == count && !noop_p)
 	{
 	  indices.new_vector (mask, second_vec_index == -1 ? 1 : 2, nunits);
-	  if (!can_vec_perm_const_p (mode, indices))
+	  if (!can_vec_perm_const_p (mode, mode, indices))
 	    {
 	      if (dump_enabled_p ())
 		{
@@ -7122,8 +7123,9 @@ vectorizable_slp_permutation (vec_info *vinfo, gimple_stmt_iterator *gsi,
 	{
 	  indices.new_vector (mask, second_vec.first == -1U ? 1 : 2, nunits);
 	  bool identity_p = indices.series_p (0, 1, 0, 1);
+	  machine_mode vmode = TYPE_MODE (vectype);
 	  if (!identity_p
-	      && !can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+	      && !can_vec_perm_const_p (vmode, vmode, indices))
 	    {
 	      if (dump_enabled_p ())
 		{
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index 8327e9d047e..207d1097d5b 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -2016,7 +2016,7 @@ perm_mask_for_reverse (tree vectype)
     sel.quick_push (nunits - 1 - i);
 
   vec_perm_indices indices (sel, 1, nunits);
-  if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+  if (!can_vec_perm_const_p (TYPE_MODE (vectype), TYPE_MODE (vectype), indices))
     return NULL_TREE;
   return vect_gen_perm_mask_checked (vectype, indices);
 }
@@ -3168,7 +3168,8 @@ vectorizable_bswap (vec_info *vinfo,
       elts.quick_push ((i + 1) * word_bytes - j - 1);
 
   vec_perm_indices indices (elts, 1, num_bytes);
-  if (!can_vec_perm_const_p (TYPE_MODE (char_vectype), indices))
+  machine_mode vmode = TYPE_MODE (char_vectype);
+  if (!can_vec_perm_const_p (vmode, vmode, indices))
     return false;
 
   if (! vec_stmt)
@@ -6712,7 +6713,7 @@ scan_store_can_perm_p (tree vectype, tree init,
 	    sel[j] = nunits + k;
 	}
       vec_perm_indices indices (sel, i == units_log2 ? 1 : 2, nunits);
-      if (!can_vec_perm_const_p (vec_mode, indices))
+      if (!can_vec_perm_const_p (vec_mode, vec_mode, indices))
 	{
 	  if (i == units_log2)
 	    return -1;
@@ -8582,7 +8583,8 @@ vect_gen_perm_mask_any (tree vectype, const vec_perm_indices &sel)
 tree
 vect_gen_perm_mask_checked (tree vectype, const vec_perm_indices &sel)
 {
-  gcc_assert (can_vec_perm_const_p (TYPE_MODE (vectype), sel));
+  machine_mode vmode = TYPE_MODE (vectype);
+  gcc_assert (can_vec_perm_const_p (vmode, vmode, sel));
   return vect_gen_perm_mask_any (vectype, sel);
 }
  

Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
> On Wed, 18 May 2022 at 17:27, Richard Sandiford
> <richard.sandiford@arm.com> wrote:
>>
>> Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
>> > Hi,
>> > The attached patch adds another parameter machine_mode op_mode to vec_perm_const
>> > hook to specify mode of input operands. The motivation for doing this
>> > is PR96463,
>> > where we create vec_perm_expr of the form:
>> > lhs = vec_perm_expr<rhs, mask>
>> > where lhs and rhs have different vector types but same element type
>> > (lhs is SVE and rhs is corresponding advsimd vector).
>> >
>> > It seems the following targets were affected: aarch64, i386, arm, ia64,
>> > mips, rs6000, s390, sparc, gcn.
>> >
>> > Bootstrapped+tested on x86_64-linux-gnu, aarch64-linux-gnu.
>> > For other targets, I did make all-gcc stage1, which seems to build OK.
>> >
>> > Thanks,
>> > Prathamesh
>> >
>> > diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
>> > index c5006afc00d..31ff6ef3f92 100644
>> > --- a/gcc/doc/tm.texi
>> > +++ b/gcc/doc/tm.texi
>> > @@ -6088,7 +6088,7 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
>> >  access using @var{type} is known to be naturally aligned.
>> >  @end deftypefn
>> >
>> > -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
>> > +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
>> >  This hook is used to test whether the target can permute up to two
>> >  vectors of mode @var{mode} using the permutation vector @code{sel}, and
>> >  also to emit such a permutation.  In the former case @var{in0}, @var{in1}
>>
>> Like Andre says, the documentation should describe op_mode (and mode).
>>
>> > diff --git a/gcc/optabs-query.cc b/gcc/optabs-query.cc
>> > index 68dc679cc6a..aef9d4c5d28 100644
>> > --- a/gcc/optabs-query.cc
>> > +++ b/gcc/optabs-query.cc
>> > @@ -417,8 +417,8 @@ can_vec_perm_var_p (machine_mode mode)
>> >     with here.  */
>> >
>> >  bool
>> > -can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
>> > -                   bool allow_variable_p)
>> > +can_vec_perm_const_p (machine_mode mode, machine_mode op_mode,
>> > +                   const vec_perm_indices &sel, bool allow_variable_p)
>> >  {
>>
>> The function comment should describe the new parameter.
>>
>> >    /* If the target doesn't implement a vector mode for the vector type,
>> >       then no operations are supported.  */
>> > @@ -448,7 +448,7 @@ can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
>> >
>> >    if (targetm.vectorize.vec_perm_const != NULL)
>> >      {
>> > -      if (targetm.vectorize.vec_perm_const (mode, NULL_RTX, NULL_RTX,
>> > +      if (targetm.vectorize.vec_perm_const (mode, op_mode, NULL_RTX, NULL_RTX,
>> >                                           NULL_RTX, sel))
>> >       return true;
>> >
>> > @@ -462,6 +462,13 @@ can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
>> >    return false;
>> >  }
>> >
>> > +bool
>> > +can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
>> > +                   bool allow_variable_p)
>> > +{
>> > +  return can_vec_perm_const_p (mode, mode, sel, allow_variable_p);
>> > +}
>> > +
>>
>> I can understand why you went for this, but now that we've opened
>> the door to mismatched modes, I think it would be better if all callers
>> specified the input mode explicitly.
>>
>> > diff --git a/gcc/optabs.cc b/gcc/optabs.cc
>> > index 3d8fa3abdfe..55f10c41789 100644
>> > --- a/gcc/optabs.cc
>> > +++ b/gcc/optabs.cc
>> > @@ -6250,7 +6250,9 @@ expand_vec_perm_const (machine_mode mode, rtx v0, rtx v1,
>> >        if (single_arg_p)
>> >       v1 = v0;
>> >
>> > -      if (targetm.vectorize.vec_perm_const (mode, target, v0, v1, indices))
>> > +      gcc_checking_assert (GET_MODE (v0) == GET_MODE (v1));
>> > +      machine_mode op_mode = GET_MODE (v0);
>> > +      if (targetm.vectorize.vec_perm_const (mode, op_mode, target, v0, v1, indices))
>> >       return target;
>> >      }
>> >
>>
>> (FWIW, I agree the assert is worth having.)
> Hi,
> I updated the patch with doc and adjusted callers to explicitly pass op_mode.
> Bootstrapped + tested on x86_64-linux-gnu and aarch64-linux-gnu.
> Does it look OK to commit ?
>
> […]
> diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> index c5006afc00d..f53068c5c53 100644
> --- a/gcc/doc/tm.texi
> +++ b/gcc/doc/tm.texi
> @@ -6088,13 +6088,13 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
>  access using @var{type} is known to be naturally aligned.
>  @end deftypefn
>  
> -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
>  This hook is used to test whether the target can permute up to two
> -vectors of mode @var{mode} using the permutation vector @code{sel}, and
> +vectors of mode @var{op_mode} using the permutation vector @code{sel}, and
>  also to emit such a permutation.  In the former case @var{in0}, @var{in1}
>  and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are

How about:

  This hook is used to test whether the target can permute up to two
  vectors of mode @var{op_mode} using the permutation vector @code{sel},
  producing a vector of mode @var{mode}.  The hook is also used to emit
  such a permutation.

  When the hook is being to test whether the target supports a permutation,
  @var{in0}, @var{in1}, and @var{out} are all null.  When the hook is
  being used to emit a permutation, @var{in0} and @var{in1} are …

so that we describe @var{mode} for both the testing and non-testing cases.

> -the source vectors and @var{out} is the destination vector; all three are
> -operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if
> +the source vectors of mode @var{op_mode} and @var{out} is the destination vector
> +of mode @var{mode}.  @var{in1} is the same as @var{in0} if
>  @var{sel} describes a permutation on one vector instead of two.
>  
>  Return true if the operation is possible, emitting instructions for it
> diff --git a/gcc/match.pd b/gcc/match.pd
> index f5efa77560c..b06d7013603 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -7703,12 +7703,14 @@ and,
>  	       2-argument version.  */
>  	    tree oldop2 = op2;
>  	    if (sel.ninputs () == 2
> -	       || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
> +	       || can_vec_perm_const_p (TYPE_MODE (type), TYPE_MODE (type),
> +					sel, false))
>  	      op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel);
>  	    else
>  	      {
>  	        vec_perm_indices sel2 (builder, 2, nelts);
> -	        if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
> +		if (can_vec_perm_const_p (TYPE_MODE (type), TYPE_MODE (type),
> +					  sel2, false))
>  	          op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel2);
>  	        else
>  	          /* Not directly supported with either encoding,

Since this is matching an existing VEC_PERM_EXPR, we need to distinguish
between mode and op_mode.  Might be worth adding both mode and op_mode
to the outermost “with” and changing later tests accordingly.

