Mercurial > hg > truffle
diff src/share/vm/opto/chaitin.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 | b683f557224b |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/opto/chaitin.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,501 @@ +/* + * 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. + * + */ + +class LoopTree; +class MachCallNode; +class MachSafePointNode; +class Matcher; +class PhaseCFG; +class PhaseLive; +class PhaseRegAlloc; +class PhaseChaitin; + +#define OPTO_DEBUG_SPLIT_FREQ BLOCK_FREQUENCY(0.001) +#define OPTO_LRG_HIGH_FREQ BLOCK_FREQUENCY(0.25) + +//------------------------------LRG-------------------------------------------- +// Live-RanGe structure. +class LRG : public ResourceObj { +public: + enum { SPILL_REG=29999 }; // Register number of a spilled LRG + + double _cost; // 2 for loads/1 for stores times block freq + double _area; // Sum of all simultaneously live values + double score() const; // Compute score from cost and area + double _maxfreq; // Maximum frequency of any def or use + + Node *_def; // Check for multi-def live ranges +#ifndef PRODUCT + GrowableArray<Node*>* _defs; +#endif + + uint _risk_bias; // Index of LRG which we want to avoid color + uint _copy_bias; // Index of LRG which we want to share color + + uint _next; // Index of next LRG in linked list + uint _prev; // Index of prev LRG in linked list +private: + uint _reg; // Chosen register; undefined if mask is plural +public: + // Return chosen register for this LRG. Error if the LRG is not bound to + // a single register. + OptoReg::Name reg() const { return OptoReg::Name(_reg); } + void set_reg( OptoReg::Name r ) { _reg = r; } + +private: + uint _eff_degree; // Effective degree: Sum of neighbors _num_regs +public: + int degree() const { assert( _degree_valid, "" ); return _eff_degree; } + // Degree starts not valid and any change to the IFG neighbor + // set makes it not valid. + void set_degree( uint degree ) { _eff_degree = degree; debug_only(_degree_valid = 1;) } + // Made a change that hammered degree + void invalid_degree() { debug_only(_degree_valid=0;) } + // Incrementally modify degree. If it was correct, it should remain correct + void inc_degree( uint mod ) { _eff_degree += mod; } + // Compute the degree between 2 live ranges + int compute_degree( LRG &l ) const; + +private: + RegMask _mask; // Allowed registers for this LRG + uint _mask_size; // cache of _mask.Size(); +public: + int compute_mask_size() const { return _mask.is_AllStack() ? 65535 : _mask.Size(); } + void set_mask_size( int size ) { + assert((size == 65535) || (size == (int)_mask.Size()), ""); + _mask_size = size; + debug_only(_msize_valid=1;) + debug_only( if( _num_regs == 2 && !_fat_proj ) _mask.VerifyPairs(); ) + } + void compute_set_mask_size() { set_mask_size(compute_mask_size()); } + int mask_size() const { assert( _msize_valid, "mask size not valid" ); + return _mask_size; } + // Get the last mask size computed, even if it does not match the + // count of bits in the current mask. + int get_invalid_mask_size() const { return _mask_size; } + const RegMask &mask() const { return _mask; } + void set_mask( const RegMask &rm ) { _mask = rm; debug_only(_msize_valid=0;)} + void AND( const RegMask &rm ) { _mask.AND(rm); debug_only(_msize_valid=0;)} + void SUBTRACT( const RegMask &rm ) { _mask.SUBTRACT(rm); debug_only(_msize_valid=0;)} + void Clear() { _mask.Clear() ; debug_only(_msize_valid=1); _mask_size = 0; } + void Set_All() { _mask.Set_All(); debug_only(_msize_valid=1); _mask_size = RegMask::CHUNK_SIZE; } + void Insert( OptoReg::Name reg ) { _mask.Insert(reg); debug_only(_msize_valid=0;) } + void Remove( OptoReg::Name reg ) { _mask.Remove(reg); debug_only(_msize_valid=0;) } + void ClearToPairs() { _mask.ClearToPairs(); debug_only(_msize_valid=0;) } + + // Number of registers this live range uses when it colors +private: + uint8 _num_regs; // 2 for Longs and Doubles, 1 for all else + // except _num_regs is kill count for fat_proj +public: + int num_regs() const { return _num_regs; } + void set_num_regs( int reg ) { assert( _num_regs == reg || !