Remove reduction chain detection from parloops

Historically SLP reduction chains were the only multi-stmt reductions
supported.  But since we have check_reduction_path more complicated
cases are handled.  As parloops doesn't do any specific chain
processing it can solely rely on that functionality instead.

	* tree-parloops.cc (parloops_is_slp_reduction): Remove.
	(parloops_is_simple_reduction): Do not call it.

1 files changed, 0 insertions, 177 deletions

diff --git a/gcc/tree-parloops.cc b/gcc/tree-parloops.cc
index 6e2f7df..388f903 100644
--- a/gcc/tree-parloops.cc
+++ b/gcc/tree-parloops.cc
@@ -205,170 +205,6 @@ parloops_valid_reduction_input_p (stmt_vec_info def_stmt_info)
 	      && !is_loop_header_bb_p (gimple_bb (def_stmt_info->stmt))));
 }
 
-/* Detect SLP reduction of the form:
-
-   #a1 = phi <a5, a0>
-   a2 = operation (a1)
-   a3 = operation (a2)
-   a4 = operation (a3)
-   a5 = operation (a4)
-
-   #a = phi <a5>
-
-   PHI is the reduction phi node (#a1 = phi <a5, a0> above)
-   FIRST_STMT is the first reduction stmt in the chain
-   (a2 = operation (a1)).
-
-   Return TRUE if a reduction chain was detected.  */
-
-static bool
-parloops_is_slp_reduction (loop_vec_info loop_info, gimple *phi,
-			   gimple *first_stmt)
-{
-  class loop *loop = (gimple_bb (phi))->loop_father;
-  class loop *vect_loop = LOOP_VINFO_LOOP (loop_info);
-  enum tree_code code;
-  gimple *loop_use_stmt = NULL;
-  stmt_vec_info use_stmt_info;
-  tree lhs;
-  imm_use_iterator imm_iter;
-  use_operand_p use_p;
-  int nloop_uses, size = 0, n_out_of_loop_uses;
-  bool found = false;
-
-  if (loop != vect_loop)
-    return false;
-
-  auto_vec<stmt_vec_info, 8> reduc_chain;
-  lhs = PHI_RESULT (phi);
-  code = gimple_assign_rhs_code (first_stmt);
-  while (1)
-    {
-      nloop_uses = 0;
-      n_out_of_loop_uses = 0;
-      FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs)
-        {
-	  gimple *use_stmt = USE_STMT (use_p);
-	  if (is_gimple_debug (use_stmt))
-	    continue;
-
-          /* Check if we got back to the reduction phi.  */
-	  if (use_stmt == phi)
-            {
-	      loop_use_stmt = use_stmt;
-              found = true;
-              break;
-            }
-
-          if (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt)))
-            {
-	      loop_use_stmt = use_stmt;
-	      nloop_uses++;
-            }
-           else
-             n_out_of_loop_uses++;
-
-           /* There are can be either a single use in the loop or two uses in
-              phi nodes.  */
-           if (nloop_uses > 1 || (n_out_of_loop_uses && nloop_uses))
-             return false;
-        }
-
-      if (found)
-        break;
-
-      /* We reached a statement with no loop uses.  */
-      if (nloop_uses == 0)
-	return false;
-
-      /* This is a loop exit phi, and we haven't reached the reduction phi.  */
-      if (gimple_code (loop_use_stmt) == GIMPLE_PHI)
-        return false;
-
-      if (!is_gimple_assign (loop_use_stmt)
-	  || code != gimple_assign_rhs_code (loop_use_stmt)
-	  || !flow_bb_inside_loop_p (loop, gimple_bb (loop_use_stmt)))
-        return false;
-
-      /* Insert USE_STMT into reduction chain.  */
-      use_stmt_info = loop_info->lookup_stmt (loop_use_stmt);
-      reduc_chain.safe_push (use_stmt_info);
-
