1 files changed, 74 insertions, 46 deletions

diff --git a/gcc/tree-switch-conversion.c b/gcc/tree-switch-conversion.c
index dba0c6f..eade177 100644
--- a/gcc/tree-switch-conversion.c
+++ b/gcc/tree-switch-conversion.c
@@ -453,12 +453,35 @@ build_constructors (gimple swtch)
 	      elt->value = val;
 
 	      pos = int_const_binop (PLUS_EXPR, pos, integer_one_node, 0);
-	    } while (!tree_int_cst_lt (high, pos) && tree_int_cst_lt (low, pos));
+	    } while (!tree_int_cst_lt (high, pos)
+		     && tree_int_cst_lt (low, pos));
 	  j++;
 	}
     }
 }
 
+/* If all values in the constructor vector are the same, return the value.
+   Otherwise return NULL_TREE.  Not supposed to be called for empty
+   vectors.  */
+
+static tree
+constructor_contains_same_values_p (VEC (constructor_elt, gc) *vec)
+{
+  int i, len = VEC_length (constructor_elt, vec);
+  tree prev = NULL_TREE;
+
+  for (i = 0; i < len; i++)
+    {
+      constructor_elt *elt = VEC_index (constructor_elt, vec, i);
+      
+      if (!prev)
+	prev = elt->value;
+      else if (!operand_equal_p (elt->value, prev, OEP_ONLY_CONST))
+	return NULL_TREE;
+    }
+  return prev;
+}
+
 /* Create an appropriate array type and declaration and assemble a static array
    variable.  Also create a load statement that initializes the variable in
    question with a value from the static array.  SWTCH is the switch statement
@@ -466,47 +489,53 @@ build_constructors (gimple swtch)
    and target SSA names for this particular array.  ARR_INDEX_TYPE is the type
    of the index of the new array, PHI is the phi node of the final BB that
    corresponds to the value that will be loaded from the created array.  TIDX
-   is a temporary variable holding the index for loads from the new array.  */
+   is an ssa name of a temporary variable holding the index for loads from the
+   new array.  */
 
 static void
 build_one_array (gimple swtch, int num, tree arr_index_type, gimple phi,
 		 tree tidx)
 {
-  tree array_type, ctor, decl, value_type, name, fetch;
+  tree name, cst;
   gimple load;
-  gimple_stmt_iterator gsi;
+  gimple_stmt_iterator gsi = gsi_for_stmt (swtch);
 
   gcc_assert (info.default_values[num]);
-  value_type = TREE_TYPE (info.default_values[num]);
-  array_type = build_array_type (value_type, arr_index_type);
-
-  ctor = build_constructor (array_type, info.constructors[num]);
-  TREE_CONSTANT (ctor) = true;
-
-  decl = build_decl (VAR_DECL, NULL_TREE, array_type);
-  TREE_STATIC (decl) = 1;
-  DECL_INITIAL (decl) = ctor;
-
-  DECL_NAME (decl) = create_tmp_var_name ("CSWTCH");
-  DECL_ARTIFICIAL (decl) = 1;
-  TREE_CONSTANT (decl) = 1;
-  add_referenced_var (decl);
-  varpool_mark_needed_node (varpool_node (decl));
-  varpool_finalize_decl (decl);
-  mark_sym_for_renaming (decl);
 
   name = make_ssa_name (SSA_NAME_VAR (PHI_RESULT (phi)), NULL);
   info.target_inbound_names[num] = name;
 
-  fetch = build4 (ARRAY_REF, value_type, decl, tidx, NULL_TREE,
-		  NULL_TREE);
-  load = gimple_build_assign (name, fetch);
-  SSA_NAME_DEF_STMT (name) = load;
+  cst = constructor_contains_same_values_p (info.constructors[num]);
+  if (cst)
+    load = gimple_build_assign (name, cst);
+  else
+    {
+      tree array_type, ctor, decl, value_type, fetch;
+
+      value_type = TREE_TYPE (info.default_values[num]);
+      array_type = build_array_type (value_type, arr_index_type);
+      ctor = build_constructor (array_type, info.constructors[num]);
+      TREE_CONSTANT (ctor) = true;
+
+      decl = build_decl (VAR_DECL, NULL_TREE, array_type);
+      TREE_STATIC (decl) = 1;
+      DECL_INITIAL (decl) = ctor;
+
+      DECL_NAME (decl) = create_tmp_var_name ("CSWTCH");
+      DECL_ARTIFICIAL (decl) = 1;
+      TREE_CONSTANT (decl) = 1;
+      add_referenced_var (decl);
+      varpool_mark_needed_node (varpool_node (decl));
+      varpool_finalize_decl (decl);
+
+      fetch = build4 (ARRAY_REF, value_type, decl, tidx, NULL_TREE,
+		      NULL_TREE);
+      load = gimple_build_assign (name, fetch);
+    }
 