_num_regs, "" ); _num_regs = reg; } + +private: + // Number of physical registers this live range uses when it colors + // Architecture and register-set dependent + uint8 _reg_pressure; +public: + void set_reg_pressure(int i) { _reg_pressure = i; } + int reg_pressure() const { return _reg_pressure; } + + // How much 'wiggle room' does this live range have? + // How many color choices can it make (scaled by _num_regs)? + int degrees_of_freedom() const { return mask_size() - _num_regs; } + // Bound LRGs have ZERO degrees of freedom. We also count + // must_spill as bound. + bool is_bound () const { return _is_bound; } + // Negative degrees-of-freedom; even with no neighbors this + // live range must spill. + bool not_free() const { return degrees_of_freedom() < 0; } + // Is this live range of "low-degree"? Trivially colorable? + bool lo_degree () const { return degree() <= degrees_of_freedom(); } + // Is this live range just barely "low-degree"? Trivially colorable? + bool just_lo_degree () const { return degree() == degrees_of_freedom(); } + + uint _is_oop:1, // Live-range holds an oop + _is_float:1, // True if in float registers + _was_spilled1:1, // True if prior spilling on def + _was_spilled2:1, // True if twice prior spilling on def + _is_bound:1, // live range starts life with no + // degrees of freedom. + _direct_conflict:1, // True if def and use registers in conflict + _must_spill:1, // live range has lost all degrees of freedom + // If _fat_proj is set, live range does NOT require aligned, adjacent + // registers and has NO interferences. + // If _fat_proj is clear, live range requires num_regs() to be a power of + // 2, and it requires registers to form an aligned, adjacent set. + _fat_proj:1, // + _was_lo:1, // Was lo-degree prior to coalesce + _msize_valid:1, // _mask_size cache valid + _degree_valid:1, // _degree cache valid + _has_copy:1, // Adjacent to some copy instruction + _at_risk:1; // Simplify says this guy is at risk to spill + + + // Alive if non-zero, dead if zero + bool alive() const { return _def != NULL; } + +#ifndef PRODUCT + void dump( ) const; +#endif +}; + +//------------------------------LRG_List--------------------------------------- +// Map Node indices to Live RanGe indices. +// Array lookup in the optimized case. +class LRG_List : public ResourceObj { + uint _cnt, _max; + uint* _lidxs; + ReallocMark _nesting; // assertion check for reallocations +public: + LRG_List( uint max ); + + uint lookup( uint nidx ) const { + return _lidxs[nidx]; + } + uint operator[] (uint nidx) const { return lookup(nidx); } + + void map( uint nidx, uint lidx ) { + assert( nidx < _cnt, "oob" ); + _lidxs[nidx] = lidx; + } + void extend( uint nidx, uint lidx ); + + uint Size() const { return _cnt; } +}; + +//------------------------------IFG-------------------------------------------- +// InterFerence Graph +// An undirected graph implementation. Created with a fixed number of +// vertices. Edges can be added & tested. Vertices can be removed, then +// added back later with all edges intact. Can add edges between one vertex +// and a list of other vertices. Can union vertices (and their edges) +// together. The IFG needs to be really really fast, and also fairly +// abstract! It needs abstraction so I can fiddle with the implementation to +// get even more speed. +class PhaseIFG : public Phase { + // Current implementation: a triangular adjacency list. + + // Array of adjacency-lists, indexed by live-range number + IndexSet *_adjs; + + // Assertion bit for proper use of Squaring + bool _is_square; + + // Live range structure goes here + LRG *_lrgs; // Array of LRG structures + +public: + // Largest live-range number + uint _maxlrg; + + Arena *_arena; + + // Keep track of inserted and deleted Nodes + VectorSet *_yanked; + + PhaseIFG( Arena *arena ); + void init( uint maxlrg ); + + // Add edge between a and b. Returns true if actually addded. + int add_edge( uint a, uint b ); + + // Add edge between a and everything in the vector + void add_vector( uint a, IndexSet *vec ); + + // Test for edge existance + int test_edge( uint a, uint b ) const; + + // Square-up matrix for faster Union + void SquareUp(); + + // Return number of LRG neighbors + uint neighbor_cnt( uint a ) const { return _adjs[a].count(); } + // Union edges of b into a on Squared-up matrix + void Union( uint a, uint b ); + // Test for edge in Squared-up matrix + int test_edge_sq( uint a, uint b ) const; + // Yank a Node and all connected edges from the IFG. Be prepared to + // re-insert the yanked Node in reverse order of yanking. Return a + // list of neighbors (edges) yanked. + IndexSet *remove_node( uint a ); + // Reinsert a yanked Node + void re_insert( uint a ); + // Return set of neighbors + IndexSet *neighbors( uint a ) const { return &_adjs[a]; } + +#ifndef PRODUCT + // Dump the IFG + void dump() const; + void stats() const; + void verify( const PhaseChaitin * ) const; +#endif + + //--------------- Live Range Accessors + LRG &lrgs(uint idx) const { assert(idx < _maxlrg, "oob"); return _lrgs[idx]; } + + // Compute and set effective degree. Might be folded into SquareUp(). + void Compute_Effective_Degree(); + + // Compute effective degree as the sum of neighbors' _sizes. + int effective_degree( uint lidx ) const; +}; + +// TEMPORARILY REPLACED WITH COMMAND LINE FLAG + +//// !!!!! Magic Constants need to move into ad file +#ifdef SPARC +//#define FLOAT_PRESSURE 30 /* SFLT_REG_mask.Size() - 1 */ +//#define INT_PRESSURE 23 /* NOTEMP_I_REG_mask.Size() - 1 */ +#define FLOAT_INCREMENT(regs) regs +#else +//#define FLOAT_PRESSURE 6 +//#define INT_PRESSURE 6 +#define FLOAT_INCREMENT(regs) 1 +#endif + +//------------------------------Chaitin---------------------------------------- +// Briggs-Chaitin style allocation, mostly. +class PhaseChaitin : public PhaseRegAlloc { + + int _trip_cnt; + int _alternate; + + uint _maxlrg; // Max live range number + LRG &lrgs(uint idx) const { return _ifg->lrgs(idx); } + PhaseLive *_live; // Liveness, used in the interference graph + PhaseIFG *_ifg; // Interference graph (for original chunk) + Node_List **_lrg_nodes; // Array of node; lists for lrgs which spill + VectorSet _spilled_once; // Nodes that have been spilled + VectorSet _spilled_twice; // Nodes that have been spilled twice + + LRG_List _names; // Map from Nodes to Live RanGes + + // Union-find map. Declared as a short for speed. + // Indexed by live-range number, it returns the compacted live-range number + LRG_List _uf_map; + // Reset the Union-Find map to identity + void reset_uf_map( uint maxlrg ); + // Remove the need for the Union-Find mapping + void compress_uf_map_for_nodes( ); + + // Combine the Live Range Indices for these 2 Nodes into a single live + // range. Future requests for any Node in either live range will + // return the live range index for the combined live range. + void Union( const Node *src, const Node *dst ); + + void new_lrg( const Node *x, uint lrg ); + + // Compact live ranges, removing unused ones. Return new maxlrg. + void compact(); + + uint _lo_degree; // Head of lo-degree LRGs list + uint _lo_stk_degree; // Head of