| /* |
| * Copyright (c) 1997, 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. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "memory/allocation.inline.hpp" |
| #include "opto/block.hpp" |
| #include "opto/callnode.hpp" |
| #include "opto/cfgnode.hpp" |
| #include "opto/connode.hpp" |
| #include "opto/idealGraphPrinter.hpp" |
| #include "opto/loopnode.hpp" |
| #include "opto/machnode.hpp" |
| #include "opto/opcodes.hpp" |
| #include "opto/phaseX.hpp" |
| #include "opto/regalloc.hpp" |
| #include "opto/rootnode.hpp" |
| |
| //============================================================================= |
| #define NODE_HASH_MINIMUM_SIZE 255 |
| //------------------------------NodeHash--------------------------------------- |
| NodeHash::NodeHash(uint est_max_size) : |
| _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ), |
| _a(Thread::current()->resource_area()), |
| _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ), // (Node**)_a->Amalloc(_max * sizeof(Node*)) ), |
| _inserts(0), _insert_limit( insert_limit() ), |
| _look_probes(0), _lookup_hits(0), _lookup_misses(0), |
| _total_insert_probes(0), _total_inserts(0), |
| _insert_probes(0), _grows(0) { |
| // _sentinel must be in the current node space |
| _sentinel = new (Compile::current()) ProjNode(NULL, TypeFunc::Control); |
| memset(_table,0,sizeof(Node*)*_max); |
| } |
| |
| //------------------------------NodeHash--------------------------------------- |
| NodeHash::NodeHash(Arena *arena, uint est_max_size) : |
| _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ), |
| _a(arena), |
| _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ), |
| _inserts(0), _insert_limit( insert_limit() ), |
| _look_probes(0), _lookup_hits(0), _lookup_misses(0), |
| _delete_probes(0), _delete_hits(0), _delete_misses(0), |
| _total_insert_probes(0), _total_inserts(0), |
| _insert_probes(0), _grows(0) { |
| // _sentinel must be in the current node space |
| _sentinel = new (Compile::current()) ProjNode(NULL, TypeFunc::Control); |
| memset(_table,0,sizeof(Node*)*_max); |
| } |
| |
| //------------------------------NodeHash--------------------------------------- |
| NodeHash::NodeHash(NodeHash *nh) { |
| debug_only(_table = (Node**)badAddress); // interact correctly w/ operator= |
| // just copy in all the fields |
| *this = *nh; |
| // nh->_sentinel must be in the current node space |
| } |
| |
| void NodeHash::replace_with(NodeHash *nh) { |
| debug_only(_table = (Node**)badAddress); // interact correctly w/ operator= |
| // just copy in all the fields |
| *this = *nh; |
| // nh->_sentinel must be in the current node space |
| } |
| |
| //------------------------------hash_find-------------------------------------- |
| // Find in hash table |
| Node *NodeHash::hash_find( const Node *n ) { |
| // ((Node*)n)->set_hash( n->hash() ); |
| uint hash = n->hash(); |
| if (hash == Node::NO_HASH) { |
| debug_only( _lookup_misses++ ); |
| return NULL; |
| } |
| uint key = hash & (_max-1); |
| uint stride = key | 0x01; |
| debug_only( _look_probes++ ); |
| Node *k = _table[key]; // Get hashed value |
| if( !k ) { // ?Miss? |
| debug_only( _lookup_misses++ ); |
| return NULL; // Miss! |
| } |
| |
| int op = n->Opcode(); |
| uint req = n->req(); |
| while( 1 ) { // While probing hash table |
| if( k->req() == req && // Same count of inputs |
| k->Opcode() == op ) { // Same Opcode |
| for( uint i=0; i<req; i++ ) |
| if( n->in(i)!=k->in(i)) // Different inputs? |
| goto collision; // "goto" is a speed hack... |
| if( n->cmp(*k) ) { // Check for any special bits |
| debug_only( _lookup_hits++ ); |
| return k; // Hit! |
| } |
| } |
| collision: |
| debug_only( _look_probes++ ); |
| key = (key + stride/*7*/) & (_max-1); // Stride through table with relative prime |
| k = _table[key]; // Get hashed value |
| if( !k ) { // ?Miss? |
| debug_only( _lookup_misses++ ); |
| return NULL; // Miss! |
| } |
| } |
| ShouldNotReachHere(); |
| return NULL; |
| } |
| |
| //------------------------------hash_find_insert------------------------------- |
| // Find in hash table, insert if not already present |
| // Used to preserve unique entries in hash table |
| Node *NodeHash::hash_find_insert( Node *n ) { |
| // n->set_hash( ); |
| uint hash = n->hash(); |
| if (hash == Node::NO_HASH) { |
| debug_only( _lookup_misses++ ); |
| return NULL; |
| } |
| uint key = hash & (_max-1); |
| uint stride = key | 0x01; // stride must be relatively prime to table siz |
| uint first_sentinel = 0; // replace a sentinel if seen. |
| debug_only( _look_probes++ ); |
| Node *k = _table[key]; // Get hashed value |
| if( !k ) { // ?Miss? |
| debug_only( _lookup_misses++ ); |
| _table[key] = n; // Insert into table! |
| debug_only(n->enter_hash_lock()); // Lock down the node while in the table. |
| check_grow(); // Grow table if insert hit limit |
| return NULL; // Miss! |
| } |
| else if( k == _sentinel ) { |
| first_sentinel = key; // Can insert here |
| } |
| |
| int op = n->Opcode(); |
| uint req = n->req(); |
| while( 1 ) { // While probing hash table |
| if( k->req() == req && // Same count of inputs |
| k->Opcode() == op ) { // Same Opcode |
| for( uint i=0; i<req; i++ ) |
| if( n->in(i)!=k->in(i)) // Different inputs? |
| goto collision; // "goto" is a speed hack... |
| if( n->cmp(*k) ) { // Check for any special bits |
| debug_only( _lookup_hits++ ); |
| return k; // Hit! |
| } |
| } |
| collision: |
| debug_only( _look_probes++ ); |
| key = (key + stride) & (_max-1); // Stride through table w/ relative prime |
| k = _table[key]; // Get hashed value |
| if( !k ) { // ?Miss? |
| debug_only( _lookup_misses++ ); |
| key = (first_sentinel == 0) ? key : first_sentinel; // ?saw sentinel? |
| _table[key] = n; // Insert into table! |
| debug_only(n->enter_hash_lock()); // Lock down the node while in the table. |
| check_grow(); // Grow table if insert hit limit |
| return NULL; // Miss! |
| } |
| else if( first_sentinel == 0 && k == _sentinel ) { |
| first_sentinel = key; // Can insert here |
| } |
| |
| } |
| ShouldNotReachHere(); |
| return NULL; |
| } |
| |
| //------------------------------hash_insert------------------------------------ |
| // Insert into hash table |
| void NodeHash::hash_insert( Node *n ) { |
| // // "conflict" comments -- print nodes that conflict |
| // bool conflict = false; |
| // n->set_hash(); |
| uint hash = n->hash(); |
| if (hash == Node::NO_HASH) { |
| return; |
| } |
| check_grow(); |
| uint key = hash & (_max-1); |
| uint stride = key | 0x01; |
| |
| while( 1 ) { // While probing hash table |
| debug_only( _insert_probes++ ); |
| Node *k = _table[key]; // Get hashed value |
| if( !k || (k == _sentinel) ) break; // Found a slot |
| assert( k != n, "already inserted" ); |
| // if( PrintCompilation && PrintOptoStatistics && Verbose ) { tty->print(" conflict: "); k->dump(); conflict = true; } |
| key = (key + stride) & (_max-1); // Stride through table w/ relative prime |
| } |
| _table[key] = n; // Insert into table! |
| debug_only(n->enter_hash_lock()); // Lock down the node while in the table. |
| // if( conflict ) { n->dump(); } |
| } |
| |
| //------------------------------hash_delete------------------------------------ |
| // Replace in hash table with sentinel |
| bool NodeHash::hash_delete( const Node *n ) { |
| Node *k; |
| uint hash = n->hash(); |
| if (hash == Node::NO_HASH) { |
| debug_only( _delete_misses++ ); |
| return false; |
| } |
| uint key = hash & (_max-1); |
| uint stride = key | 0x01; |
| debug_only( uint counter = 0; ); |
| for( ; /* (k != NULL) && (k != _sentinel) */; ) { |
| debug_only( counter++ ); |
| debug_only( _delete_probes++ ); |
| k = _table[key]; // Get hashed value |
| if( !k ) { // Miss? |
| debug_only( _delete_misses++ ); |
| #ifdef ASSERT |
| if( VerifyOpto ) { |
