Robust/src/Analysis/Locality/DiscoverConflicts.java

   1 package Analysis.Locality;
   2
   3 import IR.Flat.*;
   4 import java.util.Set;
   5 import java.util.Arrays;
   6 import java.util.HashSet;
   7 import java.util.Iterator;
   8 import java.util.Hashtable;
   9 import IR.State;
  10 import IR.Operation;
  11 import IR.TypeDescriptor;
  12 import IR.MethodDescriptor;
  13 import IR.FieldDescriptor;
  14
  15 public class DiscoverConflicts {
  16   Set<FieldDescriptor> fields;
  17   Set<TypeDescriptor> arrays;
  18   LocalityAnalysis locality;
  19   State state;
  20   Hashtable<LocalityBinding, Set<FlatNode>> treadmap;
  21   Hashtable<LocalityBinding, Set<TempFlatPair>> transreadmap;
  22   Hashtable<LocalityBinding, Set<FlatNode>> srcmap;
  23   Hashtable<LocalityBinding, Set<FlatNode>> leftsrcmap;
  24   Hashtable<LocalityBinding, Set<FlatNode>> rightsrcmap;
  25   TypeAnalysis typeanalysis;
  26   HashSet<FlatNode>cannotdelay;
  27   Hashtable<LocalityBinding, Hashtable<FlatNode, Hashtable<TempDescriptor, Set<TempFlatPair>>>> lbtofnmap;
  28
  29
  30   public DiscoverConflicts(LocalityAnalysis locality, State state, TypeAnalysis typeanalysis) {
  31     this.locality=locality;
  32     this.fields=new HashSet<FieldDescriptor>();
  33     this.arrays=new HashSet<TypeDescriptor>();
  34     this.state=state;
  35     this.typeanalysis=typeanalysis;
  36     transreadmap=new Hashtable<LocalityBinding, Set<TempFlatPair>>();
  37     treadmap=new Hashtable<LocalityBinding, Set<FlatNode>>();
  38     srcmap=new Hashtable<LocalityBinding, Set<FlatNode>>();
  39     leftsrcmap=new Hashtable<LocalityBinding, Set<FlatNode>>();
  40     rightsrcmap=new Hashtable<LocalityBinding, Set<FlatNode>>();
  41     lbtofnmap=new Hashtable<LocalityBinding, Hashtable<FlatNode, Hashtable<TempDescriptor, Set<TempFlatPair>>>>();
  42   }
  43
  44   public DiscoverConflicts(LocalityAnalysis locality, State state, TypeAnalysis typeanalysis, HashSet<FlatNode> cannotdelay) {
  45     this.locality=locality;
  46     this.fields=new HashSet<FieldDescriptor>();
  47     this.arrays=new HashSet<TypeDescriptor>();
  48     this.state=state;
  49     this.typeanalysis=typeanalysis;
  50     this.cannotdelay=cannotdelay;
  51     transreadmap=new Hashtable<LocalityBinding, Set<TempFlatPair>>();
  52     treadmap=new Hashtable<LocalityBinding, Set<FlatNode>>();
  53     srcmap=new Hashtable<LocalityBinding, Set<FlatNode>>();
  54     leftsrcmap=new Hashtable<LocalityBinding, Set<FlatNode>>();
  55     rightsrcmap=new Hashtable<LocalityBinding, Set<FlatNode>>();
  56     lbtofnmap=new Hashtable<LocalityBinding, Hashtable<FlatNode, Hashtable<TempDescriptor, Set<TempFlatPair>>>>();
  57   }
  58
  59   public Set<FieldDescriptor> getFields() {
  60     return fields;
  61   }
  62
  63   public Set<TypeDescriptor> getArrays() {
  64     return arrays;
  65   }
  66
  67   public void doAnalysis() {
  68     //Compute fields and arrays for all transactions.  Note that we
  69     //only look at changes to old objects
  70
  71     Set<LocalityBinding> localityset=locality.getLocalityBindings();
  72     for(Iterator<LocalityBinding> lb=localityset.iterator();lb.hasNext();) {
  73       computeModified(lb.next());
  74     }
  75     expandTypes();
  76     //Compute set of nodes that need transread
  77     for(Iterator<LocalityBinding> lb=localityset.iterator();lb.hasNext();) {
  78       LocalityBinding l=lb.next();
  79       analyzeLocality(l);
  80       setNeedReadTrans(l);
  81     }
  82   }
  83
  84   //Change flatnode/temp pairs to just flatnodes that need transactional reads
  85
  86   public void setNeedReadTrans(LocalityBinding lb) {
  87     HashSet<FlatNode> set=new HashSet<FlatNode>();
  88     for(Iterator<TempFlatPair> it=transreadmap.get(lb).iterator();it.hasNext();) {
  89       TempFlatPair tfp=it.next();
  90       set.add(tfp.f);
  91     }
  92     treadmap.put(lb, set);
  93   }
  94
  95   //We have a set of things we write to, figure out what things this
  96   //could effect.
