3226N/A * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 0N/A * published by the Free Software Foundation. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 1472N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 3619N/A // Add unknown java object. 253N/A // Add ConP(#NULL) and ConN(#NULL) nodes. 3619N/A // EA brings benefits only when the code has allocations and/or locks which 3619N/A // are represented by ideal Macro nodes. 3619N/A // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction 3619N/A // to create space for them in ConnectionGraph::_nodes[]. 3619N/A // There are non escaping objects. 3619N/A // 1. Populate Connection Graph (CG) with PointsTo nodes. 3619N/A // Create PointsTo nodes and add them to Connection Graph. Called 3619N/A // only once per ideal node since ideal_nodes is Unique_Node list. 3619N/A // Only allocations and java static calls results are interesting. 3619N/A // Collect all MergeMem nodes to add memory slices for 3619N/A // scalar replaceable objects in split_unique_types(). 3619N/A // Collect compare pointers nodes. 3619N/A // Collect all MemBarStoreStore nodes so that depending on the 3619N/A // escape status of the associated Allocate node some of them 3619N/A // Collect address nodes for graph verification. 3619N/A return false;
// Nothing to do. 3619N/A // Add final simple edges to graph. 3619N/A // Verify that no new simple edges could be created and all 3619N/A // 2. Finish Graph construction by propagating references to all 3619N/A // java objects through graph. 3619N/A // All objects escaped or hit time or iterations limits. 3619N/A // 3. Adjust scalar_replaceable state of nonescaping objects and push 3619N/A // scalar replaceable allocations on alloc_worklist for processing 3619N/A // in split_unique_types(). 3619N/A // Verify that graph is complete - no new edges could be added or needed. 3619N/A }
// TracePhase t3("connectionGraph") 3619N/A // 4. Optimize ideal graph based on EA information. 3619N/A // 5. Separate memory graph for scalar replaceable allcations. 3619N/A // Now use the escape information to create unique types for 3619N/A // scalar replaceable objects. 3619N/A tty->
print(
" since there are no scalar replaceable candidates ===");
4015N/A// Utility function for nodes that load an object 4015N/A // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because 4015N/A // ThreadLocal has RawPtr type. 3619N/A// Populate Connection Graph with PointsTo nodes and create simple 3619N/A return;
// No need to redefine PointsTo node during first iteration. 3619N/A // Arguments to allocation and locking don't escape. 3619N/A // Put Lock and Unlock nodes on IGVN worklist to process them during 3619N/A // first IGVN optimization when escape information is still available. 3619N/A return;
// Skip uncommon traps 3619N/A // Don't mark as processed since call's arguments have to be processed. 3619N/A // Check if a call returns an object. 3619N/A // Put this check here to process call arguments since some call nodes 3619N/A return;
// Skip predefined nodes. 3619N/A // Field nodes are created for all field types. They are used in 3619N/A // adjust_scalar_replaceable_state() and split_unique_types(). 3619N/A // Note, non-oop fields will have only base edges in Connection 3619N/A // Graph because such fields are not used for oop loads and stores. 3619N/A // Do not add edges during first iteration because some could be 3619N/A // assume all oop constants globally escape except for null 3619N/A // assume that all exception objects globally escape 3619N/A // Produces Null or notNull and is used in only in CmpP so 3619N/A // phantom_obj could be used. 3619N/A // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because 4015N/A // ThreadLocal has RawPtr type. 3619N/A // Do not add edges during first iteration because some could be 3619N/A // we are only interested in the oop result projection from a call 3619N/A // Treat Return value as LocalVar with GlobalEscape escape state. 3619N/A // Verify a raw address for a store captured by Initialize node. 3619N/A // Ignore copy the displaced header to the BoxNode (OSR compilation). 3625N/A // Stored value escapes in unsafe access. 3625N/A // Pointer stores in G1 barriers looks like unsafe access. 3625N/A // Ignore such stores to be able scalar replace non-escaping 3625N/A break;
