/* * Copyright 2001-2007 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/_graphKit.cpp.incl" //----------------------------GraphKit----------------------------------------- // Main utility constructor. GraphKit::GraphKit(JVMState* jvms) : Phase(Phase::Parser), _env(C->env()), _gvn(*C->initial_gvn()) { _exceptions = jvms->map()->next_exception(); if (_exceptions != NULL) jvms->map()->set_next_exception(NULL); set_jvms(jvms); } // Private constructor for parser. GraphKit::GraphKit() : Phase(Phase::Parser), _env(C->env()), _gvn(*C->initial_gvn()) { _exceptions = NULL; set_map(NULL); debug_only(_sp = -99); debug_only(set_bci(-99)); } //---------------------------clean_stack--------------------------------------- // Clear away rubbish from the stack area of the JVM state. // This destroys any arguments that may be waiting on the stack. void GraphKit::clean_stack(int from_sp) { SafePointNode* map = this->map(); JVMState* jvms = this->jvms(); int stk_size = jvms->stk_size(); int stkoff = jvms->stkoff(); Node* top = this->top(); for (int i = from_sp; i < stk_size; i++) { if (map->in(stkoff + i) != top) { map->set_req(stkoff + i, top); } } } //--------------------------------sync_jvms----------------------------------- // Make sure our current jvms agrees with our parse state. JVMState* GraphKit::sync_jvms() const { JVMState* jvms = this->jvms(); jvms->set_bci(bci()); // Record the new bci in the JVMState jvms->set_sp(sp()); // Record the new sp in the JVMState assert(jvms_in_sync(), "jvms is now in sync"); return jvms; } #ifdef ASSERT bool GraphKit::jvms_in_sync() const { Parse* parse = is_Parse(); if (parse == NULL) { if (bci() != jvms()->bci()) return false; if (sp() != (int)jvms()->sp()) return false; return true; } if (jvms()->method() != parse->method()) return false; if (jvms()->bci() != parse->bci()) return false; int jvms_sp = jvms()->sp(); if (jvms_sp != parse->sp()) return false; int jvms_depth = jvms()->depth(); if (jvms_depth != parse->depth()) return false; return true; } // Local helper checks for special internal merge points // used to accumulate and merge exception states. // They are marked by the region's in(0) edge being the map itself. // Such merge points must never "escape" into the parser at large, // until they have been handed to gvn.transform. static bool is_hidden_merge(Node* reg) { if (reg == NULL) return false; if (reg->is_Phi()) { reg = reg->in(0); if (reg == NULL) return false; } return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root(); } void GraphKit::verify_map() const { if (map() == NULL) return; // null map is OK assert(map()->req() <= jvms()->endoff(), "no extra garbage on map"); assert(!map()->has_exceptions(), "call add_exception_states_from 1st"); assert(!is_hidden_merge(control()), "call use_exception_state, not set_map"); } void GraphKit::verify_exception_state(SafePointNode* ex_map) { assert(ex_map->next_exception() == NULL, "not already part of a chain"); assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop"); } #endif //---------------------------stop_and_kill_map--------------------------------- // Set _map to NULL, signalling a stop to further bytecode execution. // First smash the current map's control to a constant, to mark it dead. void GraphKit::stop_and_kill_map() { SafePointNode* dead_map = stop(); if (dead_map != NULL) { dead_map->disconnect_inputs(NULL); // Mark the map as killed. assert(dead_map->is_killed(), "must be so marked"); } } //--------------------------------stopped-------------------------------------- // Tell if _map is NULL, or control is top. bool GraphKit::stopped() { if (map() == NULL) return true; else if (control() == top()) return true; else return false; } //-----------------------------has_ex_handler---------------------------------- // Tell if this method or any caller method has exception handlers. bool GraphKit::has_ex_handler() { for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) { if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) { return true; } } return false; } //------------------------------save_ex_oop------------------------------------ // Save an exception without blowing stack contents or other JVM state. void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) { assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again"); ex_map->add_req(ex_oop); debug_only(verify_exception_state(ex_map)); } inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) { assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there"); Node* ex_oop = ex_map->in(ex_map->req()-1); if (clear_it) ex_map->del_req(ex_map->req()-1); return ex_oop; } //-----------------------------saved_ex_oop------------------------------------ // Recover a saved exception from its map. Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) { return common_saved_ex_oop(ex_map, false); } //--------------------------clear_saved_ex_oop--------------------------------- // Erase a previously saved exception from its map. Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) { return common_saved_ex_oop(ex_map, true); } #ifdef ASSERT //---------------------------has_saved_ex_oop---------------------------------- // Erase a previously saved exception from its map. bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) { return ex_map->req() == ex_map->jvms()->endoff()+1; } #endif //-------------------------make_exception_state-------------------------------- // Turn the current JVM state into an exception state, appending the ex_oop. SafePointNode* GraphKit::make_exception_state(Node* ex_oop) { sync_jvms(); SafePointNode* ex_map = stop(); // do not manipulate this map any more set_saved_ex_oop(ex_map, ex_oop); return ex_map; } //--------------------------add_exception_state-------------------------------- // Add an exception to my list of exceptions. void GraphKit::add_exception_state(SafePointNode* ex_map) { if (ex_map == NULL || ex_map->control() == top()) { return; } #ifdef ASSERT verify_exception_state(ex_map); if (has_exceptions()) { assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place"); } #endif // If there is already an exception of exactly this type, merge with it. // In particular, null-checks and other low-level exceptions common up here. Node* ex_oop = saved_ex_oop(ex_map); const Type* ex_type = _gvn.type(ex_oop); if (ex_oop == top()) { // No action needed. return; } assert(ex_type->isa_instptr(), "exception must be an instance"); for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) { const Type* ex_type2 = _gvn.type(saved_ex_oop(e2)); // We check sp also because call bytecodes can generate exceptions // both before and after arguments are popped! if (ex_type2 == ex_type && e2->_jvms->sp() == ex_map->_jvms->sp()) { combine_exception_states(ex_map, e2); return; } } // No pre-existing exception of the same type. Chain it on the list. push_exception_state(ex_map); } //-----------------------add_exception_states_from----------------------------- void GraphKit::add_exception_states_from(JVMState* jvms) { SafePointNode* ex_map = jvms->map()->next_exception(); if (ex_map != NULL) { jvms->map()->set_next_exception(NULL); for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) { next_map = ex_map->next_exception(); ex_map->set_next_exception(NULL); add_exception_state(ex_map); } } } //-----------------------transfer_exceptions_into_jvms------------------------- JVMState* GraphKit::transfer_exceptions_into_jvms() { if (map() == NULL) { // We need a JVMS to carry the exceptions, but the map has gone away. // Create a scratch JVMS, cloned from any of the exception states... if (has_exceptions()) { _map = _exceptions; _map = clone_map(); _map->set_next_exception(NULL); clear_saved_ex_oop(_map); debug_only(verify_map()); } else { // ...or created from scratch JVMState* jvms = new (C) JVMState(_method, NULL); jvms->set_bci(_bci); jvms->set_sp(_sp); jvms->set_map(new (C, TypeFunc::Parms) SafePointNode(TypeFunc::Parms, jvms)); set_jvms(jvms); for (uint i = 0; i < map()->req(); i++) map()->init_req(i, top()); set_all_memory(top()); while (map()->req() < jvms->endoff()) map()->add_req(top()); } // (This is a kludge, in case you didn't notice.) set_control(top()); } JVMState* jvms = sync_jvms(); assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet"); jvms->map()->set_next_exception(_exceptions); _exceptions = NULL; // done with this set of exceptions return jvms; } static inline void add_n_reqs(Node* dstphi, Node* srcphi) { assert(is_hidden_merge(dstphi), "must be a special merge node"); assert(is_hidden_merge(srcphi), "must be a special merge node"); uint limit = srcphi->req(); for (uint i = PhiNode::Input; i < limit; i++) { dstphi->add_req(srcphi->in(i)); } } static inline void add_one_req(Node* dstphi, Node* src) { assert(is_hidden_merge(dstphi), "must be a special merge node"); assert(!is_hidden_merge(src), "must not be a special merge node"); dstphi->add_req(src); } //-----------------------combine_exception_states------------------------------ // This helper function combines exception states by building phis on a // specially marked state-merging region. These regions and phis are // untransformed, and can build up gradually. The region is marked by // having a control input of its exception map, rather than NULL. Such // regions do not appear except in this function, and in use_exception_state. void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) { if (failing()) return; // dying anyway... JVMState* ex_jvms = ex_map->_jvms; assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains"); assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals"); assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes"); assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS"); assert(ex_map->req() == phi_map->req(), "matching maps"); uint tos = ex_jvms->stkoff() + ex_jvms->sp(); Node* hidden_merge_mark = root(); Node* region = phi_map->control(); MergeMemNode* phi_mem = phi_map->merged_memory(); MergeMemNode* ex_mem = ex_map->merged_memory(); if (region->in(0) != hidden_merge_mark) { // The control input is not (yet) a specially-marked region in phi_map. // Make it so, and build some phis. region = new (C, 2) RegionNode(2); _gvn.set_type(region, Type::CONTROL); region->set_req(0, hidden_merge_mark); // marks an internal ex-state region->init_req(1, phi_map->control()); phi_map->set_control(region); Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO); record_for_igvn(io_phi); _gvn.set_type(io_phi, Type::ABIO); phi_map->set_i_o(io_phi); for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) { Node* m = mms.memory(); Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C)); record_for_igvn(m_phi); _gvn.set_type(m_phi, Type::MEMORY); mms.set_memory(m_phi); } } // Either or both of phi_map and ex_map might already be converted into phis. Node* ex_control = ex_map->control(); // if there is special marking on ex_map also, we add multiple edges from src bool add_multiple = (ex_control->in(0) == hidden_merge_mark); // how wide was the destination phi_map, originally? uint orig_width = region->req(); if (add_multiple) { add_n_reqs(region, ex_control); add_n_reqs(phi_map->i_o(), ex_map->i_o()); } else { // ex_map has no merges, so we just add single edges everywhere add_one_req(region, ex_control); add_one_req(phi_map->i_o(), ex_map->i_o()); } for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) { if (mms.is_empty()) { // get a copy of the base memory, and patch some inputs into it const TypePtr* adr_type = mms.adr_type(C); Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type); assert(phi->as_Phi()->region() == mms.base_memory()->in(0), ""); mms.set_memory(phi); // Prepare to append interesting stuff onto the newly sliced phi: while (phi->req() > orig_width) phi->del_req(phi->req()-1); } // Append stuff from ex_map: if (add_multiple) { add_n_reqs(mms.memory(), mms.memory2()); } else { add_one_req(mms.memory(), mms.memory2()); } } uint limit = ex_map->req(); for (uint i = TypeFunc::Parms; i < limit; i++) { // Skip everything in the JVMS after tos. (The ex_oop follows.) if (i == tos) i = ex_jvms->monoff(); Node* src = ex_map->in(i); Node* dst = phi_map->in(i); if (src != dst) { PhiNode* phi; if (dst->in(0) != region) { dst = phi = PhiNode::make(region, dst, _gvn.type(dst)); record_for_igvn(phi); _gvn.set_type(phi, phi->type()); phi_map->set_req(i, dst); // Prepare to append interesting stuff onto the new phi: while (dst->req() > orig_width) dst->del_req(dst->req()-1); } else { assert(dst->is_Phi(), "nobody else uses a hidden region"); phi = (PhiNode*)dst; } if (add_multiple && src->in(0) == ex_control) { // Both are phis. add_n_reqs(dst, src); } else { while (dst->req() < region->req()) add_one_req(dst, src); } const Type* srctype = _gvn.type(src); if (phi->type() != srctype) { const Type* dsttype = phi->type()->meet(srctype); if (phi->type() != dsttype) { phi->set_type(dsttype); _gvn.set_type(phi, dsttype); } } } } } //--------------------------use_exception_state-------------------------------- Node* GraphKit::use_exception_state(SafePointNode* phi_map) { if (failing()) { stop(); return top(); } Node* region = phi_map->control(); Node* hidden_merge_mark = root(); assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation"); Node* ex_oop = clear_saved_ex_oop(phi_map); if (region->in(0) == hidden_merge_mark) { // Special marking for internal ex-states. Process the phis now. region->set_req(0, region); // now it's an ordinary region set_jvms(phi_map->jvms()); // ...so now we can use it as a map // Note: Setting the jvms also sets the bci and sp. set_control(_gvn.transform(region)); uint tos = jvms()->stkoff() + sp(); for (uint i = 1; i < tos; i++) { Node* x = phi_map->in(i); if (x->in(0) == region) { assert(x->is_Phi(), "expected a special phi"); phi_map->set_req(i, _gvn.transform(x)); } } for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) { Node* x = mms.memory(); if (x->in(0) == region) { assert(x->is_Phi(), "nobody