duke@435: /* trims@1907: * Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved. duke@435: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. duke@435: * duke@435: * This code is free software; you can redistribute it and/or modify it duke@435: * under the terms of the GNU General Public License version 2 only, as duke@435: * published by the Free Software Foundation. duke@435: * duke@435: * This code is distributed in the hope that it will be useful, but WITHOUT duke@435: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or duke@435: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License duke@435: * version 2 for more details (a copy is included in the LICENSE file that duke@435: * accompanied this code). duke@435: * duke@435: * You should have received a copy of the GNU General Public License version duke@435: * 2 along with this work; if not, write to the Free Software Foundation, duke@435: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. duke@435: * trims@1907: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA trims@1907: * or visit www.oracle.com if you need additional information or have any trims@1907: * questions. duke@435: * duke@435: */ duke@435: duke@435: // Portions of code courtesy of Clifford Click duke@435: duke@435: // Optimization - Graph Style duke@435: duke@435: class Matcher; duke@435: class Node; duke@435: class RegionNode; duke@435: class TypeNode; duke@435: class PhiNode; duke@435: class GotoNode; duke@435: class MultiNode; duke@435: class MultiBranchNode; duke@435: class IfNode; duke@435: class PCTableNode; duke@435: class JumpNode; duke@435: class CatchNode; duke@435: class NeverBranchNode; duke@435: class ProjNode; duke@435: class CProjNode; duke@435: class IfTrueNode; duke@435: class IfFalseNode; duke@435: class CatchProjNode; duke@435: class JProjNode; duke@435: class JumpProjNode; duke@435: class SCMemProjNode; duke@435: class PhaseIdealLoop; duke@435: duke@435: //------------------------------RegionNode------------------------------------- duke@435: // The class of RegionNodes, which can be mapped to basic blocks in the duke@435: // program. Their inputs point to Control sources. PhiNodes (described duke@435: // below) have an input point to a RegionNode. Merged data inputs to PhiNodes duke@435: // correspond 1-to-1 with RegionNode inputs. The zero input of a PhiNode is duke@435: // the RegionNode, and the zero input of the RegionNode is itself. duke@435: class RegionNode : public Node { duke@435: public: duke@435: // Node layout (parallels PhiNode): duke@435: enum { Region, // Generally points to self. duke@435: Control // Control arcs are [1..len) duke@435: }; duke@435: duke@435: RegionNode( uint required ) : Node(required) { duke@435: init_class_id(Class_Region); duke@435: init_req(0,this); duke@435: } duke@435: duke@435: Node* is_copy() const { duke@435: const Node* r = _in[Region]; duke@435: if (r == NULL) duke@435: return nonnull_req(); duke@435: return NULL; // not a copy! duke@435: } duke@435: PhiNode* has_phi() const; // returns an arbitrary phi user, or NULL duke@435: PhiNode* has_unique_phi() const; // returns the unique phi user, or NULL duke@435: // Is this region node unreachable from root? duke@435: bool is_unreachable_region(PhaseGVN *phase) const; duke@435: virtual int Opcode() const; duke@435: virtual bool pinned() const { return (const Node *)in(0) == this; } duke@435: virtual bool is_CFG () const { return true; } duke@435: virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash duke@435: virtual bool depends_only_on_test() const { return false; } duke@435: virtual const Type *bottom_type() const { return Type::CONTROL; } duke@435: virtual const Type *Value( PhaseTransform *phase ) const; duke@435: virtual Node *Identity( PhaseTransform *phase ); duke@435: virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); duke@435: virtual const RegMask &out_RegMask() const; duke@435: }; duke@435: duke@435: //------------------------------JProjNode-------------------------------------- duke@435: // jump projection for node that produces multiple