view src/share/vm/opto/subnode.hpp @ 452:00b023ae2d78

6722113: CMS: Incorrect overflow handling during precleaning of Reference lists Summary: When we encounter marking stack overflow during precleaning of Reference lists, we were using the overflow list mechanism, which can cause problems on account of mutating the mark word of the header because of conflicts with mutator accesses and updates of that field. Instead we should use the usual mechanism for overflow handling in concurrent phases, namely dirtying of the card on which the overflowed object lies. Since precleaning effectively does a form of discovered list processing, albeit with discovery enabled, we needed to adjust some code to be correct in the face of interleaved processing and discovery. Reviewed-by: apetrusenko, jcoomes
author ysr
date Thu, 20 Nov 2008 12:27:41 -0800
parents d1605aabd0a1
children d7f654633cfe
line wrap: on
line source

/*
 * Copyright 1997-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

// Portions of code courtesy of Clifford Click

//------------------------------SUBNode----------------------------------------
// Class SUBTRACTION functionality.  This covers all the usual 'subtract'
// behaviors.  Subtract-integer, -float, -double, binary xor, compare-integer,
// -float, and -double are all inherited from this class.  The compare
// functions behave like subtract functions, except that all negative answers
// are compressed into -1, and all positive answers compressed to 1.
class SubNode : public Node {
public:
  SubNode( Node *in1, Node *in2 ) : Node(0,in1,in2) {
    init_class_id(Class_Sub);
  }

  // Handle algebraic identities here.  If we have an identity, return the Node
  // we are equivalent to.  We look for "add of zero" as an identity.
  virtual Node *Identity( PhaseTransform *phase );

  // Compute a new Type for this node.  Basically we just do the pre-check,
  // then call the virtual add() to set the type.
  virtual const Type *Value( PhaseTransform *phase ) const;

  // Supplied function returns the subtractend of the inputs.
  // This also type-checks the inputs for sanity.  Guaranteed never to
  // be passed a TOP or BOTTOM type, these are filtered out by a pre-check.
  virtual const Type *sub( const Type *, const Type * ) const = 0;

  // Supplied function to return the additive identity type.
  // This is returned whenever the subtracts inputs are the same.
  virtual const Type *add_id() const = 0;

};


// NOTE: SubINode should be taken away and replaced by add and negate
//------------------------------SubINode---------------------------------------
// Subtract 2 integers
class SubINode : public SubNode {
public:
  SubINode( Node *in1, Node *in2 ) : SubNode(in1,in2) {}
  virtual int Opcode() const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *sub( const Type *, const Type * ) const;
  const Type *add_id() const { return TypeInt::ZERO; }
  const Type *bottom_type() const { return TypeInt::INT; }
  virtual uint ideal_reg() const { return Op_RegI; }
};

//------------------------------SubLNode---------------------------------------
// Subtract 2 integers
class SubLNode : public SubNode {
public:
  SubLNode( Node *in1, Node *in2 ) : SubNode(in1,in2) {}
  virtual int Opcode() const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *sub( const Type *, const Type * ) const;
  const Type *add_id() const { return TypeLong::ZERO; }
  const Type *bottom_type() const { return TypeLong::LONG; }
  virtual uint ideal_reg() const { return Op_RegL; }
};

// NOTE: SubFPNode should be taken away and replaced by add and negate
//------------------------------SubFPNode--------------------------------------
// Subtract 2 floats or doubles
class SubFPNode : public SubNode {
protected:
  SubFPNode( Node *in1, Node *in2 ) : SubNode(in1,in2) {}
public:
  const Type *Value( PhaseTransform *phase ) const;
};

// NOTE: SubFNode should be taken away and replaced by add and negate
//------------------------------SubFNode---------------------------------------
// Subtract 2 doubles
class SubFNode : public SubFPNode {
public:
  SubFNode( Node *in1, Node *in2 ) : SubFPNode(in1,in2) {}
  virtual int Opcode() const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *sub( const Type *, const Type * ) const;
  const Type   *add_id() const { return TypeF::ZERO; }
  const Type   *bottom_type() const { return Type::FLOAT; }
  virtual uint  ideal_reg() const { return Op_RegF; }
};