> diff --git a/gcc/optabs-query.h b/gcc/optabs-query.h
> index b9c9fd6f64d..32e52b20109 100644
> --- a/gcc/optabs-query.h
> +++ b/gcc/optabs-query.h
> @@ -178,7 +178,7 @@ bool can_conditionally_move_p (machine_mode mode);
>  opt_machine_mode qimode_for_vec_perm (machine_mode);
>  bool selector_fits_mode_p (machine_mode, const vec_perm_indices &);
>  bool can_vec_perm_var_p (machine_mode);
> -bool can_vec_perm_const_p (machine_mode, const vec_perm_indices &,
> +bool can_vec_perm_const_p (machine_mode, machine_mode, const vec_perm_indices &,
>  			   bool = true);

Nit: long line.

>  /* Find a widening optab even if it doesn't widen as much as we want.  */
>  #define find_widening_optab_handler(A, B, C) \
> […]
> diff --git a/gcc/tree-vect-generic.cc b/gcc/tree-vect-generic.cc
> index d99e3207fbe..17de3375127 100644
> --- a/gcc/tree-vect-generic.cc
> +++ b/gcc/tree-vect-generic.cc
> @@ -1527,7 +1527,8 @@ lower_vec_perm (gimple_stmt_iterator *gsi)
>        && tree_to_vec_perm_builder (&sel_int, mask))
>      {
>        vec_perm_indices indices (sel_int, 2, elements);
> -      if (can_vec_perm_const_p (TYPE_MODE (vect_type), indices))
> +      machine_mode vmode = TYPE_MODE (vect_type);
> +      if (can_vec_perm_const_p (vmode, vmode, indices))

Similarly here: since this is testing an existing VEC_PERM_EXPR, I think
we need to read the mode of the lhs and pass both modes.

> […]
> diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
> index 8327e9d047e..207d1097d5b 100644
> --- a/gcc/tree-vect-stmts.cc
> +++ b/gcc/tree-vect-stmts.cc
> @@ -2016,7 +2016,7 @@ perm_mask_for_reverse (tree vectype)
>      sel.quick_push (nunits - 1 - i);
>  
>    vec_perm_indices indices (sel, 1, nunits);
> -  if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
> +  if (!can_vec_perm_const_p (TYPE_MODE (vectype), TYPE_MODE (vectype), indices))

Nit: long line.

Thanks,
Richard
  

On Mon, 23 May 2022 at 18:14, Richard Sandiford
<richard.sandiford@arm.com> wrote:
>
> Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
> > On Wed, 18 May 2022 at 17:27, Richard Sandiford
> > <richard.sandiford@arm.com> wrote:
> >>
> >> Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
> >> > Hi,
> >> > The attached patch adds another parameter machine_mode op_mode to vec_perm_const
> >> > hook to specify mode of input operands. The motivation for doing this
> >> > is PR96463,
> >> > where we create vec_perm_expr of the form:
> >> > lhs = vec_perm_expr<rhs, mask>
> >> > where lhs and rhs have different vector types but same element type
> >> > (lhs is SVE and rhs is corresponding advsimd vector).
> >> >
> >> > It seems the following targets were affected: aarch64, i386, arm, ia64,
> >> > mips, rs6000, s390, sparc, gcn.
> >> >
> >> > Bootstrapped+tested on x86_64-linux-gnu, aarch64-linux-gnu.
> >> > For other targets, I did make all-gcc stage1, which seems to build OK.
> >> >
> >> > Thanks,
> >> > Prathamesh
> >> >
> >> > diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> >> > index c5006afc00d..31ff6ef3f92 100644
> >> > --- a/gcc/doc/tm.texi
> >> > +++ b/gcc/doc/tm.texi
> >> > @@ -6088,7 +6088,7 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
> >> >  access using @var{type} is known to be naturally aligned.
> >> >  @end deftypefn
> >> >
> >> > -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> >> > +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> >> >  This hook is used to test whether the target can permute up to two
> >> >  vectors of mode @var{mode} using the permutation vector @code{sel}, and
> >> >  also to emit such a permutation.  In the former case @var{in0}, @var{in1}
> >>
> >> Like Andre says, the documentation should describe op_mode (and mode).
> >>
> >> > diff --git a/gcc/optabs-query.cc b/gcc/optabs-query.cc
> >> > index 68dc679cc6a..aef9d4c5d28 100644
> >> > --- a/gcc/optabs-query.cc
> >> > +++ b/gcc/optabs-query.cc
> >> > @@ -417,8 +417,8 @@ can_vec_perm_var_p (machine_mode mode)
> >> >     with here.  */
> >> >
> >> >  bool
> >> > -can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
> >> > -                   bool allow_variable_p)
> >> > +can_vec_perm_const_p (machine_mode mode, machine_mode op_mode,
> >> > +                   const vec_perm_indices &sel, bool allow_variable_p)
> >> >  {
> >>
> >> The function comment should describe the new parameter.
> >>
> >> >    /* If the target doesn't implement a vector mode for the vector type,
> >> >       then no operations are supported.  */
> >> > @@ -448,7 +448,7 @@ can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
> >> >
> >> >    if (targetm.vectorize.vec_perm_const != NULL)
> >> >      {
> >> > -      if (targetm.vectorize.vec_perm_const (mode, NULL_RTX, NULL_RTX,
> >> > +      if (targetm.vectorize.vec_perm_const (mode, op_mode, NULL_RTX, NULL_RTX,
> >> >                                           NULL_RTX, sel))
> >> >       return true;
> >> >
> >> > @@ -462,6 +462,13 @@ can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
> >> >    return false;
> >> >  }
> >> >
> >> > +bool
> >> > +can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
> >> > +                   bool allow_variable_p)
> >> > +{
> >> > +  return can_vec_perm_const_p (mode, mode, sel, allow_variable_p);
> >> > +}
> >> > +
> >>
> >> I can understand why you went for this, but now that we've opened
> >> the door to mismatched modes, I think it would be better if all callers
> >> specified the input mode explicitly.
> >>
> >> > diff --git a/gcc/optabs.cc b/gcc/optabs.cc
> >> > index 3d8fa3abdfe..55f10c41789 100644
> >> > --- a/gcc/optabs.cc
> >> > +++ b/gcc/optabs.cc
> >> > @@ -6250,7 +6250,9 @@ expand_vec_perm_const (machine_mode mode, rtx v0, rtx v1,
> >> >        if (single_arg_p)
> >> >       v1 = v0;
> >> >
> >> > -      if (targetm.vectorize.vec_perm_const (mode, target, v0, v1, indices))
> >> > +      gcc_checking_assert (GET_MODE (v0) == GET_MODE (v1));
> >> > +      machine_mode op_mode = GET_MODE (v0);
> >> > +      if (targetm.vectorize.vec_perm_const (mode, op_mode, target, v0, v1, indices))
> >> >       return target;
> >> >      }
> >> >
> >>
> >> (FWIW, I agree the assert is worth having.)
> > Hi,
> > I updated the patch with doc and adjusted callers to explicitly pass op_mode.
> > Bootstrapped + tested on x86_64-linux-gnu and aarch64-linux-gnu.
> > Does it look OK to commit ?
> >
> > […]
> > diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> > index c5006afc00d..f53068c5c53 100644
> > --- a/gcc/doc/tm.texi
> > +++ b/gcc/doc/tm.texi
> > @@ -6088,13 +6088,13 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
> >  access using @var{type} is known to be naturally aligned.
> >  @end deftypefn
> >
> > -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> > +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> >  This hook is used to test whether the target can permute up to two
> > -vectors of mode @var{mode} using the permutation vector @code{sel}, and
> > +vectors of mode @var{op_mode} using the permutation vector @code{sel}, and
> >  also to emit such a permutation.  In the former case @var{in0}, @var{in1}
> >  and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are
>
> How about:
>
>   This hook is used to test whether the target can permute up to two
>   vectors of mode @var{op_mode} using the permutation vector @code{sel},
>   producing a vector of mode @var{mode}.  The hook is also used to emit
>   such a permutation.
>
>   When the hook is being to test whether the target supports a permutation,
>   @var{in0}, @var{in1}, and @var{out} are all null.  When the hook is
>   being used to emit a permutation, @var{in0} and @var{in1} are …
>
> so that we describe @var{mode} for both the testing and non-testing cases.
>
> > -the source vectors and @var{out} is the destination vector; all three are
> > -operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if
> > +the source vectors of mode @var{op_mode} and @var{out} is the destination vector
> > +of mode @var{mode}.  @var{in1} is the same as @var{in0} if
> >  @var{sel} describes a permutation on one vector instead of two.
> >
> >  Return true if the operation is possible, emitting instructions for it
> > diff --git a/gcc/match.pd b/gcc/match.pd
> > index f5efa77560c..b06d7013603 100644
> > --- a/gcc/match.pd
> > +++ b/gcc/match.pd
> > @@ -7703,12 +7703,14 @@ and,
> >              2-argument version.  */
> >           tree oldop2 = op2;
> >           if (sel.ninputs () == 2
> > -            || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
> > +            || can_vec_perm_const_p (TYPE_MODE (type), TYPE_MODE (type),
> > +                                     sel, false))
> >             op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel);
> >           else
> >             {
> >               vec_perm_indices sel2 (builder, 2, nelts);
> > -             if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
> > +             if (can_vec_perm_const_p (TYPE_MODE (type), TYPE_MODE (type),
> > +                                       sel2, false))
> >                 op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel2);
> >               else
> >                 /* Not directly supported with either encoding,
>
> Since this is matching an existing VEC_PERM_EXPR, we need to distinguish
> between mode and op_mode.  Might be worth adding both mode and op_mode
> to the outermost “with” and changing later tests accordingly.
>
> > diff --git a/gcc/optabs-query.h b/gcc/optabs-query.h
> > index b9c9fd6f64d..32e52b20109 100644
> > --- a/gcc/optabs-query.h
> > +++ b/gcc/optabs-query.h
> > @@ -178,7 +178,7 @@ bool can_conditionally_move_p (machine_mode mode);
> >  opt_machine_mode qimode_for_vec_perm (machine_mode);
> >  bool selector_fits_mode_p (machine_mode, const vec_perm_indices &);
> >  bool can_vec_perm_var_p (machine_mode);
> > -bool can_vec_perm_const_p (machine_mode, const vec_perm_indices &,
> > +bool can_vec_perm_const_p (machine_mode, machine_mode, const vec_perm_indices &,
> >                          bool = true);
>
> Nit: long line.
>
> >  /* Find a widening optab even if it doesn't widen as much as we want.  */
> >  #define find_widening_optab_handler(A, B, C) \
> > […]
> > diff --git a/gcc/tree-vect-generic.cc b/gcc/tree-vect-generic.cc
> > index d99e3207fbe..17de3375127 100644
> > --- a/gcc/tree-vect-generic.cc
> > +++ b/gcc/tree-vect-generic.cc
> > @@ -1527,7 +1527,8 @@ lower_vec_perm (gimple_stmt_iterator *gsi)
> >        && tree_to_vec_perm_builder (&sel_int, mask))
> >      {
> >        vec_perm_indices indices (sel_int, 2, elements);
> > -      if (can_vec_perm_const_p (TYPE_MODE (vect_type), indices))
> > +      machine_mode vmode = TYPE_MODE (vect_type);
> > +      if (can_vec_perm_const_p (vmode, vmode, indices))
>
> Similarly here: since this is testing an existing VEC_PERM_EXPR, I think
> we need to read the mode of the lhs and pass both modes.
>
> > […]
> > diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
> > index 8327e9d047e..207d1097d5b 100644
> > --- a/gcc/tree-vect-stmts.cc
> > +++ b/gcc/tree-vect-stmts.cc
> > @@ -2016,7 +2016,7 @@ perm_mask_for_reverse (tree vectype)
> >      sel.quick_push (nunits - 1 - i);
> >
> >    vec_perm_indices indices (sel, 1, nunits);
> > -  if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
> > +  if (!can_vec_perm_const_p (TYPE_MODE (vectype), TYPE_MODE (vectype), indices))
>
> Nit: long line.
Hi Richard,
Thanks for the suggestions. Does the attached patch look OK ?
Bootstrapped+tested on x86_64-linux-gnu and aarch64-linux-gnu.