// G1 pre barier previous oop value store. 3625N/A break;
// G1 post barier card address store. 3619N/A ;
// Do nothing for nodes not related to EA. 3619N/A /* Should not be called for not pointer type. */ \
3619N/A// Add final simple edges to graph. 3619N/A return;
// This method does not change graph for JavaObject. 3619N/A "node should be registered already");
3619N/A continue;
// ignore top or inputs which go back this node 3619N/A // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because 4015N/A // ThreadLocal has RawPtr type. 3619N/A // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because 4015N/A // ThreadLocal has RawPtr type. 3619N/A continue;
// ignore top or inputs which go back this node 3619N/A // we are only interested in the oop result projection from a call 3619N/A // Treat Return value as LocalVar with GlobalEscape escape state. 3625N/A // Stored value escapes in unsafe access. 3625N/A // Add edge to object for unsafe access with offset. 3619N/A // char[] arrays passed to string intrinsic do not escape but 3619N/A // they are not scalar replaceable. Adjust escape state for them. 3619N/A // Start from in(2) edge since in(1) is memory edge. 3619N/A // This method should be called only for EA specific nodes which may 3619N/A // miss some edges when they were created. 3619N/A // Not scalar replaceable if the length is not constant or too big. 3619N/A }
else {
// Allocate instance 3619N/A // Call nodes could be different types: 3619N/A // 1. CallDynamicJavaNode (what happened during call is unknown): 3619N/A // - mapped to GlobalEscape JavaObject node if oop is returned; 3619N/A // - all oop arguments are escaping globally; 3619N/A // 2. CallStaticJavaNode (execute bytecode analysis if possible): 3619N/A // - the same as CallDynamicJavaNode if can't do bytecode analysis; 3619N/A // - mapped to GlobalEscape JavaObject node if unknown oop is returned; 3619N/A // - mapped to NoEscape JavaObject node if non-escaping object allocated 3619N/A // during call is returned; 3619N/A // - mapped to ArgEscape LocalVar node pointed to object arguments 3619N/A // which are returned and does not escape during call; 3619N/A // - oop arguments escaping status is defined by bytecode analysis; 3619N/A // For a static call, we know exactly what method is being called. 3619N/A // Use bytecode estimator to record whether the call's return value escapes. 3619N/A // Returns a newly allocated unescaped object. 3619N/A // Returns a newly allocated unescaped object, simply 3619N/A // update dependency information. 3619N/A // Mark it as NoEscape so that objects referenced by 3619N/A // it's fields will be marked as NoEscape at least. 3619N/A // Determine whether any arguments are returned. 3619N/A // An other type of call, assume the worst case: 3619N/A // returned value is unknown and globally escapes. 3619N/A // Stub calls, objects do not escape but they are not scale replaceable. 3619N/A // Adjust escape state for outgoing arguments. 3619N/A // The inline_native_clone() case when the arraycopy stub is called 3619N/A // after the allocation before Initialize and CheckCastPP nodes. 3619N/A // Or normal arraycopy for object arrays case. 3619N/A // Set AddP's base (Allocate) as not scalar replaceable since 3619N/A // pointer to the base (with offset) is passed as argument. 3619N/A // src or dst could be j.l.Object when other is basic type array: 3619N/A // arraycopy(char[],0,Object*,0,size); 3619N/A // arraycopy(Object*,0,char[],0,size); 3619N/A // Don't add edges in such cases. 3619N/A // Always process arraycopy's destination object since 3619N/A // we need to add all possible edges to references in 3619N/A // A destination object's field can't have the source object 3619N/A // as base since objects escape states are not related. 3619N/A // Only escape state of destination object's fields affects 3619N/A // escape state of fields in source object. 3619N/A // For a static call, we know exactly what method is being called. 3619N/A // Use bytecode estimator to record the call's escape affects 3619N/A // fall-through if not a Java method or no analyzer information 3619N/A // The call returns arguments. 