Mercurial > hg > truffle
diff src/share/vm/opto/phaseX.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 874b2c4f43d1 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/opto/phaseX.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,1758 @@ +/* + * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +#include "incls/_precompiled.incl" +#include "incls/_phaseX.cpp.incl" + +//============================================================================= +#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(), 1) 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(), 1) 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 +} + +//------------------------------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 sentinal +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 != _sentinal) */; ) { + 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) ) { // PrintOptoGVN + if( PrintCompilation2 ) { + 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); + + // 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 + } + // Collect points-to information for escape analysys + ConnectionGraph *cgr = C->congraph(); + if (cgr != NULL) { + cgr->record_escape(x, this); + } + } 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. The Node passed in here must have no other +// pointers to it, as its storage will be reclaimed if the Node can be +// optimized away. +Node *PhaseGVN::transform( 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" ); + // Can never reclaim storage for Ideal calls, because the Ideal call + // returns a new Node, bumping the High Water Mark and our old Node + // is caught behind the new one. + //if( k != i ) { + //k->destruct(); // Reclaim storage for recent node + 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); + + // Cache result of Value call since it can be expensive + // (abstract interpretation of node 'k' using phase->_types[ inputs ]) + 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 record transformation or value construction on first visit + 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() ) { + //k->destruct(); // Reclaim storage for recent node + 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! + //k->destruct(); // Reclaim storage for recent node + NOT_PRODUCT( set_progress(); ) + return i; + } + + // Try Global Value Numbering + i = hash_find_insert(k); // Found older value when i != NULL + if( i && i != k ) { // Hit? Return the old guy + NOT_PRODUCT( set_progress(); ) + return i; + } + + // Collect points-to information for escape analysys + ConnectionGraph *cgr = C->congraph(); + if (cgr != NULL) { + cgr->record_escape(k, this); + } + + // Return Idealized original + return k; +} + +//------------------------------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 direcly +// 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( ) { +} + +//------------------------------PhaseIterGVN----------------------------------- +// Initialize with previous PhaseIterGVN info; used by PhaseCCP +PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn ) : PhaseGVN(igvn), + _worklist( igvn->_worklist ) +{ +} + +//------------------------------PhaseIterGVN----------------------------------- +// Initialize with previous PhaseGVN info from Parser +PhaseIterGVN::PhaseIterGVN( PhaseGVN *gvn ) : PhaseGVN(gvn), + _worklist(*C->for_igvn()) +{ + 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 + + // Pull from worklist; transform node; + // If node has changed: update edge info and put uses on worklist. + while( _worklist.size() ) { + Node *n = _worklist.pop(); + 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 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);) + Node *i = k->Ideal(this, /*can_reshape=*/true); +#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 + i = k->Ideal(this, /*can_reshape=*/true); +#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 ) { + assert(dead != C->root(), "killing root, eh?"); + if (dead->is_top()) return; + NOT_PRODUCT( set_progress(); ) + // Remove from iterative worklist + _worklist.remove(dead); + if (!dead->is_Con()) { // Don't kill cons but uses + // 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 ) { // Points to something? + dead->set_req(i,NULL); // Kill the edge + if (in->outcnt() == 0 && in != C->top()) {// Made input go dead? + remove_dead_node(in); // Recursively remove + } 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 (dead->is_macro()) { + C->remove_macro_node(dead); + } + } + // Aggressively kill globally dead uses + // (Cannot use DUIterator_Last because of the indefinite number + // of edge deletions per loop trip.) + while (dead->outcnt() > 0) { + remove_globally_dead_node(dead->raw_out(0)); + } +} + +//------------------------------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, 1) 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->Opcode() == Op_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 reciever 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."); + add_users_to_worklist(m); + hash_delete(m); // Yank from hash before hacking edges + subsume_node(m, nn); + --i; // deleted this phi; rescan starting with next position + } + } + } + add_users_to_worklist(n); // Users of about-to-be-constant 'n' + hash_delete(n); // Removed 'n' from table before subsuming it + subsume_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); + 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._num_blocks; ++block_number ) { + Block *block = _cfg._blocks[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: // Kill all his inputs, and recursively kill other dead nodes. + if (!old->is_top()) + igvn->remove_dead_node( 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