else uses a hidden region"); mms.set_memory(_gvn.transform(x)); } } if (ex_oop->in(0) == region) { assert(ex_oop->is_Phi(), "expected a special phi"); ex_oop = _gvn.transform(ex_oop); } } else { set_jvms(phi_map->jvms()); } assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared"); assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared"); return ex_oop; } //---------------------------------java_bc------------------------------------- Bytecodes::Code GraphKit::java_bc() const { ciMethod* method = this->method(); int bci = this->bci(); if (method != NULL && bci != InvocationEntryBci) return method->java_code_at_bci(bci); else return Bytecodes::_illegal; } //------------------------------builtin_throw---------------------------------- void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) { bool must_throw = true; if (JvmtiExport::can_post_exceptions()) { // Do not try anything fancy if we're notifying the VM on every throw. // Cf. case Bytecodes::_athrow in parse2.cpp. uncommon_trap(reason, Deoptimization::Action_none, (ciKlass*)NULL, (char*)NULL, must_throw); return; } // If this particular condition has not yet happened at this // bytecode, then use the uncommon trap mechanism, and allow for // a future recompilation if several traps occur here. // If the throw is hot, try to use a more complicated inline mechanism // which keeps execution inside the compiled code. bool treat_throw_as_hot = false; ciMethodData* md = method()->method_data(); if (ProfileTraps) { if (too_many_traps(reason)) { treat_throw_as_hot = true; } // (If there is no MDO at all, assume it is early in // execution, and that any deopts are part of the // startup transient, and don't need to be remembered.) // Also, if there is a local exception handler, treat all throws // as hot if there has been at least one in this method. if (C->trap_count(reason) != 0 && method()->method_data()->trap_count(reason) != 0 && has_ex_handler()) { treat_throw_as_hot = true; } } // If this throw happens frequently, an uncommon trap might cause // a performance pothole. If there is a local exception handler, // and if this particular bytecode appears to be deoptimizing often, // let us handle the throw inline, with a preconstructed instance. // Note: If the deopt count has blown up, the uncommon trap // runtime is going to flush this nmethod, not matter what. if (treat_throw_as_hot && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) { // If the throw is local, we use a pre-existing instance and // punt on the backtrace. This would lead to a missing backtrace // (a repeat of 4292742) if the backtrace object is ever asked // for its backtrace. // Fixing this remaining case of 4292742 requires some flavor of // escape analysis. Leave that for the future. ciInstance* ex_obj = NULL; switch (reason) { case Deoptimization::Reason_null_check: ex_obj = env()->NullPointerException_instance(); break; case Deoptimization::Reason_div0_check: ex_obj = env()->ArithmeticException_instance(); break; case Deoptimization::Reason_range_check: ex_obj = env()->ArrayIndexOutOfBoundsException_instance(); break; case Deoptimization::Reason_class_check: if (java_bc() == Bytecodes::_aastore) { ex_obj = env()->ArrayStoreException_instance(); } else { ex_obj = env()->ClassCastException_instance(); } break; } if (failing()) { stop(); return; } // exception allocation might fail if (ex_obj != NULL) { // Cheat with a preallocated exception object. if (C->log() != NULL) C->log()->elem("hot_throw preallocated='1' reason='%s'", Deoptimization::trap_reason_name(reason)); const TypeInstPtr* ex_con = TypeInstPtr::make(ex_obj); Node* ex_node = _gvn.transform(new (C, 1) ConPNode(ex_con)); // Clear the detail message of the preallocated exception object. // Weblogic sometimes mutates the detail message of exceptions // using reflection. int offset = java_lang_Throwable::get_detailMessage_offset(); const TypePtr* adr_typ = ex_con->add_offset(offset); Node *adr = basic_plus_adr(ex_node, ex_node, offset); Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), ex_con, T_OBJECT); add_exception_state(make_exception_state(ex_node)); return; } } // %%% Maybe add entry to OptoRuntime which directly throws the exc.? // It won't be much cheaper than bailing to the interp., since we'll // have to pass up all the debug-info, and the runtime will have to // create the stack trace. // Usual case: Bail to interpreter. // Reserve the right to recompile if we haven't seen anything yet. Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile; if (treat_throw_as_hot && (method()->method_data()->trap_recompiled_at(bci()) || C->too_many_traps(reason))) { // We cannot afford to take more traps here. Suffer in the interpreter. if (C->log() != NULL) C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'", Deoptimization::trap_reason_name(reason), C->trap_count(reason)); action = Deoptimization::Action_none; } // "must_throw" prunes the JVM state to include only the stack, if there // are no local exception handlers. This should cut down on register // allocation time and code size, by drastically reducing the number // of in-edges on the call to the uncommon trap. uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw); } //----------------------------PreserveJVMState--------------------------------- PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) { debug_only(kit->verify_map()); _kit = kit; _map = kit->map(); // preserve the map _sp = kit->sp(); kit->set_map(clone_map ? kit->clone_map() : NULL); #ifdef ASSERT _bci = kit->bci(); Parse* parser = kit->is_Parse(); int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->pre_order(); _block = block; #endif } PreserveJVMState::~PreserveJVMState() { GraphKit* kit = _kit; #ifdef ASSERT assert(kit->bci() == _bci, "bci must not shift"); Parse* parser = kit->is_Parse(); int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->pre_order(); assert(block == _block, "block must not shift"); #endif kit->set_map(_map); kit->set_sp(_sp); } //-----------------------------BuildCutout------------------------------------- BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt) : PreserveJVMState(kit) { assert(p->is_Con() || p->is_Bool(), "test must be a bool"); SafePointNode* outer_map = _map; // preserved map is caller's SafePointNode* inner_map = kit->map(); IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt); outer_map->set_control(kit->gvn().transform( new (kit->C, 1) IfTrueNode(iff) )); inner_map->set_control(kit->gvn().transform( new (kit->C, 1) IfFalseNode(iff) )); } BuildCutout::~BuildCutout() { GraphKit* kit = _kit; assert(kit->stopped(), "cutout code must stop, throw, return, etc."); } //------------------------------clone_map-------------------------------------- // Implementation of PreserveJVMState // // Only clone_map(...) here. If this function is only used in the // PreserveJVMState class we may want to get rid of this extra // function eventually and do it all there. SafePointNode* GraphKit::clone_map() { if (map() == NULL) return NULL; // Clone the memory edge first Node* mem = MergeMemNode::make(C, map()->memory()); gvn().set_type_bottom(mem); SafePointNode *clonemap = (SafePointNode*)map()->clone(); JVMState* jvms = this->jvms(); JVMState* clonejvms = jvms->clone_shallow(C); clonemap->set_memory(mem); clonemap->set_jvms(clonejvms); clonejvms->set_map(clonemap); record_for_igvn(clonemap); gvn().set_type_bottom(clonemap); return clonemap; } //-----------------------------set_map_clone----------------------------------- void GraphKit::set_map_clone(SafePointNode* m) { _map = m; _map = clone_map(); _map->set_next_exception(NULL); debug_only(verify_map()); } //----------------------------kill_dead_locals--------------------------------- // Detect any locals which are known to be dead, and force them to top. void GraphKit::kill_dead_locals() { // Consult the liveness information for the locals. If any // of them are unused, then they can be replaced by top(). This // should help register allocation time and cut down on the size // of the deoptimization information. // This call is made from many of the bytecode handling // subroutines called from the Big Switch in do_one_bytecode. // Every bytecode which might include a slow path is responsible // for killing its dead locals. The more consistent we // are about killing deads, the fewer useless phis will be // constructed for them at various merge points. // bci can be -1 (InvocationEntryBci). We return the entry // liveness for the method. if (method() == NULL || method()->code_size() == 0) { // We are building a graph for a call to a native method. // All locals are live. return; } ResourceMark rm; // Consult the liveness information for the locals. If any // of them are unused, then they can be replaced by top(). This // should help register allocation time and cut down on the size // of the deoptimization information. MethodLivenessResult live_locals = method()->liveness_at_bci(bci()); int len = (int)live_locals.size(); assert(len <= jvms()->loc_size(), "too many live locals"); for (int local = 0; local < len; local++) { if (!live_locals.at(local)) { set_local(local, top()); } } } #ifdef ASSERT //-------------------------dead_locals_are_killed------------------------------ // Return true if all dead locals are set to top in the map. // Used to assert "clean" debug info at various points. bool GraphKit::dead_locals_are_killed() { if (method() == NULL || method()->code_size() == 0) { // No locals need to be dead, so all is as it should be. return true; } // Make sure somebody called kill_dead_locals upstream. ResourceMark rm; for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) { if (jvms->loc_size() == 0) continue; // no locals to consult SafePointNode* map = jvms->map(); ciMethod* method = jvms->method(); int bci = jvms->bci(); if (jvms == this->jvms()) { bci = this->bci(); // it might not yet be synched } MethodLivenessResult live_locals = method->liveness_at_bci(bci); int len = (int)live_locals.size(); if (!live_locals.is_valid() || len == 0) // This method is trivial, or is poisoned by a breakpoint. return true; assert(len == jvms->loc_size(), "live map consistent with locals map"); for (int local = 0; local < len; local++) { if (!live_locals.at(local) && map->local(jvms, local) != top()) { if (PrintMiscellaneous && (Verbose || WizardMode)) { tty->print_cr("Zombie local %d: ", local); jvms->dump(); } return false; } } } return true; } #endif //ASSERT // Helper function for adding JVMState and debug information to node void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) { // Add the safepoint edges to the call (or other safepoint). // Make sure dead locals are set to top. This // should help register allocation time and cut down on the size // of the deoptimization information. assert(dead_locals_are_killed(), "garbage in debug info before safepoint"); // Walk the inline list to fill in the correct set of JVMState's // Also fill in the associated edges for each JVMState. JVMState* youngest_jvms = sync_jvms(); // Do we need debug info here? If it is a SafePoint and this method // cannot de-opt, then we do NOT need any debug info. bool full_info = (C->deopt_happens() || call->Opcode() != Op_SafePoint); // If we are guaranteed to throw, we can prune everything but the // input to the current bytecode. bool can_prune_locals = false; uint stack_slots_not_pruned = 0; int inputs = 0, depth = 0; if (must_throw) { assert(method() == youngest_jvms->method(), "sanity"); if (compute_stack_effects(inputs, depth)) { can_prune_locals = true; stack_slots_not_pruned = inputs; } } if (JvmtiExport::can_examine_or_deopt_anywhere()) { // At any safepoint, this method can get breakpointed, which would // then require an immediate deoptimization. full_info = true; can_prune_locals = false; // do not prune locals stack_slots_not_pruned = 0; } // do not scribble on the input jvms JVMState* out_jvms = youngest_jvms->clone_deep(C); call->set_jvms(out_jvms); // Start jvms list for call node // Presize the call: debug_only(uint non_debug_edges = call->req()); call->add_req_batch(top(), youngest_jvms->debug_depth()); assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), ""); // Set up edges so that the call looks like this: // Call [state:] ctl io mem fptr retadr // [parms:] parm0 ... parmN // [root:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN // [...mid:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...] // [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN // Note that caller debug info precedes callee debug info. // Fill pointer walks backwards from "young:" to "root:" in the diagram above: uint debug_ptr = call->req(); // Loop over the map input edges associated with jvms, add them // to the call node, & reset all offsets to match call node array. for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) { uint debug_end = debug_ptr; uint debug_start = debug_ptr - in_jvms->debug_size(); debug_ptr = debug_start; // back up the ptr uint p = debug_start; // walks forward in [debug_start, debug_end) uint j, k, l; SafePointNode* in_map = in_jvms->map(); out_jvms->set_map(call); if (can_prune_locals) { assert(in_jvms->method() == out_jvms->method(), "sanity"); // If the current throw can reach an exception handler in this JVMS, // then we must keep everything live that can reach that handler. // As a quick and dirty approximation, we look for any handlers at all. if (in_jvms->method()->has_exception_handlers()) { can_prune_locals = false; } } // Add the Locals k = in_jvms->locoff(); l = in_jvms->loc_size(); out_jvms->set_locoff(p); if (full_info && !can_prune_locals) { for (j = 0; j < l; j++) call->set_req(p++, in_map->in(k+j)); } else { p += l; // already set to top above by add_req_batch } // Add the Expression Stack k = in_jvms->stkoff(); l = in_jvms->sp(); out_jvms->set_stkoff(p); if (full_info && !can_prune_locals) { for (j = 0; j < l; j++) call->set_req(p++, in_map->in(k+j)); } else