Propagating variable name via compiler's pipeline

classlib/src/main/java/org/teavm/classlib/java/lang/reflect/TArray.java

@@ -49,7 +49,7 @@ public final class TArray extends TObject {
 
     @SuppressWarnings("unused")
     private static RuntimeObject newInstanceLowLevel(RuntimeClass cls, int length) {
-        return Allocator.allocateArray(cls, length).toStructure();
+        return Allocator.allocateArray(cls.arrayType, length).toStructure();
     }
 
     public static TObject get(TObject array, int index) throws TIllegalArgumentException,

core/src/main/java/org/teavm/ast/AssignmentStatement.java

@@ -15,15 +15,12 @@
  */
 package org.teavm.ast;
 
-import java.util.HashSet;
-import java.util.Set;
 import org.teavm.model.TextLocation;
 
 public class AssignmentStatement extends Statement {
     private Expr leftValue;
     private Expr rightValue;
     private TextLocation location;
-    private Set<String> debugNames = new HashSet<>();
     private boolean async;
 
     public Expr getLeftValue() {
@@ -50,10 +47,6 @@ public class AssignmentStatement extends Statement {
         this.location = location;
     }
 
-    public Set<String> getDebugNames() {
-        return debugNames;
-    }
-
     public boolean isAsync() {
         return async;
     }

core/src/main/java/org/teavm/ast/AsyncMethodNode.java

@@ -17,8 +17,6 @@ package org.teavm.ast;
 
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Set;
-import java.util.stream.Collectors;
 import org.teavm.model.MethodReference;
 
 public class AsyncMethodNode extends MethodNode {
@@ -33,19 +31,11 @@ public class AsyncMethodNode extends MethodNode {
         return body;
     }
 
+    @Override
     public List<VariableNode> getVariables() {
         return variables;
     }
 
-    @Override
-    public List<Set<String>> getParameterDebugNames() {
-        return variables.subList(0, getReference().parameterCount())
-                .stream()
-                .map(VariableNode::getDebugNames)
-                .collect(Collectors.toList());
-    }
-
-
     @Override
     public void acceptVisitor(MethodNodeVisitor visitor) {
         visitor.visit(this);

core/src/main/java/org/teavm/ast/MethodNode.java

@@ -42,5 +42,5 @@ public abstract class MethodNode {
 
     public abstract boolean isAsync();
 
-    public abstract List<Set<String>> getParameterDebugNames();
+    public abstract List<VariableNode> getVariables();
 }

core/src/main/java/org/teavm/ast/NativeMethodNode.java

@@ -17,7 +17,6 @@ package org.teavm.ast;
 
 import java.util.Collections;
 import java.util.List;
-import java.util.Set;
 import org.teavm.backend.javascript.spi.Generator;
 import org.teavm.model.MethodReference;
 
@@ -52,7 +51,7 @@ public class NativeMethodNode extends MethodNode {
     }
 
     @Override
-    public List<Set<String>> getParameterDebugNames() {
+    public List<VariableNode> getVariables() {
         return Collections.emptyList();
     }
 }

core/src/main/java/org/teavm/ast/RegularMethodNode.java

@@ -17,8 +17,6 @@ package org.teavm.ast;
 
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Set;
-import java.util.stream.Collectors;
 import org.teavm.model.MethodReference;
 
 public class RegularMethodNode extends MethodNode {
@@ -37,18 +35,11 @@ public class RegularMethodNode extends MethodNode {
         this.body = body;
     }
 
+    @Override
     public List<VariableNode> getVariables() {
         return variables;
     }
 
-    @Override
-    public List<Set<String>> getParameterDebugNames() {
-        return variables.subList(0, getReference().parameterCount())
-                .stream()
-                .map(VariableNode::getDebugNames)
-                .collect(Collectors.toList());
-    }
-
     @Override
     public void acceptVisitor(MethodNodeVisitor visitor) {
         visitor.visit(this);

core/src/main/java/org/teavm/ast/VariableNode.java

@@ -15,14 +15,12 @@
  */
 package org.teavm.ast;
 