lo-stk-degree LRGs list + uint _hi_degree; // Head of hi-degree LRGs list + uint _simplified; // Linked list head of simplified LRGs + + // Helper functions for Split() + uint split_DEF( Node *def, Block *b, int loc, uint max, Node **Reachblock, Node **debug_defs, GrowableArray<uint> splits, int slidx ); + uint split_USE( Node *def, Block *b, Node *use, uint useidx, uint max, bool def_down, bool cisc_sp, GrowableArray<uint> splits, int slidx ); + int clone_projs( Block *b, uint idx, Node *con, Node *copy, uint &maxlrg ); + Node *split_Rematerialize( Node *def, Block *b, uint insidx, uint &maxlrg, GrowableArray<uint> splits, int slidx, uint *lrg2reach, Node **Reachblock, bool walkThru ); + // True if lidx is used before any real register is def'd in the block + bool prompt_use( Block *b, uint lidx ); + Node *get_spillcopy_wide( Node *def, Node *use, uint uidx ); + // Insert the spill at chosen location. Skip over any interveneing Proj's or + // Phis. Skip over a CatchNode and projs, inserting in the fall-through block + // instead. Update high-pressure indices. Create a new live range. + void insert_proj( Block *b, uint i, Node *spill, uint maxlrg ); + + bool is_high_pressure( Block *b, LRG *lrg, uint insidx ); + + uint _oldphi; // Node index which separates pre-allocation nodes + + Block **_blks; // Array of blocks sorted by frequency for coalescing + +#ifndef PRODUCT + bool _trace_spilling; +#endif + +public: + PhaseChaitin( uint unique, PhaseCFG &cfg, Matcher &matcher ); + ~PhaseChaitin() {} + + // Convert a Node into a Live Range Index - a lidx + uint Find( const Node *n ) { + uint lidx = n2lidx(n); + uint uf_lidx = _uf_map[lidx]; + return (uf_lidx == lidx) ? uf_lidx : Find_compress(n); + } + uint Find_const( uint lrg ) const; + uint Find_const( const Node *n ) const; + + // Do all the real work of allocate + void Register_Allocate(); + + uint n2lidx( const Node *n ) const { return _names[n->_idx]; } + +#ifndef PRODUCT + bool trace_spilling() const { return _trace_spilling; } +#endif + +private: + // De-SSA the world. Assign registers to Nodes. Use the same register for + // all inputs to a PhiNode, effectively coalescing live ranges. Insert + // copies as needed. + void de_ssa(); + uint Find_compress( const Node *n ); + uint Find( uint lidx ) { + uint uf_lidx = _uf_map[lidx]; + return (uf_lidx == lidx) ? uf_lidx : Find_compress(lidx); + } + uint Find_compress( uint lidx ); + + uint Find_id( const Node *n ) { + uint retval = n2lidx(n); + assert(retval == Find(n),"Invalid node to lidx mapping"); + return retval; + } + + // Add edge between reg and everything in the vector. + // Same as _ifg->add_vector(reg,live) EXCEPT use the RegMask + // information to trim the set of interferences. Return the + // count of edges added. + void interfere_with_live( uint reg, IndexSet *live ); + // Count register pressure for asserts + uint count_int_pressure( IndexSet *liveout ); + uint count_float_pressure( IndexSet *liveout ); + + // Build the interference graph using virtual registers only. + // Used for aggressive coalescing. + void build_ifg_virtual( ); + + // Build the interference graph using physical registers when available. + // That is, if 2 live ranges are simultaneously alive but in their + // acceptable register sets do not overlap, then they do not interfere. + uint build_ifg_physical( ResourceArea *a ); + + // Gather LiveRanGe information, including register masks and base pointer/ + // derived pointer relationships. + void gather_lrg_masks( bool mod_cisc_masks ); + + // Force the bases of derived pointers to be alive at GC points. + bool stretch_base_pointer_live_ranges( ResourceArea *a ); + // Helper to stretch above; recursively discover the base Node for + // a given derived