if (can_prune_locals && stack_slots_not_pruned != 0) { // Divide stack into {S0,...,S1}, where S0 is set to top. uint s1 = stack_slots_not_pruned; stack_slots_not_pruned = 0; // for next iteration if (s1 > l) s1 = l; uint s0 = l - s1; p += s0; // skip the tops preinstalled by add_req_batch for (j = s0; j < l; j++) call->set_req(p++, in_map->in(k+j)); } else { p += l; // already set to top above by add_req_batch } // Add the Monitors k = in_jvms->monoff(); l = in_jvms->mon_size(); out_jvms->set_monoff(p); for (j = 0; j < l; j++) call->set_req(p++, in_map->in(k+j)); // Finish the new jvms. out_jvms->set_endoff(p); assert(out_jvms->endoff() == debug_end, "fill ptr must match"); assert(out_jvms->depth() == in_jvms->depth(), "depth must match"); assert(out_jvms->loc_size() == in_jvms->loc_size(), "size must match"); assert(out_jvms->mon_size() == in_jvms->mon_size(), "size must match"); assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match"); // Update the two tail pointers in parallel. out_jvms = out_jvms->caller(); in_jvms = in_jvms->caller(); } assert(debug_ptr == non_debug_edges, "debug info must fit exactly"); // Test the correctness of JVMState::debug_xxx accessors: assert(call->jvms()->debug_start() == non_debug_edges, ""); assert(call->jvms()->debug_end() == call->req(), ""); assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, ""); } bool GraphKit::compute_stack_effects(int& inputs, int& depth) { Bytecodes::Code code = java_bc(); if (code == Bytecodes::_wide) { code = method()->java_code_at_bci(bci() + 1); } BasicType rtype = T_ILLEGAL; int rsize = 0; if (code != Bytecodes::_illegal) { depth = Bytecodes::depth(code); // checkcast=0, athrow=-1 rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V if (rtype < T_CONFLICT) rsize = type2size[rtype]; } switch (code) { case Bytecodes::_illegal: return false; case Bytecodes::_ldc: case Bytecodes::_ldc_w: case Bytecodes::_ldc2_w: inputs = 0; break; case Bytecodes::_dup: inputs = 1; break; case Bytecodes::_dup_x1: inputs = 2; break; case Bytecodes::_dup_x2: inputs = 3; break; case Bytecodes::_dup2: inputs = 2; break; case Bytecodes::_dup2_x1: inputs = 3; break; case Bytecodes::_dup2_x2: inputs = 4; break; case Bytecodes::_swap: inputs = 2; break; case Bytecodes::_arraylength: inputs = 1; break; case Bytecodes::_getstatic: case Bytecodes::_putstatic: case Bytecodes::_getfield: case Bytecodes::_putfield: { bool is_get = (depth >= 0), is_static = (depth & 1); bool ignore; ciBytecodeStream iter(method()); iter.reset_to_bci(bci()); iter.next(); ciField* field = iter.get_field(ignore); int size = field->type()->size(); inputs = (is_static ? 0 : 1); if (is_get) { depth = size - inputs; } else { inputs += size; // putxxx pops the value from the stack depth = - inputs; } } break; case Bytecodes::_invokevirtual: case Bytecodes::_invokespecial: case Bytecodes::_invokestatic: case Bytecodes::_invokeinterface: { bool is_static = (depth == 0); bool ignore; ciBytecodeStream iter(method()); iter.reset_to_bci(bci()); iter.next(); ciMethod* method = iter.get_method(ignore); inputs = method->arg_size_no_receiver(); if (!is_static) inputs += 1; int size = method->return_type()->size(); depth = size - inputs; } break; case Bytecodes::_multianewarray: { ciBytecodeStream iter(method()); iter.reset_to_bci(bci()); iter.next(); inputs = iter.get_dimensions(); assert(rsize == 1, ""); depth = rsize - inputs; } break; case Bytecodes::_ireturn: case Bytecodes::_lreturn: case Bytecodes::_freturn: case Bytecodes::_dreturn: case Bytecodes::_areturn: assert(rsize = -depth, ""); inputs = rsize; break; case Bytecodes::_jsr: case Bytecodes::_jsr_w: inputs = 0; depth = 1; // S.B. depth=1, not zero break; default: // bytecode produces a typed result inputs = rsize - depth; assert(inputs >= 0, ""); break; } #ifdef ASSERT // spot check int outputs = depth + inputs; assert(outputs >= 0, "sanity"); switch (code) { case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break; case Bytecodes::_athrow: assert(inputs == 1 && outputs == 0, ""); break; case Bytecodes::_aload_0: assert(inputs == 0 && outputs == 1, ""); break; case Bytecodes::_return: assert(inputs == 0 && outputs == 0, ""); break; case Bytecodes::_drem: assert(inputs == 4 && outputs == 2, ""); break; } #endif //ASSERT return true; } //------------------------------basic_plus_adr--------------------------------- Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) { // short-circuit a common case if (offset == intcon(0)) return ptr; return _gvn.transform( new (C, 4) AddPNode(base, ptr, offset) ); } Node* GraphKit::ConvI2L(Node* offset) { // short-circuit a common case jint offset_con = find_int_con(offset, Type::OffsetBot); if (offset_con != Type::OffsetBot) { return longcon((long) offset_con); } return _gvn.transform( new (C, 2) ConvI2LNode(offset)); } Node* GraphKit::ConvL2I(Node* offset) { // short-circuit a common case jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot); if (offset_con != (jlong)Type::OffsetBot) { return intcon((int) offset_con); } return _gvn.transform( new (C, 2) ConvL2INode(offset)); } //-------------------------load_object_klass----------------------------------- Node* GraphKit::load_object_klass(Node* obj) { // Special-case a fresh allocation to avoid building nodes: Node* akls = AllocateNode::Ideal_klass(obj, &_gvn); if (akls != NULL) return akls; Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes()); return _gvn.transform( new (C, 3) LoadKlassNode(0, immutable_memory(), k_adr, TypeInstPtr::KLASS) ); } //-------------------------load_array_length----------------------------------- Node* GraphKit::load_array_length(Node* array) { // Special-case a fresh allocation to avoid building nodes: Node* alen = AllocateArrayNode::Ideal_length(array, &_gvn); if (alen != NULL) return alen; Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes()); return _gvn.transform( new (C, 3) LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS)); } //------------------------------do_null_check---------------------------------- // Helper function to do a NULL pointer check. Returned value is // the incoming address with NULL casted away. You are allowed to use the // not-null value only if you are control dependent on the test. extern int explicit_null_checks_inserted, explicit_null_checks_elided; Node* GraphKit::null_check_common(Node* value, BasicType type, // optional arguments for variations: bool assert_null, Node* *null_control) { assert(!assert_null || null_control == NULL, "not both at once"); if (stopped()) return top(); if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) { // For some performance testing, we may wish to suppress null checking. value = cast_not_null(value); // Make it appear to be non-null (4962416). return value; } explicit_null_checks_inserted++; // Construct NULL check Node *chk = NULL; switch(type) { case T_LONG : chk = new (C, 3) CmpLNode(value, _gvn.zerocon(T_LONG)); break; case T_INT : chk = new (C, 3) CmpINode( value, _gvn.intcon(0)); break; case T_ARRAY : // fall through type = T_OBJECT; // simplify further tests case T_OBJECT : { const Type *t = _gvn.type( value ); const TypeInstPtr* tp = t->isa_instptr(); if (tp != NULL && !tp->klass()->is_loaded() // Only for do_null_check, not any of its siblings: && !assert_null && null_control == NULL) { // Usually, any field access or invocation on an unloaded oop type // will simply fail to link, since the statically linked class is // likely also to be unloaded. However, in -Xcomp mode, sometimes // the static class is loaded but the sharper oop type is not. // Rather than checking for this obscure case in lots of places, // we simply observe that a null check on an unloaded class // will always be followed by a nonsense operation, so we // can just issue the uncommon trap here. // Our access to the unloaded class will only be correct // after it has been loaded and initialized, which requires // a trip through the interpreter. #ifndef PRODUCT if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); } #endif uncommon_trap(Deoptimization::Reason_unloaded, Deoptimization::Action_reinterpret, tp->klass(), "!loaded"); return top(); } if (assert_null) { // See if the type is contained in NULL_PTR. // If so, then the value is already null. if (t->higher_equal(TypePtr::NULL_PTR)) { explicit_null_checks_elided++; return value; // Elided null assert quickly! } } else { // See if mixing in the NULL pointer changes type. // If so, then the NULL pointer was not allowed in the original // type. In other words, "value" was not-null. if (t->meet(TypePtr::NULL_PTR) != t) { // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ... explicit_null_checks_elided++; return value; // Elided null check quickly! } } chk = new (C, 3) CmpPNode( value, null() ); break; } default : ShouldNotReachHere(); } assert(chk != NULL, "sanity check"); chk = _gvn.transform(chk); BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne; BoolNode *btst = new (C, 2) BoolNode( chk, btest); Node *tst = _gvn.transform( btst ); //----------- // if peephole optimizations occured, a prior test existed. // If a prior test existed, maybe it dominates as we can avoid this test. if (tst != btst && type == T_OBJECT) { // At this point we want to scan up the CFG to see if we can // find an identical test (and so avoid this test altogether). Node *cfg = control(); int depth = 0; while( depth < 16 ) { // Limit search depth for speed if( cfg->Opcode() == Op_IfTrue && cfg->in(0)->in(1) == tst ) { // Found prior test. Use "cast_not_null" to construct an identical // CastPP (and hence hash to) as already exists for the prior test. // Return that casted value. if (assert_null) { replace_in_map(value, null()); return null(); // do not issue the redundant test } Node *oldcontrol = control(); set_control(cfg); Node *res = cast_not_null(value); set_control(oldcontrol); explicit_null_checks_elided++; return res; } cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true); if (cfg == NULL) break; // Quit at region nodes depth++; } } //----------- // Branch to failure if null float ok_prob = PROB_MAX; // a priori estimate: nulls never happen Deoptimization::DeoptReason reason; if (assert_null) reason = Deoptimization::Reason_null_assert; else if (type == T_OBJECT) reason = Deoptimization::Reason_null_check; else reason = Deoptimization::Reason_div0_check; // To cause an implicit null check, we set the not-null probability // to the maximum (PROB_MAX). For an explicit check the probablity // is set to a smaller value. if (null_control != NULL || too_many_traps(reason)) { // probability is less likely ok_prob = PROB_LIKELY_MAG(3); } else if (!assert_null && (ImplicitNullCheckThreshold > 0) && method() != NULL && (method()->method_data()->trap_count(reason) >= (uint)ImplicitNullCheckThreshold)) { ok_prob = PROB_LIKELY_MAG(3); } if (null_control != NULL) { IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN); Node* null_true = _gvn.transform( new (C, 1) IfFalseNode(iff)); set_control( _gvn.transform( new (C, 1) IfTrueNode(iff))); if (null_true == top()) explicit_null_checks_elided++; (*null_control) = null_true; } else { BuildCutout unless(this, tst, ok_prob); // Check for optimizer eliding test at parse time if (stopped()) { // Failure not possible; do not bother making uncommon trap. explicit_null_checks_elided++; } else if (assert_null) { uncommon_trap(reason, Deoptimization::Action_make_not_entrant, NULL, "assert_null"); } else { builtin_throw(reason); } } // Must throw exception, fall-thru not possible? if (stopped()) { return top(); // No result } if (assert_null) { // Cast obj to null on this path. replace_in_map(value, zerocon(type)); return zerocon(type); } // Cast obj to not-null on this path, if there is no null_control. // (If there is a null_control, a non-null value may come back to haunt us.) if (type == T_OBJECT) { Node* cast = cast_not_null(value, false); if (null_control == NULL || (*null_control) == top()) replace_in_map(value, cast); value = cast; } return value; } //------------------------------cast_not_null---------------------------------- // Cast obj to not-null on this path Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) { const Type *t = _gvn.type(obj); const Type *t_not_null = t->join(TypePtr::NOTNULL); // Object is already not-null? if( t == t_not_null ) return obj; Node *cast = new (C, 2) CastPPNode(obj,t_not_null); cast->init_req(0, control()); cast = _gvn.transform( cast ); // Scan for instances of 'obj' in the current JVM mapping. // These instances are known to be not-null after the test. if (do_replace_in_map) replace_in_map(obj, cast); return cast; // Return casted value } //--------------------------replace_in_map------------------------------------- void GraphKit::replace_in_map(Node* old, Node* neww) { this->map()->replace_edge(old, neww); // Note: This operation potentially replaces any edge // on the map. This includes locals, stack, and monitors // of the current (innermost) JVM state. // We can consider replacing in caller maps. // The idea would be that an inlined function's null checks // can be shared with the entire inlining tree. // The expense of doing this is that the PreserveJVMState class // would have to preserve caller states too, with a deep copy. } //============================================================================= //--------------------------------memory--------------------------------------- Node* GraphKit::memory(uint alias_idx) { MergeMemNode* mem = merged_memory(); Node* p = mem->memory_at(alias_idx); _gvn.set_type(p, Type::MEMORY); // must be mapped return p; } //-----------------------------reset_memory------------------------------------ Node* GraphKit::reset_memory() { Node* mem = map()->memory(); // do not use this node for any more parsing! debug_only( map()->set_memory((Node*)NULL) ); return _gvn.transform( mem ); } //------------------------------set_all_memory--------------------------------- void