-import java.util.HashSet;
-import java.util.Set;
 import org.teavm.model.util.VariableType;
 
 public class VariableNode {
     private int index;
     private VariableType type;
-    private Set<String> debugNames = new HashSet<>();
+    private String name;
 
     public VariableNode(int index, VariableType type) {
         this.index = index;
@@ -45,7 +43,11 @@ public class VariableNode {
         this.type = type;
     }
 
-    public Set<String> getDebugNames() {
+    public String getName() {
-        return debugNames;
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
     }
 }

core/src/main/java/org/teavm/ast/decompilation/Decompiler.java

@@ -65,7 +65,6 @@ import org.teavm.model.Program;
 import org.teavm.model.TextLocation;
 import org.teavm.model.TryCatchBlock;
 import org.teavm.model.ValueType;
-import org.teavm.model.Variable;
 import org.teavm.model.util.AsyncProgramSplitter;
 import org.teavm.model.util.ListingBuilder;
 import org.teavm.model.util.ProgramUtils;
@@ -271,17 +270,14 @@ public class Decompiler {
         typeInferer.inferTypes(program, method.getReference());
         for (int i = 0; i < program.variableCount(); ++i) {
             VariableNode variable = new VariableNode(program.variableAt(i).getRegister(), typeInferer.typeOf(i));
+            variable.setName(program.variableAt(i).getDebugName());
             methodNode.getVariables().add(variable);
         }
 
         Optimizer optimizer = new Optimizer();
         optimizer.optimize(methodNode, method.getProgram());
         methodNode.getModifiers().addAll(method.getModifiers());
-        int paramCount = Math.min(method.getSignature().length, program.variableCount());
+
-        for (int i = 0; i < paramCount; ++i) {
-            Variable var = program.variableAt(i);
-            methodNode.getParameterDebugNames().add(new HashSet<>(var.getDebugNames()));
-        }
         return methodNode;
     }
 
@@ -338,17 +334,14 @@ public class Decompiler {
         typeInferer.inferTypes(program, method.getReference());
         for (int i = 0; i < program.variableCount(); ++i) {
             VariableNode variable = new VariableNode(program.variableAt(i).getRegister(), typeInferer.typeOf(i));
+            variable.setName(program.variableAt(i).getDebugName());
             node.getVariables().add(variable);
         }
 
         Optimizer optimizer = new Optimizer();
         optimizer.optimize(node, splitter);
         node.getModifiers().addAll(method.getModifiers());
-        int paramCount = Math.min(method.getSignature().length, program.variableCount());
+
-        for (int i = 0; i < paramCount; ++i) {
-            Variable var = program.variableAt(i);
-            node.getParameterDebugNames().add(new HashSet<>(var.getDebugNames()));
-        }
         return node;
     }
 

core/src/main/java/org/teavm/ast/decompilation/StatementGenerator.java

@@ -202,7 +202,6 @@ class StatementGenerator implements InstructionVisitor {
     public void visit(AssignInstruction insn) {
         AssignmentStatement stmt = Statement.assign(Expr.var(insn.getReceiver().getIndex()),
                 Expr.var(insn.getAssignee().getIndex()));
-        stmt.getDebugNames().addAll(insn.getReceiver().getDebugNames());
         stmt.setLocation(currentLocation);
         statements.add(stmt);
     }
@@ -500,7 +499,6 @@ class StatementGenerator implements InstructionVisitor {
         AssignmentStatement stmt;
         if (insn.getReceiver() != null) {
             stmt = Statement.assign(Expr.var(insn.getReceiver().getIndex()), invocationExpr);
-            stmt.getDebugNames().addAll(insn.getReceiver().getDebugNames());
         } else {
             stmt = Statement.assign(null, invocationExpr);
         }
@@ -523,7 +521,6 @@ class StatementGenerator implements InstructionVisitor {
     private void assign(Expr source, Variable target) {
         AssignmentStatement stmt = Statement.assign(Expr.var(target.getIndex()), source);
         stmt.setLocation(currentLocation);
-        stmt.getDebugNames().addAll(target.getDebugNames());
         statements.add(stmt);
     }
 

