On Tue, Jul 24, 2018 at 11:53 AM Richard Sandiford
<richard.sandif...@arm.com> wrote:
>
> This minor clean-up avoids repeating the test for double reductions
> and also moves the vect_get_vec_def_for_operand call to the same
> function as the corresponding vect_get_vec_def_for_stmt_copy.
OK.
>
> 2018-07-24 Richard Sandiford <richard.sandif...@arm.com>
>
> gcc/
> * tree-vect-loop.c (get_initial_def_for_reduction): Move special
> cases for nested loops from here to ...
> (vect_create_epilog_for_reduction): ...here. Only call
> vect_is_simple_use for inner-loop reductions.
>
> Index: gcc/tree-vect-loop.c
> ===================================================================
> --- gcc/tree-vect-loop.c 2018-07-13 10:11:14.429843575 +0100
> +++ gcc/tree-vect-loop.c 2018-07-24 10:22:02.965552667 +0100
> @@ -4113,10 +4113,8 @@ get_initial_def_for_reduction (gimple *s
> enum tree_code code = gimple_assign_rhs_code (stmt);
> tree def_for_init;
> tree init_def;
> - bool nested_in_vect_loop = false;
> REAL_VALUE_TYPE real_init_val = dconst0;
> int int_init_val = 0;
> - gimple *def_stmt = NULL;
> gimple_seq stmts = NULL;
>
> gcc_assert (vectype);
> @@ -4124,39 +4122,12 @@ get_initial_def_for_reduction (gimple *s
> gcc_assert (POINTER_TYPE_P (scalar_type) || INTEGRAL_TYPE_P (scalar_type)
> || SCALAR_FLOAT_TYPE_P (scalar_type));
>
> - if (nested_in_vect_loop_p (loop, stmt))
> - nested_in_vect_loop = true;
> - else
> - gcc_assert (loop == (gimple_bb (stmt))->loop_father);
> -
> - /* In case of double reduction we only create a vector variable to be put
> - in the reduction phi node. The actual statement creation is done in
> - vect_create_epilog_for_reduction. */
> - if (adjustment_def && nested_in_vect_loop
> - && TREE_CODE (init_val) == SSA_NAME
> - && (def_stmt = SSA_NAME_DEF_STMT (init_val))
> - && gimple_code (def_stmt) == GIMPLE_PHI
> - && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt))
> - && vinfo_for_stmt (def_stmt)
> - && STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def_stmt))
> - == vect_double_reduction_def)
> - {
> - *adjustment_def = NULL;
> - return vect_create_destination_var (init_val, vectype);
> - }
> + gcc_assert (nested_in_vect_loop_p (loop, stmt)
> + || loop == (gimple_bb (stmt))->loop_father);
>
> vect_reduction_type reduction_type
> = STMT_VINFO_VEC_REDUCTION_TYPE (stmt_vinfo);
>
> - /* In case of a nested reduction do not use an adjustment def as
> - that case is not supported by the epilogue generation correctly
> - if ncopies is not one. */
> - if (adjustment_def && nested_in_vect_loop)
> - {
> - *adjustment_def = NULL;
> - return vect_get_vec_def_for_operand (init_val, stmt);
> - }
> -
> switch (code)
> {
> case WIDEN_SUM_EXPR:
> @@ -4586,9 +4557,22 @@ vect_create_epilog_for_reduction (vec<tr
> || (induc_code == MIN_EXPR
> && tree_int_cst_lt (induc_val, initial_def))))
> induc_val = initial_def;
> - vect_is_simple_use (initial_def, loop_vinfo, &initial_def_dt);
> - vec_initial_def = get_initial_def_for_reduction (stmt, initial_def,
> - &adjustment_def);
> +
> + if (double_reduc)
> + /* In case of double reduction we only create a vector variable
> + to be put in the reduction phi node. The actual statement
> + creation is done later in this function. */
> + vec_initial_def = vect_create_destination_var (initial_def, vectype);
> + else if (nested_in_vect_loop)
> + {
> + /* Do not use an adjustment def as that case is not supported
> + correctly if ncopies is not one. */
> + vect_is_simple_use (initial_def, loop_vinfo, &initial_def_dt);
> + vec_initial_def = vect_get_vec_def_for_operand (initial_def, stmt);
> + }
> + else
> + vec_initial_def = get_initial_def_for_reduction (stmt, initial_def,
> + &adjustment_def);
> vec_initial_defs.create (1);
> vec_initial_defs.quick_push (vec_initial_def);
> }