| for( uint i=0; i < _max; i++ ) |
| assert( _table[i] != n, "changed edges with rehashing" ); |
| } |
| #endif |
| return false; // Miss! Not in chain |
| } |
| else if( n == k ) { |
| debug_only( _delete_hits++ ); |
| _table[key] = _sentinel; // Hit! Label as deleted entry |
| debug_only(((Node*)n)->exit_hash_lock()); // Unlock the node upon removal from table. |
| return true; |
| } |
| else { |
| // collision: move through table with prime offset |
| key = (key + stride/*7*/) & (_max-1); |
| assert( counter <= _insert_limit, "Cycle in hash-table"); |
| } |
| } |
| ShouldNotReachHere(); |
| return false; |
| } |
| |
| //------------------------------round_up--------------------------------------- |
| // Round up to nearest power of 2 |
| uint NodeHash::round_up( uint x ) { |
| x += (x>>2); // Add 25% slop |
| if( x <16 ) return 16; // Small stuff |
| uint i=16; |
| while( i < x ) i <<= 1; // Double to fit |
| return i; // Return hash table size |
| } |
| |
| //------------------------------grow------------------------------------------- |
| // Grow _table to next power of 2 and insert old entries |
| void NodeHash::grow() { |
| // Record old state |
| uint old_max = _max; |
| Node **old_table = _table; |
| // Construct new table with twice the space |
| _grows++; |
| _total_inserts += _inserts; |
| _total_insert_probes += _insert_probes; |
| _inserts = 0; |
| _insert_probes = 0; |
| _max = _max << 1; |
| _table = NEW_ARENA_ARRAY( _a , Node* , _max ); // (Node**)_a->Amalloc( _max * sizeof(Node*) ); |
| memset(_table,0,sizeof(Node*)*_max); |
| _insert_limit = insert_limit(); |
| // Insert old entries into the new table |
| for( uint i = 0; i < old_max; i++ ) { |
| Node *m = *old_table++; |
| if( !m || m == _sentinel ) continue; |
| debug_only(m->exit_hash_lock()); // Unlock the node upon removal from old table. |
| hash_insert(m); |
| } |
| } |
| |
| //------------------------------clear------------------------------------------ |
| // Clear all entries in _table to NULL but keep storage |
| void NodeHash::clear() { |
| #ifdef ASSERT |
| // Unlock all nodes upon removal from table. |
| for (uint i = 0; i < _max; i++) { |
| Node* n = _table[i]; |
| if (!n || n == _sentinel) continue; |
| n->exit_hash_lock(); |
| } |
| #endif |
| |
| memset( _table, 0, _max * sizeof(Node*) ); |
| } |
| |
| //-----------------------remove_useless_nodes---------------------------------- |
| // Remove useless nodes from value table, |
| // implementation does not depend on hash function |
| void NodeHash::remove_useless_nodes(VectorSet &useful) { |
| |
| // Dead nodes in the hash table inherited from GVN should not replace |
| // existing nodes, remove dead nodes. |
| uint max = size(); |
| Node *sentinel_node = sentinel(); |
| for( uint i = 0; i < max; ++i ) { |
| Node *n = at(i); |
| if(n != NULL && n != sentinel_node && !useful.test(n->_idx)) { |
| debug_only(n->exit_hash_lock()); // Unlock the node when removed |
| _table[i] = sentinel_node; // Replace with placeholder |
| } |
| } |
| } |
| |
| #ifndef PRODUCT |
| //------------------------------dump------------------------------------------- |
| // Dump statistics for the hash table |
| void NodeHash::dump() { |
| _total_inserts += _inserts; |
| _total_insert_probes += _insert_probes; |
| if (PrintCompilation && PrintOptoStatistics && Verbose && (_inserts > 0)) { |
| if (WizardMode) { |
| for (uint i=0; i<_max; i++) { |
| if (_table[i]) |
| tty->print("%d/%d/%d ",i,_table[i]->hash()&(_max-1),_table[i]->_idx); |
| } |
| } |
| tty->print("\nGVN Hash stats: %d grows to %d max_size\n", _grows, _max); |
| tty->print(" %d/%d (%8.1f%% full)\n", _inserts, _max, (double)_inserts/_max*100.0); |
| tty->print(" %dp/(%dh+%dm) (%8.2f probes/lookup)\n", _look_probes, _lookup_hits, _lookup_misses, (double)_look_probes/(_lookup_hits+_lookup_misses)); |
| tty->print(" %dp/%di (%8.2f probes/insert)\n", _total_insert_probes, _total_inserts, (double)_total_insert_probes/_total_inserts); |
| // sentinels increase lookup cost, but not insert cost |
| assert((_lookup_misses+_lookup_hits)*4+100 >= _look_probes, "bad hash function"); |
| assert( _inserts+(_inserts>>3) < _max, "table too full" ); |
| assert( _inserts*3+100 >= _insert_probes, "bad hash function" ); |
| } |
| } |
| |
| Node *NodeHash::find_index(uint idx) { // For debugging |
| // Find an entry by its index value |
| for( uint i = 0; i < _max; i++ ) { |
| Node *m = _table[i]; |
| if( !m || m == _sentinel ) continue; |
| if( m->_idx == (uint)idx ) return m; |
| } |
| return NULL; |
| } |
| #endif |
| |
| #ifdef ASSERT |
| NodeHash::~NodeHash() { |
| // Unlock all nodes upon destruction of table. |
| if (_table != (Node**)badAddress) clear(); |
| } |
| |
| void NodeHash::operator=(const NodeHash& nh) { |
| // Unlock all nodes upon replacement of table. |
| if (&nh == this) return; |
| if (_table != (Node**)badAddress) clear(); |
| memcpy(this, &nh, sizeof(*this)); |
| // Do not increment hash_lock counts again. |
| // Instead, be sure we never again use the source table. |
| ((NodeHash*)&nh)->_table = (Node**)badAddress; |
| } |
| |
| |
| #endif |
| |
| |
| //============================================================================= |
| //------------------------------PhaseRemoveUseless----------------------------- |
| // 1) Use a breadthfirst walk to collect useful nodes reachable from root. |
| PhaseRemoveUseless::PhaseRemoveUseless( PhaseGVN *gvn, Unique_Node_List *worklist ) : Phase(Remove_Useless), |
| _useful(Thread::current()->resource_area()) { |
| |
| // Implementation requires 'UseLoopSafepoints == true' and an edge from root |
| // to each SafePointNode at a backward branch. Inserted in add_safepoint(). |
| if( !UseLoopSafepoints || !OptoRemoveUseless ) return; |
| |
| // Identify nodes that are reachable from below, useful. |
| C->identify_useful_nodes(_useful); |
| // Update dead node list |
| C->update_dead_node_list(_useful); |
| |
| // Remove all useless nodes from PhaseValues' recorded types |
| // Must be done before disconnecting nodes to preserve hash-table-invariant |
| gvn->remove_useless_nodes(_useful.member_set()); |
| |
| // Remove all useless nodes from future worklist |
| worklist->remove_useless_nodes(_useful.member_set()); |
| |
| // Disconnect 'useless' nodes that are adjacent to useful nodes |
| C->remove_useless_nodes(_useful); |
| |
| // Remove edges from "root" to each SafePoint at a backward branch. |
| // They were inserted during parsing (see add_safepoint()) to make infinite |
| // loops without calls or exceptions visible to root, i.e., useful. |
| Node *root = C->root(); |
| if( root != NULL ) { |
| for( uint i = root->req(); i < root->len(); ++i ) { |
| Node *n = root->in(i); |
| if( n != NULL && n->is_SafePoint() ) { |
| root->rm_prec(i); |
| --i; |
| } |
| } |
| } |
| } |
| |
| |
| //============================================================================= |
| //------------------------------PhaseTransform--------------------------------- |
| PhaseTransform::PhaseTransform( PhaseNumber pnum ) : Phase(pnum), |
| _arena(Thread::current()->resource_area()), |
| _nodes(_arena), |
| _types(_arena) |
| { |
| init_con_caches(); |
| #ifndef PRODUCT |
| clear_progress(); |
| clear_transforms(); |
| set_allow_progress(true); |
| #endif |
| // Force allocation for currently existing nodes |
| _types.map(C->unique(), NULL); |
| } |
| |
| //------------------------------PhaseTransform--------------------------------- |
| PhaseTransform::PhaseTransform( Arena *arena, PhaseNumber pnum ) : Phase(pnum), |
| _arena(arena), |
| _nodes(arena), |
| _types(arena) |
| { |
| init_con_caches(); |
| #ifndef PRODUCT |
| clear_progress(); |
| clear_transforms(); |
| set_allow_progress(true); |
| #endif |
| // Force allocation for currently existing nodes |
