jdk8-mips64-public/hotspot: src/share/vm/opto/cfgnode.hpp@1bd45abaa507 (annotated)

src/share/vm/opto/cfgnode.hpp@1bd45abaa507 (annotated)

src/share/vm/opto/cfgnode.hpp

Wed, 16 Nov 2011 09:13:57 -0800

author: kvn
date: Wed, 16 Nov 2011 09:13:57 -0800
changeset 3311: 1bd45abaa507
parent 3040: c7b60b601eb4
child 4409: d092d1b31229
permissions: -rw-r--r--

6890673: Eliminate allocations immediately after EA
Summary: Try to eliminate allocations and related locks immediately after escape analysis.
Reviewed-by: never

 /*
  * Copyright (c) 1997, 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_OPTO_CFGNODE_HPP
 #define SHARE_VM_OPTO_CFGNODE_HPP
 #include "opto/multnode.hpp"
 #include "opto/node.hpp"
 #include "opto/opcodes.hpp"
 #include "opto/type.hpp"
 // Portions of code courtesy of Clifford Click
 // Optimization - Graph Style
 class Matcher;
 class Node;
 class   RegionNode;
 class   TypeNode;
 class     PhiNode;
 class   GotoNode;
 class   MultiNode;
 class     MultiBranchNode;
 class       IfNode;
 class       PCTableNode;
 class         JumpNode;
 class         CatchNode;
 class       NeverBranchNode;
 class   ProjNode;
 class     CProjNode;
 class       IfTrueNode;
 class       IfFalseNode;
 class       CatchProjNode;
 class     JProjNode;
 class       JumpProjNode;
 class     SCMemProjNode;
 class PhaseIdealLoop;
 //------------------------------RegionNode-------------------------------------
 // The class of RegionNodes, which can be mapped to basic blocks in the
 // program.  Their inputs point to Control sources.  PhiNodes (described
 // below) have an input point to a RegionNode.  Merged data inputs to PhiNodes
 // correspond 1-to-1 with RegionNode inputs.  The zero input of a PhiNode is
 // the RegionNode, and the zero input of the RegionNode is itself.
 class RegionNode : public Node {
 public:
   // Node layout (parallels PhiNode):
   enum { Region,                // Generally points to self.
          Control                // Control arcs are [1..len)
   };
   RegionNode( uint required ) : Node(required) {
     init_class_id(Class_Region);
     init_req(0,this);
   }
   Node* is_copy() const {
     const Node* r = _in[Region];
     if (r == NULL)
       return nonnull_req();
     return NULL;  // not a copy!
   }
   PhiNode* has_phi() const;        // returns an arbitrary phi user, or NULL
   PhiNode* has_unique_phi() const; // returns the unique phi user, or NULL
   // Is this region node unreachable from root?
   bool is_unreachable_region(PhaseGVN *phase) const;
   virtual int Opcode() const;
   virtual bool pinned() const { return (const Node *)in(0) == this; }
   virtual bool  is_CFG   () const { return true; }
   virtual uint hash() const { return NO_HASH; }  // CFG nodes do not hash
   virtual bool depends_only_on_test() const { return false; }
   virtual const Type *bottom_type() const { return Type::CONTROL; }
   virtual const Type *Value( PhaseTransform *phase ) const;
   virtual Node *Identity( PhaseTransform *phase );
   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
   virtual const RegMask &out_RegMask() const;
 };
 //------------------------------JProjNode--------------------------------------
 // jump projection for node that produces multiple control-flow paths
 class JProjNode : public ProjNode {
  public:
   JProjNode( Node* ctrl, uint idx ) : ProjNode(ctrl,idx) {}
   virtual int Opcode() const;
   virtual bool  is_CFG() const { return true; }
   virtual uint  hash() const { return NO_HASH; }  // CFG nodes do not hash
   virtual const Node* is_block_proj() const { return in(0); }
   virtual const RegMask& out_RegMask() const;
   virtual uint  ideal_reg() const { return 0; }
 };
 //------------------------------PhiNode----------------------------------------
 // PhiNodes merge values from different Control paths.  Slot 0 points to the
 // controlling RegionNode.  Other slots map 1-for-1 with incoming control flow
 // paths to the RegionNode.  For speed reasons (to avoid another pass) we
 // can turn PhiNodes into copys in-place by NULL'ing out their RegionNode
 // input in slot 0.
 class PhiNode : public TypeNode {
   const TypePtr* const _adr_type; // non-null only for Type::MEMORY nodes.
   const int _inst_id;     // Instance id of the memory slice.
   const int _inst_index;  // Alias index of the instance memory slice.
