Re: [PATCH 1/2] Streamline vect_gen_while

[Richard Sandiford <richard.sandiford@arm.com>]

Richard Biener <rguenther@suse.de> writes:
> This adjusts the vect_gen_while API to match that of
> vect_gen_while_not allowing further patches to generate more
> than one stmt for the while case.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu, tested a
> toy example on SVE that it still produces the same code.
>
> OK?
>
> 2021-07-15  Richard Biener  <rguenther@suse.de>
>
> 	* tree-vectorizer.h (vect_gen_while): Match up with
> 	vect_gen_while_not.
> 	* tree-vect-stmts.c (vect_gen_while): Adjust API to that
> 	of vect_gen_while_not.
> 	(vect_gen_while_not): Adjust.
> 	* tree-vect-loop-manip.c (vect_set_loop_controls_directly): Likewise.
> ---
>  gcc/tree-vect-loop-manip.c | 14 ++++++--------
>  gcc/tree-vect-stmts.c      | 16 ++++++++--------
>  gcc/tree-vectorizer.h      |  3 ++-
>  3 files changed, 16 insertions(+), 17 deletions(-)
>
> diff --git a/gcc/tree-vect-loop-manip.c b/gcc/tree-vect-loop-manip.c
> index c29ffb3356c..1f3d6614e6c 100644
> --- a/gcc/tree-vect-loop-manip.c
> +++ b/gcc/tree-vect-loop-manip.c
> @@ -609,11 +609,8 @@ vect_set_loop_controls_directly (class loop *loop, loop_vec_info loop_vinfo,
>  	    }
>  
>  	  if (use_masks_p)
> -	    {
> -	      init_ctrl = make_temp_ssa_name (ctrl_type, NULL, "max_mask");
> -	      gimple *tmp_stmt = vect_gen_while (init_ctrl, start, end);
> -	      gimple_seq_add_stmt (preheader_seq, tmp_stmt);
> -	    }
> +	    init_ctrl = vect_gen_while (preheader_seq, ctrl_type,
> +					start, end, "max_mask");
>  	  else
>  	    {
>  	      init_ctrl = make_temp_ssa_name (compare_type, NULL, "max_len");
> @@ -652,9 +649,10 @@ vect_set_loop_controls_directly (class loop *loop, loop_vec_info loop_vinfo,
>        /* Get the control value for the next iteration of the loop.  */
>        if (use_masks_p)
>  	{
> -	  next_ctrl = make_temp_ssa_name (ctrl_type, NULL, "next_mask");
> -	  gcall *call = vect_gen_while (next_ctrl, test_index, this_test_limit);
> -	  gsi_insert_before (test_gsi, call, GSI_SAME_STMT);
> +	  gimple_seq stmts = NULL;
> +	  next_ctrl = vect_gen_while (&stmts, ctrl_type, test_index,
> +				      this_test_limit, "next_mask");
> +	  gsi_insert_seq_before (test_gsi, stmts, GSI_SAME_STMT);
>  	}
>        else
>  	{
> diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
> index d9eeda50278..6a25d661800 100644
> --- a/gcc/tree-vect-stmts.c
> +++ b/gcc/tree-vect-stmts.c
> @@ -12002,19 +12002,21 @@ supportable_narrowing_operation (enum tree_code code,
>  /* Generate and return a statement that sets vector mask MASK such that
>     MASK[I] is true iff J + START_INDEX < END_INDEX for all J <= I.  */

Comment needs updating.  LGTM otherwise, thanks.

Richard

> -gcall *
> -vect_gen_while (tree mask, tree start_index, tree end_index)
> +tree
> +vect_gen_while (gimple_seq *seq, tree mask_type, tree start_index,
> +		tree end_index, const char *name)
>  {
>    tree cmp_type = TREE_TYPE (start_index);
> -  tree mask_type = TREE_TYPE (mask);
>    gcc_checking_assert (direct_internal_fn_supported_p (IFN_WHILE_ULT,
>  						       cmp_type, mask_type,
>  						       OPTIMIZE_FOR_SPEED));
>    gcall *call = gimple_build_call_internal (IFN_WHILE_ULT, 3,
>  					    start_index, end_index,
>  					    build_zero_cst (mask_type));
> -  gimple_call_set_lhs (call, mask);
> -  return call;
> +  tree tmp = make_temp_ssa_name (mask_type, NULL, name);
> +  gimple_call_set_lhs (call, tmp);
> +  gimple_seq_add_stmt (seq, call);
> +  return tmp;
>  }
>  
>  /* Generate a vector mask of type MASK_TYPE for which index I is false iff
> @@ -12024,9 +12026,7 @@ tree
>  vect_gen_while_not (gimple_seq *seq, tree mask_type, tree start_index,
>  		    tree end_index)
>  {
> -  tree tmp = make_ssa_name (mask_type);
> -  gcall *call = vect_gen_while (tmp, start_index, end_index);
> -  gimple_seq_add_stmt (seq, call);
> +  tree tmp = vect_gen_while (seq, mask_type, start_index, end_index);
>    return gimple_build (seq, BIT_NOT_EXPR, mask_type, tmp);
>  }
>  
> diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h
> index 4c4bc810c35..49afdd898d0 100644
> --- a/gcc/tree-vectorizer.h
> +++ b/gcc/tree-vectorizer.h
> @@ -1948,7 +1948,8 @@ extern bool vect_supportable_shift (vec_info *, enum tree_code, tree);
>  extern tree vect_gen_perm_mask_any (tree, const vec_perm_indices &);
>  extern tree vect_gen_perm_mask_checked (tree, const vec_perm_indices &);
>  extern void optimize_mask_stores (class loop*);
> -extern gcall *vect_gen_while (tree, tree, tree);
> +extern tree vect_gen_while (gimple_seq *, tree, tree, tree,
> +			    const char * = nullptr);
>  extern tree vect_gen_while_not (gimple_seq *, tree, tree, tree);
>  extern opt_result vect_get_vector_types_for_stmt (vec_info *,
>  						  stmt_vec_info, tree *,