src/share/vm/opto/idealKit.cpp

Mon, 14 Sep 2009 09:49:54 -0700

author
cfang
date
Mon, 14 Sep 2009 09:49:54 -0700
changeset 1420
685e959d09ea
parent 1286
fc4be448891f
child 1435
a1423fe86a18
permissions
-rw-r--r--

6877254: Server vm crashes with no branches off of store slice" when run with CMS and UseSuperWord(default)
Summary: design StoreCMNode::Ideal to promote its oopStore input if the input is a MergeMem node
Reviewed-by: kvn, never

     1 /*
     2  * Copyright 2005-2008 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 #include "incls/_precompiled.incl"
    26 #include "incls/_idealKit.cpp.incl"
    28 // Static initialization
    30 // This declares the position where vars are kept in the cvstate
    31 // For some degree of consistency we use the TypeFunc enum to
    32 // soak up spots in the inputs even though we only use early Control
    33 // and Memory slots. (So far.)
    34 const uint IdealKit::first_var = TypeFunc::Parms + 1;
    36 //----------------------------IdealKit-----------------------------------------
    37 IdealKit::IdealKit(PhaseGVN &gvn, Node* control, Node* mem, bool delay_all_transforms, bool has_declarations) :
    38   _gvn(gvn), C(gvn.C) {
    39   _initial_ctrl = control;
    40   _initial_memory = mem;
    41   _delay_all_transforms = delay_all_transforms;
    42   _var_ct = 0;
    43   _cvstate = NULL;
    44   // We can go memory state free or else we need the entire memory state
    45   assert(mem == NULL || mem->Opcode() == Op_MergeMem, "memory must be pre-split");
    46   int init_size = 5;
    47   _pending_cvstates = new (C->node_arena()) GrowableArray<Node*>(C->node_arena(), init_size, 0, 0);
    48   _delay_transform  = new (C->node_arena()) GrowableArray<Node*>(C->node_arena(), init_size, 0, 0);
    49   DEBUG_ONLY(_state = new (C->node_arena()) GrowableArray<int>(C->node_arena(), init_size, 0, 0));
    50   if (!has_declarations) {
    51      declarations_done();
    52   }
    53 }
    55 //-------------------------------if_then-------------------------------------
    56 // Create:  if(left relop right)
    57 //          /  \
    58 //   iffalse    iftrue
    59 // Push the iffalse cvstate onto the stack. The iftrue becomes the current cvstate.
    60 void IdealKit::if_then(Node* left, BoolTest::mask relop,
    61                        Node* right, float prob, float cnt, bool push_new_state) {
    62   assert((state() & (BlockS|LoopS|IfThenS|ElseS)), "bad state for new If");
    63   Node* bol;
    64   if (left->bottom_type()->isa_ptr() == NULL) {
    65     if (left->bottom_type()->isa_int() != NULL) {
    66       bol = Bool(CmpI(left, right), relop);
    67     } else {
    68       assert(left->bottom_type()->isa_long() != NULL, "what else?");
    69       bol = Bool(CmpL(left, right), relop);
    70     }
    72   } else {
    73     bol = Bool(CmpP(left, right), relop);
    74   }
    75   // Delay gvn.tranform on if-nodes until construction is finished
    76   // to prevent a constant bool input from discarding a control output.
    77   IfNode* iff = delay_transform(new (C, 2) IfNode(ctrl(), bol, prob, cnt))->as_If();
    78   Node* then  = IfTrue(iff);
    79   Node* elsen = IfFalse(iff);
    80   Node* else_cvstate = copy_cvstate();
    81   else_cvstate->set_req(TypeFunc::Control, elsen);
    82   _pending_cvstates->push(else_cvstate);
    83   DEBUG_ONLY(if (push_new_state) _state->push(IfThenS));
    84   set_ctrl(then);
    85 }
    87 //-------------------------------else_-------------------------------------
    88 // Pop the else cvstate off the stack, and push the (current) then cvstate.
    89 // The else cvstate becomes the current cvstate.
    90 void IdealKit::else_() {
    91   assert(state() == IfThenS, "bad state for new Else");
    92   Node* else_cvstate = _pending_cvstates->pop();
    93   DEBUG_ONLY(_state->pop());
    94   // save current (then) cvstate for later use at endif
    95   _pending_cvstates->push(_cvstate);
    96   DEBUG_ONLY(_state->push(ElseS));
    97   _cvstate = else_cvstate;
    98 }
   100 //-------------------------------end_if-------------------------------------
   101 // Merge the "then" and "else" cvstates.