// NOTE: SubDNode should be taken away and replaced by add and negate
//------------------------------SubDNode---------------------------------------
// Subtract 2 doubles
class SubDNode : public SubFPNode {
public:
  SubDNode( Node *in1, Node *in2 ) : SubFPNode(in1,in2) {}
  virtual int Opcode() const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *sub( const Type *, const Type * ) const;
  const Type   *add_id() const { return TypeD::ZERO; }
  const Type   *bottom_type() const { return Type::DOUBLE; }
  virtual uint  ideal_reg() const { return Op_RegD; }
};

//------------------------------CmpNode---------------------------------------
// Compare 2 values, returning condition codes (-1, 0 or 1).
class CmpNode : public SubNode {
public:
  CmpNode( Node *in1, Node *in2 ) : SubNode(in1,in2) {
    init_class_id(Class_Cmp);
  }
  virtual Node *Identity( PhaseTransform *phase );
  const Type *add_id() const { return TypeInt::ZERO; }
  const Type *bottom_type() const { return TypeInt::CC; }
  virtual uint ideal_reg() const { return Op_RegFlags; }
};

//------------------------------CmpINode---------------------------------------
// Compare 2 signed values, returning condition codes (-1, 0 or 1).
class CmpINode : public CmpNode {
public:
  CmpINode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
  virtual int Opcode() const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *sub( const Type *, const Type * ) const;
};

//------------------------------CmpUNode---------------------------------------
// Compare 2 unsigned values (integer or pointer), returning condition codes (-1, 0 or 1).
class CmpUNode : public CmpNode {
public:
  CmpUNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
  virtual int Opcode() const;
  virtual const Type *sub( const Type *, const Type * ) const;
};

//------------------------------CmpPNode---------------------------------------
// Compare 2 pointer values, returning condition codes (-1, 0 or 1).
class CmpPNode : public CmpNode {
public:
  CmpPNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
  virtual int Opcode() const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *sub( const Type *, const Type * ) const;
};

//------------------------------CmpNNode--------------------------------------
// Compare 2 narrow oop values, returning condition codes (-1, 0 or 1).
class CmpNNode : public CmpNode {
public:
  CmpNNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
  virtual int Opcode() const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *sub( const Type *, const Type * ) const;
};

//------------------------------CmpLNode---------------------------------------
// Compare 2 long values, returning condition codes (-1, 0 or 1).
class CmpLNode : public CmpNode {
public:
  CmpLNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
  virtual int    Opcode() const;
  virtual const Type *sub( const Type *, const Type * ) const;
};

//------------------------------CmpL3Node--------------------------------------
// Compare 2 long values, returning integer value (-1, 0 or 1).
class CmpL3Node : public CmpLNode {
public:
  CmpL3Node( Node *in1, Node *in2 ) : CmpLNode(in1,in2) {
    // Since it is not consumed by Bools, it is not really a Cmp.
    init_class_id(Class_Sub);
  }
  virtual int    Opcode() const;
  virtual uint ideal_reg() const { return Op_RegI; }
};

//------------------------------CmpFNode---------------------------------------
// Compare 2 float values, returning condition codes (-1, 0 or 1).
// This implements the Java bytecode fcmpl, so unordered returns -1.
// Operands may not commute.
class CmpFNode : public CmpNode {
public:
  CmpFNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
  virtual int Opcode() const;
  virtual const Type *sub( const Type *, const Type * ) const { ShouldNotReachHere(); return NULL; }
  const Type *Value( PhaseTransform *phase ) const;
};

//------------------------------CmpF3Node--------------------------------------
// Compare 2 float values, returning integer value (-1, 0 or 1).
// This implements the Java bytecode fcmpl, so unordered returns -1.
// Operands may not commute.
class CmpF3Node : public CmpFNode {
public:
  CmpF3Node( Node *in1, Node *in2 ) : CmpFNode(in1,in2) {
    // Since it is not consumed by Bools, it is not really a Cmp.
    init_class_id(Class_Sub);
  }
  virtual int Opcode() const;
  // Since it is not consumed by Bools, it is not really a Cmp.
  virtual uint ideal_reg() const { return Op_RegI; }
};


//------------------------------CmpDNode---------------------------------------
// Compare 2 double values, returning condition codes (-1, 0 or 1).
// This implements the Java bytecode dcmpl, so unordered returns -1.
// Operands may not commute.
class CmpDNode : public CmpNode {
public:
  CmpDNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
  virtual int Opcode() const;
  virtual const Type *sub( const Type *, const Type * ) const { ShouldNotReachHere(); return NULL; }
  const Type *Value( PhaseTransform *phase ) const;
  virtual Node  *Ideal(PhaseGVN *phase, bool can_reshape);
};