core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java

@@ -126,8 +126,8 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
     private boolean async;
     private Precedence precedence;
     private final Map<String, String> blockIdMap = new HashMap<>();
-    private final List<Set<String>> debugNames = new ArrayList<>();
     private final List<String> cachedVariableNames = new ArrayList<>();
+    private MethodNode currentMethod;
     private boolean end;
     private int currentPart;
     private List<PostponedFieldInitializer> postponedFieldInitializers = new ArrayList<>();
@@ -652,9 +652,8 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
     }
 
     private void renderBody(MethodNode method, boolean inner) throws IOException {
-        debugNames.clear();
+        currentMethod = method;
         cachedVariableNames.clear();
-        debugNames.addAll(method.getParameterDebugNames());
         blockIdMap.clear();
         MethodReference ref = method.getReference();
         debugEmitter.emitMethod(ref.getDescriptor());
@@ -704,8 +703,8 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
                 Renderer.this.async = false;
                 this.async = false;
                 MethodReference ref = method.getReference();
-                for (int i = 0; i < method.getParameterDebugNames().size(); ++i) {
+                for (int i = 0; i < method.getVariables().size(); ++i) {
-                    debugEmitter.emitVariable(method.getParameterDebugNames().get(i).toArray(new String[0]),
+                    debugEmitter.emitVariable(new String[] { method.getVariables().get(i).getName() },
                             variableName(i));
                 }
 
@@ -748,8 +747,8 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
                 Renderer.this.async = true;
                 this.async = true;
                 MethodReference ref = methodNode.getReference();
-                for (int i = 0; i < methodNode.getParameterDebugNames().size(); ++i) {
+                for (int i = 0; i < methodNode.getVariables().size(); ++i) {
-                    debugEmitter.emitVariable(methodNode.getParameterDebugNames().get(i).toArray(new String[0]),
+                    debugEmitter.emitVariable(new String[] { methodNode.getVariables().get(i).getName() },
                             variableName(i));
                 }
                 int variableCount = 0;
@@ -967,11 +966,6 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
             if (statement.getLocation() != null) {
                 popLocation();
             }
-            if (statement.getLeftValue() instanceof VariableExpr) {
-                VariableExpr receiver = (VariableExpr) statement.getLeftValue();
-                debugEmitter.emitVariable(statement.getDebugNames().toArray(new String[0]),
-                        variableName(receiver.getIndex()));
-            }
         } catch (IOException e) {
             throw new RenderingException("IO error occurred", e);
         }
@@ -1258,7 +1252,6 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
             return minifying ? "$t" : "$this";
         }
 
-        Set<String> names = index < debugNames.size() ? debugNames.get(index) : null;
         StringBuilder sb = new StringBuilder();
         --index;
         if (index < variableNames.length()) {
@@ -1267,11 +1260,13 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
             sb.append(Character.toString(variableNames.charAt(index % variableNames.length()))
                     + index / variableNames.length());
         }
-        if (!minifying && names != null && !names.isEmpty()) {
+        if (!minifying) {
-            List<String> nameList = new ArrayList<>(names);
+            VariableNode variable = index < currentMethod.getVariables().size()
-            Collections.sort(nameList);
+                    ? currentMethod.getVariables().get(index)
-            for (String name : nameList) {
+                    : null;
-                sb.append('_').append(escapeName(name));
+            if (variable != null && variable.getName() != null) {
+                sb.setLength(0);
+                sb.append(escapeName(variable.getName()));
             }
         }
         return sb.toString();

core/src/main/java/org/teavm/backend/wasm/generate/WasmGenerator.java

@@ -65,7 +65,7 @@ public class WasmGenerator {
             WasmType type = variable.getType() != null
                     ? WasmGeneratorUtil.mapType(variable.getType())
                     : WasmType.INT32;
-            function.add(new WasmLocal(type));
+            function.add(new WasmLocal(type, variable.getName()));
         }
 
