1 /*
  2  * Copyright (c) 2005, 2025, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
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 23  */
 24 
 25 #include "opto/addnode.hpp"
 26 #include "opto/callnode.hpp"
 27 #include "opto/cfgnode.hpp"
 28 #include "opto/idealKit.hpp"
 29 #include "opto/runtime.hpp"
 30 
 31 // Static initialization
 32 
 33 // This declares the position where vars are kept in the cvstate
 34 // For some degree of consistency we use the TypeFunc enum to
 35 // soak up spots in the inputs even though we only use early Control
 36 // and Memory slots. (So far.)
 37 const uint IdealKit::first_var = TypeFunc::Parms + 1;
 38 
 39 //----------------------------IdealKit-----------------------------------------
 40 IdealKit::IdealKit(GraphKit* gkit, bool delay_all_transforms, bool has_declarations) :
 41   C(gkit->C), _gvn(gkit->gvn()) {
 42   _initial_ctrl = gkit->control();
 43   _initial_memory = gkit->merged_memory();
 44   _initial_i_o = gkit->i_o();
 45   _delay_all_transforms = delay_all_transforms;
 46   _var_ct = 0;
 47   _cvstate = nullptr;
 48   // We can go memory state free or else we need the entire memory state
 49   assert(_initial_memory == nullptr || _initial_memory->Opcode() == Op_MergeMem, "memory must be pre-split");
 50   assert(!_gvn.is_IterGVN(), "IdealKit can't be used during Optimize phase");
 51   int init_size = 5;
 52   _pending_cvstates = new (C->node_arena()) GrowableArray<Node*>(C->node_arena(), init_size, 0, nullptr);
 53   DEBUG_ONLY(_state = new (C->node_arena()) GrowableArray<int>(C->node_arena(), init_size, 0, 0));
 54   if (!has_declarations) {
 55      declarations_done();
 56   }
 57 }
 58 
 59 //----------------------------sync_kit-----------------------------------------
 60 void IdealKit::sync_kit(GraphKit* gkit) {
 61   set_all_memory(gkit->merged_memory());
 62   set_i_o(gkit->i_o());
 63   set_ctrl(gkit->control());
 64 }
 65 
 66 //-------------------------------if_then-------------------------------------
 67 // Create:  if(left relop right)
 68 //          /  \
 69 //   iffalse    iftrue
 70 // Push the iffalse cvstate onto the stack. The iftrue becomes the current cvstate.
 71 void IdealKit::if_then(Node* left, BoolTest::mask relop,
 72                        Node* right, float prob, float cnt, bool push_new_state) {
 73   assert((state() & (BlockS|LoopS|IfThenS|ElseS)), "bad state for new If");
 74   Node* bol;
 75   if (left->bottom_type()->isa_ptr() == nullptr) {
 76     if (left->bottom_type()->isa_int() != nullptr) {
 77       bol = Bool(CmpI(left, right), relop);
 78     } else {
 79       assert(left->bottom_type()->isa_long() != nullptr, "what else?");
 80       bol = Bool(CmpL(left, right), relop);
 81     }
 82 
 83   } else {
 84     bol = Bool(CmpP(left, right), relop);
 85   }




 86   // Delay gvn.transform on if-nodes until construction is finished
 87   // to prevent a constant bool input from discarding a control output.
 88   IfNode* iff = delay_transform(new IfNode(ctrl(), bol, prob, cnt))->as_If();
 89   Node* then  = IfTrue(iff);
 90   Node* elsen = IfFalse(iff);
 91   Node* else_cvstate = copy_cvstate();
 92   else_cvstate->set_req(TypeFunc::Control, elsen);
 93   _pending_cvstates->push(else_cvstate);
 94   DEBUG_ONLY(if (push_new_state) _state->push(IfThenS));
 95   set_ctrl(then);
 96 }
 97 
 98 //-------------------------------else_-------------------------------------
 99 // Pop the else cvstate off the stack, and push the (current) then cvstate.
