/* Soot - a J*va Optimization Framework
* Copyright (C) 1997-1999 Raja Vallee-Rai
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the Sable Research Group and others 1997-1999.
* See the 'credits' file distributed with Soot for the complete list of
* contributors. (Soot is distributed at http://www.sable.mcgill.ca/soot)
*/
package soot.toolkits.scalar;
import soot.*;
import soot.toolkits.graph.*;
import soot.util.*;
import java.util.*;
/** Provides methods for register coloring. Jimple uses these methods
* to assign the local slots appropriately. */
public class FastColorer
{
/** Provides a coloring for the locals of
* <code>unitBody</code>, attempting to not
* split locals assigned the same name in the original Jimple. */
public static void unsplitAssignColorsToLocals(Body unitBody,
Map<Local, Object> localToGroup,
Map<Local, Integer> localToColor,
Map<Object, Integer> groupToColorCount)
{
ExceptionalUnitGraph unitGraph = new ExceptionalUnitGraph(unitBody);
LiveLocals liveLocals;
liveLocals = new SimpleLiveLocals(unitGraph);
UnitInterferenceGraph intGraph =
new UnitInterferenceGraph(unitBody, localToGroup, liveLocals);
Map<Local, String> localToOriginalName = new HashMap<Local, String>();
// Map each local variable to its original name
{
Iterator localIt = intGraph.getLocals().iterator();
while(localIt.hasNext())
{
Local local = (Local) localIt.next();
int signIndex;
signIndex = local.getName().indexOf("#");
if(signIndex != -1)
{
localToOriginalName.put(local,
local.getName().substring(0, signIndex));
}
else
localToOriginalName.put(local, local.getName());
}
}
Map<StringGroupPair, List> originalNameAndGroupToColors = new HashMap<StringGroupPair, List>();
// maps an original name to the colors being used for it
// Assign a color for each local.
{
int[] freeColors = new int[10];
Iterator localIt = intGraph.getLocals().iterator();
while(localIt.hasNext())
{
Local local = (Local) localIt.next();
if(localToColor.containsKey(local))
{
// Already assigned, probably a parameter
continue;
}
Object group = localToGroup.get(local);
int colorCount =
groupToColorCount.get(group).intValue();
if(freeColors.length < colorCount)
freeColors =
new int[Math.max(freeColors.length * 2, colorCount)];
// Set all colors to free.
{
for(int i= 0; i < colorCount; i++)
freeColors[i] = 1;
}
// Remove unavailable colors for this local
{
Local[] interferences =
intGraph.getInterferencesOf(local);
for (Local element : interferences) {
if(localToColor.containsKey(element))
{
int usedColor =
localToColor.get(element)
.intValue();
freeColors[usedColor] = 0;
}
}
}
// Assign a color to this local.
{
String originalName =
localToOriginalName.get(local);
List<Integer> originalNameColors =
originalNameAndGroupToColors.get
(new StringGroupPair(originalName, group));
if(originalNameColors == null)
{
originalNameColors = new ArrayList<Integer>();
originalNameAndGroupToColors.put
(new StringGroupPair(originalName, group),
originalNameColors);
}
boolean found = false;
int assignedColor = 0;
// Check if the colors assigned to this
// original name is already free
{
Iterator<Integer> colorIt = originalNameColors.iterator();
while(colorIt.hasNext())
{
Integer color = colorIt.next();
if(freeColors[color.intValue()] == 1)
{
found = true;
assignedColor = color.intValue();
}
}
}
if(!found)
{
assignedColor = colorCount++;
groupToColorCount.put(group, new Integer(colorCount));
originalNameColors.add(new Integer(assignedColor));
}
localToColor.put(local, new Integer(assignedColor));
}
}
}
}
/** Provides an economical coloring for the locals of
* <code>unitBody</code>. */
public static void assignColorsToLocals(Body unitBody, Map<Local, Object> localToGroup,
Map<Local, Integer> localToColor, Map<Object, Integer> groupToColorCount)
{
ExceptionalUnitGraph unitGraph = new ExceptionalUnitGraph(unitBody);
LiveLocals liveLocals;
liveLocals = new SimpleLiveLocals(unitGraph);
UnitInterferenceGraph intGraph =
new UnitInterferenceGraph(unitBody, localToGroup, liveLocals);
// Assign a color for each local.