//------------------------------CmpD3Node--------------------------------------
// Compare 2 double values, returning integer value (-1, 0 or 1).
// This implements the Java bytecode dcmpl, so unordered returns -1.
// Operands may not commute.
class CmpD3Node : public CmpDNode {
public:
  CmpD3Node( Node *in1, Node *in2 ) : CmpDNode(in1,in2) {
    // Since it is not consumed by Bools, it is not really a Cmp.
    init_class_id(Class_Sub);
  }
  virtual int Opcode() const;
  virtual uint ideal_reg() const { return Op_RegI; }
};


//------------------------------BoolTest---------------------------------------
// Convert condition codes to a boolean test value (0 or -1).
// We pick the values as 3 bits; the low order 2 bits we compare against the
// condition codes, the high bit flips the sense of the result.
struct BoolTest VALUE_OBJ_CLASS_SPEC {
  enum mask { eq = 0, ne = 4, le = 5, ge = 7, lt = 3, gt = 1, illegal = 8 };
  mask _test;
  BoolTest( mask btm ) : _test(btm) {}
  const Type *cc2logical( const Type *CC ) const;
  // Commute the test.  I use a small table lookup.  The table is created as
  // a simple char array where each element is the ASCII version of a 'mask'
  // enum from above.
  mask commute( ) const { return mask("038147858"[_test]-'0'); }
  mask negate( ) const { return mask(_test^4); }
  bool is_canonical( ) const { return (_test == BoolTest::ne || _test == BoolTest::lt || _test == BoolTest::le); }
#ifndef PRODUCT
  void dump_on(outputStream *st) const;
#endif
};

//------------------------------BoolNode---------------------------------------
// A Node to convert a Condition Codes to a Logical result.
class BoolNode : public Node {
  virtual uint hash() const;
  virtual uint cmp( const Node &n ) const;
  virtual uint size_of() const;
public:
  const BoolTest _test;
  BoolNode( Node *cc, BoolTest::mask t): _test(t), Node(0,cc) {
    init_class_id(Class_Bool);
  }
  // Convert an arbitrary int value to a Bool or other suitable predicate.
  static Node* make_predicate(Node* test_value, PhaseGVN* phase);
  // Convert self back to an integer value.
  Node* as_int_value(PhaseGVN* phase);
  // Invert sense of self, returning new Bool.
  BoolNode* negate(PhaseGVN* phase);
  virtual int Opcode() const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  virtual const Type *Value( PhaseTransform *phase ) const;
  virtual const Type *bottom_type() const { return TypeInt::BOOL; }
  uint match_edge(uint idx) const { return 0; }
  virtual uint ideal_reg() const { return Op_RegI; }

  bool is_counted_loop_exit_test();
#ifndef PRODUCT
  virtual void dump_spec(outputStream *st) const;
#endif
};

//------------------------------AbsNode----------------------------------------
// Abstract class for absolute value.  Mostly used to get a handy wrapper
// for finding this pattern in the graph.
class AbsNode : public Node {
public:
  AbsNode( Node *value ) : Node(0,value) {}
};

//------------------------------AbsINode---------------------------------------
// Absolute value an integer.  Since a naive graph involves control flow, we
// "match" it in the ideal world (so the control flow can be removed).
class AbsINode : public AbsNode {
public:
  AbsINode( Node *in1 ) : AbsNode(in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return TypeInt::INT; }
  virtual uint ideal_reg() const { return Op_RegI; }
};

//------------------------------AbsFNode---------------------------------------
// Absolute value a float, a common float-point idiom with a cheap hardware
// implemention on most chips.  Since a naive graph involves control flow, we
// "match" it in the ideal world (so the control flow can be removed).
class AbsFNode : public AbsNode {
public:
  AbsFNode( Node *in1 ) : AbsNode(in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return Type::FLOAT; }
  virtual uint ideal_reg() const { return Op_RegF; }
};

//------------------------------AbsDNode---------------------------------------
// Absolute value a double, a common float-point idiom with a cheap hardware
// implemention on most chips.  Since a naive graph involves control flow, we
// "match" it in the ideal world (so the control flow can be removed).
class AbsDNode : public AbsNode {
public:
  AbsDNode( Node *in1 ) : AbsNode(in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
};


