truffle: src/share/vm/opto/block.hpp comparison

comparison src/share/vm/opto/block.hpp @ 0:a61af66fc99e jdk7-b24

Initial load

author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
parents
children	72c5366e5d86

comparison

equal deleted inserted replaced

--1:000000000000
+:a61af66fc99e
+/*
+* Copyright 1997-2007 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.
+*
+*/
+// Optimization - Graph Style
+class Block;
+class CFGLoop;
+class MachCallNode;
+class Matcher;
+class RootNode;
+class VectorSet;
+struct Tarjan;
+//------------------------------Block_Array------------------------------------
+// Map dense integer indices to Blocks.  Uses classic doubling-array trick.
+// Abstractly provides an infinite array of Block*'s, initialized to NULL.
+// Note that the constructor just zeros things, and since I use Arena
+// allocation I do not need a destructor to reclaim storage.
+class Block_Array : public ResourceObj {
+uint _size;                   // allocated size, as opposed to formal limit
+debug_only(uint _limit;)      // limit to formal domain
+protected:
+Block **_blocks;
+void grow( uint i );          // Grow array node to fit
+public:
+Arena *_arena;                // Arena to allocate in
+Block_Array(Arena *a) : _arena(a), _size(OptoBlockListSize) {
+debug_only(_limit=0);
+_blocks = NEW_ARENA_ARRAY( a, Block *, OptoBlockListSize );
+for( int i = 0; i < OptoBlockListSize; i++ ) {
+_blocks[i] = NULL;
+}
+}
+Block *lookup( uint i ) const // Lookup, or NULL for not mapped
+{ return (i<Max()) ? _blocks[i] : (Block*)NULL; }
+Block *operator[] ( uint i ) const // Lookup, or assert for not mapped
+{ assert( i < Max(), "oob" ); return _blocks[i]; }
+// Extend the mapping: index i maps to Block *n.
+void map( uint i, Block *n ) { if( i>=Max() ) grow(i); _blocks[i] = n; }
+uint Max() const { debug_only(return _limit); return _size; }
+};
+class Block_List : public Block_Array {
+public:
+uint _cnt;
+Block_List() : Block_Array(Thread::current()->resource_area()), _cnt(0) {}
+void push( Block *b ) { map(_cnt++,b); }
+Block *pop() { return _blocks[--_cnt]; }
+Block *rpop() { Block *b = _blocks[0]; _blocks[0]=_blocks[--_cnt]; return b;}
+void remove( uint i );
+void insert( uint i, Block *n );
+uint size() const { return _cnt; }
+void reset() { _cnt = 0; }
+};
+class CFGElement : public ResourceObj {
+public:
+float _freq; // Execution frequency (estimate)
+CFGElement() : _freq(0.0f) {}
+virtual bool is_block() { return false; }
+virtual bool is_loop()  { return false; }
+Block*   as_Block() { assert(is_block(), "must be block"); return (Block*)this; }
+CFGLoop* as_CFGLoop()  { assert(is_loop(),  "must be loop");  return (CFGLoop*)this;  }
+};
+//------------------------------Block------------------------------------------
+// This class defines a Basic Block.
+// Basic blocks are used during the output routines, and are not used during
+// any optimization pass.  They are created late in the game.
+class Block : public CFGElement {
+public:
+// Nodes in this block, in order
+Node_List _nodes;
+// Basic blocks have a Node which defines Control for all Nodes pinned in
+// this block.  This Node is a RegionNode.  Exception-causing Nodes
+// (division, subroutines) and Phi functions are always pinned.  Later,
+// every Node will get pinned to some block.
+Node *head() const { return _nodes[0]; }
+// CAUTION: num_preds() is ONE based, so that predecessor numbers match
+// input edges to Regions and Phis.
