[05/11] Add a vect_stmt_to_vectorize helper function

This patch adds a helper that does the opposite of vect_orig_stmt:
go from the original scalar statement to the statement that should
actually be vectorised.

The use in the last two hunks of vectorizable_reduction are because
reduc_stmt_info (first hunk) and stmt_info (second hunk) are already
pattern statements if appropriate.


2018-07-30  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-vectorizer.h (vect_stmt_to_vectorize): New function.
	* tree-vect-loop.c (vect_update_vf_for_slp): Use it.
	(vectorizable_reduction): Likewise.
	* tree-vect-slp.c (vect_analyze_slp_instance): Likewise.
	(vect_detect_hybrid_slp_stmts): Likewise.
	* tree-vect-stmts.c (vect_is_simple_use): Likewise.

On Mon, Jul 30, 2018 at 1:39 PM Richard Sandiford
<richard.sandiford@arm.com> wrote:
>
> This patch adds a helper that does the opposite of vect_orig_stmt:
> go from the original scalar statement to the statement that should
> actually be vectorised.
>
> The use in the last two hunks of vectorizable_reduction are because
> reduc_stmt_info (first hunk) and stmt_info (second hunk) are already
> pattern statements if appropriate.

OK.

Richard.

>
> 2018-07-30  Richard Sandiford  <richard.sandiford@arm.com>
>
> gcc/
>         * tree-vectorizer.h (vect_stmt_to_vectorize): New function.
>         * tree-vect-loop.c (vect_update_vf_for_slp): Use it.
>         (vectorizable_reduction): Likewise.
>         * tree-vect-slp.c (vect_analyze_slp_instance): Likewise.
>         (vect_detect_hybrid_slp_stmts): Likewise.
>         * tree-vect-stmts.c (vect_is_simple_use): Likewise.
>
> Index: gcc/tree-vectorizer.h
> ===================================================================
> --- gcc/tree-vectorizer.h       2018-07-30 12:32:26.218536339 +0100
> +++ gcc/tree-vectorizer.h       2018-07-30 12:32:29.586506669 +0100
> @@ -1131,6 +1131,17 @@ vect_orig_stmt (stmt_vec_info stmt_info)
>    return stmt_info;
>  }
>
> +/* If STMT_INFO has been replaced by a pattern statement, return the
> +   replacement statement, otherwise return STMT_INFO itself.  */
> +
> +inline stmt_vec_info
> +vect_stmt_to_vectorize (stmt_vec_info stmt_info)
> +{
> +  if (STMT_VINFO_IN_PATTERN_P (stmt_info))
> +    return STMT_VINFO_RELATED_STMT (stmt_info);
> +  return stmt_info;
> +}
> +
>  /* Return true if BB is a loop header.  */
>
>  static inline bool
> Index: gcc/tree-vect-loop.c
> ===================================================================
> --- gcc/tree-vect-loop.c        2018-07-30 12:32:26.214536374 +0100
> +++ gcc/tree-vect-loop.c        2018-07-30 12:32:29.586506669 +0100
> @@ -1424,9 +1424,7 @@ vect_update_vf_for_slp (loop_vec_info lo
>            gsi_next (&si))
>         {
>           stmt_vec_info stmt_info = loop_vinfo->lookup_stmt (gsi_stmt (si));
> -         if (STMT_VINFO_IN_PATTERN_P (stmt_info)
> -             && STMT_VINFO_RELATED_STMT (stmt_info))
> -           stmt_info = STMT_VINFO_RELATED_STMT (stmt_info);
> +         stmt_info = vect_stmt_to_vectorize (stmt_info);
>           if ((STMT_VINFO_RELEVANT_P (stmt_info)
>                || VECTORIZABLE_CYCLE_DEF (STMT_VINFO_DEF_TYPE (stmt_info)))
>               && !PURE_SLP_STMT (stmt_info))
> @@ -6111,8 +6109,7 @@ vectorizable_reduction (stmt_vec_info st
>         return true;
>
>        stmt_vec_info reduc_stmt_info = STMT_VINFO_REDUC_DEF (stmt_info);
> -      if (STMT_VINFO_IN_PATTERN_P (reduc_stmt_info))
> -       reduc_stmt_info = STMT_VINFO_RELATED_STMT (reduc_stmt_info);
> +      reduc_stmt_info = vect_stmt_to_vectorize (reduc_stmt_info);
>
>        if (STMT_VINFO_VEC_REDUCTION_TYPE (reduc_stmt_info)
>           == EXTRACT_LAST_REDUCTION)
> @@ -6145,8 +6142,7 @@ vectorizable_reduction (stmt_vec_info st
