Remove most of the epilogue vinfo fixup

The following removes the fixup we apply to pattern stmt operands
before code generating vector epilogues.  This isn't necessary anymore
since the SLP graph now exclusively records the data flow.  Similarly
fixing up of SSA references inside DR_REF of gather/scatter isn't
necessary since we now record the analysis result and avoid re-doing
it during transform.

What we still need to keep is the adjustment of the actual pointers
to gimple stmts from stmt_vec_info and the back-reference from the DRs.

	* tree-vect-loop.cc (update_epilogue_loop_vinfo): Remove
	fixing up pattern stmt operands and gather/scatter DR_REFs.
	(find_in_mapping): Remove.

1 files changed, 5 insertions, 89 deletions

diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 0df0d77..91c3237 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -10973,42 +10973,26 @@ scale_profile_for_vect_loop (class loop *loop, edge exit_e, unsigned vf, bool fl
 		      get_likely_max_loop_iterations_int (loop));
 }
 
-/* Helper function to pass to simplify_replace_tree to enable replacing tree's
-   in the hash_map with its corresponding values.  */
-
-static tree
-find_in_mapping (tree t, void *context)
-{
-  hash_map<tree,tree>* mapping = (hash_map<tree, tree>*) context;
-
-  tree *value = mapping->get (t);
-  return value ? *value : t;
-}
-
 /* Update EPILOGUE's loop_vec_info.  EPILOGUE was constructed as a copy of the
    original loop that has now been vectorized.
 
    The inits of the data_references need to be advanced with the number of
    iterations of the main loop.  This has been computed in vect_do_peeling and
-   is stored in parameter ADVANCE.  We first restore the data_references
-   initial offset with the values recored in ORIG_DRS_INIT.
+   is stored in parameter ADVANCE.
 
    Since the loop_vec_info of this EPILOGUE was constructed for the original
    loop, its stmt_vec_infos all point to the original statements.  These need
-   to be updated to point to their corresponding copies as well as the SSA_NAMES
-   in their PATTERN_DEF_SEQs and RELATED_STMTs.
+   to be updated to point to their corresponding copies.
 
    The data_reference's connections also need to be updated.  Their
    corresponding dr_vec_info need to be reconnected to the EPILOGUE's
-   stmt_vec_infos, their statements need to point to their corresponding copy,
-   if they are gather loads or scatter stores then their reference needs to be
-   updated to point to its corresponding copy.  */
+   stmt_vec_infos, their statements need to point to their corresponding
+   copy.  */
 
 static void
 update_epilogue_loop_vinfo (class loop *epilogue, tree advance)
 {
   loop_vec_info epilogue_vinfo = loop_vec_info_for_loop (epilogue);
-  auto_vec<gimple *> stmt_worklist;
   hash_map<tree,tree> mapping;
   gimple *orig_stmt, *new_stmt;
   gimple_stmt_iterator epilogue_gsi;
@@ -11023,9 +11007,7 @@ update_epilogue_loop_vinfo (class loop *epilogue, tree advance)
 
   /* The EPILOGUE loop is a copy of the original loop so they share the same
      gimple UIDs.  In this loop we update the loop_vec_info of the EPILOGUE to
-     point to the copied statements.  We also create a mapping of all LHS' in
-     the original loop and all the LHS' in the EPILOGUE and create worklists to
-     update teh STMT_VINFO_PATTERN_DEF_SEQs and STMT_VINFO_RELATED_STMTs.  */
+     point to the copied statements.  */
   for (unsigned i = 0; i < epilogue->num_nodes; ++i)
     {
       for (epilogue_phi_gsi = gsi_start_phis (epilogue_bbs[i]);
@@ -11037,14 +11019,7 @@ update_epilogue_loop_vinfo (class loop *epilogue, tree advance)
 	  stmt_vinfo
 	    = epilogue_vinfo->stmt_vec_infos[gimple_uid (new_stmt) - 1];
 
-	  orig_stmt = STMT_VINFO_STMT (stmt_vinfo);
 	  STMT_VINFO_STMT (stmt_vinfo) = new_stmt;
-
-	  mapping.put (gimple_phi_result (orig_stmt),
-		       gimple_phi_result (new_stmt));
-	  /* PHI nodes can not have patterns or related statements.  */
-	  gcc_assert (STMT_VINFO_PATTERN_DEF_SEQ (stmt_vinfo) == NULL
-		      && STMT_VINFO_RELATED_STMT (stmt_vinfo) == NULL);
 	}
 
       for (epilogue_gsi = gsi_start_bb (epilogue_bbs[i]);
@@ -11058,25 +11033,12 @@ update_epilogue_loop_vinfo (class loop *epilogue, tree advance)
 	  stmt_vinfo
 	    = epilogue_vinfo->stmt_vec_infos[gimple_uid (new_stmt) - 1];
 