GraphKit::set_all_memory(Node* newmem) { Node* mergemem = MergeMemNode::make(C, newmem); gvn().set_type_bottom(mergemem); map()->set_memory(mergemem); } //------------------------------set_all_memory_call---------------------------- void GraphKit::set_all_memory_call(Node* call) { Node* newmem = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::Memory) ); set_all_memory(newmem); } //============================================================================= // // parser factory methods for MemNodes // // These are layered on top of the factory methods in LoadNode and StoreNode, // and integrate with the parser's memory state and _gvn engine. // // factory methods in "int adr_idx" Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt, int adr_idx, bool require_atomic_access) { assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" ); const TypePtr* adr_type = NULL; // debug-mode-only argument debug_only(adr_type = C->get_adr_type(adr_idx)); Node* mem = memory(adr_idx); Node* ld; if (require_atomic_access && bt == T_LONG) { ld = LoadLNode::make_atomic(C, ctl, mem, adr, adr_type, t); } else { ld = LoadNode::make(C, ctl, mem, adr, adr_type, t, bt); } return _gvn.transform(ld); } Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt, int adr_idx, bool require_atomic_access) { assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" ); const TypePtr* adr_type = NULL; debug_only(adr_type = C->get_adr_type(adr_idx)); Node *mem = memory(adr_idx); Node* st; if (require_atomic_access && bt == T_LONG) { st = StoreLNode::make_atomic(C, ctl, mem, adr, adr_type, val); } else { st = StoreNode::make(C, ctl, mem, adr, adr_type, val, bt); } st = _gvn.transform(st); set_memory(st, adr_idx); // Back-to-back stores can only remove intermediate store with DU info // so push on worklist for optimizer. if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address)) record_for_igvn(st); return st; } void GraphKit::pre_barrier(Node* ctl, Node* obj, Node* adr, uint adr_idx, Node *val, const Type* val_type, BasicType bt) { BarrierSet* bs = Universe::heap()->barrier_set(); set_control(ctl); switch (bs->kind()) { case BarrierSet::CardTableModRef: case BarrierSet::CardTableExtension: case BarrierSet::ModRef: break; case BarrierSet::Other: default : ShouldNotReachHere(); } } void GraphKit::post_barrier(Node* ctl, Node* store, Node* obj, Node* adr, uint adr_idx, Node *val, BasicType bt, bool use_precise) { BarrierSet* bs = Universe::heap()->barrier_set(); set_control(ctl); switch (bs->kind()) { case BarrierSet::CardTableModRef: case BarrierSet::CardTableExtension: write_barrier_post(store, obj, adr, val, use_precise); break; case BarrierSet::ModRef: break; case BarrierSet::Other: default : ShouldNotReachHere(); } } Node* GraphKit::store_oop_to_object(Node* ctl, Node* obj, Node* adr, const TypePtr* adr_type, Node *val, const Type* val_type, BasicType bt) { uint adr_idx = C->get_alias_index(adr_type); Node* store; pre_barrier(ctl, obj, adr, adr_idx, val, val_type, bt); store = store_to_memory(control(), adr, val, bt, adr_idx); post_barrier(control(), store, obj, adr, adr_idx, val, bt, false); return store; } Node* GraphKit::store_oop_to_array(Node* ctl, Node* obj, Node* adr, const TypePtr* adr_type, Node *val, const Type* val_type, BasicType bt) { uint adr_idx = C->get_alias_index(adr_type); Node* store; pre_barrier(ctl, obj, adr, adr_idx, val, val_type, bt); store = store_to_memory(control(), adr, val, bt, adr_idx); post_barrier(control(), store, obj, adr, adr_idx, val, bt, true); return store; } Node* GraphKit::store_oop_to_unknown(Node* ctl, Node* obj, Node* adr, const TypePtr* adr_type, Node *val, const Type* val_type, BasicType bt) { uint adr_idx = C->get_alias_index(adr_type); Node* store; pre_barrier(ctl, obj, adr, adr_idx, val, val_type, bt); store = store_to_memory(control(), adr, val, bt, adr_idx); post_barrier(control(), store, obj, adr, adr_idx, val, bt, true); return store; } //-------------------------array_element_address------------------------- Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt, const TypeInt* sizetype) { uint shift = exact_log2(type2aelembytes[elembt]); uint header = arrayOopDesc::base_offset_in_bytes(elembt); // short-circuit a common case (saves lots of confusing waste motion) jint idx_con = find_int_con(idx, -1); if (idx_con >= 0) { intptr_t offset = header + ((intptr_t)idx_con << shift); return basic_plus_adr(ary, offset); } // must be correct type for alignment purposes Node* base = basic_plus_adr(ary, header); #ifdef _LP64 // The scaled index operand to AddP must be a clean 64-bit value. // Java allows a 32-bit int to be incremented to a negative // value, which appears in a 64-bit register as a large // positive number. Using that large positive number as an // operand in pointer arithmetic has bad consequences. // On the other hand, 32-bit overflow is rare, and the possibility // can often be excluded, if we annotate the ConvI2L node with // a type assertion that its value is known to be a small positive // number. (The prior range check has ensured this.) // This assertion is used by ConvI2LNode::Ideal. int index_max = max_jint - 1; // array size is max_jint, index is one less if (sizetype != NULL) index_max = sizetype->_hi - 1; const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax); idx = _gvn.transform( new (C, 2) ConvI2LNode(idx, lidxtype) ); #endif Node* scale = _gvn.transform( new (C, 3) LShiftXNode(idx, intcon(shift)) ); return basic_plus_adr(ary, base, scale); } //-------------------------load_array_element------------------------- Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) { const Type* elemtype = arytype->elem(); BasicType elembt = elemtype->array_element_basic_type(); Node* adr = array_element_address(ary, idx, elembt, arytype->size()); Node* ld = make_load(ctl, adr, elemtype, elembt, arytype); return ld; } //-------------------------set_arguments_for_java_call------------------------- // Arguments (pre-popped from the stack) are taken from the JVMS. void GraphKit::set_arguments_for_java_call(CallJavaNode* call) { // Add the call arguments: uint nargs = call->method()->arg_size(); for (uint i = 0; i < nargs; i++) { Node* arg = argument(i); call->init_req(i + TypeFunc::Parms, arg); } } //---------------------------set_edges_for_java_call--------------------------- // Connect a newly created call into the current JVMS. // A return value node (if any) is returned from set_edges_for_java_call. void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw) { // Add the predefined inputs: call->init_req( TypeFunc::Control, control() ); call->init_req( TypeFunc::I_O , i_o() ); call->init_req( TypeFunc::Memory , reset_memory() ); call->init_req( TypeFunc::FramePtr, frameptr() ); call->init_req( TypeFunc::ReturnAdr, top() ); add_safepoint_edges(call, must_throw); Node* xcall = _gvn.transform(call); if (xcall == top()) { set_control(top()); return; } assert(xcall == call, "call identity is stable"); // Re-use the current map to produce the result. set_control(_gvn.transform(new (C, 1) ProjNode(call, TypeFunc::Control))); set_i_o( _gvn.transform(new (C, 1) ProjNode(call, TypeFunc::I_O ))); set_all_memory_call(xcall); //return xcall; // no need, caller already has it } Node* GraphKit::set_results_for_java_call(CallJavaNode* call) { if (stopped()) return top(); // maybe the call folded up? // Capture the return value, if any. Node* ret; if (call->method() == NULL || call->method()->return_type()->basic_type() == T_VOID) ret = top(); else ret = _gvn.transform(new (C, 1) ProjNode(call, TypeFunc::Parms)); // Note: Since any out-of-line call can produce an exception, // we always insert an I_O projection from the call into the result. make_slow_call_ex(call, env()->Throwable_klass(), false); return ret; } //--------------------set_predefined_input_for_runtime_call-------------------- // Reading and setting the memory state is way conservative here. // The real problem is that I am not doing real Type analysis on memory, // so I cannot distinguish card mark stores from other stores. Across a GC // point the Store Barrier and the card mark memory has to agree. I cannot // have a card mark store and its barrier split across the GC point from // either above or below. Here I get that to happen by reading ALL of memory. // A better answer would be to separate out card marks from other memory. // For now, return the input memory state, so that it can be reused // after the call, if this call has restricted memory effects. Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) { // Set fixed predefined input arguments Node* memory = reset_memory(); call->init_req( TypeFunc::Control, control() ); call->init_req( TypeFunc::I_O, top() ); // does no i/o call->init_req( TypeFunc::Memory, memory ); // may gc ptrs call->init_req( TypeFunc::FramePtr, frameptr() ); call->init_req( TypeFunc::ReturnAdr, top() ); return memory; } //-------------------set_predefined_output_for_runtime_call-------------------- // Set control and memory (not i_o) from the call. // If keep_mem is not NULL, use it for the output state, // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM. // If hook_mem is NULL, this call produces no memory effects at all. // If hook_mem is a Java-visible memory slice (such as arraycopy operands), // then only that memory slice is taken from the call. // In the last case, we must put an appropriate memory barrier before // the call, so as to create the correct anti-dependencies on loads // preceding the call. void GraphKit::set_predefined_output_for_runtime_call(Node* call, Node* keep_mem, const TypePtr* hook_mem) { // no i/o set_control(_gvn.transform( new (C, 1) ProjNode(call,TypeFunc::Control) )); if (keep_mem) { // First clone the existing memory state set_all_memory(keep_mem); if (hook_mem != NULL) { // Make memory for the call Node* mem = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::Memory) ); // Set the RawPtr memory state only. This covers all the heap top/GC stuff // We also use hook_mem to extract specific effects from arraycopy stubs. set_memory(mem, hook_mem); } // ...else the call has NO memory effects. // Make sure the call advertises its memory effects precisely. // This lets us build accurate anti-dependences in gcm.cpp. assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem), "call node must be constructed correctly"); } else { assert(hook_mem == NULL, ""); // This is not a "slow path" call; all memory comes from the call. set_all_memory_call(call); } } //------------------------------increment_counter------------------------------ // for statistics: increment a VM counter by 1 void GraphKit::increment_counter(address counter_addr) { Node* adr1 = makecon(TypeRawPtr::make(counter_addr)); increment_counter(adr1); } void GraphKit::increment_counter(Node* counter_addr) { int adr_type = Compile::AliasIdxRaw; Node* cnt = make_load(NULL, counter_addr, TypeInt::INT, T_INT, adr_type); Node* incr = _gvn.transform(new (C, 3) AddINode(cnt, _gvn.intcon(1))); store_to_memory( NULL, counter_addr, incr, T_INT, adr_type ); } //------------------------------uncommon_trap---------------------------------- // Bail out to the interpreter in mid-method. Implemented by calling the // uncommon_trap blob. This helper function inserts a runtime call with the // right debug info. void GraphKit::uncommon_trap(int trap_request, ciKlass* klass, const char* comment, bool must_throw, bool keep_exact_action) { if (failing()) stop(); if (stopped()) return; // trap reachable? // Note: If ProfileTraps is true, and if a deopt. actually // occurs here, the runtime will make sure an MDO exists. There is // no need to call method()->build_method_data() at this point. #ifdef ASSERT if (!must_throw) { // Make sure the stack has at least enough depth to execute // the current bytecode. int inputs, ignore; if (compute_stack_effects(inputs, ignore)) { assert(sp() >= inputs, "must have enough JVMS stack to execute"); // It is a frequent error in library_call.cpp to issue an // uncommon trap with the _sp value already popped. } } #endif Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request); Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request); switch (action) { case Deoptimization::Action_maybe_recompile: case Deoptimization::Action_reinterpret: // Temporary fix for 6529811 to allow virtual calls to be sure they // get the chance to go from mono->bi->mega if (!keep_exact_action && Deoptimization::trap_request_index(trap_request) < 0 && too_many_recompiles(reason)) { // This BCI is causing too many recompilations. action = Deoptimization::Action_none; trap_request = Deoptimization::make_trap_request(reason, action); } else { C->set_trap_can_recompile(true); } break; case Deoptimization::Action_make_not_entrant: C->set_trap_can_recompile(true); break; #ifdef ASSERT case Deoptimization::Action_none: case Deoptimization::Action_make_not_compilable: break; default: assert(false, "bad action"); #endif } if (TraceOptoParse) { char buf[100]; tty->print_cr("Uncommon trap %s at bci:%d", Deoptimization::format_trap_request(buf, sizeof(buf), trap_request), bci()); } CompileLog* log = C->log(); if (log != NULL) { int kid = (klass == NULL)? -1: log->identify(klass); log->begin_elem("uncommon_trap bci='%d'", bci()); char buf[100]; log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf), trap_request)); if (kid >= 0) log->print(" klass='%d'", kid); if (comment != NULL) log->print(" comment='%s'", comment); log->end_elem(); } // Make sure any guarding test views this path as very unlikely Node *i0 = control()->in(0); if (i0 != NULL && i0->is_If()) { // Found a guarding if test? IfNode *iff = i0->as_If(); float f = iff->_prob; // Get prob if (control()->Opcode() == Op_IfTrue) { if (f > PROB_UNLIKELY_MAG(4)) iff->_prob = PROB_MIN; } else { if (f < PROB_LIKELY_MAG(4)) iff->_prob = PROB_MAX; } } // Clear out dead values from the debug info. kill_dead_locals(); // Now insert the