control-flow paths duke@435: class JProjNode : public ProjNode { duke@435: public: duke@435: JProjNode( Node* ctrl, uint idx ) : ProjNode(ctrl,idx) {} duke@435: virtual int Opcode() const; duke@435: virtual bool is_CFG() const { return true; } duke@435: virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash duke@435: virtual const Node* is_block_proj() const { return in(0); } duke@435: virtual const RegMask& out_RegMask() const; duke@435: virtual uint ideal_reg() const { return 0; } duke@435: }; duke@435: duke@435: //------------------------------PhiNode---------------------------------------- duke@435: // PhiNodes merge values from different Control paths. Slot 0 points to the duke@435: // controlling RegionNode. Other slots map 1-for-1 with incoming control flow duke@435: // paths to the RegionNode. For speed reasons (to avoid another pass) we duke@435: // can turn PhiNodes into copys in-place by NULL'ing out their RegionNode duke@435: // input in slot 0. duke@435: class PhiNode : public TypeNode { duke@435: const TypePtr* const _adr_type; // non-null only for Type::MEMORY nodes. kvn@499: const int _inst_id; // Instance id of the memory slice. kvn@499: const int _inst_index; // Alias index of the instance memory slice. kvn@499: // Array elements references have the same alias_idx but different offset. kvn@499: const int _inst_offset; // Offset of the instance memory slice. duke@435: // Size is bigger to hold the _adr_type field. duke@435: virtual uint hash() const; // Check the type duke@435: virtual uint cmp( const Node &n ) const; duke@435: virtual uint size_of() const { return sizeof(*this); } duke@435: duke@435: // Determine if CMoveNode::is_cmove_id can be used at this join point. duke@435: Node* is_cmove_id(PhaseTransform* phase, int true_path); duke@435: duke@435: public: duke@435: // Node layout (parallels RegionNode): duke@435: enum { Region, // Control input is the Phi's region. duke@435: Input // Input values are [1..len) duke@435: }; duke@435: kvn@499: PhiNode( Node *r, const Type *t, const TypePtr* at = NULL, kvn@658: const int iid = TypeOopPtr::InstanceTop, kvn@499: const int iidx = Compile::AliasIdxTop, kvn@499: const int ioffs = Type::OffsetTop ) kvn@499: : TypeNode(t,r->req()), kvn@499: _adr_type(at), kvn@499: _inst_id(iid), kvn@499: _inst_index(iidx), kvn@499: _inst_offset(ioffs) kvn@499: { duke@435: init_class_id(Class_Phi); duke@435: init_req(0, r); duke@435: verify_adr_type(); duke@435: } duke@435: // create a new phi with in edges matching r and set (initially) to x duke@435: static PhiNode* make( Node* r, Node* x ); duke@435: // extra type arguments override the new phi's bottom_type and adr_type duke@435: static PhiNode* make( Node* r, Node* x, const Type *t, const TypePtr* at = NULL ); duke@435: // create a new phi with narrowed memory type duke@435: PhiNode* slice_memory(const TypePtr* adr_type) const; kvn@509: PhiNode* split_out_instance(const TypePtr* at, PhaseIterGVN *igvn) const; duke@435: // like make(r, x), but does not initialize the in edges to x duke@435: static PhiNode* make_blank( Node* r, Node* x ); duke@435: duke@435: // Accessors duke@435: RegionNode* region() const { Node* r = in(Region); assert(!r || r->is_Region(), ""); return (RegionNode*)r; } duke@435: duke@435: Node* is_copy() const { duke@435: // The node is a real phi if _in[0] is a Region node. duke@435: DEBUG_ONLY(const Node* r = _in[Region];) duke@435: assert(r != NULL && r->is_Region(), "Not valid control"); duke@435: return NULL; // not a copy! duke@435: } duke@435: kvn@835: bool is_tripcount() const; kvn@835: kvn@499: // Determine a unique non-trivial input, if any. kvn@499: // Ignore casts if it helps. Return NULL on failure. kvn@499: Node* unique_input(PhaseTransform *phase); kvn@499: duke@435: // Check for a simple dead loop. duke@435: enum LoopSafety { Safe = 0, Unsafe, UnsafeLoop }; duke@435: LoopSafety simple_data_loop_check(Node *in) const; duke@435: // Is it unsafe data loop? It becomes a dead loop if this phi node removed. duke@435: bool is_unsafe_data_reference(Node *in) const; duke@435: int