| _types.map(C->unique(), NULL); |
| } |
| |
| //------------------------------PhaseTransform--------------------------------- |
| // Initialize with previously generated type information |
| PhaseTransform::PhaseTransform( PhaseTransform *pt, PhaseNumber pnum ) : Phase(pnum), |
| _arena(pt->_arena), |
| _nodes(pt->_nodes), |
| _types(pt->_types) |
| { |
| init_con_caches(); |
| #ifndef PRODUCT |
| clear_progress(); |
| clear_transforms(); |
| set_allow_progress(true); |
| #endif |
| } |
| |
| void PhaseTransform::init_con_caches() { |
| memset(_icons,0,sizeof(_icons)); |
| memset(_lcons,0,sizeof(_lcons)); |
| memset(_zcons,0,sizeof(_zcons)); |
| } |
| |
| |
| //--------------------------------find_int_type-------------------------------- |
| const TypeInt* PhaseTransform::find_int_type(Node* n) { |
| if (n == NULL) return NULL; |
| // Call type_or_null(n) to determine node's type since we might be in |
| // parse phase and call n->Value() may return wrong type. |
| // (For example, a phi node at the beginning of loop parsing is not ready.) |
| const Type* t = type_or_null(n); |
| if (t == NULL) return NULL; |
| return t->isa_int(); |
| } |
| |
| |
| //-------------------------------find_long_type-------------------------------- |
| const TypeLong* PhaseTransform::find_long_type(Node* n) { |
| if (n == NULL) return NULL; |
| // (See comment above on type_or_null.) |
| const Type* t = type_or_null(n); |
| if (t == NULL) return NULL; |
| return t->isa_long(); |
| } |
| |
| |
| #ifndef PRODUCT |
| void PhaseTransform::dump_old2new_map() const { |
| _nodes.dump(); |
| } |
| |
| void PhaseTransform::dump_new( uint nidx ) const { |
| for( uint i=0; i<_nodes.Size(); i++ ) |
| if( _nodes[i] && _nodes[i]->_idx == nidx ) { |
| _nodes[i]->dump(); |
| tty->cr(); |
| tty->print_cr("Old index= %d",i); |
| return; |
| } |
| tty->print_cr("Node %d not found in the new indices", nidx); |
| } |
| |
| //------------------------------dump_types------------------------------------- |
| void PhaseTransform::dump_types( ) const { |
| _types.dump(); |
| } |
| |
| //------------------------------dump_nodes_and_types--------------------------- |
| void PhaseTransform::dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl) { |
| VectorSet visited(Thread::current()->resource_area()); |
| dump_nodes_and_types_recur( root, depth, only_ctrl, visited ); |
| } |
| |
| //------------------------------dump_nodes_and_types_recur--------------------- |
| void PhaseTransform::dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited) { |
| if( !n ) return; |
| if( depth == 0 ) return; |
| if( visited.test_set(n->_idx) ) return; |
| for( uint i=0; i<n->len(); i++ ) { |
| if( only_ctrl && !(n->is_Region()) && i != TypeFunc::Control ) continue; |
| dump_nodes_and_types_recur( n->in(i), depth-1, only_ctrl, visited ); |
| } |
| n->dump(); |
| if (type_or_null(n) != NULL) { |
| tty->print(" "); type(n)->dump(); tty->cr(); |
| } |
| } |
| |
| #endif |
| |
| |
| //============================================================================= |
| //------------------------------PhaseValues------------------------------------ |
| // Set minimum table size to "255" |
| PhaseValues::PhaseValues( Arena *arena, uint est_max_size ) : PhaseTransform(arena, GVN), _table(arena, est_max_size) { |
| NOT_PRODUCT( clear_new_values(); ) |
| } |
| |
| //------------------------------PhaseValues------------------------------------ |
| // Set minimum table size to "255" |
| PhaseValues::PhaseValues( PhaseValues *ptv ) : PhaseTransform( ptv, GVN ), |
| _table(&ptv->_table) { |
| NOT_PRODUCT( clear_new_values(); ) |
| } |
| |
| //------------------------------PhaseValues------------------------------------ |
| // Used by +VerifyOpto. Clear out hash table but copy _types array. |
| PhaseValues::PhaseValues( PhaseValues *ptv, const char *dummy ) : PhaseTransform( ptv, GVN ), |
| _table(ptv->arena(),ptv->_table.size()) { |
| NOT_PRODUCT( clear_new_values(); ) |
| } |
| |
| //------------------------------~PhaseValues----------------------------------- |
| #ifndef PRODUCT |
| PhaseValues::~PhaseValues() { |
| _table.dump(); |
| |
| // Statistics for value progress and efficiency |
| if( PrintCompilation && Verbose && WizardMode ) { |
| tty->print("\n%sValues: %d nodes ---> %d/%d (%d)", |
| is_IterGVN() ? "Iter" : " ", C->unique(), made_progress(), made_transforms(), made_new_values()); |
| if( made_transforms() != 0 ) { |
| tty->print_cr(" ratio %f", made_progress()/(float)made_transforms() ); |
| } else { |
| tty->cr(); |
| } |
| } |
| } |
| #endif |
| |
| //------------------------------makecon---------------------------------------- |
| ConNode* PhaseTransform::makecon(const Type *t) { |
| assert(t->singleton(), "must be a constant"); |
| assert(!t->empty() || t == Type::TOP, "must not be vacuous range"); |
| switch (t->base()) { // fast paths |
| case Type::Half: |
| case Type::Top: return (ConNode*) C->top(); |
| case Type::Int: return intcon( t->is_int()->get_con() ); |
| case Type::Long: return longcon( t->is_long()->get_con() ); |
| } |
| if (t->is_zero_type()) |
| return zerocon(t->basic_type()); |
| return uncached_makecon(t); |
| } |
| |
| //--------------------------uncached_makecon----------------------------------- |
| // Make an idealized constant - one of ConINode, ConPNode, etc. |
| ConNode* PhaseValues::uncached_makecon(const Type *t) { |
| assert(t->singleton(), "must be a constant"); |
| ConNode* x = ConNode::make(C, t); |
| ConNode* k = (ConNode*)hash_find_insert(x); // Value numbering |
| if (k == NULL) { |
| set_type(x, t); // Missed, provide type mapping |
| GrowableArray<Node_Notes*>* nna = C->node_note_array(); |
| if (nna != NULL) { |
| Node_Notes* loc = C->locate_node_notes(nna, x->_idx, true); |
| loc->clear(); // do not put debug info on constants |
| } |
| } else { |
| x->destruct(); // Hit, destroy duplicate constant |
| x = k; // use existing constant |
| } |
| return x; |
| } |
| |
| //------------------------------intcon----------------------------------------- |
| // Fast integer constant. Same as "transform(new ConINode(TypeInt::make(i)))" |
| ConINode* PhaseTransform::intcon(int i) { |
| // Small integer? Check cache! Check that cached node is not dead |
| if (i >= _icon_min && i <= _icon_max) { |
| ConINode* icon = _icons[i-_icon_min]; |
| if (icon != NULL && icon->in(TypeFunc::Control) != NULL) |
| return icon; |
| } |
| ConINode* icon = (ConINode*) uncached_makecon(TypeInt::make(i)); |
| assert(icon->is_Con(), ""); |
| if (i >= _icon_min && i <= _icon_max) |
| _icons[i-_icon_min] = icon; // Cache small integers |
| return icon; |
| } |
| |
| //------------------------------longcon---------------------------------------- |
| // Fast long constant. |
| ConLNode* PhaseTransform::longcon(jlong l) { |
| // Small integer? Check cache! Check that cached node is not dead |
| if (l >= _lcon_min && l <= _lcon_max) { |
| ConLNode* lcon = _lcons[l-_lcon_min]; |
| if (lcon != NULL && lcon->in(TypeFunc::Control) != NULL) |
| return lcon; |
| } |
| ConLNode* lcon = (ConLNode*) uncached_makecon(TypeLong::make(l)); |
| assert(lcon->is_Con(), ""); |
| if (l >= _lcon_min && l <= _lcon_max) |
| _lcons[l-_lcon_min] = lcon; // Cache small integers |
| return lcon; |
| } |
| |
| //------------------------------zerocon----------------------------------------- |
| // Fast zero or null constant. Same as "transform(ConNode::make(Type::get_zero_type(bt)))" |
| ConNode* PhaseTransform::zerocon(BasicType bt) { |
| assert((uint)bt <= _zcon_max, "domain check"); |
| ConNode* zcon = _zcons[bt]; |
| if (zcon != NULL && zcon->in(TypeFunc::Control) != NULL) |
| return zcon; |
| zcon = (ConNode*) uncached_makecon(Type::get_zero_type(bt)); |
| _zcons[bt] = zcon; |
| return zcon; |
| } |
| |