   // Array elements references have the same alias_idx but different offset.
   const int _inst_offset; // Offset of the instance memory slice.
   // Size is bigger to hold the _adr_type field.
   virtual uint hash() const;    // Check the type
   virtual uint cmp( const Node &n ) const;
   virtual uint size_of() const { return sizeof(*this); }
   // Determine if CMoveNode::is_cmove_id can be used at this join point.
   Node* is_cmove_id(PhaseTransform* phase, int true_path);
 public:
   // Node layout (parallels RegionNode):
   enum { Region,                // Control input is the Phi's region.
          Input                  // Input values are [1..len)
   };
   PhiNode( Node *r, const Type *t, const TypePtr* at = NULL,
            const int iid = TypeOopPtr::InstanceTop,
            const int iidx = Compile::AliasIdxTop,
            const int ioffs = Type::OffsetTop )
     : TypeNode(t,r->req()),
       _adr_type(at),
       _inst_id(iid),
       _inst_index(iidx),
       _inst_offset(ioffs)
   {
     init_class_id(Class_Phi);
     init_req(0, r);
     verify_adr_type();
   }
   // create a new phi with in edges matching r and set (initially) to x
   static PhiNode* make( Node* r, Node* x );
   // extra type arguments override the new phi's bottom_type and adr_type
   static PhiNode* make( Node* r, Node* x, const Type *t, const TypePtr* at = NULL );
   // create a new phi with narrowed memory type
   PhiNode* slice_memory(const TypePtr* adr_type) const;
   PhiNode* split_out_instance(const TypePtr* at, PhaseIterGVN *igvn) const;
   // like make(r, x), but does not initialize the in edges to x
   static PhiNode* make_blank( Node* r, Node* x );
   // Accessors
   RegionNode* region() const { Node* r = in(Region); assert(!r || r->is_Region(), ""); return (RegionNode*)r; }
   Node* is_copy() const {
     // The node is a real phi if _in[0] is a Region node.
     DEBUG_ONLY(const Node* r = _in[Region];)
     assert(r != NULL && r->is_Region(), "Not valid control");
     return NULL;  // not a copy!
   }
   bool is_tripcount() const;
   // Determine a unique non-trivial input, if any.
   // Ignore casts if it helps.  Return NULL on failure.
   Node* unique_input(PhaseTransform *phase);
   // Check for a simple dead loop.
   enum LoopSafety { Safe = 0, Unsafe, UnsafeLoop };
   LoopSafety simple_data_loop_check(Node *in) const;
   // Is it unsafe data loop? It becomes a dead loop if this phi node removed.
   bool is_unsafe_data_reference(Node *in) const;
   int  is_diamond_phi() const;
   virtual int Opcode() const;
   virtual bool pinned() const { return in(0) != 0; }
   virtual const TypePtr *adr_type() const { verify_adr_type(true); return _adr_type; }
   const int inst_id()     const { return _inst_id; }
   const int inst_index()  const { return _inst_index; }
   const int inst_offset() const { return _inst_offset; }
   bool is_same_inst_field(const Type* tp, int id, int index, int offset) {
     return type()->basic_type() == tp->basic_type() &&
            inst_id()     == id     &&
            inst_index()  == index  &&
            inst_offset() == offset &&
            type()->higher_equal(tp);
   }
   virtual const Type *Value( PhaseTransform *phase ) const;
   virtual Node *Identity( PhaseTransform *phase );
   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
   virtual const RegMask &out_RegMask() const;
   virtual const RegMask &in_RegMask(uint) const;
 #ifndef PRODUCT
   virtual void dump_spec(outputStream *st) const;
 #endif
 #ifdef ASSERT
   void verify_adr_type(VectorSet& visited, const TypePtr* at) const;
   void verify_adr_type(bool recursive = false) const;
 #else //ASSERT
   void verify_adr_type(bool recursive = false) const {}
 #endif //ASSERT
 };
 //------------------------------GotoNode---------------------------------------
 // GotoNodes perform direct branches.