is_diamond_phi() const; duke@435: virtual int Opcode() const; duke@435: virtual bool pinned() const { return in(0) != 0; } duke@435: virtual const TypePtr *adr_type() const { verify_adr_type(true); return _adr_type; } kvn@499: kvn@499: const int inst_id() const { return _inst_id; } kvn@499: const int inst_index() const { return _inst_index; } kvn@499: const int inst_offset() const { return _inst_offset; } kvn@499: bool is_same_inst_field(const Type* tp, int id, int index, int offset) { kvn@499: return type()->basic_type() == tp->basic_type() && kvn@499: inst_id() == id && kvn@499: inst_index() == index && kvn@499: inst_offset() == offset && kvn@499: type()->higher_equal(tp); kvn@499: } kvn@499: duke@435: virtual const Type *Value( PhaseTransform *phase ) const; duke@435: virtual Node *Identity( PhaseTransform *phase ); duke@435: virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); duke@435: virtual const RegMask &out_RegMask() const; duke@435: virtual const RegMask &in_RegMask(uint) const; duke@435: #ifndef PRODUCT duke@435: virtual void dump_spec(outputStream *st) const; duke@435: #endif duke@435: #ifdef ASSERT duke@435: void verify_adr_type(VectorSet& visited, const TypePtr* at) const; duke@435: void verify_adr_type(bool recursive = false) const; duke@435: #else //ASSERT duke@435: void verify_adr_type(bool recursive = false) const {} duke@435: #endif //ASSERT duke@435: }; duke@435: duke@435: //------------------------------GotoNode--------------------------------------- duke@435: // GotoNodes perform direct branches. duke@435: class GotoNode : public Node { duke@435: public: duke@435: GotoNode( Node *control ) : Node(control) { duke@435: init_flags(Flag_is_Goto); duke@435: } duke@435: virtual int Opcode() const; duke@435: virtual bool pinned() const { return true; } duke@435: virtual bool is_CFG() const { return true; } duke@435: virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash duke@435: virtual const Node *is_block_proj() const { return this; } duke@435: virtual bool depends_only_on_test() const { return false; } duke@435: virtual const Type *bottom_type() const { return Type::CONTROL; } duke@435: virtual const Type *Value( PhaseTransform *phase ) const; duke@435: virtual Node *Identity( PhaseTransform *phase ); duke@435: virtual const RegMask &out_RegMask() const; duke@435: }; duke@435: duke@435: //------------------------------CProjNode-------------------------------------- duke@435: // control projection for node that produces multiple control-flow paths duke@435: class CProjNode : public ProjNode { duke@435: public: duke@435: CProjNode( Node *ctrl, uint idx ) : ProjNode(ctrl,idx) {} duke@435: virtual int Opcode() const; duke@435: virtual bool is_CFG() const { return true; } duke@435: virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash duke@435: virtual const Node *is_block_proj() const { return in(0); } duke@435: virtual const RegMask &out_RegMask() const; duke@435: virtual uint ideal_reg() const { return 0; } duke@435: }; duke@435: duke@435: //---------------------------MultiBranchNode----------------------------------- duke@435: // This class defines a MultiBranchNode, a MultiNode which yields multiple duke@435: // control values. These are distinguished from other types of MultiNodes duke@435: // which yield multiple values, but control is always and only projection #0. duke@435: class MultiBranchNode : public MultiNode { duke@435: public: duke@435: MultiBranchNode( uint required ) : MultiNode(required) { duke@435: init_class_id(Class_MultiBranch); duke@435: } never@562: // returns required number of users to be well formed. never@562: virtual int required_outcnt() const = 0; duke@435: }; duke@435: duke@435: //------------------------------IfNode----------------------------------------- duke@435: // Output selected Control, based on a boolean test duke@435: class IfNode : public MultiBranchNode { duke@435: // Size is bigger to hold the probability field. However, _prob does not duke@435: // change the semantics so it does not appear in the hash & cmp functions. duke@435: virtual uint