   102 //
   103 // The if_then() pushed a copy of the current state for later use
   104 // as the initial state for a future "else" clause.  The
   105 // current state then became the initial state for the
   106 // then clause.  If an "else" clause was encountered, it will
   107 // pop the top state and use it for it's initial state.
   108 // It will also push the current state (the state at the end of
   109 // the "then" clause) for latter use at the end_if.
   110 //
   111 // At the endif, the states are:
   112 // 1) else exists a) current state is end of "else" clause
   113 //                b) top stack state is end of "then" clause
   114 //
   115 // 2) no else:    a) current state is end of "then" clause
   116 //                b) top stack state is from the "if_then" which
   117 //                   would have been the initial state of the else.
   118 //
   119 // Merging the states is accomplished by:
   120 //   1) make a label for the merge
   121 //   2) terminate the current state with a goto to the label
   122 //   3) pop the top state from the stack and make it the
   123 //        current state
   124 //   4) bind the label at the current state.  Binding a label
   125 //        terminates the current state with a goto to the
   126 //        label and makes the label's state the current state.
   127 //
   128 void IdealKit::end_if() {
   129   assert(state() & (IfThenS|ElseS), "bad state for new Endif");
   130   Node* lab = make_label(1);
   132   // Node* join_state = _pending_cvstates->pop();
   133                   /* merging, join */
   134   goto_(lab);
   135   _cvstate = _pending_cvstates->pop();
   137   bind(lab);
   138   DEBUG_ONLY(_state->pop());
   139 }
   141 //-------------------------------loop-------------------------------------
   142 // Create the loop head portion (*) of:
   143 //  *     iv = init
   144 //  *  top: (region node)
   145 //  *     if (iv relop limit) {
   146 //           loop body
   147 //           i = i + 1
   148 //           goto top
   149 //  *     } else // exits loop
   150 //
   151 // Pushes the loop top cvstate first, then the else (loop exit) cvstate
   152 // onto the stack.
   153 void IdealKit::loop(IdealVariable& iv, Node* init, BoolTest::mask relop, Node* limit, float prob, float cnt) {
   154   assert((state() & (BlockS|LoopS|IfThenS|ElseS)), "bad state for new loop");
   155   set(iv, init);
   156   Node* head = make_label(1);
   157   bind(head);
   158   _pending_cvstates->push(head); // push for use at end_loop
   159   _cvstate = copy_cvstate();
   160   if_then(value(iv), relop, limit, prob, cnt, false /* no new state */);
   161   DEBUG_ONLY(_state->push(LoopS));
   162   assert(ctrl()->is_IfTrue(), "true branch stays in loop");
   163   assert(_pending_cvstates->top()->in(TypeFunc::Control)->is_IfFalse(), "false branch exits loop");
   164 }
   166 //-------------------------------end_loop-------------------------------------
   167 // Creates the goto top label.
   168 // Expects the else (loop exit) cvstate to be on top of the
   169 // stack, and the loop top cvstate to be 2nd.
   170 void IdealKit::end_loop() {
   171   assert((state() == LoopS), "bad state for new end_loop");
   172   Node* exit = _pending_cvstates->pop();
   173   Node* head = _pending_cvstates->pop();
   174   goto_(head);
   175   clear(head);
   176   DEBUG_ONLY(_state->pop());
   177   _cvstate = exit;
   178 }
   180 //-------------------------------make_label-------------------------------------
   181 // Creates a label.  The number of goto's
   182 // must be specified (which should be 1 less than
   183 // the number of precedessors.)
   184 Node* IdealKit::make_label(int goto_ct) {
   185   assert(_cvstate != NULL, "must declare variables before labels");
   186   Node* lab = new_cvstate();
   187   int sz = 1 + goto_ct + 1 /* fall thru */;
   188   Node* reg = delay_transform(new (C, sz) RegionNode(sz));
   189   lab->init_req(TypeFunc::Control, reg);
   190   return lab;
   191 }
   193 //-------------------------------bind-------------------------------------
   194 // Bind a label at the current cvstate by simulating
   195 // a goto to the label.