Thanks,
Prathamesh
>
> Thanks,
> Richard
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index c5006afc00d..0a3c733ada9 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -6088,14 +6088,18 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
 access using @var{type} is known to be naturally aligned.
 @end deftypefn
 
-@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
+@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
 This hook is used to test whether the target can permute up to two
-vectors of mode @var{mode} using the permutation vector @code{sel}, and
-also to emit such a permutation.  In the former case @var{in0}, @var{in1}
-and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are
-the source vectors and @var{out} is the destination vector; all three are
-operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if
-@var{sel} describes a permutation on one vector instead of two.
+vectors of mode @var{op_mode} using the permutation vector @code{sel},
+producing a vector of mode @var{mode}.The hook is also used to emit such
+a permutation.
+
+When the hook is being used to test whether the target supports a permutation,
+@var{in0}, @var{in1}, and @var{out} are all null.When the hook is being used
+to emit a permutation, @var{in0} and @var{in1} are the source vectors of mode
+@var{op_mode} and @var{out} is the destination vector of mode @var{mode}.
+@var{in1} is the same as @var{in0} if @var{sel} describes a permutation on one
+vector instead of two.
 
 Return true if the operation is possible, emitting instructions for it
 if rtxes are provided.
diff --git a/gcc/match.pd b/gcc/match.pd
index f5efa77560c..f2a527d9c42 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -7596,6 +7596,8 @@ and,
  (with
   {
     tree op0 = @0, op1 = @1, op2 = @2;
+    machine_mode result_mode = TYPE_MODE (type);
+    machine_mode op_mode = TYPE_MODE (TREE_TYPE (op0));
 
     /* Build a vector of integers from the tree mask.  */
     vec_perm_builder builder;
@@ -7703,12 +7705,12 @@ and,
 	       2-argument version.  */
 	    tree oldop2 = op2;
 	    if (sel.ninputs () == 2
-	       || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
+	       || can_vec_perm_const_p (result_mode, op_mode, sel, false))
 	      op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel);
 	    else
 	      {
 	        vec_perm_indices sel2 (builder, 2, nelts);
-	        if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
+		if (can_vec_perm_const_p (result_mode, op_mode, sel2, false))
 	          op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel2);
 	        else
 	          /* Not directly supported with either encoding,
diff --git a/gcc/optabs-query.cc b/gcc/optabs-query.cc
index 68dc679cc6a..809482b8092 100644
--- a/gcc/optabs-query.cc
+++ b/gcc/optabs-query.cc
@@ -407,9 +407,9 @@ can_vec_perm_var_p (machine_mode mode)
 }
 
 /* Return true if the target directly supports VEC_PERM_EXPRs on vectors
-   of mode MODE using the selector SEL.  ALLOW_VARIABLE_P is true if it
-   is acceptable to force the selector into a register and use a variable
-   permute (if the target supports that).
+   of mode OP_MODE and result vector of mode MODE using the selector SEL.
+   ALLOW_VARIABLE_P is true if it is acceptable to force the selector into a
+   register and use a variable permute (if the target supports that).
 
    Note that additional permutations representing whole-vector shifts may
    also be handled via the vec_shr or vec_shl optab, but only where the
@@ -417,8 +417,8 @@ can_vec_perm_var_p (machine_mode mode)
    with here.  */
 
 bool
-can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
-		      bool allow_variable_p)
+can_vec_perm_const_p (machine_mode mode, machine_mode op_mode,
+		      const vec_perm_indices &sel, bool allow_variable_p)
 {
   /* If the target doesn't implement a vector mode for the vector type,
      then no operations are supported.  */
@@ -448,7 +448,7 @@ can_vec_perm_const_p (machine_mode mode, const vec_perm_indices &sel,
 
   if (targetm.vectorize.vec_perm_const != NULL)
     {
-      if (targetm.vectorize.vec_perm_const (mode, NULL_RTX, NULL_RTX,
+      if (targetm.vectorize.vec_perm_const (mode, op_mode, NULL_RTX, NULL_RTX,
 					    NULL_RTX, sel))
 	return true;
 
@@ -534,7 +534,7 @@ can_mult_highpart_p (machine_mode mode, bool uns_p)
 			    + (i & ~1)
 			    + ((i & 1) ? nunits : 0));
 	  vec_perm_indices indices (sel, 2, nunits);
-	  if (can_vec_perm_const_p (mode, indices))
+	  if (can_vec_perm_const_p (mode, mode, indices))
 	    return 2;
 	}
     }
@@ -550,7 +550,7 @@ can_mult_highpart_p (machine_mode mode, bool uns_p)
 	  for (unsigned int i = 0; i < 3; ++i)
 	    sel.quick_push (2 * i + (BYTES_BIG_ENDIAN ? 0 : 1));
 	  vec_perm_indices indices (sel, 2, nunits);
-	  if (can_vec_perm_const_p (mode, indices))
+	  if (can_vec_perm_const_p (mode, mode, indices))
 	    return 3;
 	}
     }
diff --git a/gcc/optabs-query.h b/gcc/optabs-query.h
index b9c9fd6f64d..945d2a803b6 100644
--- a/gcc/optabs-query.h
+++ b/gcc/optabs-query.h
@@ -178,8 +178,8 @@ bool can_conditionally_move_p (machine_mode mode);
 opt_machine_mode qimode_for_vec_perm (machine_mode);
 bool selector_fits_mode_p (machine_mode, const vec_perm_indices &);
 bool can_vec_perm_var_p (machine_mode);
-bool can_vec_perm_const_p (machine_mode, const vec_perm_indices &,
-			   bool = true);
+bool can_vec_perm_const_p (machine_mode, machine_mode,
+			   const vec_perm_indices &, bool = true);
 /* Find a widening optab even if it doesn't widen as much as we want.  */
 #define find_widening_optab_handler(A, B, C) \
   find_widening_optab_handler_and_mode (A, B, C, NULL)
diff --git a/gcc/optabs.cc b/gcc/optabs.cc
index 3d8fa3abdfe..c0a68471d2d 100644
--- a/gcc/optabs.cc
+++ b/gcc/optabs.cc
@@ -6250,7 +6250,10 @@ expand_vec_perm_const (machine_mode mode, rtx v0, rtx v1,
       if (single_arg_p)
 	v1 = v0;
 
-      if (targetm.vectorize.vec_perm_const (mode, target, v0, v1, indices))
+      gcc_checking_assert (GET_MODE (v0) == GET_MODE (v1));
+      machine_mode op_mode = GET_MODE (v0);
+      if (targetm.vectorize.vec_perm_const (mode, op_mode, target, v0, v1,
+					    indices))
 	return target;
     }
 