         for (int i = firstVariable; i <= methodReference.parameterCount(); ++i) {

core/src/main/java/org/teavm/backend/wasm/render/WasmCRenderer.java

@@ -182,12 +182,16 @@ public class WasmCRenderer {
         }
         sb.append(WasmCRenderingVisitor.mapType(function.getResult())).append(' ');
         sb.append(function.getName()).append("(");
+        WasmCRenderingVisitor visitor = new WasmCRenderingVisitor(function.getResult(), function.getModule());
         for (int i = 0; i < function.getParameters().size(); ++i) {
             if (i > 0) {
                 sb.append(", ");
             }
             sb.append(WasmCRenderingVisitor.mapType(function.getParameters().get(i)));
-            sb.append(" var_" + i);
+            WasmLocal local = i < function.getLocalVariables().size()
+                    ? function.getLocalVariables().get(i)
+                    : null;
+            sb.append(" ").append(local != null ? visitor.getVariableName(local) : "var_" + i);
         }
         sb.append(")");
 

core/src/main/java/org/teavm/backend/wasm/render/WasmCRenderingVisitor.java

@@ -21,6 +21,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import org.teavm.backend.wasm.model.WasmFunction;
+import org.teavm.backend.wasm.model.WasmLocal;
 import org.teavm.backend.wasm.model.WasmModule;
 import org.teavm.backend.wasm.model.WasmType;
 import org.teavm.backend.wasm.model.expression.WasmBlock;
@@ -303,7 +304,7 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
 
     @Override
     public void visit(WasmGetLocal expression) {
-        value = new CExpression("var_" + expression.getLocal().getIndex());
+        value = new CExpression(getVariableName(expression.getLocal()));
     }
 
     @Override
@@ -313,7 +314,7 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         expression.getValue().acceptVisitor(this);
         result.getLines().addAll(value.getLines());
 
-        result.addLine("var_" + expression.getLocal().getIndex() + " = " + value.getText() + ";",
+        result.addLine(getVariableName(expression.getLocal()) + " = " + value.getText() + ";",
                 expression.getLocation());
 
         value = result;
@@ -1033,4 +1034,11 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         String temporaryVariable;
         WasmType type;
     }
+
+    String getVariableName(WasmLocal local) {
+        if (local.getName() != null) {
+            return local.getName();
+        }
+        return "var_" + local.getIndex();
+    }
 }

core/src/main/java/org/teavm/cache/AstIO.java

@@ -20,7 +20,6 @@ import java.io.DataOutput;
 import java.io.IOException;
 import java.util.EnumSet;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -45,7 +44,6 @@ import org.teavm.ast.InitClassStatement;
 import org.teavm.ast.InstanceOfExpr;
 import org.teavm.ast.InvocationExpr;
 import org.teavm.ast.InvocationType;
-import org.teavm.ast.MethodNode;
 import org.teavm.ast.MonitorEnterStatement;
 import org.teavm.ast.MonitorExitStatement;
 import org.teavm.ast.NewArrayExpr;
@@ -99,7 +97,6 @@ public class AstIO {
         for (VariableNode var : method.getVariables()) {
             write(output, var);
         }
-        output.writeShort(method.getParameterDebugNames().size());
         try {
             method.getBody().acceptVisitor(new NodeWriter(output));
         } catch (IOExceptionWrapper e) {
@@ -110,10 +107,7 @@ public class AstIO {
     private void write(DataOutput output, VariableNode variable) throws IOException {
         output.writeShort(variable.getIndex());
         output.writeByte(variable.getType().ordinal());
-        output.writeByte(variable.getDebugNames().size());
+        output.writeUTF(variable.getName() != null ? variable.getName() : "");
-        for (String debugName : variable.getDebugNames()) {
-            output.writeUTF(debugName);
-        }
     }
 