  97   public void expandTypes() {
  98     Set<TypeDescriptor> expandedarrays=new HashSet<TypeDescriptor>();
  99     for(Iterator<TypeDescriptor> it=arrays.iterator();it.hasNext();) {
 100       TypeDescriptor td=it.next();
 101       expandedarrays.addAll(typeanalysis.expand(td));
 102     }
 103     arrays=expandedarrays;
 104   }
 105
 106   Hashtable<TempDescriptor, Set<TempFlatPair>> doMerge(FlatNode fn, Hashtable<FlatNode, Hashtable<TempDescriptor, Set<TempFlatPair>>> tmptofnset) {
 107     Hashtable<TempDescriptor, Set<TempFlatPair>> table=new Hashtable<TempDescriptor, Set<TempFlatPair>>();
 108     for(int i=0;i<fn.numPrev();i++) {
 109       FlatNode fprev=fn.getPrev(i);
 110       Hashtable<TempDescriptor, Set<TempFlatPair>> tabset=tmptofnset.get(fprev);
 111       if (tabset!=null) {
 112         for(Iterator<TempDescriptor> tmpit=tabset.keySet().iterator();tmpit.hasNext();) {
 113           TempDescriptor td=tmpit.next();
 114           Set<TempFlatPair> fnset=tabset.get(td);
 115           if (!table.containsKey(td))
 116             table.put(td, new HashSet<TempFlatPair>());
 117           table.get(td).addAll(fnset);
 118         }
 119       }
 120     }
 121     return table;
 122   }
 123
 124   public Set<FlatNode> getNeedSrcTrans(LocalityBinding lb) {
 125     return srcmap.get(lb);
 126   }
 127
 128   public boolean getNeedSrcTrans(LocalityBinding lb, FlatNode fn) {
 129     return srcmap.get(lb).contains(fn);
 130   }
 131
 132   public boolean getNeedLeftSrcTrans(LocalityBinding lb, FlatNode fn) {
 133     return leftsrcmap.get(lb).contains(fn);
 134   }
 135
 136   public boolean getNeedRightSrcTrans(LocalityBinding lb, FlatNode fn) {
 137     return rightsrcmap.get(lb).contains(fn);
 138   }
 139
 140   public boolean getNeedTrans(LocalityBinding lb, FlatNode fn) {
 141     return treadmap.get(lb).contains(fn);
 142   }
 143
 144   public Hashtable<FlatNode, Hashtable<TempDescriptor, Set<TempFlatPair>>> getMap(LocalityBinding lb) {
 145     return lbtofnmap.get(lb);
 146   }
 147
 148   private void analyzeLocality(LocalityBinding lb) {
 149     MethodDescriptor md=lb.getMethod();
 150     FlatMethod fm=state.getMethodFlat(md);
 151     Hashtable<FlatNode, Hashtable<TempDescriptor, Set<TempFlatPair>>> fnmap=computeTempSets(lb);
 152     lbtofnmap.put(lb,fnmap);
 153     HashSet<TempFlatPair> tfset=computeTranslationSet(lb, fm, fnmap);
 154     HashSet<FlatNode> srctrans=new HashSet<FlatNode>();
 155     HashSet<FlatNode> leftsrctrans=new HashSet<FlatNode>();
 156     HashSet<FlatNode> rightsrctrans=new HashSet<FlatNode>();
 157     transreadmap.put(lb, tfset);
 158     srcmap.put(lb,srctrans);
 159     leftsrcmap.put(lb,leftsrctrans);
 160     rightsrcmap.put(lb,rightsrctrans);
 161
 162     //compute writes that need translation on source
 163
 164     for(Iterator<FlatNode> fnit=fm.getNodeSet().iterator();fnit.hasNext();) {
 165       FlatNode fn=fnit.next();
 166       Hashtable<FlatNode, Integer> atomictable=locality.getAtomic(lb);
 167       if (atomictable.get(fn).intValue()>0) {
 168         Hashtable<TempDescriptor, Set<TempFlatPair>> tmap=fnmap.get(fn);
 169         switch(fn.kind()) {
 170
 171           //We might need to translate arguments to pointer comparison
 172
 173         case FKind.FlatOpNode: {
 174           FlatOpNode fon=(FlatOpNode)fn;
 175           if (fon.getOp().getOp()==Operation.EQUAL||