3619N/A // The argument global escapes 3619N/A // The argument itself doesn't escape, but any fields might 3619N/A // The call returns arguments. 3619N/A // Returns also unknown object. 3619N/A // Fall-through here if not a Java method or no analyzer information 3619N/A // or some other type of call, assume the worst case: all arguments 3619N/A// Finish Graph construction. 3619N/A // Normally only 1-3 passes needed to build Connection Graph depending 3619N/A // Set limit to 20 to catch situation when something did go wrong and 3619N/A // bailout Escape Analysis. 3619N/A // Also limit build time to 30 sec (60 in debug VM). 3619N/A // Propagate GlobalEscape and ArgEscape escape states and check that 3619N/A // we still have non-escaping objects. The method pushs on _worklist 3619N/A // Field nodes which reference phantom_object. 3619N/A return false;
// Nothing to do. 3619N/A // Now propagate references to all JavaObject nodes. 3619N/A // Propagate references to phantom_object for nodes pushed on _worklist 3619N/A // by find_non_escaped_objects() and find_field_value(). 3619N/A // Update escape states on each iteration if graph was updated. 3619N/A return false;
// Nothing to do. 3619N/A // Find fields which have unknown value. 3619N/A // This code may added new edges to phantom_object. 3619N/A // Need an other cycle to propagate references to phantom_object. 3619N/A // Bailout if passed limits. 3619N/A // Possible infinite build_connection_graph loop, 3619N/A // bailout (no changes to ideal graph were made). 3619N/A tty->
print_cr(
"EA: %d iterations to build connection graph with %d nodes and worklist size %d",
3619N/A // Find fields initialized by NULL for non-escaping Allocations. 3619N/A // Adding references to NULL object does not change escape states 3619N/A // since it does not escape. Also no fields are added to NULL object. 3619N/A // The object allocated by this Allocate node will never be 3619N/A // seen by an other thread. Mark it so that when it is 3619N/A // expanded no MemBarStoreStore is added. 3619N/A return true;
// Finished graph construction. 3619N/A// Propagate GlobalEscape and ArgEscape escape states to all nodes 3619N/A// and check that we still have non-escaping java objects. 3619N/A // First, put all nodes with GlobalEscape and ArgEscape states on worklist. 3619N/A // Set escape states to referenced nodes (edges list). 3619N/A // GlobalEscape or ArgEscape state of field means it has unknown value. 3619N/A // Propagate only fields escape state through arraycopy edge. 3619N/A // fields_escape_state is also set to 'es' if it is less than 'es'. 3619N/A // Propagate field escape state. 3619N/A // Change escape state of referenced fileds. 3619N/A // Remove escaped objects from non_escaped list. 3619N/A // Find fields in non-escaped allocations which have unknown value. 3619N/A// Add all references to JavaObject node by walking over all uses. 3619N/A // Populate _worklist by uses of jobj's uses. 3619N/A // Put on worklist all field's uses (loads) and 3619N/A // related field nodes (same base and offset). 3619N/A // Add reference from jobj to field and from field to jobj (field's base). 3619N/A // Added edge from Arraycopy node to arraycopy's source java object 3619N/A continue;
// No new edge added, there was such edge already. 3619N/A // Add edge from arraycopy's destination java object to Arraycopy node. 3619N/A // Added new edge to stored in field values. 3619N/A // Put on worklist all field's uses (loads) and 3619N/A // related field nodes (same base and offset). 3619N/A// Put on worklist all related field nodes. 3619N/A // Loop over all bases of this field and push on worklist Field nodes 3619N/A // with the same offset and base (since they may reference the same field). 3619N/A // Check if the base was source object of arraycopy and go over arraycopy's 3619N/A // destination objects since values stored to a field of source object are 3619N/A // accessable by uses (loads) of fields of destination objects. 3619N/A // Look for the same arracopy reference. 3619N/A// Put on worklist all related field nodes. 3619N/A if (