size_of() const { return sizeof(*this); } duke@435: public: duke@435: duke@435: // Degrees of branch prediction probability by order of magnitude: duke@435: // PROB_UNLIKELY_1e(N) is a 1 in 1eN chance. duke@435: // PROB_LIKELY_1e(N) is a 1 - PROB_UNLIKELY_1e(N) duke@435: #define PROB_UNLIKELY_MAG(N) (1e- ## N ## f) duke@435: #define PROB_LIKELY_MAG(N) (1.0f-PROB_UNLIKELY_MAG(N)) duke@435: duke@435: // Maximum and minimum branch prediction probabilties duke@435: // 1 in 1,000,000 (magnitude 6) duke@435: // duke@435: // Although PROB_NEVER == PROB_MIN and PROB_ALWAYS == PROB_MAX duke@435: // they are used to distinguish different situations: duke@435: // duke@435: // The name PROB_MAX (PROB_MIN) is for probabilities which correspond to duke@435: // very likely (unlikely) but with a concrete possibility of a rare duke@435: // contrary case. These constants would be used for pinning duke@435: // measurements, and as measures for assertions that have high duke@435: // confidence, but some evidence of occasional failure. duke@435: // duke@435: // The name PROB_ALWAYS (PROB_NEVER) is to stand for situations for which duke@435: // there is no evidence at all that the contrary case has ever occurred. duke@435: duke@435: #define PROB_NEVER PROB_UNLIKELY_MAG(6) duke@435: #define PROB_ALWAYS PROB_LIKELY_MAG(6) duke@435: duke@435: #define PROB_MIN PROB_UNLIKELY_MAG(6) duke@435: #define PROB_MAX PROB_LIKELY_MAG(6) duke@435: duke@435: // Static branch prediction probabilities duke@435: // 1 in 10 (magnitude 1) duke@435: #define PROB_STATIC_INFREQUENT PROB_UNLIKELY_MAG(1) duke@435: #define PROB_STATIC_FREQUENT PROB_LIKELY_MAG(1) duke@435: duke@435: // Fair probability 50/50 duke@435: #define PROB_FAIR (0.5f) duke@435: duke@435: // Unknown probability sentinel duke@435: #define PROB_UNKNOWN (-1.0f) duke@435: duke@435: // Probability "constructors", to distinguish as a probability any manifest duke@435: // constant without a names duke@435: #define PROB_LIKELY(x) ((float) (x)) duke@435: #define PROB_UNLIKELY(x) (1.0f - (float)(x)) duke@435: duke@435: // Other probabilities in use, but without a unique name, are documented duke@435: // here for lack of a better place: duke@435: // duke@435: // 1 in 1000 probabilities (magnitude 3): duke@435: // threshold for converting to conditional move duke@435: // likelihood of null check failure if a null HAS been seen before duke@435: // likelihood of slow path taken in library calls duke@435: // duke@435: // 1 in 10,000 probabilities (magnitude 4): duke@435: // threshold for making an uncommon trap probability more extreme duke@435: // threshold for for making a null check implicit duke@435: // likelihood of needing a gc if eden top moves during an allocation duke@435: // likelihood of a predicted call failure duke@435: // duke@435: // 1 in 100,000 probabilities (magnitude 5): duke@435: // threshold for ignoring counts when estimating path frequency duke@435: // likelihood of FP clipping failure duke@435: // likelihood of catching an exception from a try block duke@435: // likelihood of null check failure if a null has NOT been seen before duke@435: // duke@435: // Magic manifest probabilities such as 0.83, 0.7, ... can be found in duke@435: // gen_subtype_check() and catch_inline_exceptions(). duke@435: duke@435: float _prob; // Probability of true path being taken. duke@435: float _fcnt; // Frequency counter duke@435: IfNode( Node *control, Node *b, float p, float fcnt ) duke@435: : MultiBranchNode(2), _prob(p), _fcnt(fcnt) { duke@435: init_class_id(Class_If); duke@435: init_req(0,control); duke@435: init_req(1,b); duke@435: } duke@435: virtual int Opcode() const; duke@435: virtual bool pinned() const { return true; } duke@435: virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; } duke@435: virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); duke@435: virtual const Type *Value( PhaseTransform *phase ) const; never@562: virtual int required_outcnt() const { return 2; } duke@435: virtual const RegMask &out_RegMask() const; duke@435: void dominated_by(Node* prev_dom, PhaseIterGVN* igvn); duke@435: int is_range_check(Node* &range, Node* &index, jint &offset); never@452: Node* fold_compares(PhaseGVN* phase); duke@435: static Node* up_one_dom(Node* curr, bool linear_only = false); duke@435: never@452: // Takes the type of val and filters it through the test represented never@452: // by if_proj and returns a more refined type if one is produced. never@452: // Returns NULL is it couldn't improve the type. never@452: static const TypeInt* filtered_int_type(PhaseGVN* phase, Node* val, Node* if_proj); never@452: duke@435: #ifndef PRODUCT duke@435: virtual void dump_spec(outputStream *st) const; duke@435: #endif duke@435: }; duke@435: duke@435: class IfTrueNode : public CProjNode { duke@435: public: duke@435: IfTrueNode( IfNode *ifnode ) : CProjNode(ifnode,1) { duke@435: init_class_id(Class_IfTrue); duke@435: } duke@435: virtual int Opcode() const; duke@435: virtual Node *Identity( PhaseTransform *phase ); duke@435: }; duke@435: duke@435: class IfFalseNode : public CProjNode { duke@435: public: duke@435: IfFalseNode( IfNode *ifnode ) : CProjNode(ifnode,0) { duke@435: init_class_id(Class_IfFalse); duke@435: } duke@435: virtual int Opcode() const; duke@435: virtual Node *Identity( PhaseTransform *phase ); duke@435: }; duke@435: duke@435: duke@435: //------------------------------PCTableNode------------------------------------ duke@435: // Build an indirect branch table. Given a control and a table index, duke@435: // control is passed to the Projection matching the table index. Used to duke@435: // implement switch statements and exception-handling capabilities. duke@435: // Undefined behavior if passed-in index is not inside the table. duke@435: class PCTableNode : public MultiBranchNode { duke@435: virtual uint hash() const; // Target count; table size duke@435: virtual uint cmp( const Node &n ) const; duke@435: virtual uint size_of() const { return sizeof(*this); } duke@435: duke@435: public: duke@435: const uint _size; // Number of targets duke@435: duke@435: PCTableNode( Node *ctrl, Node *idx, uint size ) : MultiBranchNode(2), _size(size) { duke@435: init_class_id(Class_PCTable); duke@435: init_req(0, ctrl); duke@435: init_req(1, idx); duke@435: } duke@435: virtual int Opcode() const; duke@435: virtual const Type *Value( PhaseTransform *phase ) const; duke@435: virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); duke@435: virtual const Type *bottom_type() const; duke@435: virtual bool pinned() const { return true; } never@562: virtual int required_outcnt() const { return _size; } duke@435: }; duke@435: duke@435: //------------------------------JumpNode--------------------------------------- duke@435: // Indirect branch. Uses PCTable above to implement a switch statement. duke@435: // It emits as a table load and local branch. duke@435: class JumpNode : public PCTableNode { duke@435: public: duke@435: JumpNode( Node* control, Node* switch_val, uint size) : PCTableNode(control, switch_val, size) { duke@435: init_class_id(Class_Jump); duke@435: } duke@435: virtual int Opcode() const; duke@435: virtual const RegMask& out_RegMask() const; duke@435: virtual const Node* is_block_proj() const { return this; } duke@435: }; duke@435: duke@435: class JumpProjNode : public JProjNode { duke@435: virtual uint hash() const; duke@435: virtual uint cmp( const Node &n ) const; duke@435: virtual uint size_of() const { return sizeof(*this); } duke@435: duke@435: private: duke@435: const int _dest_bci; duke@435: const uint _proj_no; duke@435: const int _switch_val; duke@435: public: duke@435: JumpProjNode(Node* jumpnode, uint proj_no, int dest_bci, int switch_val) duke@435: : JProjNode(jumpnode, proj_no), _dest_bci(dest_bci), _proj_no(proj_no), _switch_val(switch_val) { duke@435: init_class_id(Class_JumpProj); duke@435: } duke@435: duke@435: virtual int Opcode() const; duke@435: virtual const Type* bottom_type() const { return Type::CONTROL; } duke@435: int dest_bci() const { return _dest_bci; } duke@435: int switch_val() const { return _switch_val; } duke@435: uint proj_no() const { return _proj_no; } duke@435: #ifndef