@@ -6264,7 +6267,7 @@ expand_vec_perm_const (machine_mode mode, rtx v0, rtx v1,
       v0_qi = gen_lowpart (qimode, v0);
       v1_qi = gen_lowpart (qimode, v1);
       if (targetm.vectorize.vec_perm_const != NULL
-	  && targetm.vectorize.vec_perm_const (qimode, target_qi, v0_qi,
+	  && targetm.vectorize.vec_perm_const (qimode, qimode, target_qi, v0_qi,
 					       v1_qi, qimode_indices))
 	return gen_lowpart (mode, target_qi);
     }
diff --git a/gcc/target.def b/gcc/target.def
index d85adf36a39..db90552fc90 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -1878,12 +1878,16 @@ access using @var{type} is known to be naturally aligned.",
 DEFHOOK
 (vec_perm_const,
  "This hook is used to test whether the target can permute up to two\n\
-vectors of mode @var{mode} using the permutation vector @code{sel}, and\n\
-also to emit such a permutation.  In the former case @var{in0}, @var{in1}\n\
-and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are\n\
-the source vectors and @var{out} is the destination vector; all three are\n\
-operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if\n\
-@var{sel} describes a permutation on one vector instead of two.\n\
+vectors of mode @var{op_mode} using the permutation vector @code{sel},\n\
+producing a vector of mode @var{mode}.The hook is also used to emit such\n\
+a permutation.\n\
+\n\
+When the hook is being used to test whether the target supports a permutation,\n\
+@var{in0}, @var{in1}, and @var{out} are all null.When the hook is being used\n\
+to emit a permutation, @var{in0} and @var{in1} are the source vectors of mode\n\
+@var{op_mode} and @var{out} is the destination vector of mode @var{mode}.\n\
+@var{in1} is the same as @var{in0} if @var{sel} describes a permutation on one\n\
+vector instead of two.\n\
 \n\
 Return true if the operation is possible, emitting instructions for it\n\
 if rtxes are provided.\n\
@@ -1894,7 +1898,7 @@ try the equivalent byte operation.  If that also fails, it will try forcing\n\
 the selector into a register and using the @var{vec_perm@var{mode}}\n\
 instruction pattern.  There is no need for the hook to handle these two\n\
 implementation approaches itself.",
- bool, (machine_mode mode, rtx output, rtx in0, rtx in1,
+ bool, (machine_mode mode, machine_mode op_mode, rtx output, rtx in0, rtx in1,
 	const vec_perm_indices &sel),
  NULL)
 
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 48cab5844e0..e253e848796 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -3016,7 +3016,8 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
 			: (elts[0].second == 0 && elts[0].first == 0
 			   ? 0 : refnelts) + i);
       vec_perm_indices indices (sel, orig[1] ? 2 : 1, refnelts);
-      if (!can_vec_perm_const_p (TYPE_MODE (perm_type), indices))
+      machine_mode vmode = TYPE_MODE (perm_type);
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	return false;
       mask_type
 	= build_vector_type (build_nonstandard_integer_type (elem_size, 1),
@@ -3065,7 +3066,8 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
 	    sel.quick_push (elts[i].first
 			    ? elts[i].second + nelts : i);
 	  vec_perm_indices indices (sel, 2, nelts);
-	  if (!can_vec_perm_const_p (TYPE_MODE (type), indices))
+	  machine_mode vmode = TYPE_MODE (type);
+	  if (!can_vec_perm_const_p (vmode, vmode, indices))
 	    return false;
 	  mask_type
 	    = build_vector_type (build_nonstandard_integer_type (elem_size, 1),
diff --git a/gcc/tree-vect-data-refs.cc b/gcc/tree-vect-data-refs.cc
index 09223baf718..d20a10a1524 100644
--- a/gcc/tree-vect-data-refs.cc
+++ b/gcc/tree-vect-data-refs.cc
@@ -5347,7 +5347,7 @@ vect_grouped_store_supported (tree vectype, unsigned HOST_WIDE_INT count)
 		    sel[3 * i + nelt2] = 0;
 		}
 	      indices.new_vector (sel, 2, nelt);
-	      if (!can_vec_perm_const_p (mode, indices))
+	      if (!can_vec_perm_const_p (mode, mode, indices))
 		{
 		  if (dump_enabled_p ())
 		    dump_printf (MSG_MISSED_OPTIMIZATION,
@@ -5365,7 +5365,7 @@ vect_grouped_store_supported (tree vectype, unsigned HOST_WIDE_INT count)
 		    sel[3 * i + nelt2] = nelt + j2++;
 		}
 	      indices.new_vector (sel, 2, nelt);
-	      if (!can_vec_perm_const_p (mode, indices))
+	      if (!can_vec_perm_const_p (mode, mode, indices))
 		{
 		  if (dump_enabled_p ())
 		    dump_printf (MSG_MISSED_OPTIMIZATION,
@@ -5390,12 +5390,12 @@ vect_grouped_store_supported (tree vectype, unsigned HOST_WIDE_INT count)
 	      sel[i * 2 + 1] = i + nelt;
 	    }
 	  vec_perm_indices indices (sel, 2, nelt);
-	  if (can_vec_perm_const_p (mode, indices))
+	  if (can_vec_perm_const_p (mode, mode, indices))
 	    {
 	      for (i = 0; i < 6; i++)
 		sel[i] += exact_div (nelt, 2);
 	      indices.new_vector (sel, 2, nelt);
-	      if (can_vec_perm_const_p (mode, indices))
+	      if (can_vec_perm_const_p (mode, mode, indices))
 		return true;
 	    }
 	}
@@ -5963,7 +5963,7 @@ vect_grouped_load_supported (tree vectype, bool single_element_p,
 		else
 		  sel[i] = 0;
 	      indices.new_vector (sel, 2, nelt);
-	      if (!can_vec_perm_const_p (mode, indices))
+	      if (!can_vec_perm_const_p (mode, mode, indices))
 		{
 		  if (dump_enabled_p ())
 		    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -5977,7 +5977,7 @@ vect_grouped_load_supported (tree vectype, bool single_element_p,
 		else
 		  sel[i] = nelt + ((nelt + k) % 3) + 3 * (j++);
 	      indices.new_vector (sel, 2, nelt);
-	      if (!can_vec_perm_const_p (mode, indices))
+	      if (!can_vec_perm_const_p (mode, mode, indices))
 		{
 		  if (dump_enabled_p ())
 		    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6000,12 +6000,12 @@ vect_grouped_load_supported (tree vectype, bool single_element_p,
 	  for (i = 0; i < 3; i++)
 	    sel[i] = i * 2;
 	  vec_perm_indices indices (sel, 2, nelt);
-	  if (can_vec_perm_const_p (mode, indices))
+	  if (can_vec_perm_const_p (mode, mode, indices))
 	    {
 	      for (i = 0; i < 3; i++)
 		sel[i] = i * 2 + 1;
 	      indices.new_vector (sel, 2, nelt);
-	      if (can_vec_perm_const_p (mode, indices))
+	      if (can_vec_perm_const_p (mode, mode, indices))
 		return true;
 	    }
         }
@@ -6327,6 +6327,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
   gimple *perm_stmt;
 
   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+  machine_mode vmode = TYPE_MODE (vectype);
   unsigned int i;
   loop_vec_info loop_vinfo = dyn_cast <loop_vec_info> (vinfo);
 
@@ -6351,7 +6352,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt / 2; ++i)
 	sel[nelt / 2 + i] = i * 2 + 1;
       vec_perm_indices indices (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6366,7 +6367,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt / 2; ++i)
 	sel[nelt / 2 + i] = i * 2;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6381,7 +6382,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt; i++)
 	sel[i] = nelt / 2 + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6397,7 +6398,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = nelt / 2; i < nelt; i++)
 	sel[i] = nelt + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6461,7 +6462,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
 	  k++;
 	}
       vec_perm_indices indices (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6476,7 +6477,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt; i++)
 	sel[i] = 2 * (nelt / 3) + (nelt % 3) + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6490,7 +6491,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt; i++)
 	sel[i] = 2 * (nelt / 3) + 1 + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6504,7 +6505,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt; i++)
 	sel[i] = (nelt / 3) + (nelt % 3) / 2 + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
@@ -6518,7 +6519,7 @@ vect_shift_permute_load_chain (vec_info *vinfo, vec<tree> dr_chain,
       for (i = 0; i < nelt; i++)
 	sel[i] = 2 * (nelt / 3) + (nelt % 3) / 2 + i;
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+      if (!can_vec_perm_const_p (vmode, vmode, indices))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
diff --git a/gcc/tree-vect-generic.cc b/gcc/tree-vect-generic.cc
index d99e3207fbe..533ea68db7d 100644
--- a/gcc/tree-vect-generic.cc
+++ b/gcc/tree-vect-generic.cc
@@ -1527,7 +1527,10 @@ lower_vec_perm (gimple_stmt_iterator *gsi)
       && tree_to_vec_perm_builder (&sel_int, mask))
     {
       vec_perm_indices indices (sel_int, 2, elements);
-      if (can_vec_perm_const_p (TYPE_MODE (vect_type), indices))
+      machine_mode vmode = TYPE_MODE (vect_type);
+      tree lhs_type = TREE_TYPE (gimple_assign_lhs (stmt));
+      machine_mode lhs_mode = TYPE_MODE (lhs_type);
+      if (can_vec_perm_const_p (lhs_mode, vmode, indices))
 	{
 	  gimple_assign_set_rhs3 (stmt, mask);
 	  update_stmt (stmt);
diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
index 1d4337eb261..11dc6cbf576 100644
--- a/gcc/tree-vect-loop-manip.cc
+++ b/gcc/tree-vect-loop-manip.cc
@@ -312,7 +312,8 @@ interleave_supported_p (vec_perm_indices *indices, tree vectype,
       sel.quick_push (base + i + nelts);
     }
   indices->new_vector (sel, 2, nelts);
-  return can_vec_perm_const_p (TYPE_MODE (vectype), *indices);
+  return can_vec_perm_const_p (TYPE_MODE (vectype), TYPE_MODE (vectype),
+			       *indices);
 }
 
