[rvm-commits] SF.net SVN: jikesrvm:[15893] rvmroot/branches/RVM-RegAlloc-ELS/trunk/rvm/ src/org/jikesrvm/compilers/opt/regalloc/LinearScan.java

[<eri...@us...>]

Revision: 15893
          http://jikesrvm.svn.sourceforge.net/jikesrvm/?rev=15893&view=rev
Author:   eris2006
Date:     2010-07-10 09:15:14 +0000 (Sat, 10 Jul 2010)

Log Message:
-----------
Added method getContainer() to interface Interval so as to do away with instanceof tests

Modified Paths:
--------------
    rvmroot/branches/RVM-RegAlloc-ELS/trunk/rvm/src/org/jikesrvm/compilers/opt/regalloc/LinearScan.java

Modified: rvmroot/branches/RVM-RegAlloc-ELS/trunk/rvm/src/org/jikesrvm/compilers/opt/regalloc/LinearScan.java
===================================================================
--- rvmroot/branches/RVM-RegAlloc-ELS/trunk/rvm/src/org/jikesrvm/compilers/opt/regalloc/LinearScan.java	2010-07-10 09:13:03 UTC (rev 15892)
+++ rvmroot/branches/RVM-RegAlloc-ELS/trunk/rvm/src/org/jikesrvm/compilers/opt/regalloc/LinearScan.java	2010-07-10 09:15:14 UTC (rev 15893)
@@ -348,6 +348,20 @@
 	  public  Interval getInterval();
 	  public  Interval getInterval(int start, int end);
 	  public  Interval getInterval(int programpoint);
+	  /*
+	   * For CompoundInterval following will return the CompoundInterval itself.
+	   * for BasicInterval this will return the CompoundInterval which contains this.
+	   * This is basically provided to avoid the instanceof test on the Interval data types.
+	   * Instead check if the getContainer() equals getInterval().
+	   * If yes then it means we are using the CompoundInterval for allocation and hence Interval represents
+	   * CompoundInterval else we are doing allocation at BasicInterval level and Interval
+	   * represents the BasicInterval.
+	   * Is the instanceof test lighter than the  above comparison policy ?
+	   * With the above test we are also avoiding importing CompounInterval to many class files.
+	   *
+	   */
+	  public  Interval getContainer();
+	  public boolean intersects(Interval cmp);
   }
   /**
    * Implements a basic live interval (no holes), which is a pair
@@ -356,7 +370,7 @@
    *
    *   Begin and end are numbers given to each instruction by a numbering pass
    */
-  public static class BasicInterval  {
+  public static class BasicInterval {
 	
     /**
      * DFN of the beginning instruction of this interval
@@ -534,13 +548,6 @@
     public String toString() {
       return "<" + container.getRegister() + ">:" + super.toString();
     }
-  
-    /* 
-     * Return the physical register assigned to this interval
-     */
-    Register getAssignment() {
-      return RegisterAllocatorState.getMapping(container.getRegister(), this);
-    }
 
 	@Override
 	public Interval getInterval(int start, int finish) {
@@ -560,6 +567,18 @@
 			return null;
 	}
 
+	@Override
+	public Interval getContainer() {
+		// TODO Auto-generated method stub
+		return container;
+	}
+
+	@Override
+	public boolean intersects(Interval cmp) {
+		// TODO Auto-generated method stub
+		return false;
+	}
+
   }
 
   /**
@@ -599,7 +618,7 @@
     public Interval getInterval(int start,int end){
     	Interval result = null;
     	Interval i = ((MappedBasicInterval)first()).getInterval();
-    	if (i instanceof CompoundInterval) {
+    	if (i.getContainer().equals(i.getInterval())) {
     	  return i;
     	}
     	else {
@@ -620,7 +639,7 @@
     public Interval getInterval(int programpoint){
     	Interval result = null;
     	Interval i = ((MappedBasicInterval)first()).getInterval();
-    	if(i instanceof CompoundInterval){
+    	if(i.getContainer().equals(i.getInterval())){
     		result=i;
     	}
     	else{
@@ -999,6 +1018,18 @@
 		// TODO Auto-generated method stub
 		return this;
 	}
+
+	@Override
+	public Interval getContainer() {
+		// TODO Auto-generated method stub
+		return this;
+	}
+
+	@Override
+	public boolean intersects(Interval cmp) {
+		// TODO Auto-generated method stub
+		return intersects((CompoundInterval) cmp);
+	}
   }
 
   /**


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