   196 void IdealKit::bind(Node* lab) {
   197   goto_(lab, true /* bind */);
   198   _cvstate = lab;
   199 }
   201 //-------------------------------goto_-------------------------------------
   202 // Make the current cvstate a predecessor of the label,
   203 // creating phi's to merge values.  If bind is true and
   204 // this is not the last control edge, then ensure that
   205 // all live values have phis created. Used to create phis
   206 // at loop-top regions.
   207 void IdealKit::goto_(Node* lab, bool bind) {
   208   Node* reg = lab->in(TypeFunc::Control);
   209   // find next empty slot in region
   210   uint slot = 1;
   211   while (slot < reg->req() && reg->in(slot) != NULL) slot++;
   212   assert(slot < reg->req(), "too many gotos");
   213   // If this is last predecessor, then don't force phi creation
   214   if (slot == reg->req() - 1) bind = false;
   215   reg->init_req(slot, ctrl());
   216   assert(first_var + _var_ct == _cvstate->req(), "bad _cvstate size");
   217   for (uint i = first_var; i < _cvstate->req(); i++) {
   219     // l is the value of var reaching the label. Could be a single value
   220     // reaching the label, or a phi that merges multiples values reaching
   221     // the label.  The latter is true if the label's input: in(..) is
   222     // a phi whose control input is the region node for the label.
   224     Node* l = lab->in(i);
   225     // Get the current value of the var
   226     Node* m = _cvstate->in(i);
   227     // If the var went unused no need for a phi
   228     if (m == NULL) {
   229       continue;
   230     } else if (l == NULL || m == l) {
   231       // Only one unique value "m" is known to reach this label so a phi
   232       // is not yet necessary unless:
   233       //    the label is being bound and all predecessors have not been seen,
   234       //    in which case "bind" will be true.
   235       if (bind) {
   236         m = promote_to_phi(m, reg);
   237       }
   238       // Record the phi/value used for this var in the label's cvstate
   239       lab->set_req(i, m);
   240     } else {
   241       // More than one value for the variable reaches this label so
   242       // a create a phi if one does not already exist.
   243       if (!was_promoted_to_phi(l, reg)) {
   244         l = promote_to_phi(l, reg);
   245         lab->set_req(i, l);
   246       }
   247       // Record in the phi, the var's value from the current state
   248       l->set_req(slot, m);
   249     }
   250   }
   251   do_memory_merge(_cvstate, lab);
   252   stop();
   253 }
   255 //-----------------------------promote_to_phi-----------------------------------
   256 Node* IdealKit::promote_to_phi(Node* n, Node* reg) {
   257   assert(!was_promoted_to_phi(n, reg), "n already promoted to phi on this region");
   258   // Get a conservative type for the phi
   259   const BasicType bt = n->bottom_type()->basic_type();
   260   const Type* ct = Type::get_const_basic_type(bt);
   261   return delay_transform(PhiNode::make(reg, n, ct));
   262 }
   264 //-----------------------------declarations_done-------------------------------
   265 void IdealKit::declarations_done() {
   266   _cvstate = new_cvstate();   // initialize current cvstate
   267   set_ctrl(_initial_ctrl);    // initialize control in current cvstate
   268   set_all_memory(_initial_memory);// initialize memory in current cvstate
   269   DEBUG_ONLY(_state->push(BlockS));
   270 }
   272 //-----------------------------transform-----------------------------------
   273 Node* IdealKit::transform(Node* n) {
   274   if (_delay_all_transforms) {
   275     return delay_transform(n);
   276   } else {
   277     return gvn().transform(n);
   278   }
   279 }
   281 //-----------------------------delay_transform-----------------------------------
   282 Node* IdealKit::delay_transform(Node* n) {
   283   if (!gvn().is_IterGVN() || !gvn().is_IterGVN()->delay_transform()) {
   284     gvn().set_type(n, n->bottom_type());
   285   }
   286   _delay_transform->push(n);
   287   return n;
   288 }
   290 //-----------------------------new_cvstate-----------------------------------
   291 Node* IdealKit::new_cvstate() {
   292   uint sz = _var_ct + first_var;
   293   return new (C, sz) Node(sz);
   294 }
   296 //-----------------------------copy_cvstate-----------------------------------
   297 Node* IdealKit::copy_cvstate() {
   298   Node* ns = new_cvstate();
   299   for (uint i = 0; i < ns->req(); i++) ns->init_req(i, _cvstate->in(i));
   300   // We must clone memory since it will be updated as we do stores.