// Skip phantom_object since it is only used to indicate that 3619N/A // this field's content globally escapes. 3619N/A // NULL object node does not have fields. 3619N/A // Skip arraycopy edge since store to destination object field 3619N/A // does not update value in source object field. 3619N/A// Find fields which have unknown value. 3619N/A // Escaped fields should have init value already. 3619N/A // Skip Allocate's fields which will be processed later. 3619N/A// Find fields initializing values for allocations. 3619N/A // Do nothing for Allocate nodes since its fields values are "known". 3619N/A // Non-escaped allocation returned from Java or runtime call have 3619N/A // unknown values in fields. 3619N/A // Do nothing for Call nodes since its fields values are unknown. 3619N/A // Check if an oop field's initializing value is recorded and add 3619N/A // a corresponding NULL if field's value if it is not recorded. 3619N/A // Connection Graph does not record a default initialization by NULL 3619N/A // captured by Initialize node. 3619N/A // OffsetBot is used to reference array's element, 3619N/A // always add reference to NULL to all Field nodes since we don't 3619N/A // known which element is referenced. 3619N/A // Raw pointers are used for initializing stores so skip it 3619N/A // since it should be recorded already 4049N/A // StoreP::memory_type() == T_ADDRESS 4049N/A // Make sure initializing store has the same type as this AddP. 4049N/A // This AddP may reference non existing field because it is on a 4049N/A // dead branch of bimorphic call which is not eliminated yet. 4049N/A // Verify that AddP already points to all objects the value points to. 3619N/A // There could be initializing stores which follow allocation. 3619N/A // For example, a volatile field store is not collected 3619N/A // Need to check for dependent loads to separate such stores from 3619N/A // stores which follow loads. For now, add initial value NULL so 3619N/A // that compare pointers optimization works correctly. 3619N/A // A field's initializing value was not recorded. Add NULL. 3619N/A// Adjust scalar_replaceable state after Connection Graph is built. 3619N/A // Search for non-escaping objects which are not scalar replaceable 3619N/A // and mark them to propagate the state to referenced objects. 3619N/A // 1. An object is not scalar replaceable if the field into which it is 3619N/A // stored has unknown offset (stored into unknown element of an array). 3619N/A // 2. An object is not scalar replaceable if it is merged with other objects. 3619N/A // Non-escaping object node should point only to field nodes. 3619N/A // 3. An object is not scalar replaceable if it has a field with unknown 3619N/A // offset (array's element is accessed in loop). 3619N/A // 4. Currently an object is not scalar replaceable if a LoadStore node 3619N/A // access its field since the field value is unknown after it. 3619N/A // 5. Or the address may point to more then one object. This may produce 3619N/A // the false positive result (set not scalar replaceable) 3619N/A // since the flow-insensitive escape analysis can't separate 3619N/A // the case when stores overwrite the field's value from the case 3619N/A // when stores happened on different control branches. 3619N/A // Note: it will disable scalar replacement in some cases: 3619N/A // Point p[] = new Point[1]; 3619N/A // p[0] = new Point(); // Will be not scalar replaced 3619N/A // but it will save us from incorrect optimizations in next cases: 3619N/A // Point p[] = new Point[1]; 3619N/A // if ( x ) p[0] = new Point(); // Will be not scalar replaced 3619N/A // Don't take into account LocalVar nodes which 3619N/A // may point to only one object which should be also 3619N/A // this field's base by now. 3619N/A // Verify that graph is complete - no new edges could be added. 3619N/A // Verify that escape state is final. 3619N/A // Verify fields information. 3619N/A // Verify that field has all bases 3619N/A // Verify that all fields have initializing values. 3619N/A // Mark locks before changing ideal graph. 3619N/A // The lock could be marked eliminated by lock coarsening 3619N/A // code during first IGVN before EA. Replace coarsened flag 3619N/A // Add ConI(#CC_GT) and ConI(#CC_EQ). 3619N/A // Optimize objects compare. 3619N/A // escape status of associated AllocateNode and optimize out 3619N/A // MemBarStoreStore node if the allocated object never escapes. 