PRODUCT duke@435: virtual void dump_spec(outputStream *st) const; duke@435: #endif duke@435: }; duke@435: duke@435: //------------------------------CatchNode-------------------------------------- duke@435: // Helper node to fork exceptions. "Catch" catches any exceptions thrown by duke@435: // a just-prior call. Looks like a PCTableNode but emits no code - just the duke@435: // table. The table lookup and branch is implemented by RethrowNode. duke@435: class CatchNode : public PCTableNode { duke@435: public: duke@435: CatchNode( Node *ctrl, Node *idx, uint size ) : PCTableNode(ctrl,idx,size){ duke@435: init_class_id(Class_Catch); duke@435: } duke@435: virtual int Opcode() const; duke@435: virtual const Type *Value( PhaseTransform *phase ) const; duke@435: }; duke@435: duke@435: // CatchProjNode controls which exception handler is targetted after a call. duke@435: // It is passed in the bci of the target handler, or no_handler_bci in case duke@435: // the projection doesn't lead to an exception handler. duke@435: class CatchProjNode : public CProjNode { duke@435: virtual uint hash() const; duke@435: virtual uint cmp( const Node &n ) const; duke@435: virtual uint size_of() const { return sizeof(*this); } duke@435: duke@435: private: duke@435: const int _handler_bci; duke@435: duke@435: public: duke@435: enum { duke@435: fall_through_index = 0, // the fall through projection index duke@435: catch_all_index = 1, // the projection index for catch-alls duke@435: no_handler_bci = -1 // the bci for fall through or catch-all projs duke@435: }; duke@435: duke@435: CatchProjNode(Node* catchnode, uint proj_no, int handler_bci) duke@435: : CProjNode(catchnode, proj_no), _handler_bci(handler_bci) { duke@435: init_class_id(Class_CatchProj); duke@435: assert(proj_no != fall_through_index || handler_bci < 0, "fall through case must have bci < 0"); duke@435: } duke@435: duke@435: virtual int Opcode() const; duke@435: virtual Node *Identity( PhaseTransform *phase ); duke@435: virtual const Type *bottom_type() const { return Type::CONTROL; } duke@435: int handler_bci() const { return _handler_bci; } duke@435: bool is_handler_proj() const { return _handler_bci >= 0; } duke@435: #ifndef PRODUCT duke@435: virtual void dump_spec(outputStream *st) const; duke@435: #endif duke@435: }; duke@435: duke@435: duke@435: //---------------------------------CreateExNode-------------------------------- duke@435: // Helper node to create the exception coming back from a call duke@435: class CreateExNode : public TypeNode { duke@435: public: duke@435: CreateExNode(const Type* t, Node* control, Node* i_o) : TypeNode(t, 2) { duke@435: init_req(0, control); duke@435: init_req(1, i_o); duke@435: } duke@435: virtual int Opcode() const; duke@435: virtual Node *Identity( PhaseTransform *phase ); duke@435: virtual bool pinned() const { return true; } duke@435: uint match_edge(uint idx) const { return 0; } duke@435: virtual uint ideal_reg() const { return Op_RegP; } duke@435: }; duke@435: duke@435: //------------------------------NeverBranchNode------------------------------- duke@435: // The never-taken branch. Used to give the appearance of exiting infinite duke@435: // loops to those algorithms that like all paths to be reachable. Encodes duke@435: // empty. duke@435: class NeverBranchNode : public MultiBranchNode { duke@435: public: duke@435: NeverBranchNode( Node *ctrl ) : MultiBranchNode(1) { init_req(0,ctrl); } duke@435: virtual int Opcode() const; duke@435: virtual bool pinned() const { return true; }; duke@435: virtual const Type *bottom_type() const { return TypeTuple::IFBOTH; } never@562: virtual const Type *Value( PhaseTransform *phase ) const; never@562: virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); never@562: virtual int required_outcnt() const { return 2; } duke@435: virtual void emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const { } duke@435: virtual uint size(PhaseRegAlloc *ra_) const { return 0; } duke@435: #ifndef PRODUCT duke@435: virtual void format( PhaseRegAlloc *, outputStream *st ) const; duke@435: #endif duke@435: };