Move liveness analysis into its own class

diff --git a/Robust/src/Analysis/Liveness.java b/Robust/src/Analysis/Liveness.java
new file mode 100644 (file)
index 0000000..6fe3a67
--- /dev/null
+++ b/Robust/src/Analysis/Liveness.java
@@ -0,0 +1,44 @@
+package Analysis;
+
+import IR.Flat.*;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.List;
+import java.util.Hashtable;
+
+public class Liveness {
+  /* This methods takes in a FlatMethod and returns a map from a
+   * FlatNode to the set of live temps for that FlatNode.*/
+
+  public static Hashtable<FlatNode, Set<TempDescriptor>> computeLiveTemps(FlatMethod fm) {
+    Hashtable<FlatNode, Set<TempDescriptor>> nodetotemps=new Hashtable<FlatNode, Set<TempDescriptor>>();
+    
+    Set<FlatNode> toprocess=fm.getNodeSet();
+    
+    while(!toprocess.isEmpty()) {
+      FlatNode fn=toprocess.iterator().next();
+      toprocess.remove(fn);
+      
+      List<TempDescriptor> reads=Arrays.asList(fn.readsTemps());
+      List<TempDescriptor> writes=Arrays.asList(fn.writesTemps());
+      
+      HashSet<TempDescriptor> tempset=new HashSet<TempDescriptor>();
+      for(int i=0; i<fn.numNext(); i++) {
+       FlatNode fnnext=fn.getNext(i);
+       if (nodetotemps.containsKey(fnnext))
+         tempset.addAll(nodetotemps.get(fnnext));
+      }
+      tempset.removeAll(writes);
+      tempset.addAll(reads);
+      if (!nodetotemps.containsKey(fn)||
+          !nodetotemps.get(fn).equals(tempset)) {
+       nodetotemps.put(fn, tempset);
+       for(int i=0; i<fn.numPrev(); i++)
+         toprocess.add(fn.getPrev(i));
+      }
+    }
+    return nodetotemps;
+  }
+  
+}
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