1 /*

     2  * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 class StringConcat;

    26 

    27 class PhaseStringOpts : public Phase {

    28   friend class StringConcat;

    29 

    30  private:

    31   PhaseGVN* _gvn;

    32 

    33   // List of dead nodes to clean up aggressively at the end

    34   Unique_Node_List dead_worklist;

    35 

    36   // Memory slices needed for code gen

    37   int char_adr_idx;

    38   int value_field_idx;

    39   int count_field_idx;

    40   int offset_field_idx;

    41 

    42   // Integer.sizeTable - used for int to String conversion

    43   ciField* size_table_field;

    44 

    45   // A set for use by various stages

    46   VectorSet _visited;

    47 

    48   // Collect a list of all SB.toString calls

    49   Node_List collect_toString_calls();

    50 

    51   // Examine the use of the SB alloc to see if it can be replace with

    52   // a single string construction.

    53   StringConcat* build_candidate(CallStaticJavaNode* call);

    54 

    55   // Replace all the SB calls in concat with an optimization String allocation

    56   void replace_string_concat(StringConcat* concat);

    57 

    58   // Load the value of a static field, performing any constant folding.

    59   Node* fetch_static_field(GraphKit& kit, ciField* field);

    60 

    61   // Compute the number of characters required to represent the int value

    62   Node* int_stringSize(GraphKit& kit, Node* value);

    63 

    64   // Copy the characters representing value into char_array starting at start

    65   void int_getChars(GraphKit& kit, Node* value, Node* char_array, Node* start, Node* end);

    66 

    67   // Copy of the contents of the String str into char_array starting at index start.

    68   Node* copy_string(GraphKit& kit, Node* str, Node* char_array, Node* start);

    69 

    70   // Clean up any leftover nodes

    71   void record_dead_node(Node* node);

    72   void remove_dead_nodes();

    73 

    74   PhaseGVN* gvn() { return _gvn; }

    75 

    76   enum {

    77     // max length of constant string copy unrolling in copy_string

    78     unroll_string_copy_length = 6

    79   };

    80 

    81  public:

    82   PhaseStringOpts(PhaseGVN* gvn, Unique_Node_List* worklist);

    83 };