     public RegularMethodNode read(DataInput input, MethodReference method) throws IOException {
@@ -133,7 +127,10 @@ public class AstIO {
         VariableNode variable = new VariableNode(index, type);
         int nameCount = input.readByte();
         for (int i = 0; i < nameCount; ++i) {
-            variable.getDebugNames().add(input.readUTF());
+            variable.setName(input.readUTF());
+            if (variable.getName().isEmpty()) {
+                variable.setName(null);
+            }
         }
         return variable;
     }
@@ -144,8 +141,6 @@ public class AstIO {
         for (VariableNode var : method.getVariables()) {
             write(output, var);
         }
-        output.writeShort(method.getParameterDebugNames().size());
-        writeParameters(output, method);
         try {
              output.writeShort(method.getBody().size());
              for (int i = 0; i < method.getBody().size(); ++i) {
@@ -156,17 +151,6 @@ public class AstIO {
         }
     }
 
-    private void writeParameters(DataOutput output, MethodNode method) throws IOException {
-        for (Set<String> debugNames : method.getParameterDebugNames()) {
-            output.writeShort(debugNames != null ? debugNames.size() : 0);
-            if (debugNames != null) {
-                for (String debugName : debugNames) {
-                    output.writeUTF(debugName);
-                }
-            }
-        }
-    }
-
     public AsyncMethodNode readAsync(DataInput input, MethodReference method) throws IOException {
         AsyncMethodNode node = new AsyncMethodNode(method);
         node.getModifiers().addAll(unpackModifiers(input.readInt()));
@@ -174,7 +158,6 @@ public class AstIO {
         for (int i = 0; i < varCount; ++i) {
             node.getVariables().add(readVariable(input));
         }
-        readParameters(input, node);
         int partCount = input.readShort();
         for (int i = 0; i < partCount; ++i) {
             AsyncMethodPart part = new AsyncMethodPart();
@@ -184,18 +167,6 @@ public class AstIO {
         return node;
     }
 
-    private void readParameters(DataInput input, MethodNode node) throws IOException {
-        int paramDebugNameCount = input.readShort();
-        for (int i = 0; i < paramDebugNameCount; ++i) {
-            int debugNameCount = input.readShort();
-            Set<String> debugNames = new HashSet<>();
-            for (int j = 0; j < debugNameCount; ++j) {
-                debugNames.add(input.readUTF());
-            }
-            node.getParameterDebugNames().add(debugNames);
-        }
-    }
-
     private int packModifiers(Set<ElementModifier> modifiers) {
         int packed = 0;
         for (ElementModifier modifier : modifiers) {
@@ -257,10 +228,6 @@ public class AstIO {
             try {
                 output.writeByte(statement.getLeftValue() != null ? 0 : 1);
                 writeLocation(statement.getLocation());
-                output.writeShort(statement.getDebugNames().size());
-                for (String name : statement.getDebugNames()) {
-                    output.writeUTF(name);
-                }
                 if (statement.getLeftValue() != null) {
                     writeExpr(statement.getLeftValue());
                 }
@@ -674,10 +641,6 @@ public class AstIO {
             case 0: {
                 AssignmentStatement stmt = new AssignmentStatement();
                 stmt.setLocation(readLocation(input));
-                int debugNameCount = input.readShort();
-                for (int i = 0; i < debugNameCount; ++i) {
-                    stmt.getDebugNames().add(input.readUTF());
-                }
                 stmt.setLeftValue(readExpr(input));
                 stmt.setRightValue(readExpr(input));
                 stmt.setAsync(input.readBoolean());
@@ -686,10 +649,6 @@ public class AstIO {
             case 1: {
                 AssignmentStatement stmt = new AssignmentStatement();
                 stmt.setLocation(readLocation(input));
-                int debugNameCount = input.readShort();
-                for (int i = 0; i < debugNameCount; ++i) {
-                    stmt.getDebugNames().add(input.readUTF());
-                }
                 stmt.setRightValue(readExpr(input));
                 stmt.setAsync(input.readBoolean());
                 return stmt;

