Mercurial > hg > graal-compiler
diff src/share/vm/opto/phaseX.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 | a8880a78d355 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/opto/phaseX.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,516 @@ +/* + * 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 Compile; +class ConINode; +class ConLNode; +class Node; +class Type; +class PhaseTransform; +class PhaseGVN; +class PhaseIterGVN; +class PhaseCCP; +class PhasePeephole; +class PhaseRegAlloc; + + +//----------------------------------------------------------------------------- +// Expandable closed hash-table of nodes, initialized to NULL. +// Note that the constructor just zeros things +// Storage is reclaimed when the Arena's lifetime is over. +class NodeHash : public StackObj { +protected: + Arena *_a; // Arena to allocate in + uint _max; // Size of table (power of 2) + uint _inserts; // For grow and debug, count of hash_inserts + uint _insert_limit; // 'grow' when _inserts reaches _insert_limit + Node **_table; // Hash table of Node pointers + Node *_sentinel; // Replaces deleted entries in hash table + +public: + NodeHash(uint est_max_size); + NodeHash(Arena *arena, uint est_max_size); + NodeHash(NodeHash *use_this_state); +#ifdef ASSERT + ~NodeHash(); // Unlock all nodes upon destruction of table. + void operator=(const NodeHash&); // Unlock all nodes upon replacement of table. +#endif + Node *hash_find(const Node*);// Find an equivalent version in hash table + Node *hash_find_insert(Node*);// If not in table insert else return found node + void hash_insert(Node*); // Insert into hash table + bool hash_delete(const Node*);// Replace with _sentinel in hash table + void check_grow() { + _inserts++; + if( _inserts == _insert_limit ) { grow(); } + assert( _inserts <= _insert_limit, "hash table overflow"); + assert( _inserts < _max, "hash table overflow" ); + } + static uint round_up(uint); // Round up to nearest power of 2 + void grow(); // Grow _table to next power of 2 and rehash + // Return 75% of _max, rounded up. + uint insert_limit() const { return _max - (_max>>2); } + + void clear(); // Set all entries to NULL, keep storage. + // Size of hash table + uint size() const { return _max; } + // Return Node* at index in table + Node *at(uint table_index) { + assert(table_index < _max, "Must be within table"); + return _table[table_index]; + } + + void remove_useless_nodes(VectorSet &useful); // replace with sentinel + + Node *sentinel() { return _sentinel; } + +#ifndef PRODUCT + Node *find_index(uint idx); // For debugging + void dump(); // For debugging, dump statistics +#endif + uint _grows; // For debugging, count of table grow()s + uint _look_probes; // For debugging, count of hash probes + uint _lookup_hits; // For debugging, count of hash_finds + uint _lookup_misses; // For debugging, count of hash_finds + uint _insert_probes; // For debugging, count of hash probes + uint _delete_probes; // For debugging, count of hash probes for deletes + uint _delete_hits; // For debugging, count of hash probes for deletes + uint _delete_misses; // For debugging, count of hash probes for deletes + uint _total_inserts; // For debugging, total inserts into hash table + uint _total_insert_probes; // For debugging, total probes while inserting +}; + + +//----------------------------------------------------------------------------- +// Map dense integer indices to Types. Uses classic doubling-array trick. +// Abstractly provides an infinite array of Type*'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. +// Despite the general name, this class is customized for use by PhaseTransform. +class Type_Array : public StackObj { + Arena *_a; // Arena to allocate in + uint _max; + const Type **_types; + void grow( uint i ); // Grow array node to fit + const Type *operator[] ( uint i ) const // Lookup, or NULL for not mapped + { return (i<_max) ? _types[i] : (Type*)NULL; } + friend class PhaseTransform; +public: + Type_Array(Arena *a) : _a(a), _max(0), _types(0) {} + Type_Array(Type_Array *ta) : _a(ta->_a), _max(ta->_max), _types(ta->_types) { } + const Type *fast_lookup(uint i) const{assert(i<_max,"oob");return _types[i];} + // Extend the mapping: index i maps to Type *n. + void map( uint i, const Type *n ) { if( i>=_max ) grow(i); _types[i] = n; } + uint Size() const { return _max; } +#ifndef PRODUCT + void dump() const; +#endif +}; + + +//------------------------------PhaseRemoveUseless----------------------------- +// Remove useless nodes from GVN hash-table, worklist, and graph +class PhaseRemoveUseless : public Phase { +protected: + Unique_Node_List _useful; // Nodes reachable from root + // list is allocated from current resource area +public: + PhaseRemoveUseless( PhaseGVN *gvn, Unique_Node_List *worklist ); + + Unique_Node_List *get_useful() { return &_useful; } +}; + + +//------------------------------PhaseTransform--------------------------------- +// Phases that analyze, then transform. Constructing the Phase object does any +// global or slow analysis. The results are cached later for a fast +// transformation pass. When the Phase object is deleted the cached analysis +// results are deleted. +class PhaseTransform : public Phase { +protected: + Arena* _arena; + Node_Array _nodes; // Map old node indices to new nodes. + Type_Array _types; // Map old node indices to Types. + + // ConNode caches: + enum { _icon_min = -1 * HeapWordSize, + _icon_max = 16 * HeapWordSize, + _lcon_min = _icon_min, + _lcon_max = _icon_max, + _zcon_max = (uint)T_CONFLICT + }; + ConINode* _icons[_icon_max - _icon_min + 1]; // cached jint constant nodes + ConLNode* _lcons[_lcon_max - _lcon_min + 1]; // cached jlong constant nodes + ConNode* _zcons[_zcon_max + 1]; // cached is_zero_type nodes + void init_con_caches(); + + // Support both int and long caches because either might be an intptr_t, + // so they show up frequently in address computations. + +public: + PhaseTransform( PhaseNumber pnum ); + PhaseTransform( Arena *arena, PhaseNumber pnum ); + PhaseTransform( PhaseTransform *phase, PhaseNumber pnum ); + + Arena* arena() { return _arena; } + Type_Array& types() { return _types; } + // _nodes is used in varying ways by subclasses, which define local accessors + +public: + // Get a previously recorded type for the node n. + // This type must already have been recorded. + // If you want the type of a very new (untransformed) node, + // you must use type_or_null, and test the result for NULL. + const Type* type(const Node* n) const { + const Type* t = _types.fast_lookup(n->_idx); + assert(t != NULL, "must set before get"); + return t; + } + // Get a previously recorded type for the node n, + // or else return NULL if there is none. + const Type* type_or_null(const Node* n) const { + return _types.fast_lookup(n->_idx); + } + // Record a type for a node. + void set_type(const Node* n, const Type *t) { + assert(t != NULL, "type must not be null"); + _types.map(n->_idx, t); + } + // Record an initial type for a node, the node's bottom type. + void set_type_bottom(const Node* n) { + // Use this for initialization when bottom_type() (or better) is not handy. + // Usually the initialization shoudl be to n->Value(this) instead, + // or a hand-optimized value like Type::MEMORY or Type::CONTROL. + assert(_types[n->_idx] == NULL, "must set the initial type just once"); + _types.map(n->_idx, n->bottom_type()); + } + // Make sure the types array is big enough to record a size for the node n. + // (In product builds, we never want to do range checks on the types array!) + void ensure_type_or_null(const Node* n) { + if (n->_idx >= _types.Size()) + _types.map(n->_idx, NULL); // Grow the types array as needed. + } + + // Utility functions: + const TypeInt* find_int_type( Node* n); + const TypeLong* find_long_type(Node* n); + jint find_int_con( Node* n, jint value_if_unknown) { + const TypeInt* t = find_int_type(n); + return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown; + } + jlong find_long_con(Node* n, jlong