 class GotoNode : public Node {
 public:
   GotoNode( Node *control ) : Node(control) {}
   virtual int Opcode() const;
   virtual bool pinned() const { return true; }
   virtual bool  is_CFG() const { return true; }
   virtual uint hash() const { return NO_HASH; }  // CFG nodes do not hash
   virtual const Node *is_block_proj() const { return this; }
   virtual bool depends_only_on_test() const { return false; }
   virtual const Type *bottom_type() const { return Type::CONTROL; }
   virtual const Type *Value( PhaseTransform *phase ) const;
   virtual Node *Identity( PhaseTransform *phase );
   virtual const RegMask &out_RegMask() const;
 };
 //------------------------------CProjNode--------------------------------------
 // control projection for node that produces multiple control-flow paths
 class CProjNode : public ProjNode {
 public:
   CProjNode( Node *ctrl, uint idx ) : ProjNode(ctrl,idx) {}
   virtual int Opcode() const;
   virtual bool  is_CFG() const { return true; }
   virtual uint hash() const { return NO_HASH; }  // CFG nodes do not hash
   virtual const Node *is_block_proj() const { return in(0); }
   virtual const RegMask &out_RegMask() const;
   virtual uint ideal_reg() const { return 0; }
 };
 //---------------------------MultiBranchNode-----------------------------------
 // This class defines a MultiBranchNode, a MultiNode which yields multiple
 // control values. These are distinguished from other types of MultiNodes
 // which yield multiple values, but control is always and only projection #0.
 class MultiBranchNode : public MultiNode {
 public:
   MultiBranchNode( uint required ) : MultiNode(required) {
     init_class_id(Class_MultiBranch);
   }
   // returns required number of users to be well formed.
   virtual int required_outcnt() const = 0;
 };
 //------------------------------IfNode-----------------------------------------
 // Output selected Control, based on a boolean test
 class IfNode : public MultiBranchNode {
   // Size is bigger to hold the probability field.  However, _prob does not
   // change the semantics so it does not appear in the hash & cmp functions.
   virtual uint size_of() const { return sizeof(*this); }
 public:
   // Degrees of branch prediction probability by order of magnitude:
   // PROB_UNLIKELY_1e(N) is a 1 in 1eN chance.
   // PROB_LIKELY_1e(N) is a 1 - PROB_UNLIKELY_1e(N)
 #define PROB_UNLIKELY_MAG(N)    (1e- ## N ## f)
 #define PROB_LIKELY_MAG(N)      (1.0f-PROB_UNLIKELY_MAG(N))
   // Maximum and minimum branch prediction probabilties
   // 1 in 1,000,000 (magnitude 6)
   //
   // Although PROB_NEVER == PROB_MIN and PROB_ALWAYS == PROB_MAX
   // they are used to distinguish different situations:
   //
   // The name PROB_MAX (PROB_MIN) is for probabilities which correspond to
   // very likely (unlikely) but with a concrete possibility of a rare
   // contrary case.  These constants would be used for pinning
   // measurements, and as measures for assertions that have high
   // confidence, but some evidence of occasional failure.
   //
   // The name PROB_ALWAYS (PROB_NEVER) is to stand for situations for which
   // there is no evidence at all that the contrary case has ever occurred.
 #define PROB_NEVER              PROB_UNLIKELY_MAG(6)
 #define PROB_ALWAYS             PROB_LIKELY_MAG(6)
 #define PROB_MIN                PROB_UNLIKELY_MAG(6)
 #define PROB_MAX                PROB_LIKELY_MAG(6)
   // Static branch prediction probabilities
   // 1 in 10 (magnitude 1)
 #define PROB_STATIC_INFREQUENT  PROB_UNLIKELY_MAG(1)
 #define PROB_STATIC_FREQUENT    PROB_LIKELY_MAG(1)
   // Fair probability 50/50
 #define PROB_FAIR               (0.5f)
   // Unknown probability sentinel
 #define PROB_UNKNOWN            (-1.0f)
   // Probability "constructors", to distinguish as a probability any manifest
   // constant without a names
 #define PROB_LIKELY(x)          ((float) (x))
 #define PROB_UNLIKELY(x)        (1.0f - (float)(x))
   // Other probabilities in use, but without a unique name, are documented
   // here for lack of a better place:
   //
   // 1 in 1000 probabilities (magnitude 3):
   //     threshold for converting to conditional move
   //     likelihood of null check failure if a null HAS been seen before
   //     likelihood of slow path taken in library calls
   //
   // 1 in 10,000 probabilities (magnitude 4):
   //     threshold for making an uncommon trap probability more extreme
   //     threshold for for making a null check implicit
   //     likelihood of needing a gc if eden top moves during an allocation
   //     likelihood of a predicted call failure
   //
   // 1 in 100,000 probabilities (magnitude 5):
   //     threshold for ignoring counts when estimating path frequency
   //     likelihood of FP clipping failure
   //     likelihood of catching an exception from a try block
   //     likelihood of null check failure if a null has NOT been seen before
   //
   // Magic manifest probabilities such as 0.83, 0.7, ... can be found in
   // gen_subtype_check() and catch_inline_exceptions().