core/src/main/java/org/teavm/cache/ProgramIO.java

@@ -43,10 +43,7 @@ public class ProgramIO {
         for (int i = 0; i < program.variableCount(); ++i) {
             Variable var = program.variableAt(i);
             data.writeShort(var.getRegister());
-            data.writeShort(var.getDebugNames().size());
+            data.writeUTF(var.getDebugName() != null ? var.getDebugName() : "");
-            for (String debugString : var.getDebugNames()) {
-                data.writeUTF(debugString);
-            }
         }
         for (int i = 0; i < program.basicBlockCount(); ++i) {
             BasicBlock basicBlock = program.basicBlockAt(i);
@@ -106,9 +103,9 @@ public class ProgramIO {
         for (int i = 0; i < varCount; ++i) {
             Variable var = program.createVariable();
             var.setRegister(data.readShort());
-            int debugNameCount = data.readShort();
+            var.setDebugName(data.readUTF());
-            for (int j = 0; j < debugNameCount; ++j) {
+            if (var.getDebugName().isEmpty()) {
-                var.getDebugNames().add(data.readUTF());
+                var.setDebugName(null);
             }
         }
         for (int i = 0; i < basicBlockCount; ++i) {

core/src/main/java/org/teavm/model/Variable.java

@@ -15,19 +15,14 @@
  */
 package org.teavm.model;
 
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.Set;
-
 public class Variable implements VariableReader {
     private Program program;
     private int index;
     private int register;
-    private Set<String> debugNames;
+    private String debugName;
 
     Variable(Program program) {
         this.program = program;
-        this.debugNames = new HashSet<>();
     }
 
     @Override
@@ -57,12 +52,12 @@ public class Variable implements VariableReader {
         this.register = register;
     }
 
-    public Set<String> getDebugNames() {
+    @Override
-        return debugNames;
+    public String getDebugName() {
+        return debugName;
     }
 
-    @Override
+    public void setDebugName(String debugName) {
-    public Set<String> readDebugNames() {
+        this.debugName = debugName;
-        return Collections.unmodifiableSet(debugNames);
     }
 }

core/src/main/java/org/teavm/model/VariableReader.java

@@ -15,18 +15,12 @@
  */
 package org.teavm.model;
 
-import java.util.Set;
-
-/**
- *
- * @author Alexey Andreev
- */
 public interface VariableReader {
     int getIndex();
 
     ProgramReader getProgram();
 
-    Set<String> readDebugNames();
+    String getDebugName();
 
     int getRegister();
 }

core/src/main/java/org/teavm/model/optimization/GlobalValueNumbering.java

@@ -154,7 +154,7 @@ public class GlobalValueNumbering implements MethodOptimization {
             if (map[i] != i) {
                 Variable var = program.variableAt(i);
                 Variable mapVar = program.variableAt(map[i]);
-                mapVar.getDebugNames().addAll(var.getDebugNames());
+                mapVar.setDebugName(var.getDebugName());
                 program.deleteVariable(i);
             }
         }
@@ -165,7 +165,12 @@ public class GlobalValueNumbering implements MethodOptimization {
     }
 
     private void bind(int var, String value) {
-        KnownValue known = knownValues.get(value);
+        String name = program.variableAt(var).getDebugName();
+        if (name == null) {
+            name = "";
+        }
+
+        KnownValue known = knownValues.get(name + ":" + value);
         if (known != null && domTree.dominates(known.location, currentBlockIndex) && known.value != var) {
             eliminate = true;
             map[var] = known.value;
@@ -173,7 +178,7 @@ public class GlobalValueNumbering implements MethodOptimization {
             known = new KnownValue();
             known.location = currentBlockIndex;
             known.value = var;
-            knownValues.put(value, known);
+            knownValues.put(name + ":" + value, known);
         }
     }
 

core/src/main/java/org/teavm/model/optimization/LoopInvariantMotion.java

@@ -225,7 +225,7 @@ public class LoopInvariantMotion implements MethodOptimization {
         @Override
         public void visit(ClassConstantInstruction insn) {
             var = program.createVariable();
-            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
+            var.setDebugName(insn.getReceiver().getDebugName());
             ClassConstantInstruction copy = new ClassConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);
@@ -235,7 +235,7 