Re: [PATCH] Use anonymous SSA name support in SLSR

[Richard Biener <richard dot guenther at gmail dot com>]

On Mon, May 6, 2013 at 5:42 PM, Bill Schmidt
<wschmidt@linux.vnet.ibm.com> wrote:
> This removes lazy_create_slsr_reg and replaces uses of make_ssa_name
> with make_temp_ssa_name, removing the need for a bunch of unnecessary
> vars.
>
> Bootstrapped and tested on powerpc64-unknown-linux-gnu with no new
> regressions.  Ok for trunk?

Ok.

Thanks,
Richard.

> Thanks,
> Bill
>
>
> 2013-05-06  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
>
>         * gimple-ssa-strength-reduction.c (lazy_create_slsr_reg): Remove.
>         (replace_mult_candidate): Remove unnecessary argument; remove
>         unnecessary parameter from call to introduce_cast_before_cand.
>         (replace_unconditional_candidate): Remove unnecessary parameter
>         from call to replace_mult_candidate.
>         (replace_conditional_candidate): Likewise.
>         (insert_initializers): Use make_temp_ssa_name.
>         (introduce_cast_before_cand): Remove unnecessary argument; use
>         make_temp_ssa_name.
>         (replace_one_candidate): Remove unnecessary argument; remove
>         unnecessary parameter from calls to introduce_cast_before_cand.
>         (replace_profitable_candidates): Remove unnecessary parameters
>         from calls to replace_one_candidate.
>
>
> Index: gcc/gimple-ssa-strength-reduction.c
> ===================================================================
> --- gcc/gimple-ssa-strength-reduction.c (revision 198627)
> +++ gcc/gimple-ssa-strength-reduction.c (working copy)
> @@ -376,7 +376,7 @@ static bool address_arithmetic_p;
>
>  /* Forward function declarations.  */
>  static slsr_cand_t base_cand_from_table (tree);
> -static tree introduce_cast_before_cand (slsr_cand_t, tree, tree, tree*);
> +static tree introduce_cast_before_cand (slsr_cand_t, tree, tree);
>
>  /* Produce a pointer to the IDX'th candidate in the candidate vector.  */
>
> @@ -1818,16 +1818,6 @@ cand_abs_increment (slsr_cand_t c)
>    return increment;
>  }
>
> -/* If *VAR is NULL or is not of a compatible type with TYPE, create a
> -   new temporary reg of type TYPE and store it in *VAR.  */
> -
> -static inline void
> -lazy_create_slsr_reg (tree *var, tree type)
> -{
> -  if (!*var || !types_compatible_p (TREE_TYPE (*var), type))
> -    *var = create_tmp_reg (type, "slsr");
> -}
> -
>  /* Return TRUE iff candidate C has already been replaced under
>     another interpretation.  */
>
> @@ -1841,8 +1831,7 @@ cand_already_replaced (slsr_cand_t c)
>     replace_conditional_candidate.  */
>
>  static void
> -replace_mult_candidate (slsr_cand_t c, tree basis_name, double_int bump,
> -                       tree *var)
> +replace_mult_candidate (slsr_cand_t c, tree basis_name, double_int bump)
>  {
>    tree target_type = TREE_TYPE (gimple_assign_lhs (c->cand_stmt));
>    enum tree_code cand_code = gimple_assign_rhs_code (c->cand_stmt);
> @@ -1869,8 +1858,7 @@ static void
>        /* If the basis name and the candidate's LHS have incompatible
>          types, introduce a cast.  */
>        if (!useless_type_conversion_p (target_type, TREE_TYPE (basis_name)))
> -       basis_name = introduce_cast_before_cand (c, target_type,
> -                                                basis_name, var);
> +       basis_name = introduce_cast_before_cand (c, target_type, basis_name);
>        if (bump.is_negative ())
>         {
>           code = MINUS_EXPR;
> @@ -1945,7 +1933,6 @@ replace_unconditional_candidate (slsr_cand_t c)
>  {
>    slsr_cand_t basis;
>    double_int stride, bump;
> -  tree var = NULL;
>
>    if (cand_already_replaced (c))
>      return;
> @@ -1954,7 +1941,7 @@ replace_unconditional_candidate (slsr_cand_t c)
>    stride = tree_to_double_int (c->stride);
>    bump = cand_increment (c) * stride;
>
> -  replace_mult_candidate (c, gimple_assign_lhs (basis->cand_stmt), bump, &var);
> +  replace_mult_candidate (c, gimple_assign_lhs (basis->cand_stmt), bump);
>  }
>
>  /* Return the index in the increment vector of the given INCREMENT.  */
> @@ -2150,7 +2137,7 @@ create_phi_basis (slsr_cand_t c, gimple from_phi,
>  static void
>  replace_conditional_candidate (slsr_cand_t c)
>  {
> -  tree basis_name, name, var = NULL;
> +  tree basis_name, name;
>    slsr_cand_t basis;
>    location_t loc;
>    double_int stride, bump;