{
int[] freeColors = new int[10];
Iterator localIt = intGraph.getLocals().iterator();
while(localIt.hasNext())
{
Local local = (Local) localIt.next();
if(localToColor.containsKey(local))
{
// Already assigned, probably a parameter
continue;
}
Object group = localToGroup.get(local);
int colorCount =
groupToColorCount.get(group).intValue();
if(freeColors.length < colorCount)
freeColors = new int[Math.max(freeColors.length * 2,
colorCount)];
// Set all colors to free.
{
for(int i= 0; i < colorCount; i++)
freeColors[i] = 1;
}
// Remove unavailable colors for this local
{
Local[] interferences =
intGraph.getInterferencesOf(local);
for (Local element : interferences) {
if(localToColor.containsKey(element))
{
int usedColor =
localToColor.
get(element).intValue();
freeColors[usedColor] = 0;
}
}
}
// Assign a color to this local.
{
boolean found = false;
int assignedColor = 0;
for(int i = 0; i < colorCount; i++)
if(freeColors[i] == 1)
{
found = true;
assignedColor = i;
}
if(!found)
{
assignedColor = colorCount++;
groupToColorCount.put(group, new Integer(colorCount));
}
localToColor.put(local, new Integer(assignedColor));
}
}
}
}
/** Implementation of a unit interference graph. */
public static class UnitInterferenceGraph
{
Map<Local, ArraySet> localToLocals;// Maps a local to its interfering locals.
List locals;
private UnitInterferenceGraph()
{
}
public List getLocals()
{
return locals;
}
public UnitInterferenceGraph(Body body, Map<Local, Object> localToGroup,
LiveLocals liveLocals)
{
locals = new ArrayList();
locals.addAll(body.getLocals());
// Initialize localToLocals
{
localToLocals = new HashMap<Local, ArraySet>(body.getLocalCount() * 2 + 1,
0.7f);
Iterator localIt = body.getLocals().iterator();
while(localIt.hasNext())
{
Local local = (Local) localIt.next();
localToLocals.put(local, new ArraySet());
}
}
// Go through code, noting interferences
{
Iterator codeIt = body.getUnits().iterator();
while(codeIt.hasNext())
{
Unit unit = (Unit) codeIt.next();
List liveLocalsAtUnit =
liveLocals.getLiveLocalsAfter(unit);
// Note interferences if this stmt is a definition
{
List defBoxes = unit.getDefBoxes();
if(!defBoxes.isEmpty()) {
if(!(defBoxes.size() ==1))
throw new RuntimeException
("invalid number of def boxes");
if(((ValueBox)defBoxes.get(0)).getValue()
instanceof Local)
{
Local defLocal = (Local) ((ValueBox)defBoxes.get(0)).getValue();
Iterator localIt = liveLocalsAtUnit.iterator();
while(localIt.hasNext())
{
Local otherLocal = (Local) localIt.next();
if(localToGroup.get(otherLocal)
.equals(localToGroup.get(defLocal)))
setInterference(defLocal, otherLocal);
}
}
}
}
}
}
}
public boolean localsInterfere(Local l1, Local l2)
{
return localToLocals.get(l1).contains(l2);
}
public void setInterference(Local l1, Local l2)
{
localToLocals.get(l1).add(l2);
localToLocals.get(l2).add(l1);
}
public boolean isEmpty()
{
return localToLocals.isEmpty();
}
Local[] getInterferencesOf(Local l)
{
Object[] objects = localToLocals.get(l).toArray();
Local[] locals = new Local[objects.length];
for(int i = 0; i < objects.length; i++)
locals[i] = (Local) objects[i];
return locals;
}
}
}
/** Binds together a String and a Group. */
class StringGroupPair
{
String string;
Object group;
public StringGroupPair(String s, Object g)
{
string = s;
group = g;
}
public boolean equals(Object p)
{
if(p instanceof StringGroupPair)
{
return ((StringGroupPair) p).string.equals(this.string) &&
((StringGroupPair) p).group.equals(this.group);
}
return false;
}
public int hashCode()
{
return string.hashCode() * 101 + group.hashCode() + 17;
}
}