 /* Try to use permutes to define the masks in DEST_RGM using the masks
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index ab7dade1c74..7ac938b3c7b 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -4527,7 +4527,7 @@ have_whole_vector_shift (machine_mode mode)
     {
       calc_vec_perm_mask_for_shift (i, nelt, &sel);
       indices.new_vector (sel, 2, nelt);
-      if (!can_vec_perm_const_p (mode, indices, false))
+      if (!can_vec_perm_const_p (mode, mode, indices, false))
 	return false;
     }
   return true;
diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index 8c61eb965a6..51803ec97c2 100644
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -2643,7 +2643,8 @@ vect_recog_rotate_pattern (vec_info *vinfo,
 
 	  vec_perm_indices indices (elts, 1,
 				    TYPE_VECTOR_SUBPARTS (char_vectype));
-	  if (can_vec_perm_const_p (TYPE_MODE (char_vectype), indices))
+	  machine_mode vmode = TYPE_MODE (char_vectype);
+	  if (can_vec_perm_const_p (vmode, vmode, indices))
 	    {
 	      /* vectorizable_bswap can handle the __builtin_bswap16 if we
 		 undo the argument promotion.  */
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index cdfff1ab9f6..fe9361c338e 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -420,8 +420,9 @@ can_duplicate_and_interleave_p (vec_info *vinfo, unsigned int count,
 		}
 	      vec_perm_indices indices1 (sel1, 2, nelts);
 	      vec_perm_indices indices2 (sel2, 2, nelts);
-	      if (can_vec_perm_const_p (TYPE_MODE (vector_type), indices1)
-		  && can_vec_perm_const_p (TYPE_MODE (vector_type), indices2))
+	      machine_mode vmode = TYPE_MODE (vector_type);
+	      if (can_vec_perm_const_p (vmode, vmode, indices1)
+		  && can_vec_perm_const_p (vmode, vmode, indices2))
 		{
 		  if (nvectors_out)
 		    *nvectors_out = nvectors;
@@ -6762,7 +6763,7 @@ vect_transform_slp_perm_load (vec_info *vinfo,
       if (index == count && !noop_p)
 	{
 	  indices.new_vector (mask, second_vec_index == -1 ? 1 : 2, nunits);
-	  if (!can_vec_perm_const_p (mode, indices))
+	  if (!can_vec_perm_const_p (mode, mode, indices))
 	    {
 	      if (dump_enabled_p ())
 		{
@@ -7122,8 +7123,9 @@ vectorizable_slp_permutation (vec_info *vinfo, gimple_stmt_iterator *gsi,
 	{
 	  indices.new_vector (mask, second_vec.first == -1U ? 1 : 2, nunits);
 	  bool identity_p = indices.series_p (0, 1, 0, 1);
+	  machine_mode vmode = TYPE_MODE (vectype);
 	  if (!identity_p
-	      && !can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+	      && !can_vec_perm_const_p (vmode, vmode, indices))
 	    {
 	      if (dump_enabled_p ())
 		{
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index 8327e9d047e..346d8ce2804 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -2016,7 +2016,8 @@ perm_mask_for_reverse (tree vectype)
     sel.quick_push (nunits - 1 - i);
 
   vec_perm_indices indices (sel, 1, nunits);
-  if (!can_vec_perm_const_p (TYPE_MODE (vectype), indices))
+  if (!can_vec_perm_const_p (TYPE_MODE (vectype), TYPE_MODE (vectype),
+			     indices))
     return NULL_TREE;
   return vect_gen_perm_mask_checked (vectype, indices);
 }
@@ -3168,7 +3169,8 @@ vectorizable_bswap (vec_info *vinfo,
       elts.quick_push ((i + 1) * word_bytes - j - 1);
 
   vec_perm_indices indices (elts, 1, num_bytes);
-  if (!can_vec_perm_const_p (TYPE_MODE (char_vectype), indices))
+  machine_mode vmode = TYPE_MODE (char_vectype);
+  if (!can_vec_perm_const_p (vmode, vmode, indices))
     return false;
 
   if (! vec_stmt)
@@ -6712,7 +6714,7 @@ scan_store_can_perm_p (tree vectype, tree init,
 	    sel[j] = nunits + k;
 	}
       vec_perm_indices indices (sel, i == units_log2 ? 1 : 2, nunits);
-      if (!can_vec_perm_const_p (vec_mode, indices))
+      if (!can_vec_perm_const_p (vec_mode, vec_mode, indices))
 	{
 	  if (i == units_log2)
 	    return -1;
@@ -8582,7 +8584,8 @@ vect_gen_perm_mask_any (tree vectype, const vec_perm_indices &sel)
 tree
 vect_gen_perm_mask_checked (tree vectype, const vec_perm_indices &sel)
 {
-  gcc_assert (can_vec_perm_const_p (TYPE_MODE (vectype), sel));
+  machine_mode vmode = TYPE_MODE (vectype);
+  gcc_assert (can_vec_perm_const_p (vmode, vmode, sel));
   return vect_gen_perm_mask_any (vectype, sel);
 }
  

Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
> diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> index c5006afc00d..0a3c733ada9 100644
> --- a/gcc/doc/tm.texi
> +++ b/gcc/doc/tm.texi
> @@ -6088,14 +6088,18 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
>  access using @var{type} is known to be naturally aligned.
>  @end deftypefn
>  
> -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
>  This hook is used to test whether the target can permute up to two
> -vectors of mode @var{mode} using the permutation vector @code{sel}, and
> -also to emit such a permutation.  In the former case @var{in0}, @var{in1}
> -and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are
> -the source vectors and @var{out} is the destination vector; all three are
> -operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if
> -@var{sel} describes a permutation on one vector instead of two.
> +vectors of mode @var{op_mode} using the permutation vector @code{sel},
> +producing a vector of mode @var{mode}.The hook is also used to emit such

Should be two spaces between “@var{mode}.” and “The”.

> +a permutation.
> +
> +When the hook is being used to test whether the target supports a permutation,
> +@var{in0}, @var{in1}, and @var{out} are all null.When the hook is being used

Same here: missing spaces before “When”.

> +to emit a permutation, @var{in0} and @var{in1} are the source vectors of mode
> +@var{op_mode} and @var{out} is the destination vector of mode @var{mode}.
> +@var{in1} is the same as @var{in0} if @var{sel} describes a permutation on one
> +vector instead of two.
>  
>  Return true if the operation is possible, emitting instructions for it
>  if rtxes are provided.
> diff --git a/gcc/match.pd b/gcc/match.pd
> index f5efa77560c..f2a527d9c42 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -7596,6 +7596,8 @@ and,
>   (with
>    {
>      tree op0 = @0, op1 = @1, op2 = @2;
> +    machine_mode result_mode = TYPE_MODE (type);
> +    machine_mode op_mode = TYPE_MODE (TREE_TYPE (op0));
>  
>      /* Build a vector of integers from the tree mask.  */
>      vec_perm_builder builder;
> @@ -7703,12 +7705,12 @@ and,
>  	       2-argument version.  */
>  	    tree oldop2 = op2;
>  	    if (sel.ninputs () == 2
> -	       || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
> +	       || can_vec_perm_const_p (result_mode, op_mode, sel, false))
>  	      op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel);
>  	    else
>  	      {
>  	        vec_perm_indices sel2 (builder, 2, nelts);
> -	        if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
> +		if (can_vec_perm_const_p (result_mode, op_mode, sel2, false))
>  	          op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel2);
>  	        else
>  	          /* Not directly supported with either encoding,

Please replace the use of TYPE_MODE here:

	/* See if the permutation is performing a single element
	   insert from a CONSTRUCTOR or constant and use a BIT_INSERT_EXPR
	   in that case.  But only if the vector mode is supported,
	   otherwise this is invalid GIMPLE.  */
        if (TYPE_MODE (type) != BLKmode

as well.

OK with those changes, thanks.

