[PATCH 2/9 v2] vect: Adjust vectorizable_load costing on VMAT_GATHER_SCATTER && gs_info.decl

["Kewen.Lin" <linkw@linux.ibm.com>]

Hi Richi,

on 2023/6/30 19:11, Richard Biener wrote:
> On Tue, Jun 13, 2023 at 4:03 AM Kewen Lin <linkw@linux.ibm.com> wrote:
>>
>> This patch adds one extra argument cost_vec to function
>> vect_build_gather_load_calls, so that we can do costing
>> next to the tranform in vect_build_gather_load_calls.
>> For now, the implementation just follows the handlings in
>> vect_model_load_cost, it isn't so good, so placing one
>> FIXME for any further improvement.  This patch should not
>> cause any functional changes.
>>
>> gcc/ChangeLog:
>>
>>         * tree-vect-stmts.cc (vect_build_gather_load_calls): Add the handlings
>>         on costing with one extra argument cost_vec.
>>         (vectorizable_load): Adjust the call to vect_build_gather_load_calls.
>>         (vect_model_load_cost): Assert it won't get VMAT_GATHER_SCATTER with
>>         gs_info.decl set any more.
>> ---
>>  gcc/tree-vect-stmts.cc | 31 +++++++++++++++++++++++--------
>>  1 file changed, 23 insertions(+), 8 deletions(-)
>>
>> diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
>> index 44514658be3..744cdf40e26 100644
>> --- a/gcc/tree-vect-stmts.cc
>> +++ b/gcc/tree-vect-stmts.cc
>> @@ -1135,6 +1135,8 @@ vect_model_load_cost (vec_info *vinfo,
>>                       slp_tree slp_node,
>>                       stmt_vector_for_cost *cost_vec)
>>  {
>> +  gcc_assert (memory_access_type != VMAT_GATHER_SCATTER || !gs_info->decl);
>> +
>>    unsigned int inside_cost = 0, prologue_cost = 0;
>>    bool grouped_access_p = STMT_VINFO_GROUPED_ACCESS (stmt_info);
>>
>> @@ -2819,7 +2821,8 @@ vect_build_gather_load_calls (vec_info *vinfo, stmt_vec_info stmt_info,
>>                               gimple_stmt_iterator *gsi,
>>                               gimple **vec_stmt,
>>                               gather_scatter_info *gs_info,
>> -                             tree mask)
>> +                             tree mask,
>> +                             stmt_vector_for_cost *cost_vec)
>>  {
>>    loop_vec_info loop_vinfo = dyn_cast <loop_vec_info> (vinfo);
>>    class loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
>> @@ -2831,6 +2834,23 @@ vect_build_gather_load_calls (vec_info *vinfo, stmt_vec_info stmt_info,
>>    poly_uint64 gather_off_nunits
>>      = TYPE_VECTOR_SUBPARTS (gs_info->offset_vectype);
>>
>> +  /* FIXME: Keep the previous costing way in vect_model_load_cost by costing
>> +     N scalar loads, but it should be tweaked to use target specific costs
>> +     on related gather load calls.  */
>> +  if (!vec_stmt)
> 
> going over the series now, I'm collecting comments but wanted to get
> this one out here:
> I'd rather see if (cost_vec) here, that 'vec_stmt' argument is quite
> legacy (I think it can
> be completely purged everywhere)
> 

OK, updated with the below new version v2.  I guessed you meant we would like to
use cost_vec for checking costing or not and use vec_stmts in stmt_info to store
the vectorized stmt. 

diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index ec177dcad82..dd8f5421d4e 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -1136,6 +1136,8 @@ vect_model_load_cost (vec_info *vinfo,
 		      slp_tree slp_node,
 		      stmt_vector_for_cost *cost_vec)
 {
+  gcc_assert (memory_access_type != VMAT_GATHER_SCATTER || !gs_info->decl);
+
   unsigned int inside_cost = 0, prologue_cost = 0;
   bool grouped_access_p = STMT_VINFO_GROUPED_ACCESS (stmt_info);

@@ -2846,7 +2848,8 @@ vect_build_gather_load_calls (vec_info *vinfo, stmt_vec_info stmt_info,
 			      gimple_stmt_iterator *gsi,
 			      gimple **vec_stmt,
 			      gather_scatter_info *gs_info,
-			      tree mask)
+			      tree mask,
+			      stmt_vector_for_cost *cost_vec)
 {
   loop_vec_info loop_vinfo = dyn_cast <loop_vec_info> (vinfo);
   class loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
@@ -2858,6 +2861,23 @@ vect_build_gather_load_calls (vec_info *vinfo, stmt_vec_info stmt_info,
   poly_uint64 gather_off_nunits
     = TYPE_VECTOR_SUBPARTS (gs_info->offset_vectype);

+  /* FIXME: Keep the previous costing way in vect_model_load_cost by costing
+     N scalar loads, but it should be tweaked to use target specific costs
+     on related gather load calls.  */
+  if (cost_vec)
+    {
+      unsigned int assumed_nunits = vect_nunits_for_cost (vectype);
+      unsigned int inside_cost;
+      inside_cost = record_stmt_cost (cost_vec, ncopies * assumed_nunits,
+				      scalar_load, stmt_info, 0, vect_body);
+      if (dump_enabled_p ())
+	dump_printf_loc (MSG_NOTE, vect_location,
+			 "vect_model_load_cost: inside_cost = %d, "
+			 "prologue_cost = 0 .\n",
+			 inside_cost);
+      return;
+    }
+
   tree arglist = TYPE_ARG_TYPES (TREE_TYPE (gs_info->decl));
   tree rettype = TREE_TYPE (TREE_TYPE (gs_info->decl));
   tree srctype = TREE_VALUE (arglist); arglist = TREE_CHAIN (arglist);
@@ -9631,13 +9651,8 @@ vectorizable_load (vec_info *vinfo,

   if (memory_access_type == VMAT_GATHER_SCATTER && gs_info.decl)
     {
-      if (costing_p)
-	vect_model_load_cost (vinfo, stmt_info, ncopies, vf, memory_access_type,
-			      alignment_support_scheme, misalignment, &gs_info,
-			      slp_node, cost_vec);
-      else
-	vect_build_gather_load_calls (vinfo, stmt_info, gsi, vec_stmt, &gs_info,
-				      mask);
+      vect_build_gather_load_calls (vinfo, stmt_info, gsi, vec_stmt, &gs_info,
+				    mask, cost_vec);
       return true;
     }

--
2.31.1