   301   ns->set_req(TypeFunc::Memory, MergeMemNode::make(C, ns->in(TypeFunc::Memory)));
   302   return ns;
   303 }
   305 //-----------------------------clear-----------------------------------
   306 void IdealKit::clear(Node* m) {
   307   for (uint i = 0; i < m->req(); i++) m->set_req(i, NULL);
   308 }
   310 //-----------------------------drain_delay_transform----------------------------
   311 void IdealKit::drain_delay_transform() {
   312   while (_delay_transform->length() > 0) {
   313     Node* n = _delay_transform->pop();
   314     gvn().transform(n);
   315     if (!gvn().is_IterGVN()) {
   316       C->record_for_igvn(n);
   317     }
   318   }
   319 }
   321 //-----------------------------IdealVariable----------------------------
   322 IdealVariable::IdealVariable(IdealKit &k) {
   323   k.declare(this);
   324 }
   326 Node* IdealKit::memory(uint alias_idx) {
   327   MergeMemNode* mem = merged_memory();
   328   Node* p = mem->memory_at(alias_idx);
   329   if (!gvn().is_IterGVN() || !gvn().is_IterGVN()->delay_transform()) {
   330     _gvn.set_type(p, Type::MEMORY);  // must be mapped
   331   }
   332   return p;
   333 }
   335 void IdealKit::set_memory(Node* mem, uint alias_idx) {
   336   merged_memory()->set_memory_at(alias_idx, mem);
   337 }
   339 //----------------------------- make_load ----------------------------
   340 Node* IdealKit::load(Node* ctl,
   341                      Node* adr,
   342                      const Type* t,
   343                      BasicType bt,
   344                      int adr_idx,
   345                      bool require_atomic_access) {
   347   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
   348   const TypePtr* adr_type = NULL; // debug-mode-only argument
   349   debug_only(adr_type = C->get_adr_type(adr_idx));
   350   Node* mem = memory(adr_idx);
   351   Node* ld;
   352   if (require_atomic_access && bt == T_LONG) {
   353     ld = LoadLNode::make_atomic(C, ctl, mem, adr, adr_type, t);
   354   } else {
   355     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt);
   356   }
   357   return transform(ld);
   358 }
   360 Node* IdealKit::store(Node* ctl, Node* adr, Node *val, BasicType bt,
   361                                 int adr_idx,
   362                                 bool require_atomic_access) {
   363   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
   364   const TypePtr* adr_type = NULL;
   365   debug_only(adr_type = C->get_adr_type(adr_idx));
   366   Node *mem = memory(adr_idx);
   367   Node* st;
   368   if (require_atomic_access && bt == T_LONG) {
   369     st = StoreLNode::make_atomic(C, ctl, mem, adr, adr_type, val);
   370   } else {
   371     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt);
   372   }
   373   st = transform(st);
   374   set_memory(st, adr_idx);
   376   return st;
   377 }
   379 // Card mark store. Must be ordered so that it will come after the store of
   380 // the oop.
   381 Node* IdealKit::storeCM(Node* ctl, Node* adr, Node *val, Node* oop_store, int oop_adr_idx,
   382                         BasicType bt,
   383                         int adr_idx) {
   384   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
   385   const TypePtr* adr_type = NULL;
   386   debug_only(adr_type = C->get_adr_type(adr_idx));
   387   Node *mem = memory(adr_idx);
   389   // Add required edge to oop_store, optimizer does not support precedence edges.
   390   // Convert required edge to precedence edge before allocation.
   391   Node* st = new (C, 5) StoreCMNode(ctl, mem, adr, adr_type, val, oop_store, oop_adr_idx);
   393   st = transform(st);
   394   set_memory(st, adr_idx);
   396   return st;
   397 }
   399 //---------------------------- do_memory_merge --------------------------------
   400 // The memory from one merging cvstate needs to be merged with the memory for another
   401 // join cvstate. If the join cvstate doesn't have a merged memory yet then we
   402 // can just copy the state from the merging cvstate
   404 // Merge one slow path into the rest of memory.
