--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/opto/superword.hpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,506 @@
+/*
+ * Copyright 2007 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.
+ */
+
+//
+// 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 preceeding 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();
+ // Within a pack, move stores down to the last executed store,
+ // and move loads up to the first 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;
+};