 176               fon.getOp().getOp()==Operation.NOTEQUAL) {
 177             if (!fon.getLeft().getType().isPtr())
 178               break;
 179             Set<TempFlatPair> lefttfpset=tmap.get(fon.getLeft());
 180             Set<TempFlatPair> righttfpset=tmap.get(fon.getRight());
 181             //handle left operand
 182             if (lefttfpset!=null) {
 183               for(Iterator<TempFlatPair> tfpit=lefttfpset.iterator();tfpit.hasNext();) {
 184                 TempFlatPair tfp=tfpit.next();
 185                 if (tfset.contains(tfp)||outofscope(tfp)) {
 186                   leftsrctrans.add(fon);
 187                   break;
 188                 }
 189               }
 190             }
 191             //handle right operand
 192             if (righttfpset!=null) {
 193               for(Iterator<TempFlatPair> tfpit=righttfpset.iterator();tfpit.hasNext();) {
 194                 TempFlatPair tfp=tfpit.next();
 195                 if (tfset.contains(tfp)||outofscope(tfp)) {
 196                   rightsrctrans.add(fon);
 197                   break;
 198                 }
 199               }
 200             }
 201           }
 202           break;
 203         }
 204
 205         case FKind.FlatGlobalConvNode: {
 206           //need to translate these if the value we read from may be a
 207           //shadow...  check this by seeing if any of the values we
 208           //may read are in the transread set or came from our caller
 209           //or a method we called
 210
 211           FlatGlobalConvNode fgcn=(FlatGlobalConvNode)fn;
 212           if (fgcn.getLocality()!=lb)
 213             break;
 214
 215           Set<TempFlatPair> tfpset=tmap.get(fgcn.getSrc());
 216           if (tfpset!=null) {
 217             for(Iterator<TempFlatPair> tfpit=tfpset.iterator();tfpit.hasNext();) {
 218               TempFlatPair tfp=tfpit.next();
 219               if (tfset.contains(tfp)||outofscope(tfp)) {
 220                 srctrans.add(fgcn);
 221                 break;
 222               }
 223             }
 224           }
 225           break;
 226         }
 227
 228         case FKind.FlatSetFieldNode: {
 229           //need to translate these if the value we read from may be a
 230           //shadow...  check this by seeing if any of the values we
 231           //may read are in the transread set or came from our caller
 232           //or a method we called
 233
 234           FlatSetFieldNode fsfn=(FlatSetFieldNode)fn;
 235           if (!fsfn.getField().getType().isPtr())
 236             break;
 237           Set<TempFlatPair> tfpset=tmap.get(fsfn.getSrc());
 238           if (tfpset!=null) {
 239             for(Iterator<TempFlatPair> tfpit=tfpset.iterator();tfpit.hasNext();) {
 240               TempFlatPair tfp=tfpit.next();
 241               if (tfset.contains(tfp)||outofscope(tfp)) {
 242                 srctrans.add(fsfn);
 243                 break;
 244               }
 245             }
 246           }
 247           break;
 248         }
 249         case FKind.FlatSetElementNode: {
 250           //need to translate these if the value we read from may be a
 251           //shadow...  check this by seeing if any of the values we
 252           //may read are in the transread set or came from our caller
 253           //or a method we called
 254
 255           FlatSetElementNode fsen=(FlatSetElementNode)fn;