> @@ -2169,7 +2156,7 @@ replace_conditional_candidate (slsr_cand_t c)
>    stride = tree_to_double_int (c->stride);
>    bump = c->index * stride;
>
> -  replace_mult_candidate (c, name, bump, &var);
> +  replace_mult_candidate (c, name, bump);
>  }
>
>  /* Compute the expected costs of inserting basis adjustments for
> @@ -2925,7 +2912,6 @@ static void
>  insert_initializers (slsr_cand_t c)
>  {
>    unsigned i;
> -  tree new_var = NULL_TREE;
>
>    for (i = 0; i < incr_vec_len; i++)
>      {
> @@ -2963,8 +2949,7 @@ insert_initializers (slsr_cand_t c)
>
>        /* Create a new SSA name to hold the initializer's value.  */
>        stride_type = TREE_TYPE (c->stride);
> -      lazy_create_slsr_reg (&new_var, stride_type);
> -      new_name = make_ssa_name (new_var, NULL);
> +      new_name = make_temp_ssa_name (stride_type, NULL, "slsr");
>        incr_vec[i].initializer = new_name;
>
>        /* Create the initializer and insert it in the latest possible
> @@ -3062,15 +3047,13 @@ all_phi_incrs_profitable (slsr_cand_t c, gimple ph
>     the new SSA name.  */
>
>  static tree
> -introduce_cast_before_cand (slsr_cand_t c, tree to_type,
> -                           tree from_expr, tree *new_var)
> +introduce_cast_before_cand (slsr_cand_t c, tree to_type, tree from_expr)
>  {
>    tree cast_lhs;
>    gimple cast_stmt;
>    gimple_stmt_iterator gsi = gsi_for_stmt (c->cand_stmt);
>
> -  lazy_create_slsr_reg (new_var, to_type);
> -  cast_lhs = make_ssa_name (*new_var, NULL);
> +  cast_lhs = make_temp_ssa_name (to_type, NULL, "slsr");
>    cast_stmt = gimple_build_assign_with_ops (NOP_EXPR, cast_lhs,
>                                             from_expr, NULL_TREE);
>    gimple_set_location (cast_stmt, gimple_location (c->cand_stmt));
> @@ -3124,8 +3107,7 @@ replace_rhs_if_not_dup (enum tree_code new_code, t
>     is the rhs1 to use in creating the add/subtract.  */
>
>  static void
> -replace_one_candidate (slsr_cand_t c, unsigned i, tree *new_var,
> -                      tree basis_name)
> +replace_one_candidate (slsr_cand_t c, unsigned i, tree basis_name)
>  {
>    gimple stmt_to_print = NULL;
>    tree orig_rhs1, orig_rhs2;
> @@ -3161,8 +3143,7 @@ static void
>         rhs2 = incr_vec[i].initializer;
>        else
>         rhs2 = introduce_cast_before_cand (c, orig_type,
> -                                          incr_vec[i].initializer,
> -                                          new_var);
> +                                          incr_vec[i].initializer);
>
>        if (incr_vec[i].incr != cand_incr)
>         {
> @@ -3188,7 +3169,7 @@ static void
>        if (types_compatible_p (orig_type, stride_type))
>         rhs2 = c->stride;
>        else
> -       rhs2 = introduce_cast_before_cand (c, orig_type, c->stride, new_var);
> +       rhs2 = introduce_cast_before_cand (c, orig_type, c->stride);
>
>        stmt_to_print = replace_rhs_if_not_dup (repl_code, basis_name, rhs2,
>                                               orig_code, orig_rhs1, orig_rhs2,
> @@ -3204,7 +3185,7 @@ static void
>        if (types_compatible_p (orig_type, stride_type))
>         rhs2 = c->stride;
>        else
> -       rhs2 = introduce_cast_before_cand (c, orig_type, c->stride, new_var);
> +       rhs2 = introduce_cast_before_cand (c, orig_type, c->stride);
>
>        if (orig_code != MINUS_EXPR
>           || !operand_equal_p (basis_name, orig_rhs1, 0)
> @@ -3270,7 +3251,6 @@ replace_profitable_candidates (slsr_cand_t c)
>    if (!cand_already_replaced (c))
>      {
>        double_int increment = cand_abs_increment (c);
> -      tree new_var = NULL;
>        enum tree_code orig_code = gimple_assign_rhs_code (c->cand_stmt);
>        unsigned i;
>
> @@ -3302,14 +3282,14 @@ replace_profitable_candidates (slsr_cand_t c)
>
>                   /* Replace C with an add of the new basis phi and the
>                      increment.  */
> -                 replace_one_candidate (c, i, &new_var, name);
> +                 replace_one_candidate (c, i, name);
>                 }
>             }
>           else
>             {
>               slsr_cand_t basis = lookup_cand (c->basis);
>               tree basis_name = gimple_assign_lhs (basis->cand_stmt);
> -             replace_one_candidate (c, i, &new_var, basis_name);
> +             replace_one_candidate (c, i, basis_name);
>             }
>         }
>      }
>
>