view src/share/vm/ci/ciMethodBlocks.hpp @ 20543:e7d0505c8a30

8059758: Footprint regressions with JDK-8038423 Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything. Reviewed-by: jwilhelm, brutisso
author tschatzl
date Fri, 10 Oct 2014 15:51:58 +0200
parents f95d63e2154a
children
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/*
 * Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#ifndef SHARE_VM_CI_CIMETHODBLOCKS_HPP
#define SHARE_VM_CI_CIMETHODBLOCKS_HPP

#include "ci/ciMethod.hpp"
#include "memory/resourceArea.hpp"
#include "utilities/growableArray.hpp"


class ciBlock;

typedef short ciBlockIndex;

class ciMethodBlocks : public ResourceObj {
private:
  ciMethod *_method;
  Arena *_arena;
  GrowableArray<ciBlock *>  *_blocks;
  ciBlock  **_bci_to_block;
  int _num_blocks;
  int _code_size;

  void do_analysis();
public:
  ciMethodBlocks(Arena *arena, ciMethod *meth);

  ciBlock *block_containing(int bci);
  ciBlock *block(int index)  { return _blocks->at(index); }
  ciBlock *make_block_at(int bci);
  ciBlock *split_block_at(int bci);
  bool is_block_start(int bci);
  int num_blocks()  { return _num_blocks;}
  void clear_processed();

  ciBlock *make_dummy_block(); // a block not associated with a bci

#ifndef PRODUCT
  void dump();
#endif
};

class ciBlock : public ResourceObj {
private:
  int _idx;
  int _start_bci;
  int _limit_bci;
  int _control_bci;
  uint _flags;
  int _ex_start_bci;
  int _ex_limit_bci;
#ifndef PRODUCT
  ciMethod *_method;
#endif
  enum {
    Processed   = (1 << 0),
    Handler     = (1 << 1),
    MayThrow    = (1 << 2),
    DoesJsr     = (1 << 3),
    DoesRet     = (1 << 4),
    RetTarget   = (1 << 5),
    HasHandler  = (1 << 6)
  };


public:
  enum {
    fall_through_bci = -1
  };

  ciBlock(ciMethod *method, int index, int start_bci);
  int start_bci() const         { return _start_bci; }
  int limit_bci() const         { return _limit_bci; }
  int control_bci() const       { return _control_bci; }
  int index() const             { return _idx; }
  void set_start_bci(int bci)   { _start_bci = bci; }
  void set_limit_bci(int bci)   { _limit_bci = bci; }
  void set_control_bci(int bci) { _control_bci = bci;}
  void set_exception_range(int start_bci, int limit_bci);
  int ex_start_bci() const      { return _ex_start_bci; }
  int ex_limit_bci() const      { return _ex_limit_bci; }
  bool contains(int bci) const { return start_bci() <= bci && bci < limit_bci(); }

  // flag handling
  bool  processed() const           { return (_flags & Processed) != 0; }
  bool  is_handler() const          { return (_flags & Handler) != 0; }
  bool  may_throw() const           { return (_flags & MayThrow) != 0; }
  bool  does_jsr() const            { return (_flags & DoesJsr) != 0; }
  bool  does_ret() const            { return (_flags & DoesRet) != 0; }
  bool  has_handler() const         { return (_flags & HasHandler) != 0; }
  bool  is_ret_target() const       { return (_flags & RetTarget) != 0; }
  void  set_processed()             { _flags |= Processed; }
  void  clear_processed()           { _flags &= ~Processed; }
  void  set_handler()               { _flags |= Handler; }
  void  set_may_throw()             { _flags |= MayThrow; }
  void  set_does_jsr()              { _flags |= DoesJsr; }
  void  clear_does_jsr()            { _flags &= ~DoesJsr; }
  void  set_does_ret()              { _flags |= DoesRet; }
  void  clear_does_ret()            { _flags &= ~DoesRet; }
  void  set_is_ret_target()         { _flags |= RetTarget; }
  void  set_has_handler()           { _flags |= HasHandler; }
  void  clear_exception_handler()   { _flags &= ~Handler; _ex_start_bci = -1; _ex_limit_bci = -1; }
#ifndef PRODUCT
  ciMethod *method() const          { return _method; }
  void dump();
  void print_on(outputStream* st) const  PRODUCT_RETURN;
#endif
};

#endif // SHARE_VM_CI_CIMETHODBLOCKS_HPP