 256           if (!fsen.getSrc().getType().isPtr())
 257             break;
 258           Set<TempFlatPair> tfpset=tmap.get(fsen.getSrc());
 259           if (tfpset!=null) {
 260             for(Iterator<TempFlatPair> tfpit=tfpset.iterator();tfpit.hasNext();) {
 261               TempFlatPair tfp=tfpit.next();
 262               if (tfset.contains(tfp)||outofscope(tfp)) {
 263                 srctrans.add(fsen);
 264                 break;
 265               }
 266             }
 267           }
 268           break;
 269         }
 270         default:
 271         }
 272       }
 273     }
 274   }
 275
 276   public boolean outofscope(TempFlatPair tfp) {
 277     FlatNode fn=tfp.f;
 278     return fn.kind()==FKind.FlatCall||fn.kind()==FKind.FlatMethod;
 279   }
 280
 281
 282   /** Need to figure out which nodes need a transread to make local
 283   copies.  Transread conceptually tracks conflicts.  This depends on
 284   what fields/elements are accessed We iterate over all flatnodes that
 285   access fields...If these accesses could conflict, we mark the source
 286   tempflat pair as needing a transread */
 287
 288   HashSet<TempFlatPair> computeTranslationSet(LocalityBinding lb, FlatMethod fm, Hashtable<FlatNode, Hashtable<TempDescriptor, Set<TempFlatPair>>> fnmap) {
 289     HashSet<TempFlatPair> tfset=new HashSet<TempFlatPair>();
 290
 291     for(Iterator<FlatNode> fnit=fm.getNodeSet().iterator();fnit.hasNext();) {
 292       FlatNode fn=fnit.next();
 293       Hashtable<FlatNode, Integer> atomictable=locality.getAtomic(lb);
 294
 295       //Check whether this node matters for delayed computation
 296       if (cannotdelay!=null&&!cannotdelay.contains(fn))
 297         continue;
 298
 299       if (atomictable.get(fn).intValue()>0) {
 300         Hashtable<TempDescriptor, Set<TempFlatPair>> tmap=fnmap.get(fn);
 301         switch(fn.kind()) {
 302         case FKind.FlatElementNode: {
 303           FlatElementNode fen=(FlatElementNode)fn;
 304           if (arrays.contains(fen.getSrc().getType())) {
 305             //this could cause conflict...figure out conflict set
 306             Set<TempFlatPair> tfpset=tmap.get(fen.getSrc());
 307             if (tfpset!=null)
 308               tfset.addAll(tfpset);
 309           }
 310           break;
 311         }
 312         case FKind.FlatFieldNode: {
 313           FlatFieldNode ffn=(FlatFieldNode)fn;
 314           if (fields.contains(ffn.getField())) {
 315             //this could cause conflict...figure out conflict set
 316             Set<TempFlatPair> tfpset=tmap.get(ffn.getSrc());
 317             if (tfpset!=null)
 318               tfset.addAll(tfpset);
 319           }
 320           break;
 321         }
 322         case FKind.FlatSetFieldNode: {
 323           //definitely need to translate these
 324           FlatSetFieldNode fsfn=(FlatSetFieldNode)fn;
 325           Set<TempFlatPair> tfpset=tmap.get(fsfn.getDst());
 326           if (tfpset!=null)
 327             tfset.addAll(tfpset);
 328           break;
 329         }
 330         case FKind.FlatSetElementNode: {
 331           //definitely need to translate these
 332           FlatSetElementNode fsen=(FlatSetElementNode)fn;
 333           Set<TempFlatPair> tfpset=tmap.get(fsen.getDst());
 334           if (tfpset!=null)
 335             tfset.addAll(tfpset);
 336           break;