value_if_unknown) { + const TypeLong* t = find_long_type(n); + return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown; + } + + // Make an idealized constant, i.e., one of ConINode, ConPNode, ConFNode, etc. + // Same as transform(ConNode::make(t)). + ConNode* makecon(const Type* t); + virtual ConNode* uncached_makecon(const Type* t) // override in PhaseValues + { ShouldNotCallThis(); return NULL; } + + // Fast int or long constant. Same as TypeInt::make(i) or TypeLong::make(l). + ConINode* intcon(jint i); + ConLNode* longcon(jlong l); + + // Fast zero or null constant. Same as makecon(Type::get_zero_type(bt)). + ConNode* zerocon(BasicType bt); + + // Return a node which computes the same function as this node, but + // in a faster or cheaper fashion. + virtual Node *transform( Node *n ) = 0; + + // Return whether two Nodes are equivalent. + // Must not be recursive, since the recursive version is built from this. + // For pessimistic optimizations this is simply pointer equivalence. + bool eqv(const Node* n1, const Node* n2) const { return n1 == n2; } + + // Return whether two Nodes are equivalent, after stripping casting. + bool eqv_uncast(const Node* n1, const Node* n2) const { + return eqv(n1->uncast(), n2->uncast()); + } + + // For pessimistic passes, the return type must monotonically narrow. + // For optimistic passes, the return type must monotonically widen. + // It is possible to get into a "death march" in either type of pass, + // where the types are continually moving but it will take 2**31 or + // more steps to converge. This doesn't happen on most normal loops. + // + // Here is an example of a deadly loop for an optimistic pass, along + // with a partial trace of inferred types: + // x = phi(0,x'); L: x' = x+1; if (x' >= 0) goto L; + // 0 1 join([0..max], 1) + // [0..1] [1..2] join([0..max], [1..2]) + // [0..2] [1..3] join([0..max], [1..3]) + // ... ... ... + // [0..max] [min]u[1..max] join([0..max], [min..max]) + // [0..max] ==> fixpoint + // We would have proven, the hard way, that the iteration space is all + // non-negative ints, with the loop terminating due to 32-bit overflow. + // + // Here is the corresponding example for a pessimistic pass: + // x = phi(0,x'); L: x' = x-1; if (x' >= 0) goto L; + // int int join([0..max], int) + // [0..max] [-1..max-1] join([0..max], [-1..max-1]) + // [0..max-1] [-1..max-2] join([0..max], [-1..max-2]) + // ... ... ... + // [0..1] [-1..0] join([0..max], [-1..0]) + // 0 -1 join([0..max], -1) + // 0 == fixpoint + // We would have proven, the hard way, that the iteration space is {0}. + // (Usually, other optimizations will make the "if (x >= 0)" fold up + // before we get into trouble. But not always.) + // + // It's a pleasant thing to observe that the pessimistic pass + // will make short work of the optimistic pass's deadly loop, + // and vice versa. That is a good example of the complementary + // purposes of the CCP (optimistic) vs. GVN (pessimistic) phases. + // + // In any case, only widen or narrow a few times before going to the + // correct flavor of top or bottom. + // + // This call only needs to be made once as the data flows around any + // given cycle. We do it at Phis, and nowhere else. + // The types presented are the new type of a phi (computed by PhiNode::Value) + // and the previously computed type, last time the phi was visited. + // + // The third argument is upper limit for the saturated value, + // if the phase wishes to widen the new_type. + // If the phase is narrowing, the old type provides a lower limit. + // Caller guarantees that old_type and new_type are no higher than limit_type. + virtual const Type* saturate(const Type* new_type, const Type* old_type, + const Type* limit_type) const + { ShouldNotCallThis(); return NULL; } + +#ifndef PRODUCT + void dump_old2new_map() const; + void dump_new( uint new_lidx ) const; + void dump_types() const; + void dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl = true); + void dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited); + + uint _count_progress; // For profiling, count transforms that make progress + void set_progress() { ++_count_progress; assert( allow_progress(),"No progress allowed during verification") } + void clear_progress() { _count_progress = 0; } + uint made_progress() const { return _count_progress; } + + uint _count_transforms; // For profiling, count transforms performed + void set_transforms() { ++_count_transforms; } + void clear_transforms() { _count_transforms = 0; } + uint made_transforms() const{ return _count_transforms; } + + bool _allow_progress; // progress not allowed during verification pass + void set_allow_progress(bool allow) { _allow_progress = allow; } + bool allow_progress() { return _allow_progress; } +#endif +}; + +//------------------------------PhaseValues------------------------------------ +// Phase infrastructure to support values +class PhaseValues : public PhaseTransform { +protected: + NodeHash _table; // Hash table for value-numbering + +public: + PhaseValues( Arena *arena, uint est_max_size ); + PhaseValues( PhaseValues *pt ); + PhaseValues( PhaseValues *ptv, const char *dummy ); + NOT_PRODUCT( ~PhaseValues(); ) + virtual PhaseIterGVN *is_IterGVN() { return 0; } + + // Some Ideal and other transforms delete --> modify --> insert values + bool hash_delete(Node *n) { return _table.hash_delete(n); } + void hash_insert(Node *n) { _table.hash_insert(n); } + Node *hash_find_insert(Node *n){ return _table.hash_find_insert(n); } + Node *hash_find(const Node *n) { return _table.hash_find(n); } + + // Used after parsing to eliminate values that are no longer in program + void remove_useless_nodes(VectorSet &useful) { _table.remove_useless_nodes(useful); } + + virtual ConNode* uncached_makecon(const Type* t); // override from PhaseTransform + + virtual const Type* saturate(const Type* new_type, const Type* old_type, + const Type* limit_type) const + { return new_type; } + +#ifndef PRODUCT + uint _count_new_values; // For profiling, count new values produced + void inc_new_values() { ++_count_new_values; } + void clear_new_values() { _count_new_values = 0; } + uint made_new_values() const { return _count_new_values; } +#endif +}; + + +//------------------------------PhaseGVN--------------------------------------- +// Phase for performing local, pessimistic GVN-style optimizations. +class PhaseGVN : public PhaseValues { +public: + PhaseGVN( Arena *arena, uint est_max_size ) : PhaseValues( arena, est_max_size ) {} + PhaseGVN( PhaseGVN *gvn ) : PhaseValues( gvn ) {} + PhaseGVN( PhaseGVN *gvn, const char *dummy ) : PhaseValues( gvn, dummy ) {} + + // Return a node which computes the same function as this node, but + // in a faster or cheaper fashion. + Node *transform( Node *n ); + Node *transform_no_reclaim( Node *n ); + + // Check for a simple dead loop when a data node references itself. + DEBUG_ONLY(void dead_loop_check(Node *n);) +}; + +//------------------------------PhaseIterGVN----------------------------------- +// Phase for iteratively performing local, pessimistic GVN-style optimizations. +// and ideal transformations on the graph. +class PhaseIterGVN : public PhaseGVN { + // Idealize old Node 'n' with respect to its inputs and its value + virtual Node *transform_old( Node *a_node ); +protected: + + // Idealize new Node 'n' with respect to its inputs and its value + virtual Node *transform( Node *a_node ); + + // Warm up hash table, type table and initial worklist + void init_worklist( Node *a_root ); + + virtual const Type* saturate(const Type* new_type, const Type* old_type, + const Type* limit_type) const; + // Usually returns new_type. Returns old_type if new_type is only a slight + // improvement, such that it would take many (>>10) steps to reach 2**32. + +public: + PhaseIterGVN( PhaseIterGVN *igvn ); // Used by CCP constructor + PhaseIterGVN( PhaseGVN *gvn ); // Used after Parser + PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ); // Used after +VerifyOpto + + virtual PhaseIterGVN *is_IterGVN() { return