Node. Easy for AddP-related machine nodes, but + // needs to be recursive for derived Phis. + Node *find_base_for_derived( Node **derived_base_map, Node *derived, uint &maxlrg ); + + // Set the was-lo-degree bit. Conservative coalescing should not change the + // colorability of the graph. If any live range was of low-degree before + // coalescing, it should Simplify. This call sets the was-lo-degree bit. + void set_was_low(); + + // Split live-ranges that must spill due to register conflicts (as opposed + // to capacity spills). Typically these are things def'd in a register + // and used on the stack or vice-versa. + void pre_spill(); + + // Init LRG caching of degree, numregs. Init lo_degree list. + void cache_lrg_info( ); + + // Simplify the IFG by removing LRGs of low degree with no copies + void Pre_Simplify(); + + // Simplify the IFG by removing LRGs of low degree + void Simplify(); + + // Select colors by re-inserting edges into the IFG. + // Return TRUE if any spills occured. + uint Select( ); + // Helper function for select which allows biased coloring + OptoReg::Name choose_color( LRG &lrg, int chunk ); + // Helper function which implements biasing heuristic + OptoReg::Name bias_color( LRG &lrg, int chunk ); + + // Split uncolorable live ranges + // Return new number of live ranges + uint Split( uint maxlrg ); + + // Copy 'was_spilled'-edness from one Node to another. + void copy_was_spilled( Node *src, Node *dst ); + // Set the 'spilled_once' or 'spilled_twice' flag on a node. + void set_was_spilled( Node *n ); + + // Convert ideal spill-nodes into machine loads & stores + // Set C->failing when fixup spills could not complete, node limit exceeded. + void fixup_spills(); + + // Post-Allocation peephole copy removal + void post_allocate_copy_removal(); + Node *skip_copies( Node *c ); + int yank_if_dead( Node *old, Block *current_block, Node_List *value, Node_List *regnd ); + int elide_copy( Node *n, int k, Block *current_block, Node_List &value, Node_List ®nd, bool can_change_regs ); + int use_prior_register( Node *copy, uint idx, Node *def, Block *current_block, Node_List &value, Node_List ®nd ); + bool may_be_copy_of_callee( Node *def ) const; + + // If nreg already contains the same constant as val then eliminate it + bool eliminate_copy_of_constant(Node* val, Block *current_block, Node_List& value, Node_List ®nd, + OptoReg::Name nreg, OptoReg::Name nreg2); + // Extend the node to LRG mapping + void add_reference( const Node *node, const Node *old_node); + +private: + + static int _final_loads, _final_stores, _final_copies, _final_memoves; + static double _final_load_cost, _final_store_cost, _final_copy_cost, _final_memove_cost; + static int _conserv_coalesce, _conserv_coalesce_pair; + static int _conserv_coalesce_trie, _conserv_coalesce_quad; + static int _post_alloc; + static int _lost_opp_pp_coalesce, _lost_opp_cflow_coalesce; + static int _used_cisc_instructions, _unused_cisc_instructions; + static int _allocator_attempts, _allocator_successes; + +#ifndef PRODUCT + static uint _high_pressure, _low_pressure; + + void dump() const; + void dump( const Node *n ) const; + void dump( const Block * b ) const; + void dump_degree_lists() const; + void dump_simplified() const; + void dump_lrg( uint lidx ) const; + void dump_bb( uint pre_order ) const; + + // Verify that base pointers and derived pointers are still sane + void verify_base_ptrs( ResourceArea *a ) const; + + void dump_for_spill_split_recycle() const; + +public: + void dump_frame() const; + char *dump_register( const Node *n, char *buf ) const; +private: + static void print_chaitin_statistics(); +#endif + friend class PhaseCoalesce; + friend class PhaseAggressiveCoalesce; + friend class PhaseConservativeCoalesce; +};