Richard
  

On Tue, 24 May 2022 at 14:50, Richard Sandiford
<richard.sandiford@arm.com> wrote:
>
> Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
> > diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> > index c5006afc00d..0a3c733ada9 100644
> > --- a/gcc/doc/tm.texi
> > +++ b/gcc/doc/tm.texi
> > @@ -6088,14 +6088,18 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
> >  access using @var{type} is known to be naturally aligned.
> >  @end deftypefn
> >
> > -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> > +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> >  This hook is used to test whether the target can permute up to two
> > -vectors of mode @var{mode} using the permutation vector @code{sel}, and
> > -also to emit such a permutation.  In the former case @var{in0}, @var{in1}
> > -and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are
> > -the source vectors and @var{out} is the destination vector; all three are
> > -operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if
> > -@var{sel} describes a permutation on one vector instead of two.
> > +vectors of mode @var{op_mode} using the permutation vector @code{sel},
> > +producing a vector of mode @var{mode}.The hook is also used to emit such
>
> Should be two spaces between “@var{mode}.” and “The”.
>
> > +a permutation.
> > +
> > +When the hook is being used to test whether the target supports a permutation,
> > +@var{in0}, @var{in1}, and @var{out} are all null.When the hook is being used
>
> Same here: missing spaces before “When”.
>
> > +to emit a permutation, @var{in0} and @var{in1} are the source vectors of mode
> > +@var{op_mode} and @var{out} is the destination vector of mode @var{mode}.
> > +@var{in1} is the same as @var{in0} if @var{sel} describes a permutation on one
> > +vector instead of two.
> >
> >  Return true if the operation is possible, emitting instructions for it
> >  if rtxes are provided.
> > diff --git a/gcc/match.pd b/gcc/match.pd
> > index f5efa77560c..f2a527d9c42 100644
> > --- a/gcc/match.pd
> > +++ b/gcc/match.pd
> > @@ -7596,6 +7596,8 @@ and,
> >   (with
> >    {
> >      tree op0 = @0, op1 = @1, op2 = @2;
> > +    machine_mode result_mode = TYPE_MODE (type);
> > +    machine_mode op_mode = TYPE_MODE (TREE_TYPE (op0));
> >
> >      /* Build a vector of integers from the tree mask.  */
> >      vec_perm_builder builder;
> > @@ -7703,12 +7705,12 @@ and,
> >              2-argument version.  */
> >           tree oldop2 = op2;
> >           if (sel.ninputs () == 2
> > -            || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
> > +            || can_vec_perm_const_p (result_mode, op_mode, sel, false))
> >             op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel);
> >           else
> >             {
> >               vec_perm_indices sel2 (builder, 2, nelts);
> > -             if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
> > +             if (can_vec_perm_const_p (result_mode, op_mode, sel2, false))
> >                 op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel2);
> >               else
> >                 /* Not directly supported with either encoding,
>
> Please replace the use of TYPE_MODE here:
>
>         /* See if the permutation is performing a single element
>            insert from a CONSTRUCTOR or constant and use a BIT_INSERT_EXPR
>            in that case.  But only if the vector mode is supported,
>            otherwise this is invalid GIMPLE.  */
>         if (TYPE_MODE (type) != BLKmode
>
> as well.
>
> OK with those changes, thanks.
Thanks, committed the patch in ae8decf1d2b8329af59592b4fa78ee8dfab3ba5e.

Thanks,
Prathamesh
>
> Richard
  

On Tue, May 24, 2022 at 9:22 PM Prathamesh Kulkarni via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Tue, 24 May 2022 at 14:50, Richard Sandiford
> <richard.sandiford@arm.com> wrote:
> >
> > Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
> > > diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> > > index c5006afc00d..0a3c733ada9 100644
> > > --- a/gcc/doc/tm.texi
> > > +++ b/gcc/doc/tm.texi
> > > @@ -6088,14 +6088,18 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
> > >  access using @var{type} is known to be naturally aligned.
> > >  @end deftypefn
> > >
> > > -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> > > +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> > >  This hook is used to test whether the target can permute up to two
> > > -vectors of mode @var{mode} using the permutation vector @code{sel}, and
> > > -also to emit such a permutation.  In the former case @var{in0}, @var{in1}
> > > -and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are
> > > -the source vectors and @var{out} is the destination vector; all three are
> > > -operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if
> > > -@var{sel} describes a permutation on one vector instead of two.
> > > +vectors of mode @var{op_mode} using the permutation vector @code{sel},
> > > +producing a vector of mode @var{mode}.The hook is also used to emit such
> >
> > Should be two spaces between “@var{mode}.” and “The”.
> >
> > > +a permutation.
> > > +
> > > +When the hook is being used to test whether the target supports a permutation,
> > > +@var{in0}, @var{in1}, and @var{out} are all null.When the hook is being used
> >
> > Same here: missing spaces before “When”.
> >
> > > +to emit a permutation, @var{in0} and @var{in1} are the source vectors of mode
> > > +@var{op_mode} and @var{out} is the destination vector of mode @var{mode}.
> > > +@var{in1} is the same as @var{in0} if @var{sel} describes a permutation on one
> > > +vector instead of two.
> > >
> > >  Return true if the operation is possible, emitting instructions for it
> > >  if rtxes are provided.
> > > diff --git a/gcc/match.pd b/gcc/match.pd
> > > index f5efa77560c..f2a527d9c42 100644
> > > --- a/gcc/match.pd
> > > +++ b/gcc/match.pd
> > > @@ -7596,6 +7596,8 @@ and,
> > >   (with
> > >    {
> > >      tree op0 = @0, op1 = @1, op2 = @2;
> > > +    machine_mode result_mode = TYPE_MODE (type);
> > > +    machine_mode op_mode = TYPE_MODE (TREE_TYPE (op0));
> > >
> > >      /* Build a vector of integers from the tree mask.  */
> > >      vec_perm_builder builder;
> > > @@ -7703,12 +7705,12 @@ and,
> > >              2-argument version.  */
> > >           tree oldop2 = op2;
> > >           if (sel.ninputs () == 2
> > > -            || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
> > > +            || can_vec_perm_const_p (result_mode, op_mode, sel, false))
> > >             op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel);
> > >           else
> > >             {
> > >               vec_perm_indices sel2 (builder, 2, nelts);
> > > -             if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
> > > +             if (can_vec_perm_const_p (result_mode, op_mode, sel2, false))
> > >                 op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel2);
> > >               else
> > >                 /* Not directly supported with either encoding,
> >
> > Please replace the use of TYPE_MODE here:
> >
> >         /* See if the permutation is performing a single element
> >            insert from a CONSTRUCTOR or constant and use a BIT_INSERT_EXPR
> >            in that case.  But only if the vector mode is supported,
> >            otherwise this is invalid GIMPLE.  */
> >         if (TYPE_MODE (type) != BLKmode
> >
> > as well.
> >
> > OK with those changes, thanks.
> Thanks, committed the patch in ae8decf1d2b8329af59592b4fa78ee8dfab3ba5e.

So the present state allows to ask can_vec_perm_const_p but the
implementation asks for

431           if (direct_optab_handler (vec_perm_optab, mode) !=
CODE_FOR_nothing)
432             return true;

which then breaks.  Also the VEC_PERMs are not yet valid.  Any reason this
was committed half-way through the review process of the series?

At least I have a user in the vectorizer ready - allowing more permutes
from existing vectors (of different sizes now) to be SLP vectorized.

Thanks,
Richard.

> Thanks,
> Prathamesh
> >
> > Richard
  

On Wed, 25 May 2022 at 18:27, Richard Biener <richard.guenther@gmail.com> wrote:
>
> On Tue, May 24, 2022 at 9:22 PM Prathamesh Kulkarni via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
> >
> > On Tue, 24 May 2022 at 14:50, Richard Sandiford
> > <richard.sandiford@arm.com> wrote:
> > >
> > > Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
> > > > diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> > > > index c5006afc00d..0a3c733ada9 100644
> > > > --- a/gcc/doc/tm.texi
> > > > +++ b/gcc/doc/tm.texi
> > > > @@ -6088,14 +6088,18 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
> > > >  access using @var{type} is known to be naturally aligned.
> > > >  @end deftypefn
> > > >
> > > > -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> > > > +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> > > >  This hook is used to test whether the target can permute up to two
> > > > -vectors of mode @var{mode} using the permutation vector @code{sel}, and
> > > > -also to emit such a permutation.  In the former case @var{in0}, @var{in1}
> > > > -and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are
> > > > -the source vectors and @var{out} is the destination vector; all three are
> > > > -operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if
> > > > -@var{sel} describes a permutation on one vector instead of two.
> > > > +vectors of mode @var{op_mode} using the permutation vector @code{sel},
> > > > +producing a vector of mode @var{mode}.The hook is also used to emit such
> > >
> > > Should be two spaces between “@var{mode}.” and “The”.
> > >
> > > > +a permutation.
> > > > +
> > > > +When the hook is being used to test whether the target supports a permutation,
> > > > +@var{in0}, @var{in1}, and @var{out} are all null.When the hook is being used
> > >
> > > Same here: missing spaces before “When”.
> > >
> > > > +to emit a permutation, @var{in0} and @var{in1} are the source vectors of mode
> > > > +@var{op_mode} and @var{out} is the destination vector of mode @var{mode}.
> > > > +@var{in1} is the same as @var{in0} if @var{sel} describes a permutation on one
> > > > +vector instead of two.
> > > >
> > > >  Return true if the operation is possible, emitting instructions for it
> > > >  if rtxes are provided.
> > > > diff --git a/gcc/match.pd b/gcc/match.pd
> > > > index f5efa77560c..f2a527d9c42 100644
> > > > --- a/gcc/match.pd
> > > > +++ b/gcc/match.pd
> > > > @@ -7596,6 +7596,8 @@ and,
> > > >   (with
> > > >    {
> > > >      tree op0 = @0, op1 = @1, op2 = @2;
> > > > +    machine_mode result_mode = TYPE_MODE (type);
> > > > +    machine_mode op_mode = TYPE_MODE (TREE_TYPE (op0));
> > > >
> > > >      /* Build a vector of integers from the tree mask.  */
> > > >      vec_perm_builder builder;
> > > > @@ -7703,12 +7705,12 @@ and,
> > > >              2-argument version.  */
> > > >           tree oldop2 = op2;
> > > >           if (sel.ninputs () == 2
> > > > -            || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
> > > > +            || can_vec_perm_const_p (result_mode, op_mode, sel, false))
> > > >             op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel);
> > > >           else
> > > >             {
> > > >               vec_perm_indices sel2 (builder, 2, nelts);
> > > > -             if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
> > > > +             if (can_vec_perm_const_p (result_mode, op_mode, sel2, false))
> > > >                 op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel2);
> > > >               else
> > > >                 /* Not directly supported with either encoding,
> > >
> > > Please replace the use of TYPE_MODE here:
> > >
> > >         /* See if the permutation is performing a single element
> > >            insert from a CONSTRUCTOR or constant and use a BIT_INSERT_EXPR
> > >            in that case.  But only if the vector mode is supported,
> > >            otherwise this is invalid GIMPLE.  */
> > >         if (TYPE_MODE (type) != BLKmode
> > >
> > > as well.
> > >
> > > OK with those changes, thanks.
> > Thanks, committed the patch in ae8decf1d2b8329af59592b4fa78ee8dfab3ba5e.
>
> So the present state allows to ask can_vec_perm_const_p but the
> implementation asks for
>
> 431           if (direct_optab_handler (vec_perm_optab, mode) !=
> CODE_FOR_nothing)
> 432             return true;
>
> which then breaks.  Also the VEC_PERMs are not yet valid.  Any reason this
> was committed half-way through the review process of the series?
Hi Richard,
I am very sorry about that. I thought the patch was approved, and
committed it after testing on x86_64 and aarch64.
Should I revert it ?