100 // The else cvstate becomes the current cvstate.
101 void IdealKit::else_() {
102   assert(state() == IfThenS, "bad state for new Else");
103   Node* else_cvstate = _pending_cvstates->pop();
104   DEBUG_ONLY(_state->pop());
105   // save current (then) cvstate for later use at endif
106   _pending_cvstates->push(_cvstate);
107   DEBUG_ONLY(_state->push(ElseS));
108   _cvstate = else_cvstate;
109 }
110 
111 //-------------------------------end_if-------------------------------------
112 // Merge the "then" and "else" cvstates.
113 //
114 // The if_then() pushed a copy of the current state for later use
115 // as the initial state for a future "else" clause.  The
116 // current state then became the initial state for the
117 // then clause.  If an "else" clause was encountered, it will
118 // pop the top state and use it for it's initial state.
119 // It will also push the current state (the state at the end of
120 // the "then" clause) for latter use at the end_if.
121 //
122 // At the endif, the states are:
123 // 1) else exists a) current state is end of "else" clause
124 //                b) top stack state is end of "then" clause
125 //
126 // 2) no else:    a) current state is end of "then" clause
127 //                b) top stack state is from the "if_then" which
128 //                   would have been the initial state of the else.
129 //
130 // Merging the states is accomplished by:
131 //   1) make a label for the merge
132 //   2) terminate the current state with a goto to the label
133 //   3) pop the top state from the stack and make it the
134 //        current state
135 //   4) bind the label at the current state.  Binding a label
136 //        terminates the current state with a goto to the
137 //        label and makes the label's state the current state.
138 //
139 void IdealKit::end_if() {
140   assert(state() & (IfThenS|ElseS), "bad state for new Endif");
141   Node* lab = make_label(1);
142 
143   // Node* join_state = _pending_cvstates->pop();
144                   /* merging, join */
145   goto_(lab);
146   _cvstate = _pending_cvstates->pop();
147 
148   bind(lab);
149   DEBUG_ONLY(_state->pop());
150 }
151 
152 //-------------------------------loop-------------------------------------
153 // Create the loop head portion (*) of:
154 //  *     iv = init
155 //  *  top: (region node)
156 //  *     if (iv relop limit) {
157 //           loop body
158 //           i = i + 1
159 //           goto top
160 //  *     } else // exits loop
161 //
162 // Pushes the loop top cvstate first, then the else (loop exit) cvstate
163 // onto the stack.
164 void IdealKit::loop(GraphKit* gkit, int nargs, IdealVariable& iv, Node* init, BoolTest::mask relop, Node* limit, float prob, float cnt) {
165   assert((state() & (BlockS|LoopS|IfThenS|ElseS)), "bad state for new loop");
166   if (UseLoopPredicate) {
167     // Sync IdealKit and graphKit.
168     gkit->sync_kit(*this);
169     // Add Parse Predicates.
170     gkit->add_parse_predicates(nargs);
171     // Update IdealKit memory.
172     sync_kit(gkit);
173   }
174   set(iv, init);
175   Node* head = make_label(1);
176   bind(head);
177   _pending_cvstates->push(head); // push for use at end_loop
178   _cvstate = copy_cvstate();
179   if_then(value(iv), relop, limit, prob, cnt, false /* no new state */);
180   DEBUG_ONLY(_state->push(LoopS));
181   assert(ctrl()->is_IfTrue(), "true branch stays in loop");
182   assert(_pending_cvstates->top()->in(TypeFunc::Control)->is_IfFalse(), "false branch exits loop");
183 }
184 
185 //-------------------------------end_loop-------------------------------------
186 // Creates the goto top label.
187 // Expects the else (loop exit) cvstate to be on top of the
188 // stack, and the loop top cvstate to be 2nd.