uncommon trap subroutine call address call_addr = SharedRuntime::uncommon_trap_blob()->instructions_begin(); const TypePtr* no_memory_effects = NULL; // Pass the index of the class to be loaded Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON | (must_throw ? RC_MUST_THROW : 0), OptoRuntime::uncommon_trap_Type(), call_addr, "uncommon_trap", no_memory_effects, intcon(trap_request)); assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request, "must extract request correctly from the graph"); assert(trap_request != 0, "zero value reserved by uncommon_trap_request"); call->set_req(TypeFunc::ReturnAdr, returnadr()); // The debug info is the only real input to this call. // Halt-and-catch fire here. The above call should never return! HaltNode* halt = new(C, TypeFunc::Parms) HaltNode(control(), frameptr()); _gvn.set_type_bottom(halt); root()->add_req(halt); stop_and_kill_map(); } //--------------------------just_allocated_object------------------------------ // Report the object that was just allocated. // It must be the case that there are no intervening safepoints. // We use this to determine if an object is so "fresh" that // it does not require card marks. Node* GraphKit::just_allocated_object(Node* current_control) { if (C->recent_alloc_ctl() == current_control) return C->recent_alloc_obj(); return NULL; } //------------------------------store_barrier---------------------------------- // Insert a write-barrier store. This is to let generational GC work; we have // to flag all oop-stores before the next GC point. void GraphKit::write_barrier_post(Node* oop_store, Node* obj, Node* adr, Node* val, bool use_precise) { // No store check needed if we're storing a NULL or an old object // (latter case is probably a string constant). The concurrent // mark sweep garbage collector, however, needs to have all nonNull // oop updates flagged via card-marks. if (val != NULL && val->is_Con()) { // must be either an oop or NULL const Type* t = val->bottom_type(); if (t == TypePtr::NULL_PTR || t == Type::TOP) // stores of null never (?) need barriers return; ciObject* con = t->is_oopptr()->const_oop(); if (con != NULL && con->is_perm() && Universe::heap()->can_elide_permanent_oop_store_barriers()) // no store barrier needed, because no old-to-new ref created return; } if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) { // We can skip marks on a freshly-allocated object. // Keep this code in sync with do_eager_card_mark in runtime.cpp. // That routine eagerly marks the occasional object which is produced // by the slow path, so that we don't have to do it here. return; } if (!use_precise) { // All card marks for a (non-array) instance are in one place: adr = obj; } // (Else it's an array (or unknown), and we want more precise card marks.) assert(adr != NULL, ""); // Get the alias_index for raw card-mark memory int adr_type = Compile::AliasIdxRaw; // Convert the pointer to an int prior to doing math on it Node* cast = _gvn.transform(new (C, 2) CastP2XNode(control(), adr)); // Divide by card size assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef, "Only one we handle so far."); CardTableModRefBS* ct = (CardTableModRefBS*)(Universe::heap()->barrier_set()); Node *b = _gvn.transform(new (C, 3) URShiftXNode( cast, _gvn.intcon(CardTableModRefBS::card_shift) )); // We store into a byte array, so do not bother to left-shift by zero // Get base of card map assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust this code"); Node *c = makecon(TypeRawPtr::make((address)ct->byte_map_base)); // Combine Node *sb_ctl = control(); Node *sb_adr = _gvn.transform(new (C, 4) AddPNode( top()/*no base ptr*/, c, b )); Node *sb_val = _gvn.intcon(0); // Smash zero into card if( !UseConcMarkSweepGC ) { BasicType bt = T_BYTE; store_to_memory(sb_ctl, sb_adr, sb_val, bt, adr_type); } else { // Specialized path for CM store barrier cms_card_mark( sb_ctl, sb_adr, sb_val, oop_store); } } // Specialized path for CMS store barrier void GraphKit::cms_card_mark(Node* ctl, Node* adr, Node* val, Node *oop_store) { BasicType bt = T_BYTE; int adr_idx = Compile::AliasIdxRaw; Node* mem = memory(adr_idx); // The type input is NULL in PRODUCT builds const TypePtr* type = NULL; debug_only(type = C->get_adr_type(adr_idx)); // Add required edge to oop_store, optimizer does not support precedence edges. // Convert required edge to precedence edge before allocation. Node *store = _gvn.transform( new (C, 5) StoreCMNode(ctl, mem, adr, type, val, oop_store) ); set_memory(store, adr_idx); // For CMS, back-to-back card-marks can only remove the first one // and this requires DU info. Push on worklist for optimizer. if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address)) record_for_igvn(store); } void GraphKit::round_double_arguments(ciMethod* dest_method) { // (Note: TypeFunc::make has a cache that makes this fast.) const TypeFunc* tf = TypeFunc::make(dest_method); int nargs = tf->_domain->_cnt - TypeFunc::Parms; for (int j = 0; j < nargs; j++) { const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms); if( targ->basic_type() == T_DOUBLE ) { // If any parameters are doubles, they must be rounded before // the call, dstore_rounding does gvn.transform Node *arg = argument(j); arg = dstore_rounding(arg); set_argument(j, arg); } } } void GraphKit::round_double_result(ciMethod* dest_method) { // A non-strict method may return a double value which has an extended // exponent, but this must not be visible in a caller which is 'strict' // If a strict caller invokes a non-strict callee, round a double result BasicType result_type = dest_method->return_type()->basic_type(); assert( method() != NULL, "must have caller context"); if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) { // Destination method's return value is on top of stack // dstore_rounding() does gvn.transform Node *result = pop_pair(); result = dstore_rounding(result); push_pair(result); } } // rounding for strict float precision conformance Node* GraphKit::precision_rounding(Node* n) { return UseStrictFP && _method->flags().is_strict() && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding ? _gvn.transform( new (C, 2) RoundFloatNode(0, n) ) : n; } // rounding for strict double precision conformance Node* GraphKit::dprecision_rounding(Node *n) { return UseStrictFP && _method->flags().is_strict() && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding ? _gvn.transform( new (C, 2) RoundDoubleNode(0, n) ) : n; } // rounding for non-strict double stores Node* GraphKit::dstore_rounding(Node* n) { return Matcher::strict_fp_requires_explicit_rounding && UseSSE <= 1 ? _gvn.transform( new (C, 2) RoundDoubleNode(0, n) ) : n; } //============================================================================= // Generate a fast path/slow path idiom. Graph looks like: // [foo] indicates that 'foo' is a parameter // // [in] NULL // \ / // CmpP // Bool ne // If // / \ // True False-<2> // / | // / cast_not_null // Load | | ^ // [fast_test] | | // gvn to opt_test | | // / \ | <1> // True False | // | \\ | // [slow_call] \[fast_result] // Ctl Val \ \ // | \ \ // Catch <1> \ \ // / \ ^ \ \ // Ex No_Ex | \ \ // | \ \ | \ <2> \ // ... \ [slow_res] | | \ [null_result] // \ \--+--+--- | | // \ | / \ | / // --------Region Phi // //============================================================================= // Code is structured as a series of driver functions all called 'do_XXX' that // call a set of helper functions. Helper functions first, then drivers. //------------------------------null_check_oop--------------------------------- // Null check oop. Set null-path control into Region in slot 3. // Make a cast-not-nullness use the other not-null control. Return cast. Node* GraphKit::null_check_oop(Node* value, Node* *null_control, bool never_see_null) { // Initial NULL check taken path (*null_control) = top(); Node* cast = null_check_common(value, T_OBJECT, false, null_control); // Generate uncommon_trap: if (never_see_null && (*null_control) != top()) { // If we see an unexpected null at a check-cast we record it and force a // recompile; the offending check-cast will be compiled to handle NULLs. // If we see more than one offending BCI, then all checkcasts in the // method will be compiled to handle NULLs. PreserveJVMState pjvms(this); set_control(*null_control); uncommon_trap(Deoptimization::Reason_null_check, Deoptimization::Action_make_not_entrant); (*null_control) = top(); // NULL path is dead } // Cast away null-ness on the result return cast; } //------------------------------opt_iff---------------------------------------- // Optimize the fast-check IfNode. Set the fast-path region slot 2. // Return slow-path control. Node* GraphKit::opt_iff(Node* region, Node* iff) { IfNode *opt_iff = _gvn.transform(iff)->as_If(); // Fast path taken; set region slot 2 Node *fast_taken = _gvn.transform( new (C, 1) IfFalseNode(opt_iff) ); region->init_req(2,fast_taken); // Capture fast-control // Fast path not-taken, i.e. slow path Node *slow_taken = _gvn.transform( new (C, 1) IfTrueNode(opt_iff) ); return slow_taken; } //-----------------------------make_runtime_call------------------------------- Node* GraphKit::make_runtime_call(int flags, const TypeFunc* call_type, address call_addr, const char* call_name, const TypePtr* adr_type, // The following parms are all optional. // The first NULL ends the list. Node* parm0, Node* parm1, Node* parm2, Node* parm3, Node* parm4, Node* parm5, Node* parm6, Node* parm7) { // Slow-path call int size = call_type->domain()->cnt(); bool is_leaf = !(flags & RC_NO_LEAF); bool has_io = (!is_leaf && !(flags & RC_NO_IO)); if (call_name == NULL) { assert(!is_leaf, "must supply name for leaf"); call_name = OptoRuntime::stub_name(call_addr); } CallNode* call; if (!is_leaf) { call = new(C, size) CallStaticJavaNode(call_type, call_addr, call_name, bci(), adr_type); } else if (flags & RC_NO_FP) { call = new(C, size) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type); } else { call = new(C, size) CallLeafNode(call_type, call_addr, call_name, adr_type); } // The following is similar to set_edges_for_java_call, // except that the memory effects of the call are restricted to AliasIdxRaw. // Slow path call has no side-effects, uses few values bool wide_in = !(flags & RC_NARROW_MEM); bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot); Node* prev_mem = NULL; if (wide_in) { prev_mem = set_predefined_input_for_runtime_call(call); } else { assert(!wide_out, "narrow in => narrow out"); Node* narrow_mem = memory(adr_type); prev_mem = reset_memory(); map()->set_memory(narrow_mem); set_predefined_input_for_runtime_call(call); } // Hook each parm in order. Stop looking at the first NULL. if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0); if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1); if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2); if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3); if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4); if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5); if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6); if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7); /* close each nested if ===> */ } } } } } } } } assert(call->in(call->req()-1) != NULL, "must initialize all parms"); if (!is_leaf) { // Non-leaves can block and take safepoints: add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0)); } // Non-leaves can throw exceptions: if (has_io) { call->set_req(TypeFunc::I_O, i_o()); } if (flags & RC_UNCOMMON) { // Set the count to a tiny probability. Cf. Estimate_Block_Frequency. // (An "if" probability corresponds roughly to an unconditional count. // Sort of.) call->set_cnt(PROB_UNLIKELY_MAG(4)); } Node* c = _gvn.transform(call); assert(c == call, "cannot disappear"); if (wide_out) { // Slow path call has full side-effects. set_predefined_output_for_runtime_call(call); } else { // Slow path call has few side-effects, and/or sets few values. set_predefined_output_for_runtime_call(call, prev_mem, adr_type); } if (has_io) { set_i_o(_gvn.transform(new (C, 1) ProjNode(call, TypeFunc::I_O))); } return call; } //------------------------------merge_memory----------------------------------- // Merge memory from one path into the current memory state. void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) { for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) { Node* old_slice = mms.force_memory(); Node* new_slice = mms.memory2(); if (old_slice != new_slice) { PhiNode* phi; if (new_slice->is_Phi() && new_slice->as_Phi()->region() == region) { phi = new_slice->as_Phi(); #ifdef ASSERT if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) old_slice = old_slice->in(new_path); // Caller is responsible for ensuring that any pre-existing // phis are already aware of old memory. int old_path = (new_path > 1) ? 