| |
| |
| //============================================================================= |
| //------------------------------transform-------------------------------------- |
| // Return a node which computes the same function as this node, but in a |
| // faster or cheaper fashion. |
| Node *PhaseGVN::transform( Node *n ) { |
| return transform_no_reclaim(n); |
| } |
| |
| //------------------------------transform-------------------------------------- |
| // Return a node which computes the same function as this node, but |
| // in a faster or cheaper fashion. |
| Node *PhaseGVN::transform_no_reclaim( Node *n ) { |
| NOT_PRODUCT( set_transforms(); ) |
| |
| // Apply the Ideal call in a loop until it no longer applies |
| Node *k = n; |
| NOT_PRODUCT( uint loop_count = 0; ) |
| while( 1 ) { |
| Node *i = k->Ideal(this, /*can_reshape=*/false); |
| if( !i ) break; |
| assert( i->_idx >= k->_idx, "Idealize should return new nodes, use Identity to return old nodes" ); |
| k = i; |
| assert(loop_count++ < K, "infinite loop in PhaseGVN::transform"); |
| } |
| NOT_PRODUCT( if( loop_count != 0 ) { set_progress(); } ) |
| |
| |
| // If brand new node, make space in type array. |
| ensure_type_or_null(k); |
| |
| // Since I just called 'Value' to compute the set of run-time values |
| // for this Node, and 'Value' is non-local (and therefore expensive) I'll |
| // cache Value. Later requests for the local phase->type of this Node can |
| // use the cached Value instead of suffering with 'bottom_type'. |
| const Type *t = k->Value(this); // Get runtime Value set |
| assert(t != NULL, "value sanity"); |
| if (type_or_null(k) != t) { |
| #ifndef PRODUCT |
| // Do not count initial visit to node as a transformation |
| if (type_or_null(k) == NULL) { |
| inc_new_values(); |
| set_progress(); |
| } |
| #endif |
| set_type(k, t); |
| // If k is a TypeNode, capture any more-precise type permanently into Node |
| k->raise_bottom_type(t); |
| } |
| |
| if( t->singleton() && !k->is_Con() ) { |
| NOT_PRODUCT( set_progress(); ) |
| return makecon(t); // Turn into a constant |
| } |
| |
| // Now check for Identities |
| Node *i = k->Identity(this); // Look for a nearby replacement |
| if( i != k ) { // Found? Return replacement! |
| NOT_PRODUCT( set_progress(); ) |
| return i; |
| } |
| |
| // Global Value Numbering |
| i = hash_find_insert(k); // Insert if new |
| if( i && (i != k) ) { |
| // Return the pre-existing node |
| NOT_PRODUCT( set_progress(); ) |
| return i; |
| } |
| |
| // Return Idealized original |
| return k; |
| } |
| |
| #ifdef ASSERT |
| //------------------------------dead_loop_check-------------------------------- |
| // Check for a simple dead loop when a data node references itself directly |
| // or through an other data node excluding cons and phis. |
| void PhaseGVN::dead_loop_check( Node *n ) { |
| // Phi may reference itself in a loop |
| if (n != NULL && !n->is_dead_loop_safe() && !n->is_CFG()) { |
| // Do 2 levels check and only data inputs. |
| bool no_dead_loop = true; |
| uint cnt = n->req(); |
| for (uint i = 1; i < cnt && no_dead_loop; i++) { |
| Node *in = n->in(i); |
| if (in == n) { |
| no_dead_loop = false; |
| } else if (in != NULL && !in->is_dead_loop_safe()) { |
| uint icnt = in->req(); |
| for (uint j = 1; j < icnt && no_dead_loop; j++) { |
| if (in->in(j) == n || in->in(j) == in) |
| no_dead_loop = false; |
| } |
| } |
| } |
| if (!no_dead_loop) n->dump(3); |
| assert(no_dead_loop, "dead loop detected"); |
| } |
| } |
| #endif |
| |
| //============================================================================= |
| //------------------------------PhaseIterGVN----------------------------------- |
| // Initialize hash table to fresh and clean for +VerifyOpto |
| PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ) : PhaseGVN(igvn,dummy), _worklist( ), |
| _stack(C->unique() >> 1), |
| _delay_transform(false) { |
| } |
| |
| //------------------------------PhaseIterGVN----------------------------------- |
| // Initialize with previous PhaseIterGVN info; used by PhaseCCP |
| PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn ) : PhaseGVN(igvn), |
| _worklist( igvn->_worklist ), |
| _stack( igvn->_stack ), |
| _delay_transform(igvn->_delay_transform) |
| { |
| } |
| |
| //------------------------------PhaseIterGVN----------------------------------- |
| // Initialize with previous PhaseGVN info from Parser |
| PhaseIterGVN::PhaseIterGVN( PhaseGVN *gvn ) : PhaseGVN(gvn), |
| _worklist(*C->for_igvn()), |
| _stack(C->unique() >> 1), |
| _delay_transform(false) |
| { |
| uint max; |
| |
| // Dead nodes in the hash table inherited from GVN were not treated as |
| // roots during def-use info creation; hence they represent an invisible |
| // use. Clear them out. |
| max = _table.size(); |
| for( uint i = 0; i < max; ++i ) { |
| Node *n = _table.at(i); |
| if(n != NULL && n != _table.sentinel() && n->outcnt() == 0) { |
| if( n->is_top() ) continue; |
| assert( false, "Parse::remove_useless_nodes missed this node"); |
| hash_delete(n); |
| } |
| } |
| |
| // Any Phis or Regions on the worklist probably had uses that could not |
| // make more progress because the uses were made while the Phis and Regions |
| // were in half-built states. Put all uses of Phis and Regions on worklist. |
| max = _worklist.size(); |
| for( uint j = 0; j < max; j++ ) { |
| Node *n = _worklist.at(j); |
| uint uop = n->Opcode(); |
| if( uop == Op_Phi || uop == Op_Region || |
| n->is_Type() || |
| n->is_Mem() ) |
| add_users_to_worklist(n); |
| } |
| } |
| |
| |
| #ifndef PRODUCT |
| void PhaseIterGVN::verify_step(Node* n) { |
| _verify_window[_verify_counter % _verify_window_size] = n; |
| ++_verify_counter; |
| ResourceMark rm; |
| ResourceArea *area = Thread::current()->resource_area(); |
| VectorSet old_space(area), new_space(area); |
| if (C->unique() < 1000 || |
| 0 == _verify_counter % (C->unique() < 10000 ? 10 : 100)) { |
| ++_verify_full_passes; |
| Node::verify_recur(C->root(), -1, old_space, new_space); |
| } |
| const int verify_depth = 4; |
| for ( int i = 0; i < _verify_window_size; i++ ) { |
| Node* n = _verify_window[i]; |
| if ( n == NULL ) continue; |
| if( n->in(0) == NodeSentinel ) { // xform_idom |
| _verify_window[i] = n->in(1); |
| --i; continue; |
| } |
| // Typical fanout is 1-2, so this call visits about 6 nodes. |
| Node::verify_recur(n, verify_depth, old_space, new_space); |
| } |
| } |
| #endif |
| |
| |
| //------------------------------init_worklist---------------------------------- |
| // Initialize worklist for each node. |
| void PhaseIterGVN::init_worklist( Node *n ) { |
| if( _worklist.member(n) ) return; |
| _worklist.push(n); |
| uint cnt = n->req(); |
| for( uint i =0 ; i < cnt; i++ ) { |
| Node *m = n->in(i); |
| if( m ) init_worklist(m); |
| } |
| } |
| |
| //------------------------------optimize--------------------------------------- |
| void PhaseIterGVN::optimize() { |
| debug_only(uint num_processed = 0;); |
| #ifndef PRODUCT |
| { |
| _verify_counter = 0; |
| _verify_full_passes = 0; |
| for ( int i = 0; i < _verify_window_size; i++ ) { |
| _verify_window[i] = NULL; |
| } |
| } |
| #endif |
| |
| #ifdef ASSERT |
| Node* prev = NULL; |
| uint rep_cnt = 0; |
| #endif |
| uint loop_count = 0; |
| |
| // Pull from worklist; transform node; |
| // If node has changed: update edge info and put uses on worklist. |
| while( _worklist.size() ) { |
| if (C->check_node_count(NodeLimitFudgeFactor * 2, |
| "out of nodes optimizing method")) { |
| return; |
| } |
| Node *n = _worklist.pop(); |
| if (++loop_count >= K * C->live_nodes()) { |
| debug_only(n->dump(4);) |
| assert(false, "infinite loop in PhaseIterGVN::optimize"); |
| C->record_method_not_compilable("infinite loop in PhaseIterGVN::optimize"); |
