Re: [PATCH v3] Vect: Support truncate after .SAT_SUB pattern in zip

[Richard Biener <richard.guenther@gmail.com>]

On Thu, Jun 27, 2024 at 3:31 AM <pan2.li@intel.com> wrote:
>
> From: Pan Li <pan2.li@intel.com>

OK

> The zip benchmark of coremark-pro have one SAT_SUB like pattern but
> truncated as below:
>
> void test (uint16_t *x, unsigned b, unsigned n)
> {
>   unsigned a = 0;
>   register uint16_t *p = x;
>
>   do {
>     a = *--p;
>     *p = (uint16_t)(a >= b ? a - b : 0); // Truncate after .SAT_SUB
>   } while (--n);
> }
>
> It will have gimple before vect pass,  it cannot hit any pattern of
> SAT_SUB and then cannot vectorize to SAT_SUB.
>
> _2 = a_11 - b_12(D);
> iftmp.0_13 = (short unsigned int) _2;
> _18 = a_11 >= b_12(D);
> iftmp.0_5 = _18 ? iftmp.0_13 : 0;
>
> This patch would like to improve the pattern match to recog above
> as truncate after .SAT_SUB pattern.  Then we will have the pattern
> similar to below,  as well as eliminate the first 3 dead stmt.
>
> _2 = a_11 - b_12(D);
> iftmp.0_13 = (short unsigned int) _2;
> _18 = a_11 >= b_12(D);
> iftmp.0_5 = (short unsigned int).SAT_SUB (a_11, b_12(D));
>
> The below tests are passed for this patch.
> 1. The rv64gcv fully regression tests.
> 2. The rv64gcv build with glibc.
> 3. The x86 bootstrap tests.
> 4. The x86 fully regression tests.
>
> gcc/ChangeLog:
>
>         * match.pd: Add convert description for minus and capture.
>         * tree-vect-patterns.cc (vect_recog_build_binary_gimple_call): Add
>         new logic to handle in_type is incompatibile with out_type,  as
>         well as rename from.
>         (vect_recog_build_binary_gimple_stmt): Rename to.
>         (vect_recog_sat_add_pattern): Leverage above renamed func.
>         (vect_recog_sat_sub_pattern): Ditto.
>
> Signed-off-by: Pan Li <pan2.li@intel.com>
> ---
>  gcc/match.pd              |  4 +--
>  gcc/tree-vect-patterns.cc | 51 ++++++++++++++++++++++++---------------
>  2 files changed, 33 insertions(+), 22 deletions(-)
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index cf8a399a744..820591a36b3 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -3164,9 +3164,9 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>  /* Unsigned saturation sub, case 2 (branch with ge):
>     SAT_U_SUB = X >= Y ? X - Y : 0.  */
>  (match (unsigned_integer_sat_sub @0 @1)
> - (cond^ (ge @0 @1) (minus @0 @1) integer_zerop)
> + (cond^ (ge @0 @1) (convert? (minus (convert1? @0) (convert1? @1))) integer_zerop)
>   (if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
> -      && types_match (type, @0, @1))))
> +      && TYPE_UNSIGNED (TREE_TYPE (@0)) && types_match (@0, @1))))
>
>  /* Unsigned saturation sub, case 3 (branchless with gt):
>     SAT_U_SUB = (X - Y) * (X > Y).  */
> diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
> index cef901808eb..519d15f2a43 100644
> --- a/gcc/tree-vect-patterns.cc
> +++ b/gcc/tree-vect-patterns.cc
> @@ -4490,26 +4490,37 @@ vect_recog_mult_pattern (vec_info *vinfo,
>  extern bool gimple_unsigned_integer_sat_add (tree, tree*, tree (*)(tree));
>  extern bool gimple_unsigned_integer_sat_sub (tree, tree*, tree (*)(tree));
>
> -static gcall *
> -vect_recog_build_binary_gimple_call (vec_info *vinfo, gimple *stmt,
> +static gimple *
> +vect_recog_build_binary_gimple_stmt (vec_info *vinfo, stmt_vec_info stmt_info,