-	  orig_stmt = STMT_VINFO_STMT (stmt_vinfo);
 	  STMT_VINFO_STMT (stmt_vinfo) = new_stmt;
 
-	  if (tree old_lhs = gimple_get_lhs (orig_stmt))
-	    mapping.put (old_lhs, gimple_get_lhs (new_stmt));
-
-	  if (STMT_VINFO_PATTERN_DEF_SEQ (stmt_vinfo))
-	    {
-	      gimple_seq seq = STMT_VINFO_PATTERN_DEF_SEQ (stmt_vinfo);
-	      for (gimple_stmt_iterator gsi = gsi_start (seq);
-		   !gsi_end_p (gsi); gsi_next (&gsi))
-		stmt_worklist.safe_push (gsi_stmt (gsi));
-	    }
-
 	  related_vinfo = STMT_VINFO_RELATED_STMT (stmt_vinfo);
 	  if (related_vinfo != NULL && related_vinfo != stmt_vinfo)
 	    {
 	      gimple *stmt = STMT_VINFO_STMT (related_vinfo);
-	      stmt_worklist.safe_push (stmt);
 	      /* Set BB such that the assert in
 		'get_initial_defs_for_reduction' is able to determine that
 		the BB of the related stmt is inside this loop.  */
@@ -11089,33 +11051,6 @@ update_epilogue_loop_vinfo (class loop *epilogue, tree advance)
 	}
     }
 
-  /* The PATTERN_DEF_SEQs and RELATED_STMTs in the epilogue were constructed
-     using the original main loop and thus need to be updated to refer to the
-     cloned variables used in the epilogue.  */
-  for (unsigned i = 0; i < stmt_worklist.length (); ++i)
-    {
-      gimple *stmt = stmt_worklist[i];
-      tree *new_op;
-
-      for (unsigned j = 1; j < gimple_num_ops (stmt); ++j)
-	{
-	  tree op = gimple_op (stmt, j);
-	  if ((new_op = mapping.get(op)))
-	    gimple_set_op (stmt, j, *new_op);
-	  else
-	    {
-	      /* PR92429: The last argument of simplify_replace_tree disables
-		 folding when replacing arguments.  This is required as
-		 otherwise you might end up with different statements than the
-		 ones analyzed in vect_loop_analyze, leading to different
-		 vectorization.  */
-	      op = simplify_replace_tree (op, NULL_TREE, NULL_TREE,
-					  &find_in_mapping, &mapping, false);
-	      gimple_set_op (stmt, j, op);
-	    }
-	}
-    }
-
   struct data_reference *dr;
   vec<data_reference_p> datarefs = LOOP_VINFO_DATAREFS (epilogue_vinfo);
   FOR_EACH_VEC_ELT (datarefs, i, dr)
@@ -11123,25 +11058,6 @@ update_epilogue_loop_vinfo (class loop *epilogue, tree advance)
       orig_stmt = DR_STMT (dr);
       gcc_assert (gimple_uid (orig_stmt) > 0);
       stmt_vinfo = epilogue_vinfo->stmt_vec_infos[gimple_uid (orig_stmt) - 1];
-      /* Data references for gather loads and scatter stores do not use the
-	 updated offset we set using ADVANCE.  Instead we have to make sure the
-	 reference in the data references point to the corresponding copy of
-	 the original in the epilogue.  Make sure to update both
-	 gather/scatters recognized by dataref analysis.  */
-      auto vstmt_vinfo = vect_stmt_to_vectorize (stmt_vinfo);
-      if (STMT_VINFO_STRIDED_P (vstmt_vinfo)
-	  || STMT_VINFO_GATHER_SCATTER_P (vstmt_vinfo))
-	{
-	  /* ???  As we copy epilogues from the main loop incremental
-	     replacement from an already replaced DR_REF from vectorizing
-	     the first epilogue will fail.  */
-	  DR_REF (dr)
-	    = simplify_replace_tree (DR_REF (dr), NULL_TREE, NULL_TREE,
-				     &find_in_mapping, &mapping);
-	  DR_BASE_ADDRESS (dr)
-	    = simplify_replace_tree (DR_BASE_ADDRESS (dr), NULL_TREE, NULL_TREE,
-				     &find_in_mapping, &mapping);
-	}
       DR_STMT (dr) = STMT_VINFO_STMT (stmt_vinfo);
     }