 337         }
 338         case FKind.FlatCall: //assume pessimistically that calls do bad things
 339         case FKind.FlatReturnNode: {
 340           TempDescriptor []readarray=fn.readsTemps();
 341           for(int i=0;i<readarray.length;i++) {
 342             TempDescriptor rtmp=readarray[i];
 343             Set<TempFlatPair> tfpset=tmap.get(rtmp);
 344             if (tfpset!=null)
 345               tfset.addAll(tfpset);
 346           }
 347           break;
 348         }
 349         default:
 350           //do nothing
 351         }
 352       }
 353     }
 354     return tfset;
 355   }
 356
 357
 358   //This method generates as output for each node
 359   //A map from from temps to a set of temp/flat pairs that the
 360   //original temp points to
 361   //A temp/flat pair gives the flatnode that the value was created at
 362   //and the original temp
 363
 364   Hashtable<FlatNode, Hashtable<TempDescriptor, Set<TempFlatPair>>> computeTempSets(LocalityBinding lb) {
 365     Hashtable<FlatNode, Hashtable<TempDescriptor, Set<TempFlatPair>>> tmptofnset=new Hashtable<FlatNode, Hashtable<TempDescriptor, Set<TempFlatPair>>>();
 366     HashSet<FlatNode> discovered=new HashSet<FlatNode>();
 367     HashSet<FlatNode> tovisit=new HashSet<FlatNode>();
 368     MethodDescriptor md=lb.getMethod();
 369     FlatMethod fm=state.getMethodFlat(md);
 370     Hashtable<FlatNode, Integer> atomictable=locality.getAtomic(lb);
 371     Hashtable<FlatNode, Set<TempDescriptor>> livetemps=locality.computeLiveTemps(fm);
 372     tovisit.add(fm);
 373     discovered.add(fm);
 374
 375     while(!tovisit.isEmpty()) {
 376       FlatNode fn=tovisit.iterator().next();
 377       tovisit.remove(fn);
 378       for(int i=0;i<fn.numNext();i++) {
 379         FlatNode fnext=fn.getNext(i);
 380         if (!discovered.contains(fnext)) {
 381           discovered.add(fnext);
 382           tovisit.add(fnext);
 383         }
 384       }
 385       Hashtable<TempDescriptor, Set<TempFlatPair>> ttofn=null;
 386       if (atomictable.get(fn).intValue()!=0) {
 387         if ((fn.numPrev()>0)&&atomictable.get(fn.getPrev(0)).intValue()==0) {
 388           //atomic node, start with new set
 389           ttofn=new Hashtable<TempDescriptor, Set<TempFlatPair>>();
 390         } else {
 391           ttofn=doMerge(fn, tmptofnset);
 392           switch(fn.kind()) {
 393           case FKind.FlatGlobalConvNode: {
 394             FlatGlobalConvNode fgcn=(FlatGlobalConvNode)fn;
 395             if (lb==fgcn.getLocality()&&
 396                 fgcn.getMakePtr()) {
 397               TempDescriptor[] writes=fn.writesTemps();
 398               for(int i=0;i<writes.length;i++) {
 399                 TempDescriptor wtmp=writes[i];
 400                 HashSet<TempFlatPair> set=new HashSet<TempFlatPair>();
 401                 set.add(new TempFlatPair(wtmp, fn));
 402                 ttofn.put(wtmp, set);
 403               }
 404             }
 405             break;
 406           }
 407           case FKind.FlatFieldNode:
 408           case FKind.FlatElementNode: {
 409             TempDescriptor[] writes=fn.writesTemps();
 410             for(int i=0;i<writes.length;i++) {
 411               TempDescriptor wtmp=writes[i];
 412               HashSet<TempFlatPair> set=new HashSet<TempFlatPair>();
 413               set.add(new TempFlatPair(wtmp, fn));
