Mercurial > hg > graal-jvmci-8
view src/share/vm/opto/superword.hpp @ 3249:e1162778c1c8
7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error
Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.
Reviewed-by: kvn, iveresov, never, tonyp, dholmes
author | johnc |
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date | Thu, 07 Apr 2011 09:53:20 -0700 |
parents | f95d63e2154a |
children | c7b60b601eb4 |
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/* * Copyright (c) 2007, 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_SUPERWORD_HPP #define SHARE_VM_OPTO_SUPERWORD_HPP #include "opto/connode.hpp" #include "opto/loopnode.hpp" #include "opto/node.hpp" #include "opto/phaseX.hpp" #include "opto/vectornode.hpp" #include "utilities/growableArray.hpp" // // S U P E R W O R D T R A N S F O R M // // SuperWords are short, fixed length vectors. // // Algorithm from: // // Exploiting SuperWord Level Parallelism with // Multimedia Instruction Sets // by // Samuel Larsen and Saman Amarasighe // MIT Laboratory for Computer Science // date // May 2000 // published in // ACM SIGPLAN Notices // Proceedings of ACM PLDI '00, Volume 35 Issue 5 // // Definition 3.1 A Pack is an n-tuple, <s1, ...,sn>, where // s1,...,sn are independent isomorphic statements in a basic // block. // // Definition 3.2 A PackSet is a set of Packs. // // Definition 3.3 A Pair is a Pack of size two, where the // first statement is considered the left element, and the // second statement is considered the right element. class SWPointer; class OrderedPair; // ========================= Dependence Graph ===================== class DepMem; //------------------------------DepEdge--------------------------- // An edge in the dependence graph. The edges incident to a dependence // node are threaded through _next_in for incoming edges and _next_out // for outgoing edges. class DepEdge : public ResourceObj { protected: DepMem* _pred; DepMem* _succ; DepEdge* _next_in; // list of in edges, null terminated DepEdge* _next_out; // list of out edges, null terminated public: DepEdge(DepMem* pred, DepMem* succ, DepEdge* next_in, DepEdge* next_out) : _pred(pred), _succ(succ), _next_in(next_in), _next_out(next_out) {} DepEdge* next_in() { return _next_in; } DepEdge* next_out() { return _next_out; } DepMem* pred() { return _pred; } DepMem* succ() { return _succ; } void print(); }; //------------------------------DepMem--------------------------- // A node in the dependence graph. _in_head starts the threaded list of // incoming edges, and _out_head starts the list of outgoing edges. class DepMem : public ResourceObj { protected: Node* _node; // Corresponding ideal node DepEdge* _in_head; // Head of list of in edges, null terminated DepEdge* _out_head; // Head of list of out edges, null terminated public: DepMem(Node* node) : _node(node), _in_head(NULL), _out_head(NULL) {} Node* node() { return _node; } DepEdge* in_head() { return _in_head; } DepEdge* out_head() { return _out_head; } void set_in_head(DepEdge* hd) { _in_head = hd; } void set_out_head(DepEdge* hd) { _out_head = hd; } int in_cnt(); // Incoming edge count int out_cnt(); // Outgoing edge count void print(); }; //------------------------------DepGraph--------------------------- class DepGraph VALUE_OBJ_CLASS_SPEC { protected: Arena* _arena; GrowableArray<DepMem*> _map; DepMem* _root; DepMem* _tail; public: DepGraph(Arena* a) : _arena(a), _map(a, 8, 0, NULL) { _root = new (_arena) DepMem(NULL); _tail = new (_arena) DepMem(NULL); } DepMem* root() { return _root; } DepMem* tail() { return _tail; } // Return dependence node corresponding to an ideal node DepMem* dep(Node* node) { return _map.at(node->_idx); } // Make a new dependence graph node for an ideal node. DepMem* make_node(Node* node); // Make a new dependence graph edge dprec->dsucc DepEdge* make_edge(DepMem* dpred, DepMem* dsucc); DepEdge* make_edge(Node* pred, Node* succ) { return make_edge(dep(pred), dep(succ)); } DepEdge* make_edge(DepMem* pred, Node* succ) { return make_edge(pred, dep(succ)); } DepEdge* make_edge(Node* pred, DepMem* succ) { return make_edge(dep(pred), succ); } void init() { _map.clear(); } // initialize void print(Node* n) { dep(n)->print(); } void print(DepMem* d) { d->print(); } }; //------------------------------DepPreds--------------------------- // Iterator over predecessors in the dependence graph and // non-memory-graph inputs of ideal nodes. class DepPreds : public StackObj { private: Node* _n; int _next_idx, _end_idx; DepEdge* _dep_next; Node* _current; bool _done; public: DepPreds(Node* n, DepGraph& dg); Node* current() { return _current; } bool done() { return _done; } void next(); }; //------------------------------DepSuccs--------------------------- // Iterator over successors in the dependence graph and // non-memory-graph outputs of ideal nodes. class DepSuccs : public StackObj { private: Node* _n; int _next_idx, _end_idx; DepEdge* _dep_next; Node* _current; bool _done; public: DepSuccs(Node* n, DepGraph& dg); Node* current() { return _current; } bool done() { return _done; } void next(); }; // ========================= SuperWord ===================== // -----------------------------SWNodeInfo--------------------------------- // Per node info needed by SuperWord class SWNodeInfo VALUE_OBJ_CLASS_SPEC { public: int _alignment; // memory alignment for a node int _depth; // Max expression (DAG) depth from block start const Type* _velt_type; // vector element type Node_List* _my_pack; // pack containing this node SWNodeInfo() : _alignment(-1), _depth(0), _velt_type(NULL), _my_pack(NULL) {} static const SWNodeInfo initial; }; // -----------------------------SuperWord--------------------------------- // Transforms scalar operations into packed (superword) operations. class SuperWord : public ResourceObj { private: PhaseIdealLoop* _phase; Arena* _arena; PhaseIterGVN &_igvn; enum consts { top_align = -1, bottom_align = -666 }; GrowableArray<Node_List*> _packset; // Packs for the current block GrowableArray<int> _bb_idx; // Map from Node _idx to index within block GrowableArray<Node*> _block; // Nodes in current block GrowableArray<Node*> _data_entry; // Nodes with all inputs from outside GrowableArray<Node*> _mem_slice_head; // Memory slice head nodes GrowableArray<Node*> _mem_slice_tail; // Memory slice tail nodes GrowableArray<SWNodeInfo> _node_info; // Info needed per node MemNode* _align_to_ref; // Memory reference that pre-loop will align to GrowableArray<OrderedPair> _disjoint_ptrs; // runtime disambiguated pointer pairs DepGraph _dg; // Dependence graph // Scratch pads VectorSet _visited; // Visited set VectorSet _post_visited; // Post-visited set Node_Stack _n_idx_list; // List of (node,index) pairs GrowableArray<Node*> _nlist; // List of nodes GrowableArray<Node*> _stk; // Stack of nodes public: SuperWord(PhaseIdealLoop* phase); void transform_loop(IdealLoopTree* lpt); // Accessors for SWPointer PhaseIdealLoop* phase() { return _phase; } IdealLoopTree* lpt() { return _lpt; } PhiNode* iv() { return _iv; } private: IdealLoopTree* _lpt; // Current loop tree node LoopNode* _lp; // Current LoopNode Node* _bb; // Current basic block PhiNode* _iv; // Induction var // Accessors Arena* arena() { return _arena; } Node* bb() { return _bb; } void set_bb(Node* bb) { _bb = bb; } void set_lpt(IdealLoopTree* lpt) { _lpt = lpt; } LoopNode* lp() { return _lp; } void set_lp(LoopNode* lp) { _lp = lp; _iv = lp->as_CountedLoop()->phi()->as_Phi(); } int iv_stride() { return lp()->as_CountedLoop()->stride_con(); } int vector_width_in_bytes() { return Matcher::vector_width_in_bytes(); } MemNode* align_to_ref() { return _align_to_ref; } void set_align_to_ref(MemNode* m) { _align_to_ref = m; } Node* ctrl(Node* n) const { return _phase->has_ctrl(n) ? _phase->get_ctrl(n) : n; } // block accessors bool in_bb(Node* n) { return n != NULL && n->outcnt() > 0 && ctrl(n) == _bb; } int bb_idx(Node* n) { assert(in_bb(n), "must be"); return _bb_idx.at(n->_idx); } void set_bb_idx(Node* n, int i) { _bb_idx.at_put_grow(n->_idx, i); } // visited set accessors void visited_clear() { _visited.Clear(); } void visited_set(Node* n) { return _visited.set(bb_idx(n)); } int visited_test(Node* n) { return _visited.test(bb_idx(n)); } int visited_test_set(Node* n) { return _visited.test_set(bb_idx(n)); } void post_visited_clear() { _post_visited.Clear(); } void post_visited_set(Node* n) { return _post_visited.set(bb_idx(n)); } int post_visited_test(Node* n) { return _post_visited.test(bb_idx(n)); } // Ensure node_info contains element "i" void grow_node_info(int i) { if (i >= _node_info.length()) _node_info.at_put_grow(i, SWNodeInfo::initial); } // memory alignment for a node int alignment(Node* n) { return _node_info.adr_at(bb_idx(n))->_alignment; } void set_alignment(Node* n, int a) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_alignment = a; } // Max expression (DAG) depth from beginning of the block for each node int depth(Node* n) { return _node_info.adr_at(bb_idx(n))->_depth; } void set_depth(Node* n, int d) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_depth = d; } // vector element type const Type* velt_type(Node* n) { return _node_info.adr_at(bb_idx(n))->_velt_type; } void set_velt_type(Node* n, const Type* t) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_velt_type = t; } // my_pack Node_List* my_pack(Node* n) { return !in_bb(n) ? NULL : _node_info.adr_at(bb_idx(n))->_my_pack; } void set_my_pack(Node* n, Node_List* p) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_my_pack = p; } // methods // Extract the superword level parallelism void SLP_extract(); // Find the adjacent memory references and create pack pairs for them. void find_adjacent_refs(); // Find a memory reference to align the loop induction variable to. void find_align_to_ref(Node_List &memops); // Can the preloop align the reference to position zero in the vector? bool ref_is_alignable(SWPointer& p); // Construct dependency graph. void dependence_graph(); // Return a memory slice (node list) in predecessor order starting at "start" void mem_slice_preds(Node* start, Node* stop, GrowableArray<Node*> &preds); // Can s1 and s2 be in a pack with s1 immediately preceding s2 and s1 aligned at "align" bool stmts_can_pack(Node* s1, Node* s2, int align); // Does s exist in a pack at position pos? bool exists_at(Node* s, uint pos); // Is s1 immediately before s2 in memory? bool are_adjacent_refs(Node* s1, Node* s2); // Are s1 and s2 similar? bool isomorphic(Node* s1, Node* s2); // Is there no data path from s1 to s2 or s2 to s1? bool independent(Node* s1, Node* s2); // Helper for independent bool independent_path(Node* shallow, Node* deep, uint dp=0); void set_alignment(Node* s1, Node* s2, int align); int data_size(Node* s); // Extend packset by following use->def and def->use links from pack members. void extend_packlist(); // Extend the packset by visiting operand definitions of nodes in pack p bool follow_use_defs(Node_List* p); // Extend the packset by visiting uses of nodes in pack p bool follow_def_uses(Node_List* p); // Estimate the savings from executing s1 and s2 as a pack int est_savings(Node* s1, Node* s2); int adjacent_profit(Node* s1, Node* s2); int pack_cost(int ct); int unpack_cost(int ct); // Combine packs A and B with A.last == B.first into A.first..,A.last,B.second,..B.last void combine_packs(); // Construct the map from nodes to packs. void construct_my_pack_map(); // Remove packs that are not implemented or not profitable. void filter_packs(); // Adjust the memory graph for the packed operations void schedule(); // Remove "current" from its current position in the memory graph and insert // it after the appropriate insert points (lip or uip); void remove_and_insert(MemNode *current, MemNode *prev, MemNode *lip, Node *uip, Unique_Node_List &schd_before); // Within a store pack, schedule stores together by moving out the sandwiched memory ops according // to dependence info; and within a load pack, move loads down to the last executed load. void co_locate_pack(Node_List* p); // Convert packs into vector node operations void output(); // Create a vector operand for the nodes in pack p for operand: in(opd_idx) VectorNode* vector_opd(Node_List* p, int opd_idx); // Can code be generated for pack p? bool implemented(Node_List* p); // For pack p, are all operands and all uses (with in the block) vector? bool profitable(Node_List* p); // If a use of pack p is not a vector use, then replace the use with an extract operation. void insert_extracts(Node_List* p); // Is use->in(u_idx) a vector use? bool is_vector_use(Node* use, int u_idx); // Construct reverse postorder list of block members void construct_bb(); // Initialize per node info void initialize_bb(); // Insert n into block after pos void bb_insert_after(Node* n, int pos); // Compute max depth for expressions from beginning of block void compute_max_depth(); // Compute necessary vector element type for expressions void compute_vector_element_type(); // Are s1 and s2 in a pack pair and ordered as s1,s2? bool in_packset(Node* s1, Node* s2); // Is s in pack p? Node_List* in_pack(Node* s, Node_List* p); // Remove the pack at position pos in the packset void remove_pack_at(int pos); // Return the node executed first in pack p. Node* executed_first(Node_List* p); // Return the node executed last in pack p. Node* executed_last(Node_List* p); // Alignment within a vector memory reference int memory_alignment(MemNode* s, int iv_adjust_in_bytes); // (Start, end] half-open range defining which operands are vector void vector_opd_range(Node* n, uint* start, uint* end); // Smallest type containing range of values static const Type* container_type(const Type* t); // Adjust pre-loop limit so that in main loop, a load/store reference // to align_to_ref will be a position zero in the vector. void align_initial_loop_index(MemNode* align_to_ref); // Find pre loop end from main loop. Returns null if none. CountedLoopEndNode* get_pre_loop_end(CountedLoopNode *cl); // Is the use of d1 in u1 at the same operand position as d2 in u2? bool opnd_positions_match(Node* d1, Node* u1, Node* d2, Node* u2); void init(); // print methods void print_packset(); void print_pack(Node_List* p); void print_bb(); void print_stmt(Node* s); char* blank(uint depth); }; //------------------------------SWPointer--------------------------- // Information about an address for dependence checking and vector alignment class SWPointer VALUE_OBJ_CLASS_SPEC { protected: MemNode* _mem; // My memory reference node SuperWord* _slp; // SuperWord class Node* _base; // NULL if unsafe nonheap reference Node* _adr; // address pointer jint _scale; // multipler for iv (in bytes), 0 if no loop iv jint _offset; // constant offset (in bytes) Node* _invar; // invariant offset (in bytes), NULL if none bool _negate_invar; // if true then use: (0 - _invar) PhaseIdealLoop* phase() { return _slp->phase(); } IdealLoopTree* lpt() { return _slp->lpt(); } PhiNode* iv() { return _slp->iv(); } // Induction var bool invariant(Node* n) { Node *n_c = phase()->get_ctrl(n); return !lpt()->is_member(phase()->get_loop(n_c)); } // Match: k*iv + offset bool scaled_iv_plus_offset(Node* n); // Match: k*iv where k is a constant that's not zero bool scaled_iv(Node* n); // Match: offset is (k [+/- invariant]) bool offset_plus_k(Node* n, bool negate = false); public: enum CMP { Less = 1, Greater = 2, Equal = 4, NotEqual = (Less | Greater), NotComparable = (Less | Greater | Equal) }; SWPointer(MemNode* mem, SuperWord* slp); // Following is used to create a temporary object during // the pattern match of an address expression. SWPointer(SWPointer* p); bool valid() { return _adr != NULL; } bool has_iv() { return _scale != 0; } Node* base() { return _base; } Node* adr() { return _adr; } int scale_in_bytes() { return _scale; } Node* invar() { return _invar; } bool negate_invar() { return _negate_invar; } int offset_in_bytes() { return _offset; } int memory_size() { return _mem->memory_size(); } // Comparable? int cmp(SWPointer& q) { if (valid() && q.valid() && (_adr == q._adr || _base == _adr && q._base == q._adr) && _scale == q._scale && _invar == q._invar && _negate_invar == q._negate_invar) { bool overlap = q._offset < _offset + memory_size() && _offset < q._offset + q.memory_size(); return overlap ? Equal : (_offset < q._offset ? Less : Greater); } else { return NotComparable; } } bool not_equal(SWPointer& q) { return not_equal(cmp(q)); } bool equal(SWPointer& q) { return equal(cmp(q)); } bool comparable(SWPointer& q) { return comparable(cmp(q)); } static bool not_equal(int cmp) { return cmp <= NotEqual; } static bool equal(int cmp) { return cmp == Equal; } static bool comparable(int cmp) { return cmp < NotComparable; } void print(); }; //------------------------------OrderedPair--------------------------- // Ordered pair of Node*. class OrderedPair VALUE_OBJ_CLASS_SPEC { protected: Node* _p1; Node* _p2; public: OrderedPair() : _p1(NULL), _p2(NULL) {} OrderedPair(Node* p1, Node* p2) { if (p1->_idx < p2->_idx) { _p1 = p1; _p2 = p2; } else { _p1 = p2; _p2 = p1; } } bool operator==(const OrderedPair &rhs) { return _p1 == rhs._p1 && _p2 == rhs._p2; } void print() { tty->print(" (%d, %d)", _p1->_idx, _p2->_idx); } static const OrderedPair initial; }; #endif // SHARE_VM_OPTO_SUPERWORD_HPP