| return; |
| } |
| #ifdef ASSERT |
| if (n == prev) { |
| if (++rep_cnt > 3) { |
| n->dump(4); |
| assert(false, "loop in Ideal transformation"); |
| } |
| } else { |
| rep_cnt = 0; |
| } |
| prev = n; |
| #endif |
| if (TraceIterativeGVN && Verbose) { |
| tty->print(" Pop "); |
| NOT_PRODUCT( n->dump(); ) |
| debug_only(if( (num_processed++ % 100) == 0 ) _worklist.print_set();) |
| } |
| |
| if (n->outcnt() != 0) { |
| |
| #ifndef PRODUCT |
| uint wlsize = _worklist.size(); |
| const Type* oldtype = type_or_null(n); |
| #endif //PRODUCT |
| |
| Node *nn = transform_old(n); |
| |
| #ifndef PRODUCT |
| if (TraceIterativeGVN) { |
| const Type* newtype = type_or_null(n); |
| if (nn != n) { |
| // print old node |
| tty->print("< "); |
| if (oldtype != newtype && oldtype != NULL) { |
| oldtype->dump(); |
| } |
| do { tty->print("\t"); } while (tty->position() < 16); |
| tty->print("<"); |
| n->dump(); |
| } |
| if (oldtype != newtype || nn != n) { |
| // print new node and/or new type |
| if (oldtype == NULL) { |
| tty->print("* "); |
| } else if (nn != n) { |
| tty->print("> "); |
| } else { |
| tty->print("= "); |
| } |
| if (newtype == NULL) { |
| tty->print("null"); |
| } else { |
| newtype->dump(); |
| } |
| do { tty->print("\t"); } while (tty->position() < 16); |
| nn->dump(); |
| } |
| if (Verbose && wlsize < _worklist.size()) { |
| tty->print(" Push {"); |
| while (wlsize != _worklist.size()) { |
| Node* pushed = _worklist.at(wlsize++); |
| tty->print(" %d", pushed->_idx); |
| } |
| tty->print_cr(" }"); |
| } |
| } |
| if( VerifyIterativeGVN && nn != n ) { |
| verify_step((Node*) NULL); // ignore n, it might be subsumed |
| } |
| #endif |
| } else if (!n->is_top()) { |
| remove_dead_node(n); |
| } |
| } |
| |
| #ifndef PRODUCT |
| C->verify_graph_edges(); |
| if( VerifyOpto && allow_progress() ) { |
| // Must turn off allow_progress to enable assert and break recursion |
| C->root()->verify(); |
| { // Check if any progress was missed using IterGVN |
| // Def-Use info enables transformations not attempted in wash-pass |
| // e.g. Region/Phi cleanup, ... |
| // Null-check elision -- may not have reached fixpoint |
| // do not propagate to dominated nodes |
| ResourceMark rm; |
| PhaseIterGVN igvn2(this,"Verify"); // Fresh and clean! |
| // Fill worklist completely |
| igvn2.init_worklist(C->root()); |
| |
| igvn2.set_allow_progress(false); |
| igvn2.optimize(); |
| igvn2.set_allow_progress(true); |
| } |
| } |
| if ( VerifyIterativeGVN && PrintOpto ) { |
| if ( _verify_counter == _verify_full_passes ) |
| tty->print_cr("VerifyIterativeGVN: %d transforms and verify passes", |
| _verify_full_passes); |
| else |
| tty->print_cr("VerifyIterativeGVN: %d transforms, %d full verify passes", |
| _verify_counter, _verify_full_passes); |
| } |
| #endif |
| } |
| |
| |
| //------------------register_new_node_with_optimizer--------------------------- |
| // Register a new node with the optimizer. Update the types array, the def-use |
| // info. Put on worklist. |
| Node* PhaseIterGVN::register_new_node_with_optimizer(Node* n, Node* orig) { |
| set_type_bottom(n); |
| _worklist.push(n); |
| if (orig != NULL) C->copy_node_notes_to(n, orig); |
| return n; |
| } |
| |
| //------------------------------transform-------------------------------------- |
| // Non-recursive: idealize Node 'n' with respect to its inputs and its value |
| Node *PhaseIterGVN::transform( Node *n ) { |
| if (_delay_transform) { |
| // Register the node but don't optimize for now |
| register_new_node_with_optimizer(n); |
| return n; |
| } |
| |
| // If brand new node, make space in type array, and give it a type. |
| ensure_type_or_null(n); |
| if (type_or_null(n) == NULL) { |
| set_type_bottom(n); |
| } |
| |
| return transform_old(n); |
| } |
| |
| //------------------------------transform_old---------------------------------- |
| Node *PhaseIterGVN::transform_old( Node *n ) { |
| #ifndef PRODUCT |
| debug_only(uint loop_count = 0;); |
| set_transforms(); |
| #endif |
| // Remove 'n' from hash table in case it gets modified |
| _table.hash_delete(n); |
| if( VerifyIterativeGVN ) { |
| assert( !_table.find_index(n->_idx), "found duplicate entry in table"); |
| } |
| |
| // Apply the Ideal call in a loop until it no longer applies |
| Node *k = n; |
| DEBUG_ONLY(dead_loop_check(k);) |
| DEBUG_ONLY(bool is_new = (k->outcnt() == 0);) |
| Node *i = k->Ideal(this, /*can_reshape=*/true); |
| assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes"); |
| #ifndef PRODUCT |
| if( VerifyIterativeGVN ) |
| verify_step(k); |
| if( i && VerifyOpto ) { |
| if( !allow_progress() ) { |
| if (i->is_Add() && i->outcnt() == 1) { |
| // Switched input to left side because this is the only use |
| } else if( i->is_If() && (i->in(0) == NULL) ) { |
| // This IF is dead because it is dominated by an equivalent IF When |
| // dominating if changed, info is not propagated sparsely to 'this' |
| // Propagating this info further will spuriously identify other |
| // progress. |
| return i; |
| } else |
| set_progress(); |
| } else |
| set_progress(); |
| } |
| #endif |
| |
| while( i ) { |
| #ifndef PRODUCT |
| debug_only( if( loop_count >= K ) i->dump(4); ) |
| assert(loop_count < K, "infinite loop in PhaseIterGVN::transform"); |
| debug_only( loop_count++; ) |
| #endif |
| assert((i->_idx >= k->_idx) || i->is_top(), "Idealize should return new nodes, use Identity to return old nodes"); |
| // Made a change; put users of original Node on worklist |
| add_users_to_worklist( k ); |
| // Replacing root of transform tree? |
| if( k != i ) { |
| // Make users of old Node now use new. |
| subsume_node( k, i ); |
| k = i; |
| } |
| DEBUG_ONLY(dead_loop_check(k);) |
| // Try idealizing again |
| DEBUG_ONLY(is_new = (k->outcnt() == 0);) |
| i = k->Ideal(this, /*can_reshape=*/true); |
| assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes"); |
| #ifndef PRODUCT |
| if( VerifyIterativeGVN ) |
| verify_step(k); |
| if( i && VerifyOpto ) set_progress(); |
| #endif |
| } |
| |
| // If brand new node, make space in type array. |
| ensure_type_or_null(k); |
| |
| // See what kind of values 'k' takes on at runtime |
| const Type *t = k->Value(this); |
| assert(t != NULL, "value sanity"); |
| |
| // Since I just called 'Value' to compute the set of run-time values |
| // for this Node, and 'Value' is non-local (and therefore expensive) I'll |
| // cache Value. Later requests for the local phase->type of this Node can |
| // use the cached Value instead of suffering with 'bottom_type'. |
| if (t != type_or_null(k)) { |
| NOT_PRODUCT( set_progress(); ) |
| NOT_PRODUCT( inc_new_values();) |
| set_type(k, t); |
| // If k is a TypeNode, capture any more-precise type permanently into Node |
| k->raise_bottom_type(t); |
| // Move users of node to worklist |
| add_users_to_worklist( k ); |
| } |
| |
| // If 'k' computes a constant, replace it with a constant |
| if( t->singleton() && !k->is_Con() ) { |
| NOT_PRODUCT( set_progress(); ) |
| Node *con = makecon(t); // Make a constant |
| add_users_to_worklist( k ); |
| subsume_node( k, con ); // Everybody using k now uses con |
| return con; |
| } |
| |
| // Now check for Identities |
| i = k->Identity(this); // Look for a nearby replacement |
| if( i != k ) { // Found? Return replacement! |
| NOT_PRODUCT( set_progress(); ) |
| add_users_to_worklist( k ); |
| subsume_node( k, i ); // Everybody using k now uses i |
| return i; |
| } |
| |
| // Global Value Numbering |
| i = hash_find_insert(k); // Check for pre-existing node |
| if( i && (i != k) ) { |
| // Return the pre-existing node if it isn't dead |
| NOT_PRODUCT( set_progress(); ) |
| add_users_to_worklist( k ); |
| subsume_node( k, i ); // Everybody using k now uses i |
| return i; |
| } |
| |
| // Return Idealized original |