189 void IdealKit::end_loop() {
190   assert((state() == LoopS), "bad state for new end_loop");
191   Node* exit = _pending_cvstates->pop();
192   Node* head = _pending_cvstates->pop();
193   goto_(head);
194   clear(head);
195   DEBUG_ONLY(_state->pop());
196   _cvstate = exit;
197 }
198 
199 //-------------------------------make_label-------------------------------------
200 // Creates a label.  The number of goto's
201 // must be specified (which should be 1 less than
202 // the number of precedessors.)
203 Node* IdealKit::make_label(int goto_ct) {
204   assert(_cvstate != nullptr, "must declare variables before labels");
205   Node* lab = new_cvstate();
206   int sz = 1 + goto_ct + 1 /* fall thru */;
207   Node* reg = delay_transform(new RegionNode(sz));
208   lab->init_req(TypeFunc::Control, reg);
209   return lab;
210 }
211 
212 //-------------------------------bind-------------------------------------
213 // Bind a label at the current cvstate by simulating
214 // a goto to the label.
215 void IdealKit::bind(Node* lab) {
216   goto_(lab, true /* bind */);
217   _cvstate = lab;
218 }
219 
220 //-------------------------------goto_-------------------------------------
221 // Make the current cvstate a predecessor of the label,
222 // creating phi's to merge values.  If bind is true and
223 // this is not the last control edge, then ensure that
224 // all live values have phis created. Used to create phis
225 // at loop-top regions.
226 void IdealKit::goto_(Node* lab, bool bind) {
227   Node* reg = lab->in(TypeFunc::Control);
228   // find next empty slot in region
229   uint slot = 1;
230   while (slot < reg->req() && reg->in(slot) != nullptr) slot++;
231   assert(slot < reg->req(), "too many gotos");
232   // If this is last predecessor, then don't force phi creation
233   if (slot == reg->req() - 1) bind = false;
234   reg->init_req(slot, ctrl());
235   assert(first_var + _var_ct == _cvstate->req(), "bad _cvstate size");
236   for (uint i = first_var; i < _cvstate->req(); i++) {
237 
238     // l is the value of var reaching the label. Could be a single value
239     // reaching the label, or a phi that merges multiples values reaching
240     // the label.  The latter is true if the label's input: in(..) is
241     // a phi whose control input is the region node for the label.
242 
243     Node* l = lab->in(i);
244     // Get the current value of the var
245     Node* m = _cvstate->in(i);
246     // If the var went unused no need for a phi
247     if (m == nullptr) {
248       continue;
249     } else if (l == nullptr || m == l) {
250       // Only one unique value "m" is known to reach this label so a phi
251       // is not yet necessary unless:
252       //    the label is being bound and all predecessors have not been seen,
253       //    in which case "bind" will be true.
254       if (bind) {
255         m = promote_to_phi(m, reg);
256       }
257       // Record the phi/value used for this var in the label's cvstate
258       lab->set_req(i, m);
259     } else {
260       // More than one value for the variable reaches this label so
261       // a create a phi if one does not already exist.
