RevisterAlloc Fixed expired intervals not removed from active

1 files changed, 57 insertions, 48 deletions

diff --git a/vaporize/RegisterAlloc.java b/vaporize/RegisterAlloc.java
index 4b956d0..ae5826b 100644
--- a/vaporize/RegisterAlloc.java
+++ b/vaporize/RegisterAlloc.java
@@ -9,63 +9,72 @@ public class RegisterAlloc {
     private String[] all_registers;
     private Stack<String> free_registers;
     private TreeSet<LIRVar> active;
-    
+
     public RegisterAlloc(LIRDict intervals, String[] all_registers) {
-	this.intervals = intervals;
-	this.all_registers = all_registers;
-	this.free_registers = new Stack<String>();
-	this.free_registers.addAll(Arrays.asList(this.all_registers));
-	this.active = new TreeSet<LIRVar>((v1, v2) -> {
-		int ret;
-		if (v1.getLastUse() > v2.getLastUse())
-		    ret = 1;
-		else if (v1.getLastUse() < v2.getLastUse())
-		    ret = -1;
-		else if (v1.equals(v2))
-		    ret = 0;
-		else
-		    ret = 1;
-		return ret;
-	});
+        this.intervals = intervals;
+        this.all_registers = all_registers;
+        this.free_registers = new Stack<String>();
+        this.free_registers.addAll(Arrays.asList(this.all_registers));
+        this.active = new TreeSet<LIRVar>((v1, v2) -> {
+                int ret;
+                if (v1.getLastUse() > v2.getLastUse())
+                    ret = 1;
+                else if (v1.getLastUse() < v2.getLastUse())
+                    ret = -1;
+                else if (v1.equals(v2))
+                    ret = 0;
+                else
+                    ret = 1;
+                return ret;
+        });
 
-	MinimalLogger.info(String.format("Starting allocation with registers %s",
-					 this.free_registers.toString()));
+        MinimalLogger.info(String.format("Starting allocation with registers %s",
+                                         this.free_registers.toString()));
 
-	String register;
-	for (LIRVar interval : this.intervals.getIntervals()) {
-	    this.expireOldIntervals(interval);
-	    if (this.active.size() >= this.all_registers.length)
-		this.spillAtInterval(interval);
-	    else {
-		register = this.free_registers.pop();
-		interval.assignRegister(register);
-		this.active.add(interval);
-		MinimalLogger.info(String.format("Assigning register %s to %s.",
-						 register,
-						 interval.toString()));
+        String register;
+        for (LIRVar interval : this.intervals.getIntervals()) {
+            this.expireOldIntervals(interval);
+            if (this.active.size() >= this.all_registers.length)
+                this.spillAtInterval(interval);
+            else {
+                register = this.free_registers.pop();
+                interval.assignRegister(register);
+                this.active.add(interval);
+                MinimalLogger.info(String.format("Assigning register %s to %s.",
+                                                 register,
+                                                 interval.toString()));
 
-	    }
-	}
+            }
+        }
     }
 
     private void expireOldIntervals(LIRVar interval) {
-	for (LIRVar active : new TreeSet<LIRVar>(this.active)) {
-	    if (active.getLastUse() >= interval.getFirstDef())
-		return;
-	    MinimalLogger.info("Register " + active.getAssignedRegister() + " expired!");
-	    this.active.remove(active);
-	    this.free_registers.push(active.getAssignedRegister());
-	}
+        // MinimalLogger.info(String.format("Active: %s",
+        //                                  this.active.toString()));
+        // MinimalLogger.info(String.format("Available: %s",
+        //                                  this.free_registers.toString()));
+
+        Iterator<LIRVar> iterator = this.active.iterator();
+        while (iterator.hasNext()) {
+            LIRVar active = iterator.next();
+            if (active.getLastUse() >= interval.getFirstDef())
+                return;
+            MinimalLogger.info(String.format("%s register %s expired!",
+                                             active.toString(),
+                                             active.getAssignedRegister()));
+            iterator.remove(); // Remove the element from the original active set
+            this.free_registers.push(active.getAssignedRegister());
+        }
     }
 
     private void spillAtInterval(LIRVar interval) {
-	MinimalLogger.severe(String.format("Ran out of free registers, but a spill for %s was not performed!",
-					   interval.toString()));
-	this.intervals.addSpilledNum();
-	// LIRVar spill = this.active.get(this.active.length()-1);
-	// if (spill.getLastUse() > interval.getLastUse()) {
-	//     ;
-	// }
+        MinimalLogger.severe(String.format("Ran out of free registers, but a spill for %s was not performed!",
+                                           interval.toString()));
+        this.intervals.addSpilledNum();
+        // LIRVar spill = this.active.get(this.active.length()-1);
+        // if (spill.getLastUse() > interval.getLastUse()) {
+        //     ;
+        // }
     }
-    
+
 }