Move reduction chain code fully to vect_analyze_slp_reduc_chain

The following moves the initial discovery of a reduction chain
to vect_analyze_slp_reduc_chain, this makes it easier to follow.

	* tree-vect-slp.cc (vect_analyze_slp_reduction): Move
	reduction chain discovery ...
	(vect_analyze_slp_reduc_chain): ... here.

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index fe3bcff94a7e8158e219b86740bb556e4f6923a7..c5a2fe823943df17557e6d3193f8de72e5e1b3ef 100644 (file)
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -4189,14 +4189,50 @@ vect_build_slp_instance (vec_info *vinfo,
 static bool
 vect_analyze_slp_reduc_chain (loop_vec_info vinfo,
                              scalar_stmts_to_slp_tree_map_t *bst_map,
-                             vec<stmt_vec_info> &scalar_stmts,
-                             stmt_vec_info reduc_phi_info,
+                             stmt_vec_info scalar_stmt,
                              unsigned max_tree_size, unsigned *limit)
 {
-  /* If there's no budget left bail out early.  */
-  if (*limit == 0)
+  vec<stmt_vec_info> scalar_stmts = vNULL;
+
+  bool fail = false;
+  /* ???  We could leave operation code checking to SLP discovery.  */
+  code_helper code = STMT_VINFO_REDUC_CODE (STMT_VINFO_REDUC_DEF
+                                             (vect_orig_stmt (scalar_stmt)));
+  bool first = true;
+  stmt_vec_info next_stmt = scalar_stmt;
+  do
+    {
+      stmt_vec_info stmt = next_stmt;
+      gimple_match_op op;
+      if (!gimple_extract_op (STMT_VINFO_STMT (stmt), &op))
+       gcc_unreachable ();
+      tree reduc_def = gimple_arg (STMT_VINFO_STMT (stmt),
+                                  STMT_VINFO_REDUC_IDX (stmt));
+      next_stmt = vect_stmt_to_vectorize (vinfo->lookup_def (reduc_def));
+      gcc_assert (is_a <gphi *> (STMT_VINFO_STMT (next_stmt))
+                 || STMT_VINFO_REDUC_IDX (next_stmt) != -1);
+      if (!gimple_extract_op (STMT_VINFO_STMT (vect_orig_stmt (stmt)), &op))
+       gcc_unreachable ();
+      if (CONVERT_EXPR_CODE_P (op.code)
+         && (first
+             || is_a <gphi *> (STMT_VINFO_STMT (next_stmt))))
+       ;
+      else if (code != op.code)
+       {
+         fail = true;
+         break;
+       }
+      else
+       scalar_stmts.safe_push (stmt);
+      first = false;
+    }
+  while (!is_a <gphi *> (STMT_VINFO_STMT (next_stmt)));
+  if (fail || scalar_stmts.length () <= 1)
     return false;
 
+  scalar_stmts.reverse ();
+  stmt_vec_info reduc_phi_info = next_stmt;
+
   /* Build the tree for the SLP instance.  */
   vec<stmt_vec_info> root_stmt_infos = vNULL;
   vec<tree> remain = vNULL;
@@ -4315,7 +4351,9 @@ vect_analyze_slp_reduc_chain (loop_vec_info vinfo,
 
       return true;
     }
+
   /* Failed to SLP.  */
+  scalar_stmts.release ();
   if (dump_enabled_p ())
     dump_printf_loc (MSG_NOTE, vect_location,
                     "SLP discovery of reduction chain failed\n");
@@ -4338,55 +4376,14 @@ vect_analyze_slp_reduction (loop_vec_info vinfo,
   if (*limit == 0)
     return false;
 
-  vec<stmt_vec_info> scalar_stmts = vNULL;
   /* Try to gather a reduction chain.  */
   if (! force_single_lane
-      && STMT_VINFO_DEF_TYPE (scalar_stmt) == vect_reduction_def)
-    {
-      bool fail = false;
-      /* ???  We could leave operation code checking to SLP discovery.  */
-      code_helper code
-       = STMT_VINFO_REDUC_CODE (STMT_VINFO_REDUC_DEF
-                                  (vect_orig_stmt (scalar_stmt)));
-      bool first = true;
-      stmt_vec_info next_stmt = scalar_stmt;
-      do
-       {
-         stmt_vec_info stmt = next_stmt;
-         gimple_match_op op;
-         if (!gimple_extract_op (STMT_VINFO_STMT (stmt), &op))
-           gcc_unreachable ();
-         tree reduc_def = gimple_arg (STMT_VINFO_STMT (stmt),
-                                      STMT_VINFO_REDUC_IDX (stmt));
-         next_stmt = vect_stmt_to_vectorize (vinfo->lookup_def (reduc_def));
-         gcc_assert (is_a <gphi *> (STMT_VINFO_STMT (next_stmt))
-                     || STMT_VINFO_REDUC_IDX (next_stmt) != -1);
-         if (!gimple_extract_op (STMT_VINFO_STMT (vect_orig_stmt (stmt)), &op))
-           gcc_unreachable ();
-         if (CONVERT_EXPR_CODE_P (op.code)
-             && (first
-                 || is_a <gphi *> (STMT_VINFO_STMT (next_stmt))))
-           ;
-         else if (code != op.code)
-           {
-             fail = true;
-             break;
-           }
-         else
-           scalar_stmts.safe_push (stmt);
-         first = false;
-       }
-      while (!is_a <gphi *> (STMT_VINFO_STMT (next_stmt)));
-      if (!fail && scalar_stmts.length () > 1)
-       {
-         scalar_stmts.reverse ();
-         if (vect_analyze_slp_reduc_chain (vinfo, bst_map, scalar_stmts,
-                                           next_stmt, max_tree_size, limit))
-           return true;
-         scalar_stmts.release ();
-       }
-    }
+      && STMT_VINFO_DEF_TYPE (scalar_stmt) == vect_reduction_def
+      && vect_analyze_slp_reduc_chain (vinfo, bst_map, scalar_stmt,
+                                      max_tree_size, limit))
+    return true;
 
+  vec<stmt_vec_info> scalar_stmts;
   scalar_stmts.create (1);
   scalar_stmts.quick_push (scalar_stmt);