262       if (!was_promoted_to_phi(l, reg)) {
263         l = promote_to_phi(l, reg);
264         lab->set_req(i, l);
265       }
266       // Record in the phi, the var's value from the current state
267       l->set_req(slot, m);
268     }
269   }
270   do_memory_merge(_cvstate, lab);
271   stop();
272 }
273 
274 //-----------------------------promote_to_phi-----------------------------------
275 Node* IdealKit::promote_to_phi(Node* n, Node* reg) {
276   assert(!was_promoted_to_phi(n, reg), "n already promoted to phi on this region");
277   // Get a conservative type for the phi
278   const BasicType bt = n->bottom_type()->basic_type();
279   const Type* ct = Type::get_const_basic_type(bt);
280   return delay_transform(PhiNode::make(reg, n, ct));
281 }
282 
283 //-----------------------------declarations_done-------------------------------
284 void IdealKit::declarations_done() {
285   _cvstate = new_cvstate();   // initialize current cvstate
286   set_ctrl(_initial_ctrl);    // initialize control in current cvstate
287   set_all_memory(_initial_memory);// initialize memory in current cvstate
288   set_i_o(_initial_i_o);      // initialize i_o in current cvstate
289   DEBUG_ONLY(_state->push(BlockS));
290 }
291 
292 //-----------------------------transform-----------------------------------
293 Node* IdealKit::transform(Node* n) {
294   if (_delay_all_transforms) {
295     return delay_transform(n);
296   } else {
297     n = gvn().transform(n);
298     C->record_for_igvn(n);
299     return n;
300   }
301 }
302 
303 //-----------------------------delay_transform-----------------------------------
304 Node* IdealKit::delay_transform(Node* n) {
305   // Delay transform until IterativeGVN
306   gvn().set_type(n, n->bottom_type());
307   C->record_for_igvn(n);
308   return n;
309 }
310 
311 //-----------------------------new_cvstate-----------------------------------
312 Node* IdealKit::new_cvstate() {
313   uint sz = _var_ct + first_var;
314   return new Node(sz);
315 }
316 
317 //-----------------------------copy_cvstate-----------------------------------
318 Node* IdealKit::copy_cvstate() {
319   Node* ns = new_cvstate();
320   for (uint i = 0; i < ns->req(); i++) ns->init_req(i, _cvstate->in(i));
321   // We must clone memory since it will be updated as we do stores.
322   ns->set_req(TypeFunc::Memory, MergeMemNode::make(ns->in(TypeFunc::Memory)));
323   return ns;
324 }
325 
326 //-----------------------------clear-----------------------------------
327 void IdealKit::clear(Node* m) {
328   for (uint i = 0; i < m->req(); i++) m->set_req(i, nullptr);
329 }
330 
331 //-----------------------------IdealVariable----------------------------
332 IdealVariable::IdealVariable(IdealKit &k) {
333   k.declare(this);
334 }
335 
336 Node* IdealKit::memory(uint alias_idx) {
337   MergeMemNode* mem = merged_memory();
338   Node* p = mem->memory_at(alias_idx);
339   _gvn.set_type(p, Type::MEMORY);  // must be mapped
340   return p;
341 }
342 
343 void IdealKit::set_memory(Node* mem, uint alias_idx) {
344   merged_memory()->set_memory_at(alias_idx, mem);
345 }
346 
347 //----------------------------- make_load ----------------------------
348 Node* IdealKit::load(Node* ctl,
349                      Node* adr,
350                      const Type* t,
351                      BasicType bt,
352                      int adr_idx,
353                      bool require_atomic_access,
354                      MemNode::MemOrd mo,
355                      LoadNode::ControlDependency control_dependency) {
356 
357   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
358   const TypePtr* adr_type = nullptr; // debug-mode-only argument
359   debug_only(adr_type = C->get_adr_type(adr_idx));
360   Node* mem = memory(adr_idx);
361   Node* ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, require_atomic_access);
362   return transform(ld);
363 }
364 
365 Node* IdealKit::store(Node* ctl, Node* adr, Node *val, BasicType bt,
366                       int adr_idx,
367                       MemNode::MemOrd mo, bool require_atomic_access,
368                       bool mismatched) {
369   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory");
370   const TypePtr* adr_type = nullptr;
371   debug_only(adr_type = C->get_adr_type(adr_idx));
372   Node *mem = memory(adr_idx);
373   Node* st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo, require_atomic_access);
374   if (mismatched) {
375     st->as_Store()->set_mismatched_access();
376   }
377   st = transform(st);
378   set_memory(st, adr_idx);
379 
380   return st;
381 }
382 
383 //---------------------------- do_memory_merge --------------------------------
384 // The memory from one merging cvstate needs to be merged with the memory for another
385 // join cvstate. If the join cvstate doesn't have a merged memory yet then we
386 // can just copy the state from the merging cvstate
387 
388 // Merge one slow path into the rest of memory.