| return k; |
| } |
| |
| //---------------------------------saturate------------------------------------ |
| const Type* PhaseIterGVN::saturate(const Type* new_type, const Type* old_type, |
| const Type* limit_type) const { |
| return new_type->narrow(old_type); |
| } |
| |
| //------------------------------remove_globally_dead_node---------------------- |
| // Kill a globally dead Node. All uses are also globally dead and are |
| // aggressively trimmed. |
| void PhaseIterGVN::remove_globally_dead_node( Node *dead ) { |
| enum DeleteProgress { |
| PROCESS_INPUTS, |
| PROCESS_OUTPUTS |
| }; |
| assert(_stack.is_empty(), "not empty"); |
| _stack.push(dead, PROCESS_INPUTS); |
| |
| while (_stack.is_nonempty()) { |
| dead = _stack.node(); |
| uint progress_state = _stack.index(); |
| assert(dead != C->root(), "killing root, eh?"); |
| assert(!dead->is_top(), "add check for top when pushing"); |
| NOT_PRODUCT( set_progress(); ) |
| if (progress_state == PROCESS_INPUTS) { |
| // After following inputs, continue to outputs |
| _stack.set_index(PROCESS_OUTPUTS); |
| if (!dead->is_Con()) { // Don't kill cons but uses |
| bool recurse = false; |
| // Remove from hash table |
| _table.hash_delete( dead ); |
| // Smash all inputs to 'dead', isolating him completely |
| for (uint i = 0; i < dead->req(); i++) { |
| Node *in = dead->in(i); |
| if (in != NULL && in != C->top()) { // Points to something? |
| int nrep = dead->replace_edge(in, NULL); // Kill edges |
| assert((nrep > 0), "sanity"); |
| if (in->outcnt() == 0) { // Made input go dead? |
| _stack.push(in, PROCESS_INPUTS); // Recursively remove |
| recurse = true; |
| } else if (in->outcnt() == 1 && |
| in->has_special_unique_user()) { |
| _worklist.push(in->unique_out()); |
| } else if (in->outcnt() <= 2 && dead->is_Phi()) { |
| if (in->Opcode() == Op_Region) { |
| _worklist.push(in); |
| } else if (in->is_Store()) { |
| DUIterator_Fast imax, i = in->fast_outs(imax); |
| _worklist.push(in->fast_out(i)); |
| i++; |
| if (in->outcnt() == 2) { |
| _worklist.push(in->fast_out(i)); |
| i++; |
| } |
| assert(!(i < imax), "sanity"); |
| } |
| } |
| if (ReduceFieldZeroing && dead->is_Load() && i == MemNode::Memory && |
| in->is_Proj() && in->in(0) != NULL && in->in(0)->is_Initialize()) { |
| // A Load that directly follows an InitializeNode is |
| // going away. The Stores that follow are candidates |
| // again to be captured by the InitializeNode. |
| for (DUIterator_Fast jmax, j = in->fast_outs(jmax); j < jmax; j++) { |
| Node *n = in->fast_out(j); |
| if (n->is_Store()) { |
| _worklist.push(n); |
| } |
| } |
| } |
| } // if (in != NULL && in != C->top()) |
| } // for (uint i = 0; i < dead->req(); i++) |
| if (recurse) { |
| continue; |
| } |
| } // if (!dead->is_Con()) |
| } // if (progress_state == PROCESS_INPUTS) |
| |
| // Aggressively kill globally dead uses |
| // (Rather than pushing all the outs at once, we push one at a time, |
| // plus the parent to resume later, because of the indefinite number |
| // of edge deletions per loop trip.) |
| if (dead->outcnt() > 0) { |
| // Recursively remove output edges |
| _stack.push(dead->raw_out(0), PROCESS_INPUTS); |
| } else { |
| // Finished disconnecting all input and output edges. |
| _stack.pop(); |
| // Remove dead node from iterative worklist |
| _worklist.remove(dead); |
| // Constant node that has no out-edges and has only one in-edge from |
| // root is usually dead. However, sometimes reshaping walk makes |
| // it reachable by adding use edges. So, we will NOT count Con nodes |
| // as dead to be conservative about the dead node count at any |
| // given time. |
| if (!dead->is_Con()) { |
| C->record_dead_node(dead->_idx); |
| } |
| if (dead->is_macro()) { |
| C->remove_macro_node(dead); |
| } |
| if (dead->is_expensive()) { |
| C->remove_expensive_node(dead); |
| } |
| } |
| } // while (_stack.is_nonempty()) |
| } |
| |
| //------------------------------subsume_node----------------------------------- |
| // Remove users from node 'old' and add them to node 'nn'. |
| void PhaseIterGVN::subsume_node( Node *old, Node *nn ) { |
| assert( old != hash_find(old), "should already been removed" ); |
| assert( old != C->top(), "cannot subsume top node"); |
| // Copy debug or profile information to the new version: |
| C->copy_node_notes_to(nn, old); |
| // Move users of node 'old' to node 'nn' |
| for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin; ) { |
| Node* use = old->last_out(i); // for each use... |
| // use might need re-hashing (but it won't if it's a new node) |
| bool is_in_table = _table.hash_delete( use ); |
| // Update use-def info as well |
| // We remove all occurrences of old within use->in, |
| // so as to avoid rehashing any node more than once. |
| // The hash table probe swamps any outer loop overhead. |
| uint num_edges = 0; |
| for (uint jmax = use->len(), j = 0; j < jmax; j++) { |
| if (use->in(j) == old) { |
| use->set_req(j, nn); |
| ++num_edges; |
| } |
| } |
| // Insert into GVN hash table if unique |
| // If a duplicate, 'use' will be cleaned up when pulled off worklist |
| if( is_in_table ) { |
| hash_find_insert(use); |
| } |
| i -= num_edges; // we deleted 1 or more copies of this edge |
| } |
| |
| // Smash all inputs to 'old', isolating him completely |
| Node *temp = new (C) Node(1); |
| temp->init_req(0,nn); // Add a use to nn to prevent him from dying |
| remove_dead_node( old ); |
| temp->del_req(0); // Yank bogus edge |
| #ifndef PRODUCT |
| if( VerifyIterativeGVN ) { |
| for ( int i = 0; i < _verify_window_size; i++ ) { |
| if ( _verify_window[i] == old ) |
| _verify_window[i] = nn; |
| } |
| } |
| #endif |
| _worklist.remove(temp); // this can be necessary |
| temp->destruct(); // reuse the _idx of this little guy |
| } |
| |
| //------------------------------add_users_to_worklist-------------------------- |
| void PhaseIterGVN::add_users_to_worklist0( Node *n ) { |
| for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { |
| _worklist.push(n->fast_out(i)); // Push on worklist |
| } |
| } |
| |
| void PhaseIterGVN::add_users_to_worklist( Node *n ) { |
| add_users_to_worklist0(n); |
| |
| // Move users of node to worklist |
| for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { |
| Node* use = n->fast_out(i); // Get use |
| |
| if( use->is_Multi() || // Multi-definer? Push projs on worklist |
| use->is_Store() ) // Enable store/load same address |
| add_users_to_worklist0(use); |
| |
| // If we changed the receiver type to a call, we need to revisit |
| // the Catch following the call. It's looking for a non-NULL |
| // receiver to know when to enable the regular fall-through path |
| // in addition to the NullPtrException path. |
| if (use->is_CallDynamicJava() && n == use->in(TypeFunc::Parms)) { |
| Node* p = use->as_CallDynamicJava()->proj_out(TypeFunc::Control); |
| if (p != NULL) { |
| add_users_to_worklist0(p); |
| } |
| } |
| |
| if( use->is_Cmp() ) { // Enable CMP/BOOL optimization |
| add_users_to_worklist(use); // Put Bool on worklist |
| // Look for the 'is_x2logic' pattern: "x ? : 0 : 1" and put the |
| // phi merging either 0 or 1 onto the worklist |
| if (use->outcnt() > 0) { |
| Node* bol = use->raw_out(0); |
| if (bol->outcnt() > 0) { |
| Node* iff = bol->raw_out(0); |
| if (iff->outcnt() == 2) { |
| Node* ifproj0 = iff->raw_out(0); |
| Node* ifproj1 = iff->raw_out(1); |
| if (ifproj0->outcnt() > 0 && ifproj1->outcnt() > 0) { |
| Node* region0 = ifproj0->raw_out(0); |
| Node* region1 = ifproj1->raw_out(0); |
| if( region0 == region1 ) |
| add_users_to_worklist0(region0); |
| } |
| } |
| } |
| } |
| } |
| |
| uint use_op = use->Opcode(); |
| // If changed Cast input, check Phi users for simple cycles |
| if( use->is_ConstraintCast() || use->is_CheckCastPP() ) { |