-  gsi = gsi_for_stmt (swtch);
+  SSA_NAME_DEF_STMT (name) = load;
   gsi_insert_before (&gsi, load, GSI_SAME_STMT);
-  mark_symbols_for_renaming (load);
-
+  update_stmt (load);
   info.arr_ref_last = load;
 }
 
@@ -526,16 +555,17 @@ build_arrays (gimple swtch)
   gsi = gsi_for_stmt (swtch);
 
   arr_index_type = build_index_type (info.range_size);
-  tidx = make_rename_temp (arr_index_type, "csti");
+  tidx = make_ssa_name (create_tmp_var (arr_index_type, "csti"), NULL);
   sub = fold_build2 (MINUS_EXPR, TREE_TYPE (info.index_expr), info.index_expr,
 		     fold_convert (TREE_TYPE (info.index_expr),
 				   info.range_min));
   sub = force_gimple_operand_gsi (&gsi, fold_convert (arr_index_type, sub),
 				  false, NULL, true, GSI_SAME_STMT);
   stmt = gimple_build_assign (tidx, sub);
+  SSA_NAME_DEF_STMT (tidx) = stmt;
 
   gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
-  mark_symbols_for_renaming (stmt);
+  update_stmt (stmt);
   info.arr_ref_first = stmt;
 
   for (gsi = gsi_start_phis (info.final_bb), i = 0;
@@ -561,8 +591,7 @@ gen_def_assigns (gimple_stmt_iterator *gsi)
       assign = gimple_build_assign (name, info.default_values[i]);
       SSA_NAME_DEF_STMT (name) = assign;
       gsi_insert_before (gsi, assign, GSI_SAME_STMT);
-      find_new_referenced_vars (assign);
-      mark_symbols_for_renaming (assign);
+      update_stmt (assign);
     }
   return assign;
 }
@@ -640,7 +669,7 @@ gen_inbound_check (gimple swtch)
   gimple label1, label2, label3;
 
   tree utype;
-  tree tmp_u;
+  tree tmp_u_1, tmp_u_2, tmp_u_var;
   tree cast;
   gimple cast_assign, minus_assign;
   tree ulb, minus;
@@ -664,30 +693,29 @@ gen_inbound_check (gimple swtch)
 
   /* (end of) block 0 */
   gsi = gsi_for_stmt (info.arr_ref_first);
-  tmp_u = make_rename_temp (utype, "csui");
+  tmp_u_var = create_tmp_var (utype, "csui");
+  tmp_u_1 = make_ssa_name (tmp_u_var, NULL);
 
   cast = fold_convert (utype, info.index_expr);
-  cast_assign = gimple_build_assign (tmp_u, cast);
-  find_new_referenced_vars (cast_assign);
+  cast_assign = gimple_build_assign (tmp_u_1, cast);
+  SSA_NAME_DEF_STMT (tmp_u_1) = cast_assign;
   gsi_insert_before (&gsi, cast_assign, GSI_SAME_STMT);
-  mark_symbols_for_renaming (cast_assign);
+  update_stmt (cast_assign);
 
   ulb = fold_convert (utype, info.range_min);
-  minus = fold_build2 (MINUS_EXPR, utype, tmp_u, ulb);
+  minus = fold_build2 (MINUS_EXPR, utype, tmp_u_1, ulb);
   minus = force_gimple_operand_gsi (&gsi, minus, false, NULL, true,
 				    GSI_SAME_STMT);
-  minus_assign = gimple_build_assign (tmp_u, minus);
-  find_new_referenced_vars (minus_assign);
+  tmp_u_2 = make_ssa_name (tmp_u_var, NULL);
+  minus_assign = gimple_build_assign (tmp_u_2, minus);
+  SSA_NAME_DEF_STMT (tmp_u_2) = minus_assign;
   gsi_insert_before (&gsi, minus_assign, GSI_SAME_STMT);
-  mark_symbols_for_renaming (minus_assign);
+  update_stmt (minus_assign);
 
   bound = fold_convert (utype, info.range_size);
-
-  cond_stmt = gimple_build_cond (LE_EXPR, tmp_u, bound, NULL_TREE, NULL_TREE);
-
-  find_new_referenced_vars (cond_stmt);
+  cond_stmt = gimple_build_cond (LE_EXPR, tmp_u_2, bound, NULL_TREE, NULL_TREE);
   gsi_insert_before (&gsi, cond_stmt, GSI_SAME_STMT);
-  mark_symbols_for_renaming (cond_stmt);
+  update_stmt (cond_stmt);
 
   /* block 2 */
   gsi = gsi_for_stmt (info.arr_ref_first);