389 void IdealKit::do_memory_merge(Node* merging, Node* join) {
390 
391   // Get the region for the join state
392   Node* join_region = join->in(TypeFunc::Control);
393   assert(join_region != nullptr, "join region must exist");
394   if (join->in(TypeFunc::I_O) == nullptr ) {
395     join->set_req(TypeFunc::I_O,  merging->in(TypeFunc::I_O));
396   }
397   if (join->in(TypeFunc::Memory) == nullptr ) {
398     join->set_req(TypeFunc::Memory,  merging->in(TypeFunc::Memory));
399     return;
400   }
401 
402   // The control flow for merging must have already been attached to the join region
403   // we need its index for the phis.
404   uint slot;
405   for (slot = 1; slot < join_region->req() ; slot ++ ) {
406     if (join_region->in(slot) == merging->in(TypeFunc::Control)) break;
407   }
408   assert(slot !=  join_region->req(), "edge must already exist");
409 
410   MergeMemNode* join_m    = join->in(TypeFunc::Memory)->as_MergeMem();
411   MergeMemNode* merging_m = merging->in(TypeFunc::Memory)->as_MergeMem();
412 
413   // join_m should be an ancestor mergemem of merging
414   // Slow path memory comes from the current map (which is from a slow call)
415   // Fast path/null path memory comes from the call's input
416 
417   // Merge the other fast-memory inputs with the new slow-default memory.
418   // for (MergeMemStream mms(merged_memory(), fast_mem->as_MergeMem()); mms.next_non_empty2(); ) {
419   for (MergeMemStream mms(join_m, merging_m); mms.next_non_empty2(); ) {
420     Node* join_slice = mms.force_memory();
421     Node* merging_slice = mms.memory2();
422     if (join_slice != merging_slice) {
423       PhiNode* phi;
424       // bool new_phi = false;
425       // Is the phi for this slice one that we created for this join region or simply
426       // one we copied? If it is ours then add
427       if (join_slice->is_Phi() && join_slice->as_Phi()->region() == join_region) {
428         phi = join_slice->as_Phi();
429       } else {
430         // create the phi with join_slice filling supplying memory for all of the
431         // control edges to the join region
432         phi = PhiNode::make(join_region, join_slice, Type::MEMORY, mms.adr_type(C));
433         phi = (PhiNode*) delay_transform(phi);
434         // gvn().set_type(phi, Type::MEMORY);
435         // new_phi = true;
436       }
437       // Now update the phi with the slice for the merging slice
438       phi->set_req(slot, merging_slice/* slow_path, slow_slice */);
439       // this updates join_m with the phi
440       mms.set_memory(phi);
441     }
442   }
443 
444   Node* join_io    = join->in(TypeFunc::I_O);
445   Node* merging_io = merging->in(TypeFunc::I_O);
446   if (join_io != merging_io) {
447     PhiNode* phi;
448     if (join_io->is_Phi() && join_io->as_Phi()->region() == join_region) {
449       phi = join_io->as_Phi();
450     } else {
451       phi = PhiNode::make(join_region, join_io, Type::ABIO);
452       phi = (PhiNode*) delay_transform(phi);
453       join->set_req(TypeFunc::I_O, phi);
454     }
455     phi->set_req(slot, merging_io);
456   }
457 }
458 
459 
460 //----------------------------- make_call  ----------------------------
461 // Trivial runtime call
462 Node* IdealKit::make_leaf_call(const TypeFunc *slow_call_type,
463                                address slow_call,
464                                const char *leaf_name,
465                                Node* parm0,
466                                Node* parm1,
467                                Node* parm2,
468                                Node* parm3) {
469 
470   // We only handle taking in RawMem and modifying RawMem
471   const TypePtr* adr_type = TypeRawPtr::BOTTOM;