| for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { |
| Node* u = use->fast_out(i2); |
| if (u->is_Phi()) |
| _worklist.push(u); |
| } |
| } |
| // If changed LShift inputs, check RShift users for useless sign-ext |
| if( use_op == Op_LShiftI ) { |
| for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { |
| Node* u = use->fast_out(i2); |
| if (u->Opcode() == Op_RShiftI) |
| _worklist.push(u); |
| } |
| } |
| // If changed AddP inputs, check Stores for loop invariant |
| if( use_op == Op_AddP ) { |
| for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { |
| Node* u = use->fast_out(i2); |
| if (u->is_Mem()) |
| _worklist.push(u); |
| } |
| } |
| // If changed initialization activity, check dependent Stores |
| if (use_op == Op_Allocate || use_op == Op_AllocateArray) { |
| InitializeNode* init = use->as_Allocate()->initialization(); |
| if (init != NULL) { |
| Node* imem = init->proj_out(TypeFunc::Memory); |
| if (imem != NULL) add_users_to_worklist0(imem); |
| } |
| } |
| if (use_op == Op_Initialize) { |
| Node* imem = use->as_Initialize()->proj_out(TypeFunc::Memory); |
| if (imem != NULL) add_users_to_worklist0(imem); |
| } |
| } |
| } |
| |
| //============================================================================= |
| #ifndef PRODUCT |
| uint PhaseCCP::_total_invokes = 0; |
| uint PhaseCCP::_total_constants = 0; |
| #endif |
| //------------------------------PhaseCCP--------------------------------------- |
| // Conditional Constant Propagation, ala Wegman & Zadeck |
| PhaseCCP::PhaseCCP( PhaseIterGVN *igvn ) : PhaseIterGVN(igvn) { |
| NOT_PRODUCT( clear_constants(); ) |
| assert( _worklist.size() == 0, "" ); |
| // Clear out _nodes from IterGVN. Must be clear to transform call. |
| _nodes.clear(); // Clear out from IterGVN |
| analyze(); |
| } |
| |
| #ifndef PRODUCT |
| //------------------------------~PhaseCCP-------------------------------------- |
| PhaseCCP::~PhaseCCP() { |
| inc_invokes(); |
| _total_constants += count_constants(); |
| } |
| #endif |
| |
| |
| #ifdef ASSERT |
| static bool ccp_type_widens(const Type* t, const Type* t0) { |
| assert(t->meet(t0) == t, "Not monotonic"); |
| switch (t->base() == t0->base() ? t->base() : Type::Top) { |
| case Type::Int: |
| assert(t0->isa_int()->_widen <= t->isa_int()->_widen, "widen increases"); |
| break; |
| case Type::Long: |
| assert(t0->isa_long()->_widen <= t->isa_long()->_widen, "widen increases"); |
| break; |
| } |
| return true; |
| } |
| #endif //ASSERT |
| |
| //------------------------------analyze---------------------------------------- |
| void PhaseCCP::analyze() { |
| // Initialize all types to TOP, optimistic analysis |
| for (int i = C->unique() - 1; i >= 0; i--) { |
| _types.map(i,Type::TOP); |
| } |
| |
| // Push root onto worklist |
| Unique_Node_List worklist; |
| worklist.push(C->root()); |
| |
| // Pull from worklist; compute new value; push changes out. |
| // This loop is the meat of CCP. |
| while( worklist.size() ) { |
| Node *n = worklist.pop(); |
| const Type *t = n->Value(this); |
| if (t != type(n)) { |
| assert(ccp_type_widens(t, type(n)), "ccp type must widen"); |
| #ifndef PRODUCT |
| if( TracePhaseCCP ) { |
| t->dump(); |
| do { tty->print("\t"); } while (tty->position() < 16); |
| n->dump(); |
| } |
| #endif |
| set_type(n, t); |
| for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { |
| Node* m = n->fast_out(i); // Get user |
| if( m->is_Region() ) { // New path to Region? Must recheck Phis too |
| for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { |
| Node* p = m->fast_out(i2); // Propagate changes to uses |
| if( p->bottom_type() != type(p) ) // If not already bottomed out |
| worklist.push(p); // Propagate change to user |
| } |
| } |
| // If we changed the receiver type to a call, we need to revisit |
| // the Catch following the call. It's looking for a non-NULL |
| // receiver to know when to enable the regular fall-through path |
| // in addition to the NullPtrException path |
| if (m->is_Call()) { |
| for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { |
| Node* p = m->fast_out(i2); // Propagate changes to uses |
| if (p->is_Proj() && p->as_Proj()->_con == TypeFunc::Control && p->outcnt() == 1) |
| worklist.push(p->unique_out()); |
| } |
| } |
| if( m->bottom_type() != type(m) ) // If not already bottomed out |
| worklist.push(m); // Propagate change to user |
| } |
| } |
| } |
| } |
| |
| //------------------------------do_transform----------------------------------- |
| // Top level driver for the recursive transformer |
| void PhaseCCP::do_transform() { |
| // Correct leaves of new-space Nodes; they point to old-space. |
| C->set_root( transform(C->root())->as_Root() ); |
| assert( C->top(), "missing TOP node" ); |
| assert( C->root(), "missing root" ); |
| } |
| |
| //------------------------------transform-------------------------------------- |
| // Given a Node in old-space, clone him into new-space. |
| // Convert any of his old-space children into new-space children. |
| Node *PhaseCCP::transform( Node *n ) { |
| Node *new_node = _nodes[n->_idx]; // Check for transformed node |
| if( new_node != NULL ) |
| return new_node; // Been there, done that, return old answer |
| new_node = transform_once(n); // Check for constant |
| _nodes.map( n->_idx, new_node ); // Flag as having been cloned |
| |
| // Allocate stack of size _nodes.Size()/2 to avoid frequent realloc |
| GrowableArray <Node *> trstack(C->unique() >> 1); |
| |
| trstack.push(new_node); // Process children of cloned node |
| while ( trstack.is_nonempty() ) { |
| Node *clone = trstack.pop(); |
| uint cnt = clone->req(); |
| for( uint i = 0; i < cnt; i++ ) { // For all inputs do |
| Node *input = clone->in(i); |
| if( input != NULL ) { // Ignore NULLs |
| Node *new_input = _nodes[input->_idx]; // Check for cloned input node |
| if( new_input == NULL ) { |
| new_input = transform_once(input); // Check for constant |
| _nodes.map( input->_idx, new_input );// Flag as having been cloned |
| trstack.push(new_input); |
| } |
| assert( new_input == clone->in(i), "insanity check"); |
| } |
| } |
| } |
| return new_node; |
| } |
| |
| |
| //------------------------------transform_once--------------------------------- |
| // For PhaseCCP, transformation is IDENTITY unless Node computed a constant. |
| Node *PhaseCCP::transform_once( Node *n ) { |
| const Type *t = type(n); |
| // Constant? Use constant Node instead |
| if( t->singleton() ) { |
| Node *nn = n; // Default is to return the original constant |
| if( t == Type::TOP ) { |
| // cache my top node on the Compile instance |
| if( C->cached_top_node() == NULL || C->cached_top_node()->in(0) == NULL ) { |
| C->set_cached_top_node( ConNode::make(C, Type::TOP) ); |
| set_type(C->top(), Type::TOP); |
| } |
| nn = C->top(); |
| } |
| if( !n->is_Con() ) { |
| if( t != Type::TOP ) { |
| nn = makecon(t); // ConNode::make(t); |
| NOT_PRODUCT( inc_constants(); ) |
| } else if( n->is_Region() ) { // Unreachable region |
| // Note: nn == C->top() |
| n->set_req(0, NULL); // Cut selfreference |
| // Eagerly remove dead phis to avoid phis copies creation. |
| for (DUIterator i = n->outs(); n->has_out(i); i++) { |
| Node* m = n->out(i); |
| if( m->is_Phi() ) { |
| assert(type(m) == Type::TOP, "Unreachable region should not have live phis."); |
| replace_node(m, nn); |
| --i; // deleted this phi; rescan starting with next position |
| } |
| } |
| } |
| replace_node(n,nn); // Update DefUse edges for new constant |
| } |
| return nn; |
| } |
| |
| // If x is a TypeNode, capture any more-precise type permanently into Node |
| if (t != n->bottom_type()) { |
| hash_delete(n); // changing bottom type may force a rehash |
| n->raise_bottom_type(t); |
| _worklist.push(n); // n re-enters the hash table via the worklist |
