On Tue, Jul 24, 2018 at 11:56 AM Richard Sandiford
<richard.sandif...@arm.com> wrote:
>
> This patch adds a helper function for seeing whether there is a single
> user of an SSA name, and whether that user has a stmt_vec_info.
OK.
>
> 2018-07-24 Richard Sandiford <richard.sandif...@arm.com>
>
> gcc/
> * tree-vectorizer.h (vec_info::lookup_single_use): Declare.
> * tree-vectorizer.c (vec_info::lookup_single_use): New function.
> * tree-vect-loop.c (vectorizable_reduction): Use it instead of
> a single_imm_use-based sequence.
> * tree-vect-stmts.c (supportable_widening_operation): Likewise.
>
> Index: gcc/tree-vectorizer.h
> ===================================================================
> --- gcc/tree-vectorizer.h 2018-07-24 10:22:27.285336715 +0100
> +++ gcc/tree-vectorizer.h 2018-07-24 10:22:30.401309046 +0100
> @@ -220,6 +220,7 @@ struct vec_info {
> stmt_vec_info add_stmt (gimple *);
> stmt_vec_info lookup_stmt (gimple *);
> stmt_vec_info lookup_def (tree);
> + stmt_vec_info lookup_single_use (tree);
>
> /* The type of vectorization. */
> vec_kind kind;
> Index: gcc/tree-vectorizer.c
> ===================================================================
> --- gcc/tree-vectorizer.c 2018-07-24 10:22:27.285336715 +0100
> +++ gcc/tree-vectorizer.c 2018-07-24 10:22:30.401309046 +0100
> @@ -548,6 +548,20 @@ vec_info::lookup_def (tree name)
> return NULL;
> }
>
> +/* See whether there is a single non-debug statement that uses LHS and
> + whether that statement has an associated stmt_vec_info. Return the
> + stmt_vec_info if so, otherwise return null. */
> +
> +stmt_vec_info
> +vec_info::lookup_single_use (tree lhs)
> +{
> + use_operand_p dummy;
> + gimple *use_stmt;
> + if (single_imm_use (lhs, &dummy, &use_stmt))
> + return lookup_stmt (use_stmt);
> + return NULL;
> +}
> +
> /* A helper function to free scev and LOOP niter information, as well as
> clear loop constraint LOOP_C_FINITE. */
>
> Index: gcc/tree-vect-loop.c
> ===================================================================
> --- gcc/tree-vect-loop.c 2018-07-24 10:22:27.277336786 +0100
> +++ gcc/tree-vect-loop.c 2018-07-24 10:22:30.401309046 +0100
> @@ -6138,6 +6138,7 @@ vectorizable_reduction (gimple *stmt, gi
>
> if (gimple_code (stmt) == GIMPLE_PHI)
> {
> + tree phi_result = gimple_phi_result (stmt);
> /* Analysis is fully done on the reduction stmt invocation. */
> if (! vec_stmt)
> {
> @@ -6158,7 +6159,8 @@ vectorizable_reduction (gimple *stmt, gi
> if (STMT_VINFO_IN_PATTERN_P (vinfo_for_stmt (reduc_stmt)))
> reduc_stmt = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (reduc_stmt));
>
> - if (STMT_VINFO_VEC_REDUCTION_TYPE (vinfo_for_stmt (reduc_stmt))
> + stmt_vec_info reduc_stmt_info = vinfo_for_stmt (reduc_stmt);
> + if (STMT_VINFO_VEC_REDUCTION_TYPE (reduc_stmt_info)
> == EXTRACT_LAST_REDUCTION)
> /* Leave the scalar phi in place. */
> return true;
> @@ -6185,15 +6187,12 @@ vectorizable_reduction (gimple *stmt, gi
> else
> ncopies = vect_get_num_copies (loop_vinfo, vectype_in);
>
> - use_operand_p use_p;
> - gimple *use_stmt;
> + stmt_vec_info use_stmt_info;
> if (ncopies > 1
> - && (STMT_VINFO_RELEVANT (vinfo_for_stmt (reduc_stmt))
> - <= vect_used_only_live)
> - && single_imm_use (gimple_phi_result (stmt), &use_p, &use_stmt)
> - && (use_stmt == reduc_stmt
> - || (STMT_VINFO_RELATED_STMT (vinfo_for_stmt (use_stmt))
> - == reduc_stmt)))
> + && 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))
> single_defuse_cycle = true;
>
> /* Create the destination vector */
> @@ -6955,13 +6954,13 @@ vectorizable_reduction (gimple *stmt, gi
> This only works when we see both the reduction PHI and its only consumer
> in vectorizable_reduction and there are no intermediate stmts
> participating. */
> - use_operand_p use_p;
> - gimple *use_stmt;
> + stmt_vec_info use_stmt_info;
> + tree reduc_phi_result = gimple_phi_result (reduc_def_stmt);
> if (ncopies > 1
> && (STMT_VINFO_RELEVANT (stmt_info) <= vect_used_only_live)
> - && single_imm_use (gimple_phi_result (reduc_def_stmt), &use_p,
> &use_stmt)
> - && (use_stmt == stmt
> - || STMT_VINFO_RELATED_STMT (vinfo_for_stmt (use_stmt)) == stmt))
> + && (use_stmt_info = loop_vinfo->lookup_single_use (reduc_phi_result))
> + && (use_stmt_info == stmt_info
> + || STMT_VINFO_RELATED_STMT (use_stmt_info) == stmt))
> {
> single_defuse_cycle = true;
> epilog_copies = 1;
> Index: gcc/tree-vect-stmts.c
> ===================================================================
> --- gcc/tree-vect-stmts.c 2018-07-24 10:22:27.281336751 +0100
> +++ gcc/tree-vect-stmts.c 2018-07-24 10:22:30.401309046 +0100
> @@ -10310,14 +10310,11 @@ supportable_widening_operation (enum tre
> same operation. One such an example is s += a * b, where
> elements
> in a and b cannot be reordered. Here we check if the vector
> defined
> by STMT is only directly used in the reduction statement. */
> - tree lhs = gimple_assign_lhs (stmt);
> - use_operand_p dummy;
> - gimple *use_stmt;
> - stmt_vec_info use_stmt_info = NULL;
> - if (single_imm_use (lhs, &dummy, &use_stmt)
> - && (use_stmt_info = vinfo_for_stmt (use_stmt))
> - && STMT_VINFO_DEF_TYPE (use_stmt_info) == vect_reduction_def)
> - return true;
> + tree lhs = gimple_assign_lhs (stmt);
> + stmt_vec_info use_stmt_info = loop_info->lookup_single_use (lhs);
> + if (use_stmt_info
> + && STMT_VINFO_DEF_TYPE (use_stmt_info) == vect_reduction_def)
> + return true;
> }
> c1 = VEC_WIDEN_MULT_LO_EXPR;
> c2 = VEC_WIDEN_MULT_HI_EXPR;