this; } + + Unique_Node_List _worklist; // Iterative worklist + + // Given def-use info and an initial worklist, apply Node::Ideal, + // Node::Value, Node::Identity, hash-based value numbering, Node::Ideal_DU + // and dominator info to a fixed point. + void optimize(); + + // Register a new node with the iter GVN pass without transforming it. + // Used when we need to restructure a Region/Phi area and all the Regions + // and Phis need to complete this one big transform before any other + // transforms can be triggered on the region. + // Optional 'orig' is an earlier version of this node. + // It is significant only for debugging and profiling. + Node* register_new_node_with_optimizer(Node* n, Node* orig = NULL); + + // Kill a globally dead Node. It is allowed to have uses which are + // assumed dead and left 'in limbo'. + void remove_globally_dead_node( Node *dead ); + + // Kill all inputs to a dead node, recursively making more dead nodes. + // The Node must be dead locally, i.e., have no uses. + void remove_dead_node( Node *dead ) { + assert(dead->outcnt() == 0 && !dead->is_top(), "node must be dead"); + remove_globally_dead_node(dead); + } + + // Subsume users of node 'old' into node 'nn' + // If no Def-Use info existed for 'nn' it will after call. + void subsume_node( Node *old, Node *nn ); + + // Add users of 'n' to worklist + void add_users_to_worklist0( Node *n ); + void add_users_to_worklist ( Node *n ); + +#ifndef PRODUCT +protected: + // Sub-quadratic implementation of VerifyIterativeGVN. + unsigned long _verify_counter; + unsigned long _verify_full_passes; + enum { _verify_window_size = 30 }; + Node* _verify_window[_verify_window_size]; + void verify_step(Node* n); +#endif +}; + +//------------------------------PhaseCCP--------------------------------------- +// Phase for performing global Conditional Constant Propagation. +// Should be replaced with combined CCP & GVN someday. +class PhaseCCP : public PhaseIterGVN { + // Non-recursive. Use analysis to transform single Node. + virtual Node *transform_once( Node *n ); + +public: + PhaseCCP( PhaseIterGVN *igvn ); // Compute conditional constants + NOT_PRODUCT( ~PhaseCCP(); ) + + // Worklist algorithm identifies constants + void analyze(); + // Recursive traversal of program. Used analysis to modify program. + virtual Node *transform( Node *n ); + // Do any transformation after analysis + void do_transform(); + + virtual const Type* saturate(const Type* new_type, const Type* old_type, + const Type* limit_type) const; + // Returns new_type->widen(old_type), which increments the widen bits until + // giving up with TypeInt::INT or TypeLong::LONG. + // Result is clipped to limit_type if necessary. + +#ifndef PRODUCT + static uint _total_invokes; // For profiling, count invocations + void inc_invokes() { ++PhaseCCP::_total_invokes; } + + static uint _total_constants; // For profiling, count constants found + uint _count_constants; + void clear_constants() { _count_constants = 0; } + void inc_constants() { ++_count_constants; } + uint count_constants() const { return _count_constants; } + + static void print_statistics(); +#endif +}; + + +//------------------------------PhasePeephole---------------------------------- +// Phase for performing peephole optimizations on register allocated basic blocks. +class PhasePeephole : public PhaseTransform { + PhaseRegAlloc *_regalloc; + PhaseCFG &_cfg; + // Recursive traversal of program. Pure function is unused in this phase + virtual Node *transform( Node *n ); + +public: + PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg ); + NOT_PRODUCT( ~PhasePeephole(); ) + + // Do any transformation after analysis + void do_transform(); + +#ifndef PRODUCT + static uint _total_peepholes; // For profiling, count peephole rules applied + uint _count_peepholes; + void clear_peepholes() { _count_peepholes = 0; } + void inc_peepholes() { ++_count_peepholes; } + uint count_peepholes() const { return _count_peepholes; } + + static void print_statistics(); +#endif +};