Um sorry to ask a silly question -- I am not sure why does the patch
break the above condition ?
The patch still passes mode to direct_optab_handler as before, and
IIUC does not affect modes
for vec_perm_optab, so it shouldn't affect the call to
direct_optab_handler above ?

Thanks,
Prathamesh
>
> At least I have a user in the vectorizer ready - allowing more permutes
> from existing vectors (of different sizes now) to be SLP vectorized.
>
> Thanks,
> Richard.
>
> > Thanks,
> > Prathamesh
> > >
> > > Richard
  

> Am 25.05.2022 um 21:03 schrieb Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>:
> 
> On Wed, 25 May 2022 at 18:27, Richard Biener <richard.guenther@gmail.com> wrote:
>> 
>>> On Tue, May 24, 2022 at 9:22 PM Prathamesh Kulkarni via Gcc-patches
>>> <gcc-patches@gcc.gnu.org> wrote:
>>> 
>>> On Tue, 24 May 2022 at 14:50, Richard Sandiford
>>> <richard.sandiford@arm.com> wrote:
>>>> 
>>>> Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
>>>>> diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
>>>>> index c5006afc00d..0a3c733ada9 100644
>>>>> --- a/gcc/doc/tm.texi
>>>>> +++ b/gcc/doc/tm.texi
>>>>> @@ -6088,14 +6088,18 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
>>>>> access using @var{type} is known to be naturally aligned.
>>>>> @end deftypefn
>>>>> 
>>>>> -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
>>>>> +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
>>>>> This hook is used to test whether the target can permute up to two
>>>>> -vectors of mode @var{mode} using the permutation vector @code{sel}, and
>>>>> -also to emit such a permutation.  In the former case @var{in0}, @var{in1}
>>>>> -and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are
>>>>> -the source vectors and @var{out} is the destination vector; all three are
>>>>> -operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if
>>>>> -@var{sel} describes a permutation on one vector instead of two.
>>>>> +vectors of mode @var{op_mode} using the permutation vector @code{sel},
>>>>> +producing a vector of mode @var{mode}.The hook is also used to emit such
>>>> 
>>>> Should be two spaces between “@var{mode}.” and “The”.
>>>> 
>>>>> +a permutation.
>>>>> +
>>>>> +When the hook is being used to test whether the target supports a permutation,
>>>>> +@var{in0}, @var{in1}, and @var{out} are all null.When the hook is being used
>>>> 
>>>> Same here: missing spaces before “When”.
>>>> 
>>>>> +to emit a permutation, @var{in0} and @var{in1} are the source vectors of mode
>>>>> +@var{op_mode} and @var{out} is the destination vector of mode @var{mode}.
>>>>> +@var{in1} is the same as @var{in0} if @var{sel} describes a permutation on one
>>>>> +vector instead of two.
>>>>> 
>>>>> Return true if the operation is possible, emitting instructions for it
>>>>> if rtxes are provided.
>>>>> diff --git a/gcc/match.pd b/gcc/match.pd
>>>>> index f5efa77560c..f2a527d9c42 100644
>>>>> --- a/gcc/match.pd
>>>>> +++ b/gcc/match.pd
>>>>> @@ -7596,6 +7596,8 @@ and,
>>>>>  (with
>>>>>   {
>>>>>     tree op0 = @0, op1 = @1, op2 = @2;
>>>>> +    machine_mode result_mode = TYPE_MODE (type);
>>>>> +    machine_mode op_mode = TYPE_MODE (TREE_TYPE (op0));
>>>>> 
>>>>>     /* Build a vector of integers from the tree mask.  */
>>>>>     vec_perm_builder builder;
>>>>> @@ -7703,12 +7705,12 @@ and,
>>>>>             2-argument version.  */
>>>>>          tree oldop2 = op2;
>>>>>          if (sel.ninputs () == 2
>>>>> -            || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
>>>>> +            || can_vec_perm_const_p (result_mode, op_mode, sel, false))
>>>>>            op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel);
>>>>>          else
>>>>>            {
>>>>>              vec_perm_indices sel2 (builder, 2, nelts);
>>>>> -             if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
>>>>> +             if (can_vec_perm_const_p (result_mode, op_mode, sel2, false))
>>>>>                op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel2);
>>>>>              else
>>>>>                /* Not directly supported with either encoding,
>>>> 
>>>> Please replace the use of TYPE_MODE here:
>>>> 
>>>>        /* See if the permutation is performing a single element
>>>>           insert from a CONSTRUCTOR or constant and use a BIT_INSERT_EXPR
>>>>           in that case.  But only if the vector mode is supported,
>>>>           otherwise this is invalid GIMPLE.  */
>>>>        if (TYPE_MODE (type) != BLKmode
>>>> 
>>>> as well.
>>>> 
>>>> OK with those changes, thanks.
>>> Thanks, committed the patch in ae8decf1d2b8329af59592b4fa78ee8dfab3ba5e.
>> 
>> So the present state allows to ask can_vec_perm_const_p but the
>> implementation asks for
>> 
>> 431           if (direct_optab_handler (vec_perm_optab, mode) !=
>> CODE_FOR_nothing)
>> 432             return true;
>> 
>> which then breaks.  Also the VEC_PERMs are not yet valid.  Any reason this
>> was committed half-way through the review process of the series?
> Hi Richard,
> I am very sorry about that. I thought the patch was approved, and
> committed it after testing on x86_64 and aarch64.
> Should I revert it ?

No need.

> Um sorry to ask a silly question -- I am not sure why does the patch
> break the above condition ?
> The patch still passes mode to direct_optab_handler as before, and
> IIUC does not affect modes
> for vec_perm_optab, so it shouldn't affect the call to
> direct_optab_handler above ?

x86 now accepts V4SI V8SI permutes because we don’t ask it correctly and thus my naive attempt to use the new function API breaks . Not to mention the VEC_PERM IL is still rejected. I will wait for the rest of the series to be approved and pushed.

Richard.

> Thanks,
> Prathamesh
>> 
>> At least I have a user in the vectorizer ready - allowing more permutes
>> from existing vectors (of different sizes now) to be SLP vectorized.
>> 
>> Thanks,
>> Richard.
>> 
>>> Thanks,
>>> Prathamesh
>>>> 
>>>> Richard
  