3619N/A// Optimize objects compare. 3619N/A // Check simple cases first. 3619N/A // Comparing the same not escaping object. 3619N/A // Comparing not escaping allocation. 3619N/A // Comparing not escaping allocation. 3619N/A // Klass or String constants compare. Need to be careful with 3619N/A // compressed pointers - compare types of ConN and ConP instead of nodes. 3619N/A // Check nullness of unknown object. 3619N/A // Disjointness by itself is not sufficient since 3619N/A // alias analysis is not complete for escaped objects. 3619N/A // Disjoint sets are definitely unrelated only when 3619N/A // at least one set has only not escaping allocations. 3619N/A// Connection Graph constuction functions. 3619N/A // Add edge from arraycopy node to source object. 3619N/A // Add edge from destination object to arraycopy node. 3619N/A // OffsetBot is used to reference array's element. Ignore first AddP. 3932N/A // Check for unsafe oop field access 3619N/A // Ignore array length load. 3619N/A // Allocation initialization, ThreadLocal field access, unsafe access 3619N/A// Returns unique pointed java object or NULL. 3619N/A // If the node was created after the escape computation we can't answer. 3619N/A // Check all java objects it points to. 3619N/A// Return true if this node points only to non-escaping allocations. 3619N/A // Check all java objects it points to. 3619N/A// Return true if we know the node does not escape globally. 3619N/A // If the node was created after the escape computation we can't answer. 3619N/A // If we have already computed a value, return it. 3619N/A return true;
// (es < PointsToNode::GlobalEscape); 3619N/A // Check all java objects it points to. 3619N/A// Return true if this node points to specified node or nodes it points to. 3619N/A// Return true if one node points to an other. 3619N/A// Return true if bases point to this java object. 65N/A // We are computing a raw address for a store captured by an Initialize 65N/A // compute an appropriate address type. AddP cases #3 and #5 (see below). 65N/A "offset must be a constant or it is initialization of array");
65N/A // AddP cases for Base and Address inputs: 65N/A // case #1. Direct object's field reference: 65N/A // Proj #5 ( oop result ) 65N/A // CheckCastPP (cast to instance type) 65N/A // AddP ( base == address ) 65N/A // case #2. Indirect object's field reference: 65N/A // CastPP (cast to instance type) 65N/A // AddP ( base == address ) 65N/A // case #3. Raw object's field reference for Initialize node: 65N/A // Proj #5 ( oop result ) 65N/A // AddP ( base == top ) 65N/A // case #4. Array's element reference: 65N/A // {CheckCastPP | CastPP} 65N/A // | AddP ( array's element offset ) 65N/A // AddP ( array's offset ) 65N/A // case #5. Raw object's field reference for arraycopy stub call: 65N/A // The inline_native_clone() case when the arraycopy stub is called 65N/A // after the allocation before Initialize and CheckCastPP nodes. 65N/A // Proj #5 ( oop result ) 65N/A // AddP ( base == address ) 77N/A // case #6. Constant Pool, ThreadLocal, CastX2P or 77N/A // Raw object's field reference: 77N/A // {ConP, ThreadLocal, CastX2P, raw Load} 65N/A // AddP ( base == top ) 77N/A // case #7. Klass's field reference. 77N/A // AddP ( base == address ) 164N/A // case #8. narrow Klass's field reference. 164N/A // AddP ( base == address ) 957N/A // Case #6 (unsafe access) may have several chained AddP nodes. 65N/A // Find array's offset to push it on worklist first and 65N/A // as result process an array's element offset first (pushed second) 65N/A // to avoid CastPP for the array's offset. 65N/A // Otherwise the inserted CastPP (LocalVar) will point to what 65N/A // the AddP (Field) points to. Which would be wrong since 65N/A // the algorithm expects the CastPP has the same point as 65N/A // as AddP's base CheckCastPP (LocalVar). 65N/A // memProj (from ArrayAllocation CheckCastPP) 65N/A // | || Int (element index) 65N/A // | || | ConI (log(element size)) 65N/A // | AddP (array's element offset) 65N/A // | | ConI (array's offset: #12(32-bits) or #24(64-bits)) 65N/A // AddP (array's offset) 0N/A// Adjust the type and inputs of an AddP which computes the 0N/A// address of a field of an instance 65N/A // We are computing a raw address for a store captured by an Initialize 293N/A // compute an appropriate address type (cases #3 and #5). 0N/A "old type must be non-instance or match new type");