>        if (ncopies > 1
>           && STMT_VINFO_RELEVANT (reduc_stmt_info) <= vect_used_only_live
>           && (use_stmt_info = loop_vinfo->lookup_single_use (phi_result))
> -         && (use_stmt_info == reduc_stmt_info
> -             || STMT_VINFO_RELATED_STMT (use_stmt_info) == reduc_stmt_info))
> +         && vect_stmt_to_vectorize (use_stmt_info) == reduc_stmt_info)
>         single_defuse_cycle = true;
>
>        /* Create the destination vector  */
> @@ -6915,8 +6911,7 @@ vectorizable_reduction (stmt_vec_info st
>    if (ncopies > 1
>        && (STMT_VINFO_RELEVANT (stmt_info) <= vect_used_only_live)
>        && (use_stmt_info = loop_vinfo->lookup_single_use (reduc_phi_result))
> -      && (use_stmt_info == stmt_info
> -         || STMT_VINFO_RELATED_STMT (use_stmt_info) == stmt_info))
> +      && vect_stmt_to_vectorize (use_stmt_info) == stmt_info)
>      {
>        single_defuse_cycle = true;
>        epilog_copies = 1;
> Index: gcc/tree-vect-slp.c
> ===================================================================
> --- gcc/tree-vect-slp.c 2018-07-30 12:32:26.218536339 +0100
> +++ gcc/tree-vect-slp.c 2018-07-30 12:32:29.586506669 +0100
> @@ -1969,11 +1969,7 @@ vect_analyze_slp_instance (vec_info *vin
>        /* Collect the stores and store them in SLP_TREE_SCALAR_STMTS.  */
>        while (next_info)
>          {
> -         if (STMT_VINFO_IN_PATTERN_P (next_info)
> -             && STMT_VINFO_RELATED_STMT (next_info))
> -           scalar_stmts.safe_push (STMT_VINFO_RELATED_STMT (next_info));
> -         else
> -           scalar_stmts.safe_push (next_info);
> +         scalar_stmts.safe_push (vect_stmt_to_vectorize (next_info));
>           next_info = DR_GROUP_NEXT_ELEMENT (next_info);
>          }
>      }
> @@ -1983,11 +1979,7 @@ vect_analyze_slp_instance (vec_info *vin
>          SLP_TREE_SCALAR_STMTS.  */
>        while (next_info)
>          {
> -         if (STMT_VINFO_IN_PATTERN_P (next_info)
> -             && STMT_VINFO_RELATED_STMT (next_info))
> -           scalar_stmts.safe_push (STMT_VINFO_RELATED_STMT (next_info));
> -         else
> -           scalar_stmts.safe_push (next_info);
> +         scalar_stmts.safe_push (vect_stmt_to_vectorize (next_info));
>           next_info = REDUC_GROUP_NEXT_ELEMENT (next_info);
>          }
>        /* Mark the first element of the reduction chain as reduction to properly
> @@ -2325,9 +2317,7 @@ vect_detect_hybrid_slp_stmts (slp_tree n
>             use_vinfo = loop_vinfo->lookup_stmt (use_stmt);
>             if (!use_vinfo)
>               continue;
> -           if (STMT_VINFO_IN_PATTERN_P (use_vinfo)
> -               && STMT_VINFO_RELATED_STMT (use_vinfo))
> -             use_vinfo = STMT_VINFO_RELATED_STMT (use_vinfo);
> +           use_vinfo = vect_stmt_to_vectorize (use_vinfo);
>             if (!STMT_SLP_TYPE (use_vinfo)
>                 && (STMT_VINFO_RELEVANT (use_vinfo)
>                     || VECTORIZABLE_CYCLE_DEF (STMT_VINFO_DEF_TYPE (use_vinfo)))
> Index: gcc/tree-vect-stmts.c
> ===================================================================
> --- gcc/tree-vect-stmts.c       2018-07-30 12:32:26.218536339 +0100
> +++ gcc/tree-vect-stmts.c       2018-07-30 12:32:29.586506669 +0100
> @@ -10031,11 +10031,8 @@ vect_is_simple_use (tree operand, vec_in
>         *dt = vect_external_def;
>        else
>         {
> -         if (STMT_VINFO_IN_PATTERN_P (stmt_vinfo))
> -           {
> -             stmt_vinfo = STMT_VINFO_RELATED_STMT (stmt_vinfo);
> -             def_stmt = stmt_vinfo->stmt;
> -           }
> +         stmt_vinfo = vect_stmt_to_vectorize (stmt_vinfo);
> +         def_stmt = stmt_vinfo->stmt;
>           switch (gimple_code (def_stmt))
>             {
>             case GIMPLE_PHI: