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view src/share/vm/opto/superword.hpp @ 15583:d331b7c3d7c4
[single-pass-iter] start of evolution towards a node iterator less memory-hungry
author | Miguel Garcia <miguel.m.garcia@oracle.com> |
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date | Fri, 09 May 2014 16:22:54 +0200 |
parents | 4ca6dc0799b6 |
children | 538cbc117324 |
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/* * Copyright (c) 2007, 2012, 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(Node* n) { BasicType bt = velt_basic_type(n); return MIN2(ABS(iv_stride()), Matcher::max_vector_size(bt)); } int vector_width_in_bytes(Node* n) { BasicType bt = velt_basic_type(n); return vector_width(n)*type2aelembytes(bt); } 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; } BasicType velt_basic_type(Node* n) { return velt_type(n)->array_element_basic_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; } bool same_velt_type(Node* n1, Node* n2); // 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. MemNode* find_align_to_ref(Node_List &memops); // Calculate loop's iv adjustment for this memory ops. int get_iv_adjustment(MemNode* mem); // 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) Node* 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 bool 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); // (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 const Type* container_type(Node* n); // 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; } MemNode* mem() { return _mem; } 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