   float _prob;                  // Probability of true path being taken.
   float _fcnt;                  // Frequency counter
   IfNode( Node *control, Node *b, float p, float fcnt )
     : MultiBranchNode(2), _prob(p), _fcnt(fcnt) {
     init_class_id(Class_If);
     init_req(0,control);
     init_req(1,b);
   }
   virtual int Opcode() const;
   virtual bool pinned() const { return true; }
   virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; }
   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
   virtual const Type *Value( PhaseTransform *phase ) const;
   virtual int required_outcnt() const { return 2; }
   virtual const RegMask &out_RegMask() const;
   void dominated_by(Node* prev_dom, PhaseIterGVN* igvn);
   int is_range_check(Node* &range, Node* &index, jint &offset);
   Node* fold_compares(PhaseGVN* phase);
   static Node* up_one_dom(Node* curr, bool linear_only = false);
   // Takes the type of val and filters it through the test represented
   // by if_proj and returns a more refined type if one is produced.
   // Returns NULL is it couldn't improve the type.
   static const TypeInt* filtered_int_type(PhaseGVN* phase, Node* val, Node* if_proj);
 #ifndef PRODUCT
   virtual void dump_spec(outputStream *st) const;
 #endif
 };
 class IfTrueNode : public CProjNode {
 public:
   IfTrueNode( IfNode *ifnode ) : CProjNode(ifnode,1) {
     init_class_id(Class_IfTrue);
   }
   virtual int Opcode() const;
   virtual Node *Identity( PhaseTransform *phase );
 };
 class IfFalseNode : public CProjNode {
 public:
   IfFalseNode( IfNode *ifnode ) : CProjNode(ifnode,0) {
     init_class_id(Class_IfFalse);
   }
   virtual int Opcode() const;
   virtual Node *Identity( PhaseTransform *phase );
 };
 //------------------------------PCTableNode------------------------------------
 // Build an indirect branch table.  Given a control and a table index,
 // control is passed to the Projection matching the table index.  Used to
 // implement switch statements and exception-handling capabilities.
 // Undefined behavior if passed-in index is not inside the table.
 class PCTableNode : public MultiBranchNode {
   virtual uint hash() const;    // Target count; table size
   virtual uint cmp( const Node &n ) const;
   virtual uint size_of() const { return sizeof(*this); }
 public:
   const uint _size;             // Number of targets
   PCTableNode( Node *ctrl, Node *idx, uint size ) : MultiBranchNode(2), _size(size) {
     init_class_id(Class_PCTable);
     init_req(0, ctrl);
     init_req(1, idx);
   }
   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;
   virtual bool pinned() const { return true; }
   virtual int required_outcnt() const { return _size; }
 };
 //------------------------------JumpNode---------------------------------------
 // Indirect branch.  Uses PCTable above to implement a switch statement.
