Mercurial > hg > graal-jvmci-8
view src/share/vm/opto/phaseX.cpp @ 17716:cdb71841f4bc
6498581: ThreadInterruptTest3 produces wrong output on Windows
Summary: There is race condition between os::interrupt and os::is_interrupted on Windows. In JVM_Sleep(Thread.sleep), check if thread gets interrupted, it may see interrupted but not really interrupted so cause spurious waking up (early return from sleep). Fix by checking if interrupt event really gets set thus prevent false return. For intrinsic of _isInterrupted, on Windows, go fastpath only on bit not set.
Reviewed-by: acorn, kvn
Contributed-by: david.holmes@oracle.com, yumin.qi@oracle.com
author | minqi |
---|---|
date | Wed, 26 Feb 2014 15:20:41 -0800 |
parents | de95063c0e34 |
children | 4ca6dc0799b6 968a17f18337 78bbf4d43a14 |
line wrap: on
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/* * Copyright (c) 1997, 2013, 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 } } } void NodeHash::check_no_speculative_types() { #ifdef ASSERT uint max = size(); Node *sentinel_node = sentinel(); for (uint i = 0; i < max; ++i) { Node *n = at(i); if(n != NULL && n != sentinel_node && n->is_Type()) { TypeNode* tn = n->as_Type(); const Type* t = tn->type(); const Type* t_no_spec = t->remove_speculative(); assert(t == t_no_spec, "dead node in hash table or missed node during speculative cleanup"); } } #endif } #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); } } } /** * Remove the speculative part of all types that we know of */ void PhaseIterGVN::remove_speculative_types() { assert(UseTypeSpeculation, "speculation is off"); for (uint i = 0; i < _types.Size(); i++) { const Type* t = _types.fast_lookup(i); if (t != NULL) { _types.map(i, t->remove_speculative()); } } _table.check_no_speculative_types(); } //============================================================================= #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->number_of_nodes(); // block->end_idx() not valid after PhaseRegAlloc for( uint instruction_index = 1; instruction_index < end_index; ++instruction_index ) { Node *n = block->get_node(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->get_node(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->remove_node( instruction_index ); } // install new node after safe_instruction_index block->insert_node(m2, safe_instruction_index + 1); end_index = block->number_of_nodes() - 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