 414               ttofn.put(wtmp, set);
 415             }
 416             break;
 417           }
 418           case FKind.FlatCall:
 419           case FKind.FlatMethod: {
 420             TempDescriptor[] writes=fn.writesTemps();
 421             for(int i=0;i<writes.length;i++) {
 422               TempDescriptor wtmp=writes[i];
 423               HashSet<TempFlatPair> set=new HashSet<TempFlatPair>();
 424               set.add(new TempFlatPair(wtmp, fn));
 425               ttofn.put(wtmp, set);
 426             }
 427             break;
 428           }
 429           case FKind.FlatOpNode: {
 430             FlatOpNode fon=(FlatOpNode)fn;
 431             if (fon.getOp().getOp()==Operation.ASSIGN&&fon.getDest().getType().isPtr()&&
 432                 ttofn.containsKey(fon.getLeft())) {
 433               ttofn.put(fon.getDest(), new HashSet<TempFlatPair>(ttofn.get(fon.getLeft())));
 434               break;
 435             }
 436           }
 437           default:
 438             //Do kill computation
 439             TempDescriptor[] writes=fn.writesTemps();
 440             for(int i=0;i<writes.length;i++) {
 441               TempDescriptor wtmp=writes[i];
 442               ttofn.remove(writes[i]);
 443             }
 444           }
 445         }
 446         if (ttofn!=null) {
 447           if (!tmptofnset.containsKey(fn)||
 448               !tmptofnset.get(fn).equals(ttofn)) {
 449             //enqueue nodes to process
 450             tmptofnset.put(fn, ttofn);
 451             for(int i=0;i<fn.numNext();i++) {
 452               FlatNode fnext=fn.getNext(i);
 453               tovisit.add(fnext);
 454             }
 455           }
 456         }
 457       }
 458     }
 459     return tmptofnset;
 460   }
 461
 462   /* See what fields and arrays transactions might modify.  We only
 463    * look at changes to old objects. */
 464
 465   public void computeModified(LocalityBinding lb) {
 466     MethodDescriptor md=lb.getMethod();
 467     FlatMethod fm=state.getMethodFlat(md);
 468     Hashtable<FlatNode, Set<TempDescriptor>> oldtemps=computeOldTemps(lb);
 469     for(Iterator<FlatNode> fnit=fm.getNodeSet().iterator();fnit.hasNext();) {
 470       FlatNode fn=fnit.next();
 471       Hashtable<FlatNode, Integer> atomictable=locality.getAtomic(lb);
 472       if (atomictable.get(fn).intValue()>0) {
 473         switch (fn.kind()) {
 474         case FKind.FlatSetFieldNode:
 475           FlatSetFieldNode fsfn=(FlatSetFieldNode) fn;
 476           fields.add(fsfn.getField());
 477           break;
 478         case FKind.FlatSetElementNode:
 479           FlatSetElementNode fsen=(FlatSetElementNode) fn;
 480           arrays.add(fsen.getDst().getType());
 481           break;
 482         default:
 483         }
 484       }
 485     }
 486   }
 487
 488
 489   //Returns a table that maps a flatnode to a set of temporaries
 490   //This set of temporaries is old (meaning they may point to object
 491   //allocated before the beginning of the current transaction
 492
 493   Hashtable<FlatNode, Set<TempDescriptor>> computeOldTemps(LocalityBinding lb) {
 494     Hashtable<FlatNode, Set<TempDescriptor>> fntooldtmp=new Hashtable<FlatNode, Set<TempDescriptor>>();
 495     HashSet<FlatNode> discovered=new HashSet<FlatNode>();
 496     HashSet<FlatNode> tovisit=new HashSet<FlatNode>();
 497     MethodDescriptor md=lb.getMethod();