472   uint adr_idx = C->get_alias_index(adr_type);
473 
474   // Slow-path leaf call
475   CallNode *call =  (CallNode*)new CallLeafNode( slow_call_type, slow_call, leaf_name, adr_type);
476 
477   // Set fixed predefined input arguments
478   call->init_req( TypeFunc::Control, ctrl() );
479   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
480   // Narrow memory as only memory input
481   call->init_req( TypeFunc::Memory , memory(adr_idx));
482   call->init_req( TypeFunc::FramePtr, top() /* frameptr() */ );
483   call->init_req( TypeFunc::ReturnAdr, top() );
484 
485   if (parm0 != nullptr)  call->init_req(TypeFunc::Parms+0, parm0);
486   if (parm1 != nullptr)  call->init_req(TypeFunc::Parms+1, parm1);
487   if (parm2 != nullptr)  call->init_req(TypeFunc::Parms+2, parm2);
488   if (parm3 != nullptr)  call->init_req(TypeFunc::Parms+3, parm3);
489 
490   // Node *c = _gvn.transform(call);
491   call = (CallNode *) _gvn.transform(call);
492   Node *c = call; // dbx gets confused with call call->dump()
493 
494   // Slow leaf call has no side-effects, sets few values
495 
496   set_ctrl(transform( new ProjNode(call,TypeFunc::Control) ));
497 
498   // Make memory for the call
499   Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
500 
501   // Set the RawPtr memory state only.
502   set_memory(mem, adr_idx);
503 
504   assert(C->alias_type(call->adr_type()) == C->alias_type(adr_type),
505          "call node must be constructed correctly");
506   Node* res = nullptr;
507   if (slow_call_type->range()->cnt() > TypeFunc::Parms) {
508     assert(slow_call_type->range()->cnt() == TypeFunc::Parms+1, "only one return value");
509     res = transform(new ProjNode(call, TypeFunc::Parms));
510   }
511   return res;
512 }
513 
514 void IdealKit::make_leaf_call_no_fp(const TypeFunc *slow_call_type,
515                               address slow_call,
516                               const char *leaf_name,
517                               const TypePtr* adr_type,
518                               Node* parm0,
519                               Node* parm1,
520                               Node* parm2,
521                               Node* parm3) {
522 
523   // We only handle taking in RawMem and modifying RawMem
524   uint adr_idx = C->get_alias_index(adr_type);
525 
526   // Slow-path leaf call
527   CallNode *call =  (CallNode*)new CallLeafNoFPNode( slow_call_type, slow_call, leaf_name, adr_type);
528 
529   // Set fixed predefined input arguments
530   call->init_req( TypeFunc::Control, ctrl() );
531   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
532   // Narrow memory as only memory input
533   call->init_req( TypeFunc::Memory , memory(adr_idx));
534   call->init_req( TypeFunc::FramePtr, top() /* frameptr() */ );
535   call->init_req( TypeFunc::ReturnAdr, top() );
536 
537   if (parm0 != nullptr)  call->init_req(TypeFunc::Parms+0, parm0);
538   if (parm1 != nullptr)  call->init_req(TypeFunc::Parms+1, parm1);
539   if (parm2 != nullptr)  call->init_req(TypeFunc::Parms+2, parm2);
540   if (parm3 != nullptr)  call->init_req(TypeFunc::Parms+3, parm3);
541 
542   // Node *c = _gvn.transform(call);
543   call = (CallNode *) _gvn.transform(call);
544   Node *c = call; // dbx gets confused with call call->dump()
545 
546   // Slow leaf call has no side-effects, sets few values
547 
548   set_ctrl(transform( new ProjNode(call,TypeFunc::Control) ));
549 
550   // Make memory for the call
551   Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
552 
553   // Set the RawPtr memory state only.
554   set_memory(mem, adr_idx);
555 
556   assert(C->alias_type(call->adr_type()) == C->alias_type(adr_type),
557          "call node must be constructed correctly");
558 }
--- EOF ---