improve propagation optimization

diff --git a/Robust/src/Analysis/Loops/CopyPropagation.java b/Robust/src/Analysis/Loops/CopyPropagation.java
index e151f82a99be54db1ebd2063b3f3ebfd48157f1d..9d211cf96b212778b63eb8d350363ae1378176da 100644 (file)
--- a/Robust/src/Analysis/Loops/CopyPropagation.java
+++ b/Robust/src/Analysis/Loops/CopyPropagation.java
@@ -18,44 +18,46 @@ public class CopyPropagation {
     do {
       changed=false;
       HashSet tovisit=new HashSet();
-      HashSet discovered=new HashSet();
       tovisit.add(fm);
-      discovered.add(fm);
       while(!tovisit.isEmpty()) {
        FlatNode fn=(FlatNode) tovisit.iterator().next();
        tovisit.remove(fn);
-       for(int i=0;i<fn.numNext();i++) {
-         FlatNode nnext=fn.getNext(i);
-         if (!discovered.contains(nnext)) {
-           discovered.add(nnext);
-           tovisit.add(nnext);
-         }
-       }
+
        Hashtable<TempDescriptor, TempDescriptor> tab;
        if (fn.numPrev()>=1&&table.containsKey(fn.getPrev(0)))
          tab=new Hashtable<TempDescriptor, TempDescriptor>(table.get(fn.getPrev(0)));
        else
          tab=new Hashtable<TempDescriptor, TempDescriptor>();
        //Compute intersection
+
+       HashSet<TempDescriptor> toremove=new HashSet<TempDescriptor>();
        for(int i=1;i<fn.numPrev();i++) {
          Hashtable<TempDescriptor, TempDescriptor> tp=table.get(fn.getPrev(i));
          for(Iterator tmpit=tab.entrySet().iterator();tmpit.hasNext();) {
            Map.Entry t=(Map.Entry)tmpit.next();
            TempDescriptor tmp=(TempDescriptor)t.getKey();
-           if (tp!=null&&(!tp.containsKey(tmp)||tp.get(tmp)!=tab.get(tmp))) {
-             tmpit.remove();
+           if (tp!=null&&tp.containsKey(tmp)&&tp.get(tmp)!=tab.get(tmp)) {
+             toremove.add(tmp);
            }
          }
        }
+
        TempDescriptor[]writes=fn.writesTemps();
        for(int i=0;i<writes.length;i++) {
          TempDescriptor tmp=writes[i];
+         toremove.add(tmp);
          for(Iterator<TempDescriptor> tmpit=tab.keySet().iterator();tmpit.hasNext();) {        
            TempDescriptor tmp2=tmpit.next();
            if (tmp==tab.get(tmp2))
-             tmpit.remove();
+             toremove.add(tmp2);
          }
        }
+
+       for(Iterator<TempDescriptor> tmpit=toremove.iterator();tmpit.hasNext();) {
+         TempDescriptor tmp=tmpit.next();
+         tab.put(tmp, bogustd);
+       }
+
        if (fn.kind()==FKind.FlatOpNode) {
          FlatOpNode fon=(FlatOpNode)fn;
          if (fon.getOp().getOp()==Operation.ASSIGN) {
@@ -70,7 +72,9 @@ public class CopyPropagation {
            tovisit.add(nnext);
          }
        }
-      }
+      } //end of dataflow while loop
+
+      //do remapping step here
       for(Iterator<FlatNode> it=fm.getNodeSet().iterator();it.hasNext();) {
        FlatNode fn=it.next();
        Hashtable<TempDescriptor, TempDescriptor> tab=table.get(fn);
@@ -78,7 +82,7 @@ public class CopyPropagation {
        TempDescriptor[]reads=fn.readsTemps();
        for(int i=0;i<reads.length;i++) {
          TempDescriptor tmp=reads[i];
-         if (tab.containsKey(tmp)) {
+         if (tab.containsKey(tmp)&&tab.get(tmp)!=bogustd) {
            if (tmap==null)
              tmap=new TempMap();
            tmap.addPair(tmp, tab.get(tmp));
@@ -86,7 +90,7 @@ public class CopyPropagation {
        }
        if (tmap!=null)
          fn.rewriteUse(tmap);
-      }
+      } //end of remapping for loop
     } while(changed);
   }
 }
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