 // It emits as a table load and local branch.
 class JumpNode : public PCTableNode {
 public:
   JumpNode( Node* control, Node* switch_val, uint size) : PCTableNode(control, switch_val, size) {
     init_class_id(Class_Jump);
   }
   virtual int   Opcode() const;
   virtual const RegMask& out_RegMask() const;
   virtual const Node* is_block_proj() const { return this; }
 };
 class JumpProjNode : public JProjNode {
   virtual uint hash() const;
   virtual uint cmp( const Node &n ) const;
   virtual uint size_of() const { return sizeof(*this); }
  private:
   const int  _dest_bci;
   const uint _proj_no;
   const int  _switch_val;
  public:
   JumpProjNode(Node* jumpnode, uint proj_no, int dest_bci, int switch_val)
     : JProjNode(jumpnode, proj_no), _dest_bci(dest_bci), _proj_no(proj_no), _switch_val(switch_val) {
     init_class_id(Class_JumpProj);
   }
   virtual int Opcode() const;
   virtual const Type* bottom_type() const { return Type::CONTROL; }
   int  dest_bci()    const { return _dest_bci; }
   int  switch_val()  const { return _switch_val; }
   uint proj_no()     const { return _proj_no; }
 #ifndef PRODUCT
   virtual void dump_spec(outputStream *st) const;
 #endif
 };
 //------------------------------CatchNode--------------------------------------
 // Helper node to fork exceptions.  "Catch" catches any exceptions thrown by
 // a just-prior call.  Looks like a PCTableNode but emits no code - just the
 // table.  The table lookup and branch is implemented by RethrowNode.
 class CatchNode : public PCTableNode {
 public:
   CatchNode( Node *ctrl, Node *idx, uint size ) : PCTableNode(ctrl,idx,size){
     init_class_id(Class_Catch);
   }
   virtual int Opcode() const;
   virtual const Type *Value( PhaseTransform *phase ) const;
 };
 // CatchProjNode controls which exception handler is targetted after a call.
 // It is passed in the bci of the target handler, or no_handler_bci in case
 // the projection doesn't lead to an exception handler.
 class CatchProjNode : public CProjNode {
   virtual uint hash() const;
   virtual uint cmp( const Node &n ) const;
   virtual uint size_of() const { return sizeof(*this); }
 private:
   const int _handler_bci;
 public:
   enum {
     fall_through_index =  0,      // the fall through projection index
     catch_all_index    =  1,      // the projection index for catch-alls
     no_handler_bci     = -1       // the bci for fall through or catch-all projs
   };
   CatchProjNode(Node* catchnode, uint proj_no, int handler_bci)
     : CProjNode(catchnode, proj_no), _handler_bci(handler_bci) {
     init_class_id(Class_CatchProj);
     assert(proj_no != fall_through_index || handler_bci < 0, "fall through case must have bci < 0");
   }
   virtual int Opcode() const;
   virtual Node *Identity( PhaseTransform *phase );
   virtual const Type *bottom_type() const { return Type::CONTROL; }
   int  handler_bci() const        { return _handler_bci; }
   bool is_handler_proj() const    { return _handler_bci >= 0; }
 #ifndef PRODUCT
   virtual void dump_spec(outputStream *st) const;
 #endif
 };
 //---------------------------------CreateExNode--------------------------------
 // Helper node to create the exception coming back from a call
 class CreateExNode : public TypeNode {
 public:
   CreateExNode(const Type* t, Node* control, Node* i_o) : TypeNode(t, 2) {
     init_req(0, control);
     init_req(1, i_o);
   }
   virtual int Opcode() const;
   virtual Node *Identity( PhaseTransform *phase );
   virtual bool pinned() const { return true; }
   uint match_edge(uint idx) const { return 0; }
   virtual uint ideal_reg() const { return Op_RegP; }
 };
 //------------------------------NeverBranchNode-------------------------------
 // The never-taken branch.  Used to give the appearance of exiting infinite
 // loops to those algorithms that like all paths to be reachable.  Encodes
 // empty.
 class NeverBranchNode : public MultiBranchNode {
 public:
   NeverBranchNode( Node *ctrl ) : MultiBranchNode(1) { init_req(0,ctrl); }
   virtual int Opcode() const;
   virtual bool pinned() const { return true; };
   virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; }
   virtual const Type *Value( PhaseTransform *phase ) const;
   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
   virtual int required_outcnt() const { return 2; }
   virtual void emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const { }
   virtual uint size(PhaseRegAlloc *ra_) const { return 0; }
 #ifndef PRODUCT
   virtual void format( PhaseRegAlloc *, outputStream *st ) const;
 #endif
 };
 #endif // SHARE_VM_OPTO_CFGNODE_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/cfgnode.hpp@1bd45abaa507 (annotated)

src/share/vm/opto/cfgnode.hpp