1 : 2; // choose old_path != new_path assert(phi->in(old_path) == old_slice, "pre-existing phis OK"); #endif mms.set_memory(phi); } else { phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C)); _gvn.set_type(phi, Type::MEMORY); phi->set_req(new_path, new_slice); mms.set_memory(_gvn.transform(phi)); // assume it is complete } } } } //------------------------------make_slow_call_ex------------------------------ // Make the exception handler hookups for the slow call void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj) { if (stopped()) return; // Make a catch node with just two handlers: fall-through and catch-all Node* i_o = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::I_O, separate_io_proj) ); Node* catc = _gvn.transform( new (C, 2) CatchNode(control(), i_o, 2) ); Node* norm = _gvn.transform( new (C, 1) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) ); Node* excp = _gvn.transform( new (C, 1) CatchProjNode(catc, CatchProjNode::catch_all_index, CatchProjNode::no_handler_bci) ); { PreserveJVMState pjvms(this); set_control(excp); set_i_o(i_o); if (excp != top()) { // Create an exception state also. // Use an exact type if the caller has specified a specific exception. const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull); Node* ex_oop = new (C, 2) CreateExNode(ex_type, control(), i_o); add_exception_state(make_exception_state(_gvn.transform(ex_oop))); } } // Get the no-exception control from the CatchNode. set_control(norm); } //-------------------------------gen_subtype_check----------------------------- // Generate a subtyping check. Takes as input the subtype and supertype. // Returns 2 values: sets the default control() to the true path and returns // the false path. Only reads invariant memory; sets no (visible) memory. // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding // but that's not exposed to the optimizer. This call also doesn't take in an // Object; if you wish to check an Object you need to load the Object's class // prior to coming here. Node* GraphKit::gen_subtype_check(Node* subklass, Node* superklass) { // Fast check for identical types, perhaps identical constants. // The types can even be identical non-constants, in cases // involving Array.newInstance, Object.clone, etc. if (subklass == superklass) return top(); // false path is dead; no test needed. if (_gvn.type(superklass)->singleton()) { ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass(); ciKlass* subk = _gvn.type(subklass)->is_klassptr()->klass(); // In the common case of an exact superklass, try to fold up the // test before generating code. You may ask, why not just generate // the code and then let it fold up? The answer is that the generated // code will necessarily include null checks, which do not always // completely fold away. If they are also needless, then they turn // into a performance loss. Example: // Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x; // Here, the type of 'fa' is often exact, so the store check // of fa[1]=x will fold up, without testing the nullness of x. switch (static_subtype_check(superk, subk)) { case SSC_always_false: { Node* always_fail = control(); set_control(top()); return always_fail; } case SSC_always_true: return top(); case SSC_easy_test: { // Just do a direct pointer compare and be done. Node* cmp = _gvn.transform( new(C, 3) CmpPNode(subklass, superklass) ); Node* bol = _gvn.transform( new(C, 2) BoolNode(cmp, BoolTest::eq) ); IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN); set_control( _gvn.transform( new(C, 1) IfTrueNode (iff) ) ); return _gvn.transform( new(C, 1) IfFalseNode(iff) ); } case SSC_full_test: break; default: ShouldNotReachHere(); } } // %%% Possible further optimization: Even if the superklass is not exact, // if the subklass is the unique subtype of the superklass, the check // will always succeed. We could leave a dependency behind to ensure this. // First load the super-klass's check-offset Node *p1 = basic_plus_adr( superklass, superklass, sizeof(oopDesc) + Klass::super_check_offset_offset_in_bytes() ); Node *chk_off = _gvn.transform( new (C, 3) LoadINode( NULL, memory(p1), p1, _gvn.type(p1)->is_ptr() ) ); int cacheoff_con = sizeof(oopDesc) + Klass::secondary_super_cache_offset_in_bytes(); bool might_be_cache = (find_int_con(chk_off, cacheoff_con) == cacheoff_con); // Load from the sub-klass's super-class display list, or a 1-word cache of // the secondary superclass list, or a failing value with a sentinel offset // if the super-klass is an interface or exceptionally deep in the Java // hierarchy and we have to scan the secondary superclass list the hard way. // Worst-case type is a little odd: NULL is allowed as a result (usually // klass loads can never produce a NULL). Node *chk_off_X = ConvI2X(chk_off); Node *p2 = _gvn.transform( new (C, 4) AddPNode(subklass,subklass,chk_off_X) ); // For some types like interfaces the following loadKlass is from a 1-word // cache which is mutable so can't use immutable memory. Other // types load from the super-class display table which is immutable. Node *kmem = might_be_cache ? memory(p2) : immutable_memory(); Node *nkls = _gvn.transform( new (C, 3) LoadKlassNode( NULL, kmem, p2, _gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL ) ); // Compile speed common case: ARE a subtype and we canNOT fail if( superklass == nkls ) return top(); // false path is dead; no test needed. // See if we get an immediate positive hit. Happens roughly 83% of the // time. Test to see if the value loaded just previously from the subklass // is exactly the superklass. Node *cmp1 = _gvn.transform( new (C, 3) CmpPNode( superklass, nkls ) ); Node *bol1 = _gvn.transform( new (C, 2) BoolNode( cmp1, BoolTest::eq ) ); IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN ); Node *iftrue1 = _gvn.transform( new (C, 1) IfTrueNode ( iff1 ) ); set_control( _gvn.transform( new (C, 1) IfFalseNode( iff1 ) ) ); // Compile speed common case: Check for being deterministic right now. If // chk_off is a constant and not equal to cacheoff then we are NOT a // subklass. In this case we need exactly the 1 test above and we can // return those results immediately. if (!might_be_cache) { Node* not_subtype_ctrl = control(); set_control(iftrue1); // We need exactly the 1 test above return not_subtype_ctrl; } // Gather the various success & failures here RegionNode *r_ok_subtype = new (C, 4) RegionNode(4); record_for_igvn(r_ok_subtype); RegionNode *r_not_subtype = new (C, 3) RegionNode(3); record_for_igvn(r_not_subtype); r_ok_subtype->init_req(1, iftrue1); // Check for immediate negative hit. Happens roughly 11% of the time (which // is roughly 63% of the remaining cases). Test to see if the loaded // check-offset points into the subklass display list or the 1-element // cache. If it points to the display (and NOT the cache) and the display // missed then it's not a subtype. Node *cacheoff = _gvn.intcon(cacheoff_con); Node *cmp2 = _gvn.transform( new (C, 3) CmpINode( chk_off, cacheoff ) ); Node *bol2 = _gvn.transform( new (C, 2) BoolNode( cmp2, BoolTest::ne ) ); IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN ); r_not_subtype->init_req(1, _gvn.transform( new (C, 1) IfTrueNode (iff2) ) ); set_control( _gvn.transform( new (C, 1) IfFalseNode(iff2) ) ); // Check for self. Very rare to get here, but its taken 1/3 the time. // No performance impact (too rare) but allows sharing of secondary arrays // which has some footprint reduction. Node *cmp3 = _gvn.transform( new (C, 3) CmpPNode( subklass, superklass ) ); Node *bol3 = _gvn.transform( new (C, 2) BoolNode( cmp3, BoolTest::eq ) ); IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN ); r_ok_subtype->init_req(2, _gvn.transform( new (C, 1) IfTrueNode ( iff3 ) ) ); set_control( _gvn.transform( new (C, 1) IfFalseNode( iff3 ) ) ); // Now do a linear scan of the secondary super-klass array. Again, no real // performance impact (too rare) but it's gotta be done. // (The stub also contains the self-check of subklass == superklass. // Since the code is rarely used, there is no penalty for moving it // out of line, and it can only improve I-cache density.) Node* psc = _gvn.transform( new (C, 3) PartialSubtypeCheckNode(control(), subklass, superklass) ); Node *cmp4 = _gvn.transform( new (C, 3) CmpPNode( psc, null() ) ); Node *bol4 = _gvn.transform( new (C, 2) BoolNode( cmp4, BoolTest::ne ) ); IfNode *iff4 = create_and_xform_if( control(), bol4, PROB_FAIR, COUNT_UNKNOWN ); r_not_subtype->init_req(2, _gvn.transform( new (C, 1) IfTrueNode (iff4) ) ); r_ok_subtype ->init_req(3, _gvn.transform( new (C, 1) IfFalseNode(iff4) ) ); // Return false path; set default control to true path. set_control( _gvn.transform(r_ok_subtype) ); return _gvn.transform(r_not_subtype); } //----------------------------static_subtype_check----------------------------- // Shortcut important common cases when superklass is exact: // (0) superklass is java.lang.Object (can occur in reflective code) // (1) subklass is already limited to a subtype of superklass => always ok // (2) subklass does not overlap with superklass => always fail // (3) superklass has NO subtypes and we can check with a simple compare. int GraphKit::static_subtype_check(ciKlass* superk, ciKlass* subk) { if (StressReflectiveCode) { return SSC_full_test; // Let caller generate the general case. } if (superk == env()->Object_klass()) { return SSC_always_true; // (0) this test cannot fail } ciType* superelem = superk; if (superelem->is_array_klass()) superelem = superelem->as_array_klass()->base_element_type(); if (!subk->is_interface()) { // cannot trust static interface types yet if (subk->is_subtype_of(superk)) { return SSC_always_true; // (1) false path dead; no dynamic test needed } if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) && !superk->is_subtype_of(subk)) { return SSC_always_false; } } // If casting to an instance klass, it must have no subtypes if (superk->is_interface()) { // Cannot trust interfaces yet. // %%% S.B. superk->nof_implementors() == 1 } else if (superelem->is_instance_klass()) { ciInstanceKlass* ik = superelem->as_instance_klass(); if (!ik->has_subklass() && !ik->is_interface()) { if (!ik->is_final()) { // Add a dependency if there is a chance of a later subclass. C->dependencies()->assert_leaf_type(ik); } return SSC_easy_test; // (3) caller can do a simple ptr comparison } } else { // A primitive array type has no subtypes. return SSC_easy_test; // (3) caller can do a simple ptr comparison } return SSC_full_test; } // Profile-driven exact type check: Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass, float prob, Node* *casted_receiver) { const TypeKlassPtr* tklass = TypeKlassPtr::make(klass); Node* recv_klass = load_object_klass(receiver); Node* want_klass = makecon(tklass); Node* cmp = _gvn.transform( new(C, 3) CmpPNode(recv_klass, want_klass) ); Node* bol = _gvn.transform( new(C, 2) BoolNode(cmp, BoolTest::eq) ); IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN); set_control( _gvn.transform( new(C, 1) IfTrueNode (iff) )); Node* fail = _gvn.transform( new(C, 1) IfFalseNode(iff) ); const TypeOopPtr* recv_xtype = tklass->as_instance_type(); assert(recv_xtype->klass_is_exact(), ""); // Subsume downstream occurrences of receiver with a cast to // recv_xtype, since now we know what the type will be. Node* cast = new(C, 2) CheckCastPPNode(control(), receiver, recv_xtype); (*casted_receiver) = _gvn.transform(cast); // (User must make the replace_in_map call.) return fail; } //-------------------------------gen_instanceof-------------------------------- // Generate an instance-of idiom. Used by both the instance-of bytecode // and the reflective instance-of call. Node* GraphKit::gen_instanceof( Node *subobj, Node* superklass ) { C->set_has_split_ifs(true); // Has chance for split-if optimization assert( !stopped(), "dead parse path should be checked in callers" ); assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()), "must check for not-null not-dead klass in callers"); // Make the merge point enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT }; RegionNode* region = new(C, PATH_LIMIT) RegionNode(PATH_LIMIT); Node* phi = new(C, PATH_LIMIT) PhiNode(region, TypeInt::BOOL); C->set_has_split_ifs(true); // Has chance for split-if optimization // Null check; get casted pointer; set region slot 3 Node* null_ctl = top(); Node* not_null_obj = null_check_oop(subobj, &null_ctl); // If not_null_obj is dead, only null-path is taken if (stopped()) { // Doing instance-of on a NULL? set_control(null_ctl); return intcon(0); } region->init_req(_null_path, null_ctl); phi ->init_req(_null_path, intcon(0)); // Set null path value // Load the object's klass Node* obj_klass = load_object_klass(not_null_obj); // Generate the subtype check Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass); // Plug in the success path to the general merge in slot 1. region->init_req(_obj_path, control()); phi ->init_req(_obj_path, intcon(1)); // Plug in the failing path to the general merge in slot 2. region->init_req(_fail_path, not_subtype_ctrl); phi ->init_req(_fail_path, intcon(0)); // Return final merged results set_control( _gvn.transform(region) ); record_for_igvn(region); return _gvn.transform(phi); } //-------------------------------gen_checkcast--------------------------------- // Generate a checkcast idiom. Used by both the checkcast bytecode and the // array store bytecode. Stack must be as-if BEFORE doing the bytecode so the // uncommon-trap paths work. Adjust stack after this call. // If failure_control is supplied and not null, it is filled in with // the control edge for the cast failure. Otherwise, an appropriate // uncommon trap or exception is thrown. Node* GraphKit::gen_checkcast(Node *obj, Node* superklass, Node* *failure_control) { kill_dead_locals(); // Benefit all the uncommon traps const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr(); const Type *toop = TypeOopPtr::make_from_klass(tk->klass()); // Fast cutout: Check the case that the cast is vacuously true. // This detects the common cases where the test will short-circuit // away completely. We do this before we perform the null check, // because if the test is going to turn into zero code, we don't // want a residual null check left around. (Causes a slowdown, // for example, in some objArray manipulations, such as a[i]=a[j].) if (tk->singleton()) { const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr(); if (objtp != NULL && objtp->klass() != NULL) { switch (static_subtype_check(tk->klass(), objtp->klass())) { case SSC_always_true: return obj; case SSC_always_false: // It needs a null check because a null will *pass* the cast check. // A non-null value will always produce an exception. return do_null_assert(obj, T_OBJECT); } } } ciProfileData* data = NULL; if (failure_control == NULL) { // use MDO in regular case only assert(java_bc() == Bytecodes::_aastore || java_bc() == Bytecodes::_checkcast, "interpreter profiles type checks only for these BCs"); data = method()->method_data()->bci_to_data(bci()); } // Make