On Thu, 26 May 2022 at 00:37, Richard Biener <richard.guenther@gmail.com> wrote:
>
>
>
> > Am 25.05.2022 um 21:03 schrieb Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>:
> >
> > On Wed, 25 May 2022 at 18:27, Richard Biener <richard.guenther@gmail.com> wrote:
> >>
> >>> On Tue, May 24, 2022 at 9:22 PM Prathamesh Kulkarni via Gcc-patches
> >>> <gcc-patches@gcc.gnu.org> wrote:
> >>>
> >>> On Tue, 24 May 2022 at 14:50, Richard Sandiford
> >>> <richard.sandiford@arm.com> wrote:
> >>>>
> >>>> Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> writes:
> >>>>> diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> >>>>> index c5006afc00d..0a3c733ada9 100644
> >>>>> --- a/gcc/doc/tm.texi
> >>>>> +++ b/gcc/doc/tm.texi
> >>>>> @@ -6088,14 +6088,18 @@ for the given scalar type @var{type}.  @var{is_packed} is false if the scalar
> >>>>> access using @var{type} is known to be naturally aligned.
> >>>>> @end deftypefn
> >>>>>
> >>>>> -@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> >>>>> +@deftypefn {Target Hook} bool TARGET_VECTORIZE_VEC_PERM_CONST (machine_mode @var{mode}, machine_mode @var{op_mode}, rtx @var{output}, rtx @var{in0}, rtx @var{in1}, const vec_perm_indices @var{&sel})
> >>>>> This hook is used to test whether the target can permute up to two
> >>>>> -vectors of mode @var{mode} using the permutation vector @code{sel}, and
> >>>>> -also to emit such a permutation.  In the former case @var{in0}, @var{in1}
> >>>>> -and @var{out} are all null.  In the latter case @var{in0} and @var{in1} are
> >>>>> -the source vectors and @var{out} is the destination vector; all three are
> >>>>> -operands of mode @var{mode}.  @var{in1} is the same as @var{in0} if
> >>>>> -@var{sel} describes a permutation on one vector instead of two.
> >>>>> +vectors of mode @var{op_mode} using the permutation vector @code{sel},
> >>>>> +producing a vector of mode @var{mode}.The hook is also used to emit such
> >>>>
> >>>> Should be two spaces between “@var{mode}.” and “The”.
> >>>>
> >>>>> +a permutation.
> >>>>> +
> >>>>> +When the hook is being used to test whether the target supports a permutation,
> >>>>> +@var{in0}, @var{in1}, and @var{out} are all null.When the hook is being used
> >>>>
> >>>> Same here: missing spaces before “When”.
> >>>>
> >>>>> +to emit a permutation, @var{in0} and @var{in1} are the source vectors of mode
> >>>>> +@var{op_mode} and @var{out} is the destination vector of mode @var{mode}.
> >>>>> +@var{in1} is the same as @var{in0} if @var{sel} describes a permutation on one
> >>>>> +vector instead of two.
> >>>>>
> >>>>> Return true if the operation is possible, emitting instructions for it
> >>>>> if rtxes are provided.
> >>>>> diff --git a/gcc/match.pd b/gcc/match.pd
> >>>>> index f5efa77560c..f2a527d9c42 100644
> >>>>> --- a/gcc/match.pd
> >>>>> +++ b/gcc/match.pd
> >>>>> @@ -7596,6 +7596,8 @@ and,
> >>>>>  (with
> >>>>>   {
> >>>>>     tree op0 = @0, op1 = @1, op2 = @2;
> >>>>> +    machine_mode result_mode = TYPE_MODE (type);
> >>>>> +    machine_mode op_mode = TYPE_MODE (TREE_TYPE (op0));
> >>>>>
> >>>>>     /* Build a vector of integers from the tree mask.  */
> >>>>>     vec_perm_builder builder;
> >>>>> @@ -7703,12 +7705,12 @@ and,
> >>>>>             2-argument version.  */
> >>>>>          tree oldop2 = op2;
> >>>>>          if (sel.ninputs () == 2
> >>>>> -            || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
> >>>>> +            || can_vec_perm_const_p (result_mode, op_mode, sel, false))
> >>>>>            op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel);
> >>>>>          else
> >>>>>            {
> >>>>>              vec_perm_indices sel2 (builder, 2, nelts);
> >>>>> -             if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
> >>>>> +             if (can_vec_perm_const_p (result_mode, op_mode, sel2, false))
> >>>>>                op2 = vec_perm_indices_to_tree (TREE_TYPE (op2), sel2);
> >>>>>              else
> >>>>>                /* Not directly supported with either encoding,
> >>>>
> >>>> Please replace the use of TYPE_MODE here:
> >>>>
> >>>>        /* See if the permutation is performing a single element
> >>>>           insert from a CONSTRUCTOR or constant and use a BIT_INSERT_EXPR
> >>>>           in that case.  But only if the vector mode is supported,
> >>>>           otherwise this is invalid GIMPLE.  */
> >>>>        if (TYPE_MODE (type) != BLKmode
> >>>>
> >>>> as well.
> >>>>
> >>>> OK with those changes, thanks.
> >>> Thanks, committed the patch in ae8decf1d2b8329af59592b4fa78ee8dfab3ba5e.
> >>
> >> So the present state allows to ask can_vec_perm_const_p but the
> >> implementation asks for
> >>
> >> 431           if (direct_optab_handler (vec_perm_optab, mode) !=
> >> CODE_FOR_nothing)
> >> 432             return true;
> >>
> >> which then breaks.  Also the VEC_PERMs are not yet valid.  Any reason this
> >> was committed half-way through the review process of the series?
> > Hi Richard,
> > I am very sorry about that. I thought the patch was approved, and
> > committed it after testing on x86_64 and aarch64.
> > Should I revert it ?
>
> No need.
>
> > Um sorry to ask a silly question -- I am not sure why does the patch
> > break the above condition ?
> > The patch still passes mode to direct_optab_handler as before, and
> > IIUC does not affect modes
> > for vec_perm_optab, so it shouldn't affect the call to
> > direct_optab_handler above ?
>
> x86 now accepts V4SI V8SI permutes because we don’t ask it correctly and thus my naive attempt to use the new function API breaks . Not to mention the VEC_PERM IL is still rejected. I will wait for the rest of the series to be approved and pushed.
Hi,
I pushed the entire series in ae8decf1d2b8329af59592b4fa78ee8dfab3ba5e
after it was approved by Richard S.

Thanks,
Prathamesh
>
> Richard.
>
> > Thanks,
> > Prathamesh
> >>
> >> At least I have a user in the vectorizer ready - allowing more permutes
> >> from existing vectors (of different sizes now) to be SLP vectorized.
> >>
> >> Thanks,
> >> Richard.
> >>
> >>> Thanks,
> >>> Prathamesh
> >>>>
> >>>> Richard
  

On Wed, May 25, 2022 at 10:24 PM Prathamesh Kulkarni
<prathamesh.kulkarni@linaro.org> wrote:
>
> On Thu, 26 May 2022 at 00:37, Richard Biener <richard.guenther@gmail.com> wrote:
[...]
> > x86 now accepts V4SI V8SI permutes because we don’t ask it correctly and thus my naive attempt to use the new function API breaks . Not to mention the VEC_PERM IL is still rejected. I will wait for the rest of the series to be approved and pushed.
> Hi,
> I pushed the entire series in ae8decf1d2b8329af59592b4fa78ee8dfab3ba5e
> after it was approved by Richard S.

Thanks.

Maybe I'm doing it wrong but I now see

          indices.new_vector (mask, second_vec.first == -1U ? 1 : 2, nunits);
          bool identity_p = indices.series_p (0, 1, 0, 1);

where nunits is 4 and mask {4, 5, 6, 7}, the number of vectors is 1,
and now indices.series_p (0, 1, 0, 1) returns true despite my input
vector having 8 elements and 'indices' should select the upper half.
That's because the function calls clamp() on the encoding but
clamp() knows nothing about the different nunits of the input vectors.

I suppose vec_perm_indices needs updating to allow for different
nunits of the input vectors as well?

Where else does this change need adjustments to other APIs?

PR101668 has a naiive user of the new capability.  The included
testcase works OK but trying to expand test coverage quickly
runs into wrong-code, like for

typedef int v8si __attribute__((vector_size (32)));
typedef long long v4di __attribute__((vector_size (32)));

void
bar_s32_s64 (v4di * dst, v8si src)
{
  long long tem[8];
  tem[0] = src[4];
  tem[1] = src[5];
  tem[2] = src[6];
  tem[3] = src[7];
  dst[0] = *(v4di *) tem;
}

which I expected to be rejected with -mavx2.

Thanks,
Richard.

> Thanks,
> Prathamesh
> >
> > Richard.
> >
> > > Thanks,
> > > Prathamesh
> > >>
> > >> At least I have a user in the vectorizer ready - allowing more permutes
> > >> from existing vectors (of different sizes now) to be SLP vectorized.
> > >>
> > >> Thanks,
> > >> Richard.
> > >>
> > >>> Thanks,
> > >>> Prathamesh
> > >>>>
> > >>>> Richard
  

(Sorry for the slow reply, was off on Friday)

Richard Biener <richard.guenther@gmail.com> writes:
> On Wed, May 25, 2022 at 10:24 PM Prathamesh Kulkarni
> <prathamesh.kulkarni@linaro.org> wrote:
>>
>> On Thu, 26 May 2022 at 00:37, Richard Biener <richard.guenther@gmail.com> wrote:
> [...]
>> > x86 now accepts V4SI V8SI permutes because we don’t ask it correctly and thus my naive attempt to use the new function API breaks . Not to mention the VEC_PERM IL is still rejected. I will wait for the rest of the series to be approved and pushed.
>> Hi,
>> I pushed the entire series in ae8decf1d2b8329af59592b4fa78ee8dfab3ba5e
>> after it was approved by Richard S.
>
> Thanks.
>
> Maybe I'm doing it wrong but I now see
>
>           indices.new_vector (mask, second_vec.first == -1U ? 1 : 2, nunits);
>           bool identity_p = indices.series_p (0, 1, 0, 1);
>
> where nunits is 4 and mask {4, 5, 6, 7}, the number of vectors is 1,
> and now indices.series_p (0, 1, 0, 1) returns true despite my input
> vector having 8 elements and 'indices' should select the upper half.
> That's because the function calls clamp() on the encoding but
> clamp() knows nothing about the different nunits of the input vectors.
>
> I suppose vec_perm_indices needs updating to allow for different
> nunits of the input vectors as well?

The final argument to new_vector is supposed to be the number of elements
per input vector, so it sounds like it should be 8 rather than 4 in this
situation.

The number of elements per output vector is taken from the mask argument.

Thanks,
Richard

>
> Where else does this change need adjustments to other APIs?
>
> PR101668 has a naiive user of the new capability.  The included
> testcase works OK but trying to expand test coverage quickly
> runs into wrong-code, like for
>
> typedef int v8si __attribute__((vector_size (32)));
> typedef long long v4di __attribute__((vector_size (32)));
>
> void
> bar_s32_s64 (v4di * dst, v8si src)
> {
>   long long tem[8];
>   tem[0] = src[4];
>   tem[1] = src[5];
>   tem[2] = src[6];
>   tem[3] = src[7];
>   dst[0] = *(v4di *) tem;
> }
>
> which I expected to be rejected with -mavx2.
>
> Thanks,
> Richard.
>
>> Thanks,
>> Prathamesh
>> >
>> > Richard.
>> >
>> > > Thanks,
>> > > Prathamesh
>> > >>
>> > >> At least I have a user in the vectorizer ready - allowing more permutes
>> > >> from existing vectors (of different sizes now) to be SLP vectorized.
>> > >>
>> > >> Thanks,
>> > >> Richard.
>> > >>
>> > >>> Thanks,
>> > >>> Prathamesh
>> > >>>>
>> > >>>> Richard