view src/share/vm/opto/divnode.hpp @ 1716:be3f9c242c9d

6948538: CMS: BOT walkers can fall into object allocation and initialization cracks Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode. Reviewed-by: chrisphi, johnc, poonam
author ysr
date Mon, 16 Aug 2010 15:58:42 -0700
parents c18cbe5936b8
children f95d63e2154a
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/*
 * Copyright (c) 1997, 2005, 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.
 *
 */

// Portions of code courtesy of Clifford Click

// Optimization - Graph Style


//------------------------------DivINode---------------------------------------
// Integer division
// Note: this is division as defined by JVMS, i.e., MinInt/-1 == MinInt.
// On processors which don't naturally support this special case (e.g., x86),
// the matcher or runtime system must take care of this.
class DivINode : public Node {
public:
  DivINode( Node *c, Node *dividend, Node *divisor ) : Node(c, dividend, divisor ) {}
  virtual int Opcode() const;
  virtual Node *Identity( PhaseTransform *phase );
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *Value( PhaseTransform *phase ) const;
  virtual const Type *bottom_type() const { return TypeInt::INT; }
  virtual uint ideal_reg() const { return Op_RegI; }
};

//------------------------------DivLNode---------------------------------------
// Long division
class DivLNode : public Node {
public:
  DivLNode( Node *c, Node *dividend, Node *divisor ) : Node(c, dividend, divisor ) {}
  virtual int Opcode() const;
  virtual Node *Identity( PhaseTransform *phase );
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *Value( PhaseTransform *phase ) const;
  virtual const Type *bottom_type() const { return TypeLong::LONG; }
  virtual uint ideal_reg() const { return Op_RegL; }
};

//------------------------------DivFNode---------------------------------------
// Float division
class DivFNode : public Node {
public:
  DivFNode( Node *c, Node *dividend, Node *divisor ) : Node(c, dividend, divisor) {}
  virtual int Opcode() const;
  virtual Node *Identity( PhaseTransform *phase );
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *Value( PhaseTransform *phase ) const;
  virtual const Type *bottom_type() const { return Type::FLOAT; }
  virtual uint ideal_reg() const { return Op_RegF; }
};

//------------------------------DivDNode---------------------------------------
// Double division
class DivDNode : public Node {
public:
  DivDNode( Node *c, Node *dividend, Node *divisor ) : Node(c,dividend, divisor) {}
  virtual int Opcode() const;
  virtual Node *Identity( PhaseTransform *phase );
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *Value( PhaseTransform *phase ) const;
  virtual const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
};

//------------------------------ModINode---------------------------------------
// Integer modulus
class ModINode : public Node {
public:
  ModINode( Node *c, Node *in1, Node *in2 ) : Node(c,in1, in2) {}
  virtual int Opcode() const;
  virtual const Type *Value( PhaseTransform *phase ) const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *bottom_type() const { return TypeInt::INT; }
  virtual uint ideal_reg() const { return Op_RegI; }
};

//------------------------------ModLNode---------------------------------------
// Long modulus
class ModLNode : public Node {
public:
  ModLNode( Node *c, Node *in1, Node *in2 ) : Node(c,in1, in2) {}
  virtual int Opcode() const;
  virtual const Type *Value( PhaseTransform *phase ) const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *bottom_type() const { return TypeLong::LONG; }
  virtual uint ideal_reg() const { return Op_RegL; }
};

//------------------------------ModFNode---------------------------------------
// Float Modulus
class ModFNode : public Node {
public:
  ModFNode( Node *c, Node *in1, Node *in2 ) : Node(c,in1, in2) {}
  virtual int Opcode() const;
  virtual const Type *Value( PhaseTransform *phase ) const;
  virtual const Type *bottom_type() const { return Type::FLOAT; }
  virtual uint ideal_reg() const { return Op_RegF; }
};

//------------------------------ModDNode---------------------------------------
// Double Modulus
class ModDNode : public Node {
public:
  ModDNode( Node *c, Node *in1, Node *in2 ) : Node(c, in1, in2) {}
  virtual int Opcode() const;
  virtual const Type *Value( PhaseTransform *phase ) const;
  virtual const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
};

//------------------------------DivModNode---------------------------------------
// Division with remainder result.
class DivModNode : public MultiNode {
protected:
  DivModNode( Node *c, Node *dividend, Node *divisor );
public:
  enum {
    div_proj_num =  0,      // quotient
    mod_proj_num =  1       // remainder
  };
  virtual int Opcode() const;
  virtual Node *Identity( PhaseTransform *phase ) { return this; }
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) { return NULL; }
  virtual const Type *Value( PhaseTransform *phase ) const { return bottom_type(); }
  virtual uint hash() const { return Node::hash(); }
  virtual bool is_CFG() const  { return false; }
  virtual uint ideal_reg() const { return NotAMachineReg; }

  ProjNode* div_proj() { return proj_out(div_proj_num); }
  ProjNode* mod_proj() { return proj_out(mod_proj_num); }
};

//------------------------------DivModINode---------------------------------------
// Integer division with remainder result.
class DivModINode : public DivModNode {
public:
  DivModINode( Node *c, Node *dividend, Node *divisor ) : DivModNode(c, dividend, divisor) {}
  virtual int Opcode() const;
  virtual const Type *bottom_type() const { return TypeTuple::INT_PAIR; }
  virtual Node *match( const ProjNode *proj, const Matcher *m );

  // Make a divmod and associated projections from a div or mod.
  static DivModINode* make(Compile* C, Node* div_or_mod);
};

//------------------------------DivModLNode---------------------------------------
// Long division with remainder result.
class DivModLNode : public DivModNode {
public:
  DivModLNode( Node *c, Node *dividend, Node *divisor ) : DivModNode(c, dividend, divisor) {}
  virtual int Opcode() const;
  virtual const Type *bottom_type() const { return TypeTuple::LONG_PAIR; }
  virtual Node *match( const ProjNode *proj, const Matcher *m );

  // Make a divmod and associated projections from a div or mod.
  static DivModLNode* make(Compile* C, Node* div_or_mod);
};