the merge point enum { _obj_path = 1, _null_path, PATH_LIMIT }; RegionNode* region = new (C, PATH_LIMIT) RegionNode(PATH_LIMIT); Node* phi = new (C, PATH_LIMIT) PhiNode(region, toop); C->set_has_split_ifs(true); // Has chance for split-if optimization // Use null-cast information if it is available bool never_see_null = false; // If we see an unexpected null at a check-cast we record it and force a // recompile; the offending check-cast will be compiled to handle NULLs. // If we see several offending BCIs, then all checkcasts in the // method will be compiled to handle NULLs. if (UncommonNullCast // Cutout for this technique && failure_control == NULL // regular case && obj != null() // And not the -Xcomp stupid case? && !too_many_traps(Deoptimization::Reason_null_check)) { // Finally, check the "null_seen" bit from the interpreter. if (data == NULL || !data->as_BitData()->null_seen()) { never_see_null = true; } } // Null check; get casted pointer; set region slot 3 Node* null_ctl = top(); Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null); // If not_null_obj is dead, only null-path is taken if (stopped()) { // Doing instance-of on a NULL? set_control(null_ctl); return null(); } region->init_req(_null_path, null_ctl); phi ->init_req(_null_path, null()); // Set null path value Node* cast_obj = NULL; // the casted version of the object // If the profile has seen exactly one type, narrow to that type. // (The subsequent subtype check will always fold up.) if (UseTypeProfile && TypeProfileCasts && data != NULL && // Counter has never been decremented (due to cast failure). // ...This is a reasonable thing to expect. It is true of // all casts inserted by javac to implement generic types. data->as_CounterData()->count() >= 0 && !too_many_traps(Deoptimization::Reason_class_check)) { // (No, this isn't a call, but it's enough like a virtual call // to use the same ciMethod accessor to get the profile info...) ciCallProfile profile = method()->call_profile_at_bci(bci()); if (profile.count() >= 0 && // no cast failures here profile.has_receiver(0) && profile.morphism() == 1) { ciKlass* exact_kls = profile.receiver(0); int ssc = static_subtype_check(tk->klass(), exact_kls); if (ssc == SSC_always_true) { // If we narrow the type to match what the type profile sees, // we can then remove the rest of the cast. // This is a win, even if the exact_kls is very specific, // because downstream operations, such as method calls, // will often benefit from the sharper type. Node* exact_obj = not_null_obj; // will get updated in place... Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0, &exact_obj); { PreserveJVMState pjvms(this); set_control(slow_ctl); uncommon_trap(Deoptimization::Reason_class_check, Deoptimization::Action_maybe_recompile); } if (failure_control != NULL) // failure is now impossible (*failure_control) = top(); replace_in_map(not_null_obj, exact_obj); // adjust the type of the phi to the exact klass: phi->raise_bottom_type(_gvn.type(exact_obj)->meet(TypePtr::NULL_PTR)); cast_obj = exact_obj; } // assert(cast_obj != NULL)... except maybe the profile lied to us. } } if (cast_obj == NULL) { // Load the object's klass Node* obj_klass = load_object_klass(not_null_obj); // Generate the subtype check Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass ); // Plug in success path into the merge cast_obj = _gvn.transform(new (C, 2) CheckCastPPNode(control(), not_null_obj, toop)); // Failure path ends in uncommon trap (or may be dead - failure impossible) if (failure_control == NULL) { if (not_subtype_ctrl != top()) { // If failure is possible PreserveJVMState pjvms(this); set_control(not_subtype_ctrl); builtin_throw(Deoptimization::Reason_class_check, obj_klass); } } else { (*failure_control) = not_subtype_ctrl; } } region->init_req(_obj_path, control()); phi ->init_req(_obj_path, cast_obj); // A merge of NULL or Casted-NotNull obj Node* res = _gvn.transform(phi); // Note I do NOT always 'replace_in_map(obj,result)' here. // if( tk->klass()->can_be_primary_super() ) // This means that if I successfully store an Object into an array-of-String // I 'forget' that the Object is really now known to be a String. I have to // do this because we don't have true union types for interfaces - if I store // a Baz into an array-of-Interface and then tell the optimizer it's an // Interface, I forget that it's also a Baz and cannot do Baz-like field // references to it. FIX THIS WHEN UNION TYPES APPEAR! // replace_in_map( obj, res ); // Return final merged results set_control( _gvn.transform(region) ); record_for_igvn(region); return res; } //------------------------------next_monitor----------------------------------- // What number should be given to the next monitor? int GraphKit::next_monitor() { int current = jvms()->monitor_depth()* C->sync_stack_slots(); int next = current + C->sync_stack_slots(); // Keep the toplevel high water mark current: if (C->fixed_slots() < next) C->set_fixed_slots(next); return current; } //------------------------------insert_mem_bar--------------------------------- // Memory barrier to avoid floating things around // The membar serves as a pinch point between both control and all memory slices. Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) { MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent); mb->init_req(TypeFunc::Control, control()); mb->init_req(TypeFunc::Memory, reset_memory()); Node* membar = _gvn.transform(mb); set_control(_gvn.transform(new (C, 1) ProjNode(membar,TypeFunc::Control) )); set_all_memory_call(membar); return membar; } //-------------------------insert_mem_bar_volatile---------------------------- // Memory barrier to avoid floating things around // The membar serves as a pinch point between both control and memory(alias_idx). // If you want to make a pinch point on all memory slices, do not use this // function (even with AliasIdxBot); use insert_mem_bar() instead. Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) { // When Parse::do_put_xxx updates a volatile field, it appends a series // of MemBarVolatile nodes, one for *each* volatile field alias category. // The first membar is on the same memory slice as the field store opcode. // This forces the membar to follow the store. (Bug 6500685 broke this.) // All the other membars (for other volatile slices, including AliasIdxBot, // which stands for all unknown volatile slices) are control-dependent // on the first membar. This prevents later volatile loads or stores // from sliding up past the just-emitted store. MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent); mb->set_req(TypeFunc::Control,control()); if (alias_idx == Compile::AliasIdxBot) { mb->set_req(TypeFunc::Memory, merged_memory()->base_memory()); } else { assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller"); mb->set_req(TypeFunc::Memory, memory(alias_idx)); } Node* membar = _gvn.transform(mb); set_control(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Control))); if (alias_idx == Compile::AliasIdxBot) { merged_memory()->set_base_memory(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Memory))); } else { set_memory(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Memory)),alias_idx); } return membar; } //------------------------------shared_lock------------------------------------ // Emit locking code. FastLockNode* GraphKit::shared_lock(Node* obj) { // bci is either a monitorenter bc or InvocationEntryBci // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces assert(SynchronizationEntryBCI == InvocationEntryBci, ""); if( !GenerateSynchronizationCode ) return NULL; // Not locking things? if (stopped()) // Dead monitor? return NULL; assert(dead_locals_are_killed(), "should kill locals before sync. point"); // Box the stack location Node* box = _gvn.transform(new (C, 1) BoxLockNode(next_monitor())); Node* mem = reset_memory(); FastLockNode * flock = _gvn.transform(new (C, 3) FastLockNode(0, obj, box) )->as_FastLock(); if (PrintPreciseBiasedLockingStatistics) { // Create the counters for this fast lock. flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci } // Add monitor to debug info for the slow path. If we block inside the // slow path and de-opt, we need the monitor hanging around map()->push_monitor( flock ); const TypeFunc *tf = LockNode::lock_type(); LockNode *lock = new (C, tf->domain()->cnt()) LockNode(C, tf); lock->init_req( TypeFunc::Control, control() ); lock->init_req( TypeFunc::Memory , mem ); lock->init_req( TypeFunc::I_O , top() ) ; // does no i/o lock->init_req( TypeFunc::FramePtr, frameptr() ); lock->init_req( TypeFunc::ReturnAdr, top() ); lock->init_req(TypeFunc::Parms + 0, obj); lock->init_req(TypeFunc::Parms + 1, box); lock->init_req(TypeFunc::Parms + 2, flock); add_safepoint_edges(lock); lock = _gvn.transform( lock )->as_Lock(); // lock has no side-effects, sets few values set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM); insert_mem_bar(Op_MemBarAcquire); // Add this to the worklist so that the lock can be eliminated record_for_igvn(lock); #ifndef PRODUCT if (PrintLockStatistics) { // Update the counter for this lock. Don't bother using an atomic // operation since we don't require absolute accuracy. lock->create_lock_counter(map()->jvms()); int adr_type = Compile::AliasIdxRaw; Node* counter_addr = makecon(TypeRawPtr::make(lock->counter()->addr())); Node* cnt = make_load(NULL, counter_addr, TypeInt::INT, T_INT, adr_type); Node* incr = _gvn.transform(new (C, 3) AddINode(cnt, _gvn.intcon(1))); store_to_memory(control(), counter_addr, incr, T_INT, adr_type); } #endif return flock; } //------------------------------shared_unlock---------------------------------- // Emit unlocking code. void GraphKit::shared_unlock(Node* box, Node* obj) { // bci is either a monitorenter bc or InvocationEntryBci // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces assert(SynchronizationEntryBCI == InvocationEntryBci, ""); if( !GenerateSynchronizationCode ) return; if (stopped()) { // Dead monitor? map()->pop_monitor(); // Kill monitor from debug info return; } // Memory barrier to avoid floating things down past the locked region insert_mem_bar(Op_MemBarRelease); const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type(); UnlockNode *unlock = new (C, tf->domain()->cnt()) UnlockNode(C, tf); uint raw_idx = Compile::AliasIdxRaw; unlock->init_req( TypeFunc::Control, control() ); unlock->init_req( TypeFunc::Memory , memory(raw_idx) ); unlock->init_req( TypeFunc::I_O , top() ) ; // does no i/o unlock->init_req( TypeFunc::FramePtr, frameptr() ); unlock->init_req( TypeFunc::ReturnAdr, top() ); unlock->init_req(TypeFunc::Parms + 0, obj); unlock->init_req(TypeFunc::Parms + 1, box); unlock = _gvn.transform(unlock)->as_Unlock(); Node* mem = reset_memory(); // unlock has no side-effects, sets few values set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM); // Kill monitor from debug info map()->pop_monitor( ); } //-------------------------------get_layout_helper----------------------------- // If the given klass is a constant or known to be an array, // fetch the constant layout helper value into constant_value // and return (Node*)NULL. Otherwise, load the non-constant // layout helper value, and return the node which represents it. // This two-faced routine is useful because allocation sites // almost always feature constant types. Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) { const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr(); if (!StressReflectiveCode && inst_klass != NULL) { ciKlass* klass = inst_klass->klass(); bool xklass = inst_klass->klass_is_exact(); if (xklass || klass->is_array_klass()) { jint lhelper = klass->layout_helper(); if (lhelper != Klass::_lh_neutral_value) { constant_value = lhelper; return (Node*) NULL; } } } constant_value = Klass::_lh_neutral_value; // put in a known value Node* lhp = basic_plus_adr(klass_node, klass_node, Klass::layout_helper_offset_in_bytes() + sizeof(oopDesc)); return make_load(NULL, lhp, TypeInt::INT, T_INT); } // We just put in an allocate/initialize with a big raw-memory effect. // Hook selected additional alias categories on the initialization. static void hook_memory_on_init(GraphKit& kit, int alias_idx, MergeMemNode* init_in_merge, Node* init_out_raw) { DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory()); assert(init_in_merge->memory_at(alias_idx) == init_in_raw, ""); Node* prevmem = kit.memory(alias_idx); init_in_merge->set_memory_at(alias_idx, prevmem); kit.set_memory(init_out_raw, alias_idx); } //---------------------------set_output_for_allocation------------------------- Node* GraphKit::set_output_for_allocation(AllocateNode* alloc, const TypeOopPtr* oop_type, bool raw_mem_only) { int rawidx = Compile::AliasIdxRaw; alloc->set_req( TypeFunc::FramePtr, frameptr() ); add_safepoint_edges(alloc); Node* allocx = _gvn.transform(alloc); set_control( _gvn.transform(new (C, 1) ProjNode(allocx, TypeFunc::Control) ) ); // create memory projection for i_o set_memory ( _gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx ); make_slow_call_ex(allocx, env()->OutOfMemoryError_klass(), true); // create a memory projection as for the normal control path Node* malloc = _gvn.transform(new (C, 1) ProjNode(allocx, TypeFunc::Memory)); set_memory(malloc, rawidx); // a normal slow-call doesn't change i_o, but an allocation does // we create a separate i_o projection for the normal control path set_i_o(_gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::I_O, false) ) ); Node* rawoop = _gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::Parms) ); // put in an initialization barrier InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx, rawoop)->as_Initialize(); assert(alloc->initialization() == init, "2-way macro link must work"); assert(init ->allocation() == alloc, "2-way macro link must work"); if (ReduceFieldZeroing && !raw_mem_only) { // Extract memory strands which may participate