//------------------------------CmpLTMaskNode----------------------------------
// If p < q, return -1 else return 0.  Nice for flow-free idioms.
class CmpLTMaskNode : public Node {
public:
  CmpLTMaskNode( Node *p, Node *q ) : Node(0, p, q) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return TypeInt::INT; }
  virtual uint ideal_reg() const { return Op_RegI; }
};


//------------------------------NegNode----------------------------------------
class NegNode : public Node {
public:
  NegNode( Node *in1 ) : Node(0,in1) {}
};

//------------------------------NegFNode---------------------------------------
// Negate value a float.  Negating 0.0 returns -0.0, but subtracting from
// zero returns +0.0 (per JVM spec on 'fneg' bytecode).  As subtraction
// cannot be used to replace negation we have to implement negation as ideal
// node; note that negation and addition can replace subtraction.
class NegFNode : public NegNode {
public:
  NegFNode( Node *in1 ) : NegNode(in1) {}
  virtual int Opcode() const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  const Type *bottom_type() const { return Type::FLOAT; }
  virtual uint ideal_reg() const { return Op_RegF; }
};

//------------------------------NegDNode---------------------------------------
// Negate value a double.  Negating 0.0 returns -0.0, but subtracting from
// zero returns +0.0 (per JVM spec on 'dneg' bytecode).  As subtraction
// cannot be used to replace negation we have to implement negation as ideal
// node; note that negation and addition can replace subtraction.
class NegDNode : public NegNode {
public:
  NegDNode( Node *in1 ) : NegNode(in1) {}
  virtual int Opcode() const;
  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
};

//------------------------------CosDNode---------------------------------------
// Cosinus of a double
class CosDNode : public Node {
public:
  CosDNode( Node *in1  ) : Node(0, in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
  virtual const Type *Value( PhaseTransform *phase ) const;
};

//------------------------------CosDNode---------------------------------------
// Sinus of a double
class SinDNode : public Node {
public:
  SinDNode( Node *in1  ) : Node(0, in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
  virtual const Type *Value( PhaseTransform *phase ) const;
};


//------------------------------TanDNode---------------------------------------
// tangens of a double
class TanDNode : public Node {
public:
  TanDNode(Node *in1  ) : Node(0, in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
  virtual const Type *Value( PhaseTransform *phase ) const;
};


//------------------------------AtanDNode--------------------------------------
// arcus tangens of a double
class AtanDNode : public Node {
public:
  AtanDNode(Node *c, Node *in1, Node *in2  ) : Node(c, in1, in2) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
};


//------------------------------SqrtDNode--------------------------------------
// square root a double
class SqrtDNode : public Node {
public:
  SqrtDNode(Node *c, Node *in1  ) : Node(c, in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
  virtual const Type *Value( PhaseTransform *phase ) const;
};

//------------------------------ExpDNode---------------------------------------
//  Exponentiate a double
class ExpDNode : public Node {
public:
  ExpDNode( Node *c, Node *in1 ) : Node(c, in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
  virtual const Type *Value( PhaseTransform *phase ) const;
};

//------------------------------LogDNode---------------------------------------
// Log_e of a double
class LogDNode : public Node {
public:
  LogDNode( Node *in1 ) : Node(0, in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
  virtual const Type *Value( PhaseTransform *phase ) const;
};

//------------------------------Log10DNode---------------------------------------
// Log_10 of a double
class Log10DNode : public Node {
public:
  Log10DNode( Node *in1 ) : Node(0, in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
  virtual const Type *Value( PhaseTransform *phase ) const;
};

//------------------------------PowDNode---------------------------------------
// Raise a double to a double power
class PowDNode : public Node {
public:
  PowDNode(Node *c, Node *in1, Node *in2  ) : Node(c, in1, in2) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return Type::DOUBLE; }
  virtual uint ideal_reg() const { return Op_RegD; }
  virtual const Type *Value( PhaseTransform *phase ) const;
};

//-------------------------------ReverseBytesINode--------------------------------
// reverse bytes of an integer
class ReverseBytesINode : public Node {
public:
  ReverseBytesINode(Node *c, Node *in1) : Node(c, in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return TypeInt::INT; }
  virtual uint ideal_reg() const { return Op_RegI; }
};

//-------------------------------ReverseBytesLNode--------------------------------
// reverse bytes of a long
class ReverseBytesLNode : public Node {
public:
  ReverseBytesLNode(Node *c, Node *in1) : Node(c, in1) {}
  virtual int Opcode() const;
  const Type *bottom_type() const { return TypeLong::LONG; }
  virtual uint ideal_reg() const { return Op_RegL; }
};