+uint num_preds() const { return head()->req(); }
+Node *pred(uint i) const { return head()->in(i); }
+// Array of successor blocks, same size as projs array
+Block_Array _succs;
+// Basic blocks have some number of Nodes which split control to all
+// following blocks.  These Nodes are always Projections.  The field in
+// the Projection and the block-ending Node determine which Block follows.
+uint _num_succs;
+// Basic blocks also carry all sorts of good old fashioned DFS information
+// used to find loops, loop nesting depth, dominators, etc.
+uint _pre_order;              // Pre-order DFS number
+// Dominator tree
+uint _dom_depth;              // Depth in dominator tree for fast LCA
+Block* _idom;                 // Immediate dominator block
+CFGLoop *_loop;               // Loop to which this block belongs
+uint _rpo;                    // Number in reverse post order walk
+virtual bool is_block() { return true; }
+float succ_prob(uint i); // return probability of i'th successor
+Block* dom_lca(Block* that);  // Compute LCA in dominator tree.
+#ifdef ASSERT
+bool dominates(Block* that) {
+int dom_diff = this->_dom_depth - that->_dom_depth;
+if (dom_diff > 0)  return false;
+for (; dom_diff < 0; dom_diff++)  that = that->_idom;
+return this == that;
+}
+#endif
+// Report the alignment required by this block.  Must be a power of 2.
+// The previous block will insert nops to get this alignment.
+uint code_alignment();
+// BLOCK_FREQUENCY is a sentinel to mark uses of constant block frequencies.
+// It is currently also used to scale such frequencies relative to
+// FreqCountInvocations relative to the old value of 1500.
+#define BLOCK_FREQUENCY(f) ((f * (float) 1500) / FreqCountInvocations)
+// Register Pressure (estimate) for Splitting heuristic
+uint _reg_pressure;
+uint _ihrp_index;
+uint _freg_pressure;
+uint _fhrp_index;
+// Mark and visited bits for an LCA calculation in insert_anti_dependences.
+// Since they hold unique node indexes, they do not need reinitialization.
+node_idx_t _raise_LCA_mark;
+void    set_raise_LCA_mark(node_idx_t x)    { _raise_LCA_mark = x; }
+node_idx_t  raise_LCA_mark() const          { return _raise_LCA_mark; }
+node_idx_t _raise_LCA_visited;
+void    set_raise_LCA_visited(node_idx_t x) { _raise_LCA_visited = x; }
+node_idx_t  raise_LCA_visited() const       { return _raise_LCA_visited; }
+// Estimated size in bytes of first instructions in a loop.
+uint _first_inst_size;
+uint first_inst_size() const     { return _first_inst_size; }
+void set_first_inst_size(uint s) { _first_inst_size = s; }
+// Compute the size of first instructions in this block.
+uint compute_first_inst_size(uint& sum_size, uint inst_cnt, PhaseRegAlloc* ra);
+// Compute alignment padding if the block needs it.
+// Align a loop if loop's padding is less or equal to padding limit
+// or the size of first instructions in the loop > padding.
+uint alignment_padding(int current_offset) {
+int block_alignment = code_alignment();
+int max_pad = block_alignment-relocInfo::addr_unit();
+if( max_pad > 0 ) {
+assert(is_power_of_2(max_pad+relocInfo::addr_unit()), "");
+int current_alignment = current_offset & max_pad;
+if( current_alignment != 0 ) {
+uint padding = (block_alignment-current_alignment) & max_pad;
+if( !head()->is_Loop() ||
+padding <= (uint)MaxLoopPad ||
+first_inst_size() > padding ) {
+return padding;
+}
+}
+}
+return 0;
+}
+// Connector blocks. Connector blocks are basic blocks devoid of
+// instructions, but may have relevant non-instruction Nodes, such as
+// Phis or MergeMems. Such blocks are discovered and marked during the
+// RemoveEmpty phase, and elided during Output.
+bool _connector;
+void set_connector() { _connector = true; }
+bool is_connector() const { return _connector; };
+// Create a new Block with given head Node.