in the new object's // initialization, and source them from the new InitializeNode. // This will allow us to observe initializations when they occur, // and link them properly (as a group) to the InitializeNode. Node* klass_node = alloc->in(AllocateNode::KlassNode); assert(init->in(InitializeNode::Memory) == malloc, ""); MergeMemNode* minit_in = MergeMemNode::make(C, malloc); init->set_req(InitializeNode::Memory, minit_in); record_for_igvn(minit_in); // fold it up later, if possible Node* minit_out = memory(rawidx); assert(minit_out->is_Proj() && minit_out->in(0) == init, ""); if (oop_type->isa_aryptr()) { const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot); int elemidx = C->get_alias_index(telemref); hook_memory_on_init(*this, elemidx, minit_in, minit_out); } else if (oop_type->isa_instptr()) { ciInstanceKlass* ik = oop_type->klass()->as_instance_klass(); for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) { ciField* field = ik->nonstatic_field_at(i); if (field->offset() >= TrackedInitializationLimit * HeapWordSize) continue; // do not bother to track really large numbers of fields // Find (or create) the alias category for this field: int fieldidx = C->alias_type(field)->index(); hook_memory_on_init(*this, fieldidx, minit_in, minit_out); } } } // Cast raw oop to the real thing... Node* javaoop = new (C, 2) CheckCastPPNode(control(), rawoop, oop_type); javaoop = _gvn.transform(javaoop); C->set_recent_alloc(control(), javaoop); assert(just_allocated_object(control()) == javaoop, "just allocated"); #ifdef ASSERT { // Verify that the AllocateNode::Ideal_foo recognizers work: Node* kn = alloc->in(AllocateNode::KlassNode); Node* ln = alloc->in(AllocateNode::ALength); assert(AllocateNode::Ideal_klass(rawoop, &_gvn) == kn, "Ideal_klass works"); assert(AllocateNode::Ideal_klass(javaoop, &_gvn) == kn, "Ideal_klass works"); if (alloc->is_AllocateArray()) { assert(AllocateArrayNode::Ideal_length(rawoop, &_gvn) == ln, "Ideal_length works"); assert(AllocateArrayNode::Ideal_length(javaoop, &_gvn) == ln, "Ideal_length works"); } else { assert(ln->is_top(), "no length, please"); } } #endif //ASSERT return javaoop; } //---------------------------new_instance-------------------------------------- // This routine takes a klass_node which may be constant (for a static type) // or may be non-constant (for reflective code). It will work equally well // for either, and the graph will fold nicely if the optimizer later reduces // the type to a constant. // The optional arguments are for specialized use by intrinsics: // - If 'extra_slow_test' if not null is an extra condition for the slow-path. // - If 'raw_mem_only', do not cast the result to an oop. // - If 'return_size_val', report the the total object size to the caller. Node* GraphKit::new_instance(Node* klass_node, Node* extra_slow_test, bool raw_mem_only, // affect only raw memory Node* *return_size_val) { // Compute size in doublewords // The size is always an integral number of doublewords, represented // as a positive bytewise size stored in the klass's layout_helper. // The layout_helper also encodes (in a low bit) the need for a slow path. jint layout_con = Klass::_lh_neutral_value; Node* layout_val = get_layout_helper(klass_node, layout_con); int layout_is_con = (layout_val == NULL); if (extra_slow_test == NULL) extra_slow_test = intcon(0); // Generate the initial go-slow test. It's either ALWAYS (return a // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective // case) a computed value derived from the layout_helper. Node* initial_slow_test = NULL; if (layout_is_con) { assert(!StressReflectiveCode, "stress mode does not use these paths"); bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con); initial_slow_test = must_go_slow? intcon(1): extra_slow_test; } else { // reflective case // This reflective path is used by Unsafe.allocateInstance. // (It may be stress-tested by specifying StressReflectiveCode.) // Basically, we want to get into the VM is there's an illegal argument. Node* bit = intcon(Klass::_lh_instance_slow_path_bit); initial_slow_test = _gvn.transform( new (C, 3) AndINode(layout_val, bit) ); if (extra_slow_test != intcon(0)) { initial_slow_test = _gvn.transform( new (C, 3) OrINode(initial_slow_test, extra_slow_test) ); } // (Macro-expander will further convert this to a Bool, if necessary.) } // Find the size in bytes. This is easy; it's the layout_helper. // The size value must be valid even if the slow path is taken. Node* size = NULL; if (layout_is_con) { size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con)); } else { // reflective case // This reflective path is used by clone and Unsafe.allocateInstance. size = ConvI2X(layout_val); // Clear the low bits to extract layout_helper_size_in_bytes: assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit"); Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong)); size = _gvn.transform( new (C, 3) AndXNode(size, mask) ); } if (return_size_val != NULL) { (*return_size_val) = size; } // This is a precise notnull oop of the klass. // (Actually, it need not be precise if this is a reflective allocation.) // It's what we cast the result to. const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr(); if (!tklass) tklass = TypeKlassPtr::OBJECT; const TypeOopPtr* oop_type = tklass->as_instance_type(); // Now generate allocation code AllocateNode* alloc = new (C, AllocateNode::ParmLimit) AllocateNode(C, AllocateNode::alloc_type(), control(), memory(Compile::AliasIdxRaw), i_o(), size, klass_node, initial_slow_test); return set_output_for_allocation(alloc, oop_type, raw_mem_only); } //-------------------------------new_array------------------------------------- // helper for both newarray and anewarray // The 'length' parameter is (obviously) the length of the array. // See comments on new_instance for the meaning of the other arguments. Node* GraphKit::new_array(Node* klass_node, // array klass (maybe variable) Node* length, // number of array elements bool raw_mem_only, // affect only raw memory Node* *return_size_val) { jint layout_con = Klass::_lh_neutral_value; Node* layout_val = get_layout_helper(klass_node, layout_con); int layout_is_con = (layout_val == NULL); if (!layout_is_con && !StressReflectiveCode && !too_many_traps(Deoptimization::Reason_class_check)) { // This is a reflective array creation site. // Optimistically assume that it is a subtype of Object[], // so that we can fold up all the address arithmetic. layout_con = Klass::array_layout_helper(T_OBJECT); Node* cmp_lh = _gvn.transform( new(C, 3) CmpINode(layout_val, intcon(layout_con)) ); Node* bol_lh = _gvn.transform( new(C, 2) BoolNode(cmp_lh, BoolTest::eq) ); { BuildCutout unless(this, bol_lh, PROB_MAX); uncommon_trap(Deoptimization::Reason_class_check, Deoptimization::Action_maybe_recompile); } layout_val = NULL; layout_is_con = true; } // Generate the initial go-slow test. Make sure we do not overflow // if length is huge (near 2Gig) or negative! We do not need // exact double-words here, just a close approximation of needed // double-words. We can't add any offset or rounding bits, lest we // take a size -1 of bytes and make it positive. Use an unsigned // compare, so negative sizes look hugely positive. int fast_size_limit = FastAllocateSizeLimit; if (layout_is_con) { assert(!StressReflectiveCode, "stress mode does not use these paths"); // Increase the size limit if we have exact knowledge of array type. int log2_esize = Klass::layout_helper_log2_element_size(layout_con); fast_size_limit <<= (LogBytesPerLong - log2_esize); } Node* initial_slow_cmp = _gvn.transform( new (C, 3) CmpUNode( length, intcon( fast_size_limit ) ) ); Node* initial_slow_test = _gvn.transform( new (C, 2) BoolNode( initial_slow_cmp, BoolTest::gt ) ); if (initial_slow_test->is_Bool()) { // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick. initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn); } // --- Size Computation --- // array_size = round_to_heap(array_header + (length << elem_shift)); // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes) // and round_to(x, y) == ((x + y-1) & ~(y-1)) // The rounding mask is strength-reduced, if possible. int round_mask = MinObjAlignmentInBytes - 1; Node* header_size = NULL; int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE); // (T_BYTE has the weakest alignment and size restrictions...) if (layout_is_con) { int hsize = Klass::layout_helper_header_size(layout_con); int eshift = Klass::layout_helper_log2_element_size(layout_con); BasicType etype = Klass::layout_helper_element_type(layout_con); if ((round_mask & ~right_n_bits(eshift)) == 0) round_mask = 0; // strength-reduce it if it goes away completely assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded"); assert(header_size_min <= hsize, "generic minimum is smallest"); header_size_min = hsize; header_size = intcon(hsize + round_mask); } else { Node* hss = intcon(Klass::_lh_header_size_shift); Node* hsm = intcon(Klass::_lh_header_size_mask); Node* hsize = _gvn.transform( new(C, 3) URShiftINode(layout_val, hss) ); hsize = _gvn.transform( new(C, 3) AndINode(hsize, hsm) ); Node* mask = intcon(round_mask); header_size = _gvn.transform( new(C, 3) AddINode(hsize, mask) ); } Node* elem_shift = NULL; if (layout_is_con) { int eshift = Klass::layout_helper_log2_element_size(layout_con); if (eshift != 0) elem_shift = intcon(eshift); } else { // There is no need to mask or shift this value. // The semantics of LShiftINode include an implicit mask to 0x1F. assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place"); elem_shift = layout_val; } // Transition to native address size for all offset calculations: Node* lengthx = ConvI2X(length); Node* headerx = ConvI2X(header_size); #ifdef _LP64 { const TypeLong* tllen = _gvn.find_long_type(lengthx); if (tllen != NULL && tllen->_lo < 0) { // Add a manual constraint to a positive range. Cf. array_element_address. jlong size_max = arrayOopDesc::max_array_length(T_BYTE); if (size_max > tllen->_hi) size_max = tllen->_hi; const TypeLong* tlcon = TypeLong::make(CONST64(0), size_max, Type::WidenMin); lengthx = _gvn.transform( new (C, 2) ConvI2LNode(length, tlcon)); } } #endif // Combine header size (plus rounding) and body size. Then round down. // This computation cannot overflow, because it is used only in two // places, one where the length is sharply limited, and the other // after a successful allocation. Node* abody = lengthx; if (elem_shift != NULL) abody = _gvn.transform( new(C, 3) LShiftXNode(lengthx, elem_shift) ); Node* size = _gvn.transform( new(C, 3) AddXNode(headerx, abody) ); if (round_mask != 0) { Node* mask = MakeConX(~round_mask); size = _gvn.transform( new(C, 3) AndXNode(size, mask) ); } // else if round_mask == 0, the size computation is self-rounding if (return_size_val != NULL) { // This is the size (*return_size_val) = size; } // Now generate allocation code // Create the AllocateArrayNode and its result projections AllocateArrayNode* alloc = new (C, AllocateArrayNode::ParmLimit) AllocateArrayNode(C, AllocateArrayNode::alloc_type(), control(), memory(Compile::AliasIdxRaw), i_o(), size, klass_node, initial_slow_test, length); // Cast to correct type. Note that the klass_node may be constant or not, // and in the latter case the actual array type will be inexact also. // (This happens via a non-constant argument to inline_native_newArray.) // In any case, the value of klass_node provides the desired array type. const TypeInt* length_type = _gvn.find_int_type(length); const TypeInt* narrow_length_type = NULL; const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type(); if (ary_type->isa_aryptr() && length_type != NULL) { // Try to get a better type than POS for the size ary_type = ary_type->is_aryptr()->cast_to_size(length_type); narrow_length_type = ary_type->is_aryptr()->size(); if (narrow_length_type == length_type) narrow_length_type = NULL; } Node* javaoop = set_output_for_allocation(alloc, ary_type, raw_mem_only); // Cast length on remaining path to be positive: if (narrow_length_type != NULL) { Node* ccast = new (C, 2) CastIINode(length, narrow_length_type); ccast->set_req(0, control()); _gvn.set_type_bottom(ccast); record_for_igvn(ccast); if (map()->find_edge(length) >= 0) { replace_in_map(length, ccast); } } return javaoop; } // The following "Ideal_foo" functions are placed here because they recognize // the graph shapes created by the functions immediately above. //---------------------------Ideal_allocation---------------------------------- // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode. AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) { if (ptr == NULL) { // reduce dumb test in callers return NULL; } if (ptr->is_CheckCastPP()) { // strip a raw-to-oop cast ptr = ptr->in(1); if (ptr == NULL) return NULL; } if (ptr->is_Proj()) { Node* allo = ptr->in(0); if (allo != NULL && allo->is_Allocate()) { return allo->as_Allocate(); } } // Report failure to match. return NULL; } // Fancy version which also strips off an offset (and reports it to caller). AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase, intptr_t& offset) { Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset); if (base == NULL) return NULL; return Ideal_allocation(base, phase); } // Trace Initialize <- Proj[Parm] <- Allocate AllocateNode* InitializeNode::allocation() { Node* rawoop = in(InitializeNode::RawAddress); if (rawoop->is_Proj()) { Node* alloc = rawoop->in(0); if (alloc->is_Allocate()) { return alloc->as_Allocate(); } } return NULL; } // Trace Allocate -> Proj[Parm] -> Initialize InitializeNode* AllocateNode::initialization() { ProjNode* rawoop = proj_out(AllocateNode::RawAddress); if (rawoop == NULL) return NULL; for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) { Node* init = rawoop->fast_out(i); if (init->is_Initialize()) { assert(init->as_Initialize()->allocation() == this, "2-way link"); return init->as_Initialize(); } } return NULL; }