-      lhs = gimple_assign_lhs (loop_use_stmt);
-      size++;
-   }
-
-  if (!found || loop_use_stmt != phi || size < 2)
-    return false;
-
-  /* Swap the operands, if needed, to make the reduction operand be the second
-     operand.  */
-  lhs = PHI_RESULT (phi);
-  for (unsigned i = 0; i < reduc_chain.length (); ++i)
-    {
-      gassign *next_stmt = as_a <gassign *> (reduc_chain[i]->stmt);
-      if (gimple_assign_rhs2 (next_stmt) == lhs)
-	{
-	  tree op = gimple_assign_rhs1 (next_stmt);
-	  stmt_vec_info def_stmt_info = loop_info->lookup_def (op);
-
-	  /* Check that the other def is either defined in the loop
-	     ("vect_internal_def"), or it's an induction (defined by a
-	     loop-header phi-node).  */
-	  if (def_stmt_info
-	      && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt_info->stmt))
-	      && parloops_valid_reduction_input_p (def_stmt_info))
-	    {
-	      lhs = gimple_assign_lhs (next_stmt);
-	      continue;
-	    }
-
-	  return false;
-	}
-      else
-	{
-          tree op = gimple_assign_rhs2 (next_stmt);
-	  stmt_vec_info def_stmt_info = loop_info->lookup_def (op);
-
-          /* Check that the other def is either defined in the loop
-            ("vect_internal_def"), or it's an induction (defined by a
-            loop-header phi-node).  */
-	  if (def_stmt_info
-	      && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt_info->stmt))
-	      && parloops_valid_reduction_input_p (def_stmt_info))
-	    {
-	      if (dump_enabled_p ())
-		dump_printf_loc (MSG_NOTE, vect_location,
-				 "swapping oprnds: %G", (gimple *) next_stmt);
-
-	      swap_ssa_operands (next_stmt,
-				 gimple_assign_rhs1_ptr (next_stmt),
-                                 gimple_assign_rhs2_ptr (next_stmt));
-	      update_stmt (next_stmt);
-	    }
-	  else
-	    return false;
-        }
-
-      lhs = gimple_assign_lhs (next_stmt);
-    }
-
-  /* Build up the actual chain.  */
-  for (unsigned i = 0; i < reduc_chain.length () - 1; ++i)
-    {
-      REDUC_GROUP_FIRST_ELEMENT (reduc_chain[i]) = reduc_chain[0];
-      REDUC_GROUP_NEXT_ELEMENT (reduc_chain[i]) = reduc_chain[i+1];
-    }
-  REDUC_GROUP_FIRST_ELEMENT (reduc_chain.last ()) = reduc_chain[0];
-  REDUC_GROUP_NEXT_ELEMENT (reduc_chain.last ()) = NULL;
-
-  /* Save the chain for further analysis in SLP detection.  */
-  LOOP_VINFO_REDUCTION_CHAINS (loop_info).safe_push (reduc_chain[0]);
-  REDUC_GROUP_SIZE (reduc_chain[0]) = size;
-
-  return true;
-}
-
 /* Return true if we need an in-order reduction for operation CODE
    on type TYPE.  NEED_WRAPPING_INTEGRAL_OVERFLOW is true if integer
    overflow must wrap.  */
@@ -836,19 +672,6 @@ parloops_is_simple_reduction (loop_vec_info loop_info, stmt_vec_info phi_info,
       return def_stmt_info;
     }
 
-  /* Try to find SLP reduction chain.  */
-  if (! nested_in_vect_loop
-      && code != COND_EXPR
-      && orig_code != MINUS_EXPR
-      && parloops_is_slp_reduction (loop_info, phi, def_stmt))
-    {
-      if (dump_enabled_p ())
-        report_ploop_op (MSG_NOTE, def_stmt,
-			 "reduction: detected reduction chain: ");
-
-      return def_stmt_info;
-    }
-
   /* Look for the expression computing loop_arg from loop PHI result.  */
   if (check_reduction_path (vect_location, loop, phi, loop_arg, code))
     return def_stmt_info;