+// Creates the (empty) predecessor arrays.
+Block( Arena *a, Node *headnode )
+: CFGElement(),
+_nodes(a),
+_succs(a),
+_num_succs(0),
+_pre_order(0),
+_idom(0),
+_loop(NULL),
+_reg_pressure(0),
+_ihrp_index(1),
+_freg_pressure(0),
+_fhrp_index(1),
+_raise_LCA_mark(0),
+_raise_LCA_visited(0),
+_first_inst_size(999999),
+_connector(false) {
+_nodes.push(headnode);
+}
+// Index of 'end' Node
+uint end_idx() const {
+// %%%%% add a proj after every goto
+// so (last->is_block_proj() != last) always, then simplify this code
+// This will not give correct end_idx for block 0 when it only contains root.
+int last_idx = _nodes.size() - 1;
+Node *last  = _nodes[last_idx];
+assert(last->is_block_proj() == last || last->is_block_proj() == _nodes[last_idx - _num_succs], "");
+return (last->is_block_proj() == last) ? last_idx : (last_idx - _num_succs);
+}
+// Basic blocks have a Node which ends them.  This Node determines which
+// basic block follows this one in the program flow.  This Node is either an
+// IfNode, a GotoNode, a JmpNode, or a ReturnNode.
+Node *end() const { return _nodes[end_idx()]; }
+// Add an instruction to an existing block.  It must go after the head
+// instruction and before the end instruction.
+void add_inst( Node *n ) { _nodes.insert(end_idx(),n); }
+// Find node in block
+uint find_node( const Node *n ) const;
+// Find and remove n from block list
+void find_remove( const Node *n );
+// Schedule a call next in the block
+uint sched_call(Matcher &matcher, Block_Array &bbs, uint node_cnt, Node_List &worklist, int *ready_cnt, MachCallNode *mcall, VectorSet &next_call);
+// Perform basic-block local scheduling
+Node *select(PhaseCFG *cfg, Node_List &worklist, int *ready_cnt, VectorSet &next_call, uint sched_slot);
+void set_next_call( Node *n, VectorSet &next_call, Block_Array &bbs );
+void needed_for_next_call(Node *this_call, VectorSet &next_call, Block_Array &bbs);
+bool schedule_local(PhaseCFG *cfg, Matcher &m, int *ready_cnt, VectorSet &next_call);
+// Cleanup if any code lands between a Call and his Catch
+void call_catch_cleanup(Block_Array &bbs);
+// Detect implicit-null-check opportunities.  Basically, find NULL checks
+// with suitable memory ops nearby.  Use the memory op to do the NULL check.
+// I can generate a memory op if there is not one nearby.
+void implicit_null_check(PhaseCFG *cfg, Node *proj, Node *val, int allowed_reasons);
+// Return the empty status of a block
+enum { not_empty, empty_with_goto, completely_empty };
+int is_Empty() const;
+// Forward through connectors
+Block* non_connector() {
+Block* s = this;
+while (s->is_connector()) {
+s = s->_succs[0];
+}
+return s;
+}
+// Successor block, after forwarding through connectors
+Block* non_connector_successor(int i) const {
+return _succs[i]->non_connector();
+}
+// Examine block's code shape to predict if it is not commonly executed.
+bool has_uncommon_code() const;
+// Use frequency calculations and code shape to predict if the block
+// is uncommon.
+bool is_uncommon( Block_Array &bbs ) const;
+#ifndef PRODUCT
+// Debugging print of basic block
+void dump_bidx(const Block* orig) const;
+void dump_pred(const Block_Array *bbs, Block* orig) const;
+void dump_head( const Block_Array *bbs ) const;
+void dump( ) const;
+void dump( const Block_Array *bbs ) const;
+#endif
+};
+//------------------------------PhaseCFG---------------------------------------
+// Build an array of Basic Block pointers, one per Node.
+class PhaseCFG : public Phase {
+private:
+// Build a proper looking cfg.  Return count of basic blocks
+uint build_cfg();
+// Perform DFS search.