293N/A // The type 't' could be subclass of 'base_t'. 293N/A // As result t->offset() could be large then base_t's size and it will 293N/A // cause the failure in add_offset() with narrow oops since TypeOopPtr() 293N/A // constructor verifies correctness of the offset. 605N/A // It could happened on subclass's branch (from the type profiling 293N/A // inlining) which was not eliminated during parsing since the exactness 293N/A // of the allocation type was not propagated to the subclass type check. 988N/A // Or the type 't' could be not related to 'base_t' at all. 988N/A // It could happened when CHA type is different from MDO type on a dead path 988N/A // (for example, from instanceof check) which is not collapsed during parsing. 293N/A // Do nothing for such AddP node and don't process its users since 293N/A // this code branch will go away. 293N/A return false;
// bail out 1062N/A // Do NOT remove the next line: ensure a new alias index is allocated 1062N/A // for the instance type. Note: C++ will not remove it since the call 0N/A // record the allocation in the node map 253N/A // Set addp's Base and Address to 'base'. 253N/A // Skip AddP cases #3 and #5. 253N/A // AddP case #4 (adr is array's element offset AddP node) 65N/A // Put on IGVN worklist since at least addp's type was changed above. 0N/A// Create a new version of orig_phi if necessary. Returns either the newly 2306N/A// created phi or an existing phi. Sets create_new to indicate whether a new 0N/A// phi was created. Cache the last newly created phi in the node map. 0N/A // nothing to do if orig_phi is bottom memory or matches alias_idx 851N/A // Have we recently created a Phi for this alias index? 851N/A // Previous check may fail when the same wide memory Phi was split into Phis 851N/A // for different memory slices. Search all Phis for this region. 38N/A // Retry compilation without escape analysis. 38N/A // If this is the first failure, the sentinel string will "stick" 38N/A // to the Compile object, and the C2Compiler will see it and retry. 2306N/A// Return a new version of Memory Phi "orig_phi" with the inputs having the 0N/A// specified alias index. 0N/A // found an phi for which we created a new split, push current one on worklist and begin 0N/A // processing new one 0N/A // verify that the new Phi has an input for each input of the original 65N/A // Check if all new phi's inputs have specified alias index. 65N/A // Otherwise use old phi. 0N/A // we have finished processing a Phi, see if there are any more to do 65N/A// The next methods are derived from methods in MemNode. 1735N/A // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally 65N/A // means an array I have not precisely typed yet. Do not do any 65N/A // alias stuff with it any time soon. 65N/A // Update input if it is progress over what we have now 1101N/A// Move memory users to their memory slices. 1101N/A // Replace previous general reference to mem node. 1101N/A // Don't move related membars. 1101N/A // Move to general memory slice. 1101N/A // Don't move related cardmark. 1101N/A // Memory nodes should have new memory input. 1101N/A "Following memory nodes should have new memory input or be on the same memory slice");
1101N/A // Phi nodes should be split and moved already. 65N/A// Search memory chain of "mem" to find a MemNode whose address 65N/A// is the specified alias index. 605N/A break;
// hit one of our sentinels 2306N/A break;
// Do not skip store to general memory slice. 65N/A continue;
// don't search further for non-instance types 65N/A // skip over a call which does not affect this memory slice 605N/A break;