   405 void IdealKit::do_memory_merge(Node* merging, Node* join) {
   407   // Get the region for the join state
   408   Node* join_region = join->in(TypeFunc::Control);
   409   assert(join_region != NULL, "join region must exist");
   410   if (join->in(TypeFunc::Memory) == NULL ) {
   411     join->set_req(TypeFunc::Memory,  merging->in(TypeFunc::Memory));
   412     return;
   413   }
   415   // The control flow for merging must have already been attached to the join region
   416   // we need its index for the phis.
   417   uint slot;
   418   for (slot = 1; slot < join_region->req() ; slot ++ ) {
   419     if (join_region->in(slot) == merging->in(TypeFunc::Control)) break;
   420   }
   421   assert(slot !=  join_region->req(), "edge must already exist");
   423   MergeMemNode* join_m    = join->in(TypeFunc::Memory)->as_MergeMem();
   424   MergeMemNode* merging_m = merging->in(TypeFunc::Memory)->as_MergeMem();
   426   // join_m should be an ancestor mergemem of merging
   427   // Slow path memory comes from the current map (which is from a slow call)
   428   // Fast path/null path memory comes from the call's input
   430   // Merge the other fast-memory inputs with the new slow-default memory.
   431   // for (MergeMemStream mms(merged_memory(), fast_mem->as_MergeMem()); mms.next_non_empty2(); ) {
   432   for (MergeMemStream mms(join_m, merging_m); mms.next_non_empty2(); ) {
   433     Node* join_slice = mms.force_memory();
   434     Node* merging_slice = mms.memory2();
   435     if (join_slice != merging_slice) {
   436       PhiNode* phi;
   437       // bool new_phi = false;
   438       // Is the phi for this slice one that we created for this join region or simply
   439       // one we copied? If it is ours then add
   440       if (join_slice->is_Phi() && join_slice->as_Phi()->region() == join_region) {
   441         phi = join_slice->as_Phi();
   442       } else {
   443         // create the phi with join_slice filling supplying memory for all of the
   444         // control edges to the join region
   445         phi = PhiNode::make(join_region, join_slice, Type::MEMORY, mms.adr_type(C));
   446         phi = (PhiNode*) delay_transform(phi);
   447         // gvn().set_type(phi, Type::MEMORY);
   448         // new_phi = true;
   449       }
   450       // Now update the phi with the slice for the merging slice
   451       phi->set_req(slot, merging_slice/* slow_path, slow_slice */);
   452       // this updates join_m with the phi
   453       mms.set_memory(phi);
   454     }
   455   }
   456 }
   459 //----------------------------- make_call  ----------------------------
   460 // Trivial runtime call
   461 void IdealKit::make_leaf_call(const TypeFunc *slow_call_type,
   462                               address slow_call,
   463                               const char *leaf_name,
   464                               Node* parm0,
   465                               Node* parm1,
   466                               Node* parm2) {
   468   // We only handle taking in RawMem and modifying RawMem
   469   const TypePtr* adr_type = TypeRawPtr::BOTTOM;
   470   uint adr_idx = C->get_alias_index(adr_type);
   472   // Slow-path leaf call
   473   int size = slow_call_type->domain()->cnt();
   474   CallNode *call =  (CallNode*)new (C, size) CallLeafNode( slow_call_type, slow_call, leaf_name, adr_type);
   476   // Set fixed predefined input arguments
   477   call->init_req( TypeFunc::Control, ctrl() );
   478   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
   479   // Narrow memory as only memory input
   480   call->init_req( TypeFunc::Memory , memory(adr_idx));
   481   call->init_req( TypeFunc::FramePtr, top() /* frameptr() */ );
   482   call->init_req( TypeFunc::ReturnAdr, top() );
   484   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);
   485   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);
   486   if (parm2 != NULL)  call->init_req(TypeFunc::Parms+2, parm2);
   488   // Node *c = _gvn.transform(call);
   489   call = (CallNode *) _gvn.transform(call);
   490   Node *c = call; // dbx gets confused with call call->dump()
   492   // Slow leaf call has no side-effects, sets few values
   494   set_ctrl(transform( new (C, 1) ProjNode(call,TypeFunc::Control) ));
   496   // Make memory for the call
   497   Node* mem = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::Memory) );
   499   // Set the RawPtr memory state only.
   500   set_memory(mem, adr_idx);
   502   assert(C->alias_type(call->adr_type()) == C->alias_type(adr_type),
   503          "call node must be constructed correctly");
   504 }

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