+// Setup 'vertex' as DFS to vertex mapping.
+// Setup 'semi' as vertex to DFS mapping.
+// Set 'parent' to DFS parent.
+uint DFS( Tarjan *tarjan );
+// Helper function to insert a node into a block
+void schedule_node_into_block( Node *n, Block *b );
+// Set the basic block for pinned Nodes
+void schedule_pinned_nodes( VectorSet &visited );
+// I'll need a few machine-specific GotoNodes.  Clone from this one.
+MachNode *_goto;
+void insert_goto_at(uint block_no, uint succ_no);
+Block* insert_anti_dependences(Block* LCA, Node* load, bool verify = false);
+void verify_anti_dependences(Block* LCA, Node* load) {
+assert(LCA == _bbs[load->_idx], "should already be scheduled");
+insert_anti_dependences(LCA, load, true);
+}
+public:
+PhaseCFG( Arena *a, RootNode *r, Matcher &m );
+uint _num_blocks;             // Count of basic blocks
+Block_List _blocks;           // List of basic blocks
+RootNode *_root;              // Root of whole program
+Block_Array _bbs;             // Map Nodes to owning Basic Block
+Block *_broot;                // Basic block of root
+uint _rpo_ctr;
+CFGLoop* _root_loop;
+// Per node latency estimation, valid only during GCM
+GrowableArray<uint> _node_latency;
+#ifndef PRODUCT
+bool _trace_opto_pipelining;  // tracing flag
+#endif
+// Build dominators
+void Dominators();
+// Estimate block frequencies based on IfNode probabilities
+void Estimate_Block_Frequency();
+// Global Code Motion.  See Click's PLDI95 paper.  Place Nodes in specific
+// basic blocks; i.e. _bbs now maps _idx for all Nodes to some Block.
+void GlobalCodeMotion( Matcher &m, uint unique, Node_List &proj_list );
+// Compute the (backwards) latency of a node from the uses
+void latency_from_uses(Node *n);
+// Compute the (backwards) latency of a node from a single use
+int latency_from_use(Node *n, const Node *def, Node *use);
+// Compute the (backwards) latency of a node from the uses of this instruction
+void partial_latency_of_defs(Node *n);
+// Schedule Nodes early in their basic blocks.
+bool schedule_early(VectorSet &visited, Node_List &roots);
+// For each node, find the latest block it can be scheduled into
+// and then select the cheapest block between the latest and earliest
+// block to place the node.
+void schedule_late(VectorSet &visited, Node_List &stack);
+// Pick a block between early and late that is a cheaper alternative
+// to late. Helper for schedule_late.
+Block* hoist_to_cheaper_block(Block* LCA, Block* early, Node* self);
+// Compute the instruction global latency with a backwards walk
+void ComputeLatenciesBackwards(VectorSet &visited, Node_List &stack);
+// Remove empty basic blocks
+void RemoveEmpty();
+bool MoveToNext(Block* bx, uint b_index);
+void MoveToEnd(Block* bx, uint b_index);
+// Check for NeverBranch at block end.  This needs to become a GOTO to the
+// true target.  NeverBranch are treated as a conditional branch that always
+// goes the same direction for most of the optimizer and are used to give a
+// fake exit path to infinite loops.  At this late stage they need to turn
+// into Goto's so that when you enter the infinite loop you indeed hang.
+void convert_NeverBranch_to_Goto(Block *b);
+CFGLoop* create_loop_tree();
+// Insert a node into a block, and update the _bbs
+void insert( Block *b, uint idx, Node *n ) {
+b->_nodes.insert( idx, n );
+_bbs.map( n->_idx, b );
+}
+#ifndef PRODUCT
+bool trace_opto_pipelining() const { return _trace_opto_pipelining; }
+// Debugging print of CFG
+void dump( ) const;           // CFG only
+void _dump_cfg( const Node *end, VectorSet &visited  ) const;
+void verify() const;
+void dump_headers();
+#else
+bool trace_opto_pipelining() const { return false; }
+#endif
+};
+//------------------------------UnionFindInfo----------------------------------
+// Map Block indices to a block-index for a cfg-cover.