>                                      internal_fn fn, tree *type_out,
> -                                    tree op_0, tree op_1)
> +                                    tree lhs, tree op_0, tree op_1)
>  {
>    tree itype = TREE_TYPE (op_0);
> -  tree vtype = get_vectype_for_scalar_type (vinfo, itype);
> +  tree otype = TREE_TYPE (lhs);
> +  tree v_itype = get_vectype_for_scalar_type (vinfo, itype);
> +  tree v_otype = get_vectype_for_scalar_type (vinfo, otype);
>
> -  if (vtype != NULL_TREE
> -    && direct_internal_fn_supported_p (fn, vtype, OPTIMIZE_FOR_BOTH))
> +  if (v_itype != NULL_TREE && v_otype != NULL_TREE
> +    && direct_internal_fn_supported_p (fn, v_itype, OPTIMIZE_FOR_BOTH))
>      {
>        gcall *call = gimple_build_call_internal (fn, 2, op_0, op_1);
> +      tree in_ssa = vect_recog_temp_ssa_var (itype, NULL);
>
> -      gimple_call_set_lhs (call, vect_recog_temp_ssa_var (itype, NULL));
> +      gimple_call_set_lhs (call, in_ssa);
>        gimple_call_set_nothrow (call, /* nothrow_p */ false);
> -      gimple_set_location (call, gimple_location (stmt));
> +      gimple_set_location (call, gimple_location (STMT_VINFO_STMT (stmt_info)));
> +
> +      *type_out = v_otype;
>
> -      *type_out = vtype;
> +      if (types_compatible_p (itype, otype))
> +       return call;
> +      else
> +       {
> +         append_pattern_def_seq (vinfo, stmt_info, call, v_itype);
> +         tree out_ssa = vect_recog_temp_ssa_var (otype, NULL);
>
> -      return call;
> +         return gimple_build_assign (out_ssa, NOP_EXPR, in_ssa);
> +       }
>      }
>
>    return NULL;
> @@ -4541,13 +4552,13 @@ vect_recog_sat_add_pattern (vec_info *vinfo, stmt_vec_info stmt_vinfo,
>
>    if (gimple_unsigned_integer_sat_add (lhs, ops, NULL))
>      {
> -      gcall *call = vect_recog_build_binary_gimple_call (vinfo, last_stmt,
> -                                                        IFN_SAT_ADD, type_out,
> -                                                        ops[0], ops[1]);
> -      if (call)
> +      gimple *stmt = vect_recog_build_binary_gimple_stmt (vinfo, stmt_vinfo,
> +                                                         IFN_SAT_ADD, type_out,
> +                                                         lhs, ops[0], ops[1]);
> +      if (stmt)
>         {
>           vect_pattern_detected ("vect_recog_sat_add_pattern", last_stmt);
> -         return call;
> +         return stmt;
>         }
>      }
>
> @@ -4579,13 +4590,13 @@ vect_recog_sat_sub_pattern (vec_info *vinfo, stmt_vec_info stmt_vinfo,
>
>    if (gimple_unsigned_integer_sat_sub (lhs, ops, NULL))
>      {
> -      gcall *call = vect_recog_build_binary_gimple_call (vinfo, last_stmt,
> -                                                        IFN_SAT_SUB, type_out,
> -                                                        ops[0], ops[1]);
> -      if (call)
> +      gimple *stmt = vect_recog_build_binary_gimple_stmt (vinfo, stmt_vinfo,
> +                                                         IFN_SAT_SUB, type_out,
> +                                                         lhs, ops[0], ops[1]);
> +      if (stmt)
>         {
>           vect_pattern_detected ("vect_recog_sat_sub_pattern", last_stmt);
> -         return call;
> +         return stmt;
>         }
>      }
>
> --
> 2.34.1
>