Mercurial > hg > truffle
diff src/share/vm/opto/cfgnode.hpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | ff5961f4c095 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/opto/cfgnode.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,481 @@ +/* + * Copyright 1997-2006 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 + +// 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. + // 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 a unique non-trivial input, if any. + // Ignore casts if it helps. Return NULL on failure. + Node* unique_input(PhaseTransform *phase); + // 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 ) + : TypeNode(t,r->req()), _adr_type(at) { + 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; + // 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! + } + + // 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; } + 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) { + init_flags(Flag_is_Goto); + } + 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); + } +}; + +//------------------------------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 const RegMask &out_RegMask() const; + void dominated_by(Node* prev_dom, PhaseIterGVN* igvn); + int is_range_check(Node* &range, Node* &index, jint &offset); + static Node* up_one_dom(Node* curr, bool linear_only = false); + +#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; } +}; + +//------------------------------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 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 +};