+// Array lookup in the optimized case.
+class UnionFind : public ResourceObj {
+uint _cnt, _max;
+uint* _indices;
+ReallocMark _nesting;  // assertion check for reallocations
+public:
+UnionFind( uint max );
+void reset( uint max );  // Reset to identity map for [0..max]
+uint lookup( uint nidx ) const {
+return _indices[nidx];
+}
+uint operator[] (uint nidx) const { return lookup(nidx); }
+void map( uint from_idx, uint to_idx ) {
+assert( from_idx < _cnt, "oob" );
+_indices[from_idx] = to_idx;
+}
+void extend( uint from_idx, uint to_idx );
+uint Size() const { return _cnt; }
+uint Find( uint idx ) {
+assert( idx < 65536, "Must fit into uint");
+uint uf_idx = lookup(idx);
+return (uf_idx == idx) ? uf_idx : Find_compress(idx);
+}
+uint Find_compress( uint idx );
+uint Find_const( uint idx ) const;
+void Union( uint idx1, uint idx2 );
+};
+//----------------------------BlockProbPair---------------------------
+// Ordered pair of Node*.
+class BlockProbPair VALUE_OBJ_CLASS_SPEC {
+protected:
+Block* _target;      // block target
+float  _prob;        // probability of edge to block
+public:
+BlockProbPair() : _target(NULL), _prob(0.0) {}
+BlockProbPair(Block* b, float p) : _target(b), _prob(p) {}
+Block* get_target() const { return _target; }
+float get_prob() const { return _prob; }
+};
+//------------------------------CFGLoop-------------------------------------------
+class CFGLoop : public CFGElement {
+int _id;
+int _depth;
+CFGLoop *_parent;      // root of loop tree is the method level "pseudo" loop, it's parent is null
+CFGLoop *_sibling;     // null terminated list
+CFGLoop *_child;       // first child, use child's sibling to visit all immediately nested loops
+GrowableArray<CFGElement*> _members; // list of members of loop
+GrowableArray<BlockProbPair> _exits; // list of successor blocks and their probabilities
+float _exit_prob;       // probability any loop exit is taken on a single loop iteration
+void update_succ_freq(Block* b, float freq);
+public:
+CFGLoop(int id) :
+CFGElement(),
+_id(id),
+_depth(0),
+_parent(NULL),
+_sibling(NULL),
+_child(NULL),
+_exit_prob(1.0f) {}
+CFGLoop* parent() { return _parent; }
+void push_pred(Block* blk, int i, Block_List& worklist, Block_Array& node_to_blk);
+void add_member(CFGElement *s) { _members.push(s); }
+void add_nested_loop(CFGLoop* cl);
+Block* head() {
+assert(_members.at(0)->is_block(), "head must be a block");
+Block* hd = _members.at(0)->as_Block();
+assert(hd->_loop == this, "just checking");
+assert(hd->head()->is_Loop(), "must begin with loop head node");
+return hd;
+}
+Block* backedge_block(); // Return the block on the backedge of the loop (else NULL)
+void compute_loop_depth(int depth);
+void compute_freq(); // compute frequency with loop assuming head freq 1.0f
+void scale_freq();   // scale frequency by loop trip count (including outer loops)
+bool in_loop_nest(Block* b);
+float trip_count() const { return 1.0f / _exit_prob; }
+virtual bool is_loop()  { return true; }
+int id() { return _id; }
+#ifndef PRODUCT
+void dump( ) const;
+void dump_tree() const;
+#endif
+};

Mercurial > hg > truffle

comparison src/share/vm/opto/block.hpp @ 0:a61af66fc99e jdk7-b24