| } |
| |
| // Idealize graph using DU info. Must clone() into new-space. |
| // DU info is generally used to show profitability, progress or safety |
| // (but generally not needed for correctness). |
| Node *nn = n->Ideal_DU_postCCP(this); |
| |
| // TEMPORARY fix to ensure that 2nd GVN pass eliminates NULL checks |
| switch( n->Opcode() ) { |
| case Op_FastLock: // Revisit FastLocks for lock coarsening |
| case Op_If: |
| case Op_CountedLoopEnd: |
| case Op_Region: |
| case Op_Loop: |
| case Op_CountedLoop: |
| case Op_Conv2B: |
| case Op_Opaque1: |
| case Op_Opaque2: |
| _worklist.push(n); |
| break; |
| default: |
| break; |
| } |
| if( nn ) { |
| _worklist.push(n); |
| // Put users of 'n' onto worklist for second igvn transform |
| add_users_to_worklist(n); |
| return nn; |
| } |
| |
| return n; |
| } |
| |
| //---------------------------------saturate------------------------------------ |
| const Type* PhaseCCP::saturate(const Type* new_type, const Type* old_type, |
| const Type* limit_type) const { |
| const Type* wide_type = new_type->widen(old_type, limit_type); |
| if (wide_type != new_type) { // did we widen? |
| // If so, we may have widened beyond the limit type. Clip it back down. |
| new_type = wide_type->filter(limit_type); |
| } |
| return new_type; |
| } |
| |
| //------------------------------print_statistics------------------------------- |
| #ifndef PRODUCT |
| void PhaseCCP::print_statistics() { |
| tty->print_cr("CCP: %d constants found: %d", _total_invokes, _total_constants); |
| } |
| #endif |
| |
| |
| //============================================================================= |
| #ifndef PRODUCT |
| uint PhasePeephole::_total_peepholes = 0; |
| #endif |
| //------------------------------PhasePeephole---------------------------------- |
| // Conditional Constant Propagation, ala Wegman & Zadeck |
| PhasePeephole::PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg ) |
| : PhaseTransform(Peephole), _regalloc(regalloc), _cfg(cfg) { |
| NOT_PRODUCT( clear_peepholes(); ) |
| } |
| |
| #ifndef PRODUCT |
| //------------------------------~PhasePeephole--------------------------------- |
| PhasePeephole::~PhasePeephole() { |
| _total_peepholes += count_peepholes(); |
| } |
| #endif |
| |
| //------------------------------transform-------------------------------------- |
| Node *PhasePeephole::transform( Node *n ) { |
| ShouldNotCallThis(); |
| return NULL; |
| } |
| |
| //------------------------------do_transform----------------------------------- |
| void PhasePeephole::do_transform() { |
| bool method_name_not_printed = true; |
| |
| // Examine each basic block |
| for (uint block_number = 1; block_number < _cfg.number_of_blocks(); ++block_number) { |
| Block* block = _cfg.get_block(block_number); |
| bool block_not_printed = true; |
| |
| // and each instruction within a block |
| uint end_index = block->_nodes.size(); |
| // block->end_idx() not valid after PhaseRegAlloc |
| for( uint instruction_index = 1; instruction_index < end_index; ++instruction_index ) { |
| Node *n = block->_nodes.at(instruction_index); |
| if( n->is_Mach() ) { |
| MachNode *m = n->as_Mach(); |
| int deleted_count = 0; |
| // check for peephole opportunities |
| MachNode *m2 = m->peephole( block, instruction_index, _regalloc, deleted_count, C ); |
| if( m2 != NULL ) { |
| #ifndef PRODUCT |
| if( PrintOptoPeephole ) { |
| // Print method, first time only |
| if( C->method() && method_name_not_printed ) { |
| C->method()->print_short_name(); tty->cr(); |
| method_name_not_printed = false; |
| } |
| // Print this block |
| if( Verbose && block_not_printed) { |
| tty->print_cr("in block"); |
| block->dump(); |
| block_not_printed = false; |
| } |
| // Print instructions being deleted |
| for( int i = (deleted_count - 1); i >= 0; --i ) { |
| block->_nodes.at(instruction_index-i)->as_Mach()->format(_regalloc); tty->cr(); |
| } |
| tty->print_cr("replaced with"); |
| // Print new instruction |
| m2->format(_regalloc); |
| tty->print("\n\n"); |
| } |
| #endif |
| // Remove old nodes from basic block and update instruction_index |
| // (old nodes still exist and may have edges pointing to them |
| // as register allocation info is stored in the allocator using |
| // the node index to live range mappings.) |
| uint safe_instruction_index = (instruction_index - deleted_count); |
| for( ; (instruction_index > safe_instruction_index); --instruction_index ) { |
| block->_nodes.remove( instruction_index ); |
| } |
| // install new node after safe_instruction_index |
| block->_nodes.insert( safe_instruction_index + 1, m2 ); |
| end_index = block->_nodes.size() - 1; // Recompute new block size |
| NOT_PRODUCT( inc_peepholes(); ) |
| } |
| } |
| } |
| } |
| } |
| |
| //------------------------------print_statistics------------------------------- |
| #ifndef PRODUCT |
| void PhasePeephole::print_statistics() { |
| tty->print_cr("Peephole: peephole rules applied: %d", _total_peepholes); |
| } |
| #endif |
| |
| |
| //============================================================================= |
| //------------------------------set_req_X-------------------------------------- |
| void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) { |
| assert( is_not_dead(n), "can not use dead node"); |
| assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" ); |
| Node *old = in(i); |
| set_req(i, n); |
| |
| // old goes dead? |
| if( old ) { |
| switch (old->outcnt()) { |
| case 0: |
| // Put into the worklist to kill later. We do not kill it now because the |
| // recursive kill will delete the current node (this) if dead-loop exists |
| if (!old->is_top()) |
| igvn->_worklist.push( old ); |
| break; |
| case 1: |
| if( old->is_Store() || old->has_special_unique_user() ) |
| igvn->add_users_to_worklist( old ); |
| break; |
| case 2: |
| if( old->is_Store() ) |
| igvn->add_users_to_worklist( old ); |
| if( old->Opcode() == Op_Region ) |
| igvn->_worklist.push(old); |
| break; |
| case 3: |
| if( old->Opcode() == Op_Region ) { |
| igvn->_worklist.push(old); |
| igvn->add_users_to_worklist( old ); |
| } |
| break; |
| default: |
| break; |
| } |
| } |
| |
| } |
| |
| //-------------------------------replace_by----------------------------------- |
| // Using def-use info, replace one node for another. Follow the def-use info |
| // to all users of the OLD node. Then make all uses point to the NEW node. |
| void Node::replace_by(Node *new_node) { |
| assert(!is_top(), "top node has no DU info"); |
| for (DUIterator_Last imin, i = last_outs(imin); i >= imin; ) { |
| Node* use = last_out(i); |
| uint uses_found = 0; |
| for (uint j = 0; j < use->len(); j++) { |
| if (use->in(j) == this) { |
| if (j < use->req()) |
| use->set_req(j, new_node); |
| else use->set_prec(j, new_node); |
| uses_found++; |
| } |
| } |
| i -= uses_found; // we deleted 1 or more copies of this edge |
| } |
| } |
| |
| //============================================================================= |
| //----------------------------------------------------------------------------- |
| void Type_Array::grow( uint i ) { |
| if( !_max ) { |
| _max = 1; |
| _types = (const Type**)_a->Amalloc( _max * sizeof(Type*) ); |
| _types[0] = NULL; |
| } |
| uint old = _max; |
| while( i >= _max ) _max <<= 1; // Double to fit |
| _types = (const Type**)_a->Arealloc( _types, old*sizeof(Type*),_max*sizeof(Type*)); |
| memset( &_types[old], 0, (_max-old)*sizeof(Type*) ); |
| } |
| |
| //------------------------------dump------------------------------------------- |
| #ifndef PRODUCT |
| void Type_Array::dump() const { |
| uint max = Size(); |
| for( uint i = 0; i < max; i++ ) { |
| if( _types[i] != NULL ) { |
| tty->print(" %d\t== ", i); _types[i]->dump(); tty->cr(); |
| } |
| } |
| } |
| #endif |