src/hotspot/share/gc/g1/c1/g1BarrierSetC1.hpp

/*
 * Copyright (c) 2018, 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
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#ifndef SHARE_GC_G1_C1_G1BARRIERSETC1_HPP
#define SHARE_GC_G1_C1_G1BARRIERSETC1_HPP

#include "c1/c1_CodeStubs.hpp"
#include "gc/shared/c1/modRefBarrierSetC1.hpp"

class G1PreBarrierStub: public CodeStub {
  friend class G1BarrierSetC1;
 private:
  bool _do_load;
  LIR_Opr _addr;
  LIR_Opr _pre_val;
  LIR_PatchCode _patch_code;
  CodeEmitInfo* _info;

 public:
  // Version that _does_ generate a load of the previous value from addr.
  // addr (the address of the field to be read) must be a LIR_Address
  // pre_val (a temporary register) must be a register;
  G1PreBarrierStub(LIR_Opr addr, LIR_Opr pre_val, LIR_PatchCode patch_code, CodeEmitInfo* info) :
    _addr(addr), _pre_val(pre_val), _do_load(true),
    _patch_code(patch_code), _info(info)
  {
    assert(_pre_val->is_register(), "should be temporary register");
    assert(_addr->is_address(), "should be the address of the field");
  }

  // Version that _does not_ generate load of the previous value; the
  // previous value is assumed to have already been loaded into pre_val.
  G1PreBarrierStub(LIR_Opr pre_val) :
    _addr(LIR_OprFact::illegalOpr), _pre_val(pre_val), _do_load(false),
    _patch_code(lir_patch_none), _info(NULL)
  {
    assert(_pre_val->is_register(), "should be a register");
  }

  LIR_Opr addr() const { return _addr; }
  LIR_Opr pre_val() const { return _pre_val; }
  LIR_PatchCode patch_code() const { return _patch_code; }
  CodeEmitInfo* info() const { return _info; }
  bool do_load() const { return _do_load; }

  virtual void emit_code(LIR_Assembler* e);
  virtual void visit(LIR_OpVisitState* visitor) {
    if (_do_load) {
      // don't pass in the code emit info since it's processed in the fast
      // path
      if (_info != NULL)
        visitor->do_slow_case(_info);
      else
        visitor->do_slow_case();

      visitor->do_input(_addr);
      visitor->do_temp(_pre_val);
    } else {
      visitor->do_slow_case();
      visitor->do_input(_pre_val);
    }
  }
#ifndef PRODUCT
  virtual void print_name(outputStream* out) const { out->print("G1PreBarrierStub"); }
#endif // PRODUCT
};

class G1PostBarrierStub: public CodeStub {
  friend class G1BarrierSetC1;
 private:
  LIR_Opr _addr;
  LIR_Opr _new_val;

 public:
  // addr (the address of the object head) and new_val must be registers.
  G1PostBarrierStub(LIR_Opr addr, LIR_Opr new_val): _addr(addr), _new_val(new_val) { }

  LIR_Opr addr() const { return _addr; }
  LIR_Opr new_val() const { return _new_val; }

  virtual void emit_code(LIR_Assembler* e);
  virtual void visit(LIR_OpVisitState* visitor) {
    // don't pass in the code emit info since it's processed in the fast path
    visitor->do_slow_case();
    visitor->do_input(_addr);
    visitor->do_input(_new_val);
  }
#ifndef PRODUCT
  virtual void print_name(outputStream* out) const { out->print("G1PostBarrierStub"); }
#endif // PRODUCT
};

class CodeBlob;

class G1BarrierSetC1 : public ModRefBarrierSetC1 {
 protected:
  CodeBlob* _pre_barrier_c1_runtime_code_blob;
  CodeBlob* _post_barrier_c1_runtime_code_blob;

  virtual void pre_barrier(LIRAccess& access, LIR_Opr addr_opr,
                           LIR_Opr pre_val, CodeEmitInfo* info);
  virtual void post_barrier(LIRAccess& access, LIR_OprDesc* addr, LIR_OprDesc* new_val);

  virtual void load_at_resolved(LIRAccess& access, LIR_Opr result);

 public:
  G1BarrierSetC1()
    : _pre_barrier_c1_runtime_code_blob(NULL),
      _post_barrier_c1_runtime_code_blob(NULL) {}

  CodeBlob* pre_barrier_c1_runtime_code_blob() { return _pre_barrier_c1_runtime_code_blob; }
  CodeBlob* post_barrier_c1_runtime_code_blob() { return _post_barrier_c1_runtime_code_blob; }

  virtual void generate_c1_runtime_stubs(BufferBlob* buffer_blob);
};

#endif // SHARE_GC_G1_C1_G1BARRIERSETC1_HPP