 498     FlatMethod fm=state.getMethodFlat(md);
 499     Hashtable<FlatNode, Integer> atomictable=locality.getAtomic(lb);
 500     Hashtable<FlatNode, Set<TempDescriptor>> livetemps=locality.computeLiveTemps(fm);
 501     tovisit.add(fm);
 502     discovered.add(fm);
 503
 504     while(!tovisit.isEmpty()) {
 505       FlatNode fn=tovisit.iterator().next();
 506       tovisit.remove(fn);
 507       for(int i=0;i<fn.numNext();i++) {
 508         FlatNode fnext=fn.getNext(i);
 509         if (!discovered.contains(fnext)) {
 510           discovered.add(fnext);
 511           tovisit.add(fnext);
 512         }
 513       }
 514       HashSet<TempDescriptor> oldtemps=null;
 515       if (atomictable.get(fn).intValue()!=0) {
 516         if ((fn.numPrev()>0)&&atomictable.get(fn.getPrev(0)).intValue()==0) {
 517           //Everything live is old
 518           Set<TempDescriptor> lives=livetemps.get(fn);
 519           oldtemps=new HashSet<TempDescriptor>();
 520
 521           for(Iterator<TempDescriptor> it=lives.iterator();it.hasNext();) {
 522             TempDescriptor tmp=it.next();
 523             if (tmp.getType().isPtr()) {
 524               oldtemps.add(tmp);
 525             }
 526           }
 527         } else {
 528           oldtemps=new HashSet<TempDescriptor>();
 529           //Compute union of old temporaries
 530           for(int i=0;i<fn.numPrev();i++) {
 531             Set<TempDescriptor> pset=fntooldtmp.get(fn.getPrev(i));
 532             if (pset!=null)
 533               oldtemps.addAll(pset);
 534           }
 535
 536           switch (fn.kind()) {
 537           case FKind.FlatNew:
 538             oldtemps.removeAll(Arrays.asList(fn.readsTemps()));
 539             break;
 540           case FKind.FlatOpNode: {
 541             FlatOpNode fon=(FlatOpNode)fn;
 542             if (fon.getOp().getOp()==Operation.ASSIGN&&fon.getDest().getType().isPtr()) {
 543               if (oldtemps.contains(fon.getLeft()))
 544                 oldtemps.add(fon.getDest());
 545               else
 546                 oldtemps.remove(fon.getDest());
 547               break;
 548             }
 549           }
 550           default: {
 551             TempDescriptor[] writes=fn.writesTemps();
 552             for(int i=0;i<writes.length;i++) {
 553               TempDescriptor wtemp=writes[i];
 554               if (wtemp.getType().isPtr())
 555                 oldtemps.add(wtemp);
 556             }
 557           }
 558           }
 559         }
 560       }
 561
 562       if (oldtemps!=null) {
 563         if (!fntooldtmp.containsKey(fn)||!fntooldtmp.get(fn).equals(oldtemps)) {
 564           fntooldtmp.put(fn, oldtemps);
 565           //propagate changes
 566           for(int i=0;i<fn.numNext();i++) {
 567             FlatNode fnext=fn.getNext(i);
 568             tovisit.add(fnext);
 569           }
 570         }
 571       }
 572     }
 573     return fntooldtmp;
 574   }
 575 }
 576
 577 class TempFlatPair {
 578     FlatNode f;
 579     TempDescriptor t;
 580     TempFlatPair(TempDescriptor t, FlatNode f) {
 581         this.t=t;
 582         this.f=f;
 583     }
 584
 585     public int hashCode() {
 586         return f.hashCode()^t.hashCode();
 587     }
 588     public boolean equals(Object o) {
 589         TempFlatPair tf=(TempFlatPair)o;
 590         return t.equals(tf.t)&&f.equals(tf.f);
 591     }
 592 }