// hit one of our sentinels 65N/A // Stop if this is the initialization for the object instance which 65N/A // which contains this memory slice, otherwise skip over it. 65N/A // Didn't find instance memory, search through general slice recursively. 1100N/A // Can not bypass initialization of the instance 1100N/A // Otherwise skip it (the call updated 'result' value). 247N/A // Push all non-instance Phis on the orig_phis worklist to update inputs 247N/A // during Phase 4 if needed. 2306N/A // Create a new Phi with the specified alias index type. 65N/A // the result is either MemNode, PhiNode, InitializeNode. 0N/A// Convert the types of unescaped object to instance types where possible, 0N/A// propagate the new type information through the graph, and update memory 0N/A// edges and MergeMem inputs to reflect the new type. 0N/A// We start with allocations (and calls which may be allocations) on alloc_worklist. 0N/A// The processing is done in 4 phases: 0N/A// Phase 1: Process possible allocations from alloc_worklist. Create instance 0N/A// types for the CheckCastPP for allocations where possible. 0N/A// Propagate the the new types through users as follows: 0N/A// casts and Phi: push users on alloc_worklist 0N/A// AddP: cast Base and Address inputs to the instance type 0N/A// push any AddP users on alloc_worklist and push any memnode 0N/A// users onto memnode_worklist. 0N/A// Phase 2: Process MemNode's from memnode_worklist. compute new address type and 0N/A// search the Memory chain for a store with the appropriate type 0N/A// address type. If a Phi is found, create a new version with 605N/A// the appropriate memory slices from each of the Phi inputs. 0N/A// For stores, process the users as follows: 0N/A// MemNode: push on memnode_worklist 0N/A// MergeMem: push on mergemem_worklist 0N/A// Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice 0N/A// moving the first node encountered of each instance type to the 0N/A// the input corresponding to its alias index. 0N/A// appropriate memory slice. 0N/A// Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes. 0N/A// In the following example, the CheckCastPP nodes are the cast of allocation 0N/A// results and the allocation of node 29 is unescaped and eligible to be an 0N/A// 19 CheckCastPP "Foo" 0N/A// 20 AddP _ 19 19 10 Foo+12 alias_index=4 0N/A// 29 CheckCastPP "Foo" 0N/A// 30 AddP _ 29 29 10 Foo+12 alias_index=4 0N/A// 40 StoreP 25 7 20 ... alias_index=4 0N/A// 50 StoreP 35 40 30 ... alias_index=4 0N/A// 60 StoreP 45 50 20 ... alias_index=4 0N/A// 70 LoadP _ 60 30 ... alias_index=4 0N/A// 80 Phi 75 50 60 Memory alias_index=4 0N/A// 90 LoadP _ 80 30 ... alias_index=4 0N/A// 100 LoadP _ 80 20 ... alias_index=4 0N/A// Phase 1 creates an instance type for node 29 assigning it an instance id of 24 0N/A// and creating a new alias index for node 30. This gives: 0N/A// 19 CheckCastPP "Foo" 0N/A// 20 AddP _ 19 19 10 Foo+12 alias_index=4 0N/A// 29 CheckCastPP "Foo" iid=24 0N/A// 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24 0N/A// 40 StoreP 25 7 20 ... alias_index=4 0N/A// 50 StoreP 35 40 30 ... alias_index=6 0N/A// 60 StoreP 45 50 20 ... alias_index=4 0N/A// 70 LoadP _ 60 30 ... alias_index=6 0N/A// 80 Phi 75 50 60 Memory alias_index=4 0N/A// 90 LoadP _ 80 30 ... alias_index=6 0N/A// 100 LoadP _ 80 20 ... alias_index=4 0N/A// In phase 2, new memory inputs are computed for the loads and stores, 0N/A// And a new version of the phi is created. In phase 4, the inputs to 0N/A// node 80 are updated and then the memory nodes are updated with the 0N/A// values computed in phase 2. This results in: 0N/A// 19 CheckCastPP "Foo" 0N/A// 20 AddP _ 19 19 10 Foo+12 alias_index=4 0N/A// 29 CheckCastPP "Foo" iid=24 0N/A// 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24 0N/A// 40 StoreP 25 7 20 ... alias_index=4 0N/A// 50 StoreP 35 7 30 ... alias_index=6 0N/A// 60 StoreP 45 40 20 ... alias_index=4 0N/A// 70 LoadP _ 50 30 ... alias_index=6 0N/A// 80 Phi 75 40 60 Memory alias_index=4 0N/A// 120 Phi 75 50 50 Memory alias_index=6 0N/A// 90 LoadP _ 120 30 ... alias_index=6 0N/A// 100 LoadP _ 80 20 ... alias_index=4 65N/A // Phase 1: Process possible allocations from alloc_worklist. 65N/A // Create instance types for the CheckCastPP for allocations where possible. 244N/A // (Note: don't forget to change the order of the second AddP node on 244N/A // the alloc_worklist if the order of the worklist processing is changed, 244N/A // see the comment in find_second_addp().) 0N/A // copy escape information to call node 65N/A // We have an allocation or call which returns a Java object, 65N/A // see if it is unescaped. 784N/A // Find CheckCastPP for the allocate or for the return value of a call 784N/A if (n ==
NULL) {
// No uses except Initialize node 784N/A // Set the scalar_replaceable flag for allocation 784N/A // so it could be eliminated if it has no uses. 65N/A // The inline code for Object.clone() casts the allocation result to 247N/A // java.lang.Object and then to the actual type of the allocated 65N/A // object. Detect this case and use the second cast. 247N/A // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when 247N/A // the allocation result is cast to java.lang.Object and then 247N/A // to the actual Array type. 784N/A // Non-scalar replaceable if the allocation type is unknown statically 784N/A // (reflection allocation), the object can't be restored during 784N/A // deoptimization without precise type. 784N/A // Set the scalar_replaceable flag for allocation 784N/A // so it could be eliminated. 247N/A // in order for an object to be scalar-replaceable, it must be: 65N/A // - a direct allocation (not a call returning an object) 65N/A // - eligible to be a unique type 65N/A // - not determined to be ineligible by escape analysis 2896N/A continue;
// not a TypeOopPtr 163N/A // First, put on the worklist all Field edges from Connection Graph 163N/A // which is more accurate then putting immediate users from Ideal Graph. 163N/A "only AddP nodes are Field edges in CG");
65N/A // An allocation may have an Initialize which has raw stores. Scan 65N/A // the users of the raw allocation result and push AddP users 65N/A // on alloc_worklist. 0N/A continue;
// already processed 1100N/A continue;
// Skip dead path with different type 1100N/A // push allocation's users on appropriate worklist 1100N/A // Look for MergeMem nodes for calls which reference unique allocation 1100N/A // (through CheckCastPP nodes) even for debug info. 65N/A // New alias types were created in split_AddP(). 0N/A // Phase 2: Process MemNode's from memnode_worklist. compute new address type and 0N/A // compute new values for Memory inputs (the Memory inputs are not 0N/A // actually updated until phase 4.) 0N/A return;
// nothing to do 1100N/A // we don't need to do anything, but the users must be pushed 1100N/A // we don't need to do anything, but the users must be pushed 1101N/A // We delay the memory edge update since we need old one in 1101N/A // MergeMem code below when instances memory slices are separated. 0N/A continue;
// don't push users 0N/A // get the memory projection 0N/A // push user on appropriate worklist 65N/A // Phase 3: Process MergeMem nodes from mergemem_worklist. 1100N/A // Walk each memory slice moving the first node encountered of each 65N/A // instance type to the the input corresponding to its alias index. 0N/A // Note: we don't want to use MergeMemStream here because we only want to 1100N/A // scan inputs which exist at the start, not ones we add during processing. 1100N/A // Note 2: MergeMem may already contains instance memory slices added 1100N/A // during find_inst_mem() call when memory nodes were processed above. 1101N/A // First, update mergemem by moving memory nodes to corresponding slices 1101N/A // if their type became more precise since this mergemem was created. 65N/A // Find any instance of the current type if we haven't encountered 1101N/A // already a memory slice of the instance along the memory chain. 65N/A // Find the rest of instances values 65N/A // Didn't find instance memory, search through general slice recursively. 65N/A // Phase 4: Update the inputs of non-instance memory Phis and 65N/A // the Memory input of memnodes 0N/A // First update the inputs of any non-instance Phi's from 0N/A // which we split out an instance Phi. Note we don't have 0N/A // to recursively process Phi's encounted on the input memory 0N/A // chains as is done in split_memory_phi() since they will 0N/A // also be processed here. 0N/A // Update the memory inputs of MemNodes with the value we computed 1101N/A // in Phase 2 and move stores memory users to corresponding memory slices. 2375N/A // Disable memory split verification code until the fix for 6984348. 2375N/A // Currently it produces false negative results since it does not cover all cases. 3619N/A // Move memory users of a store first. 1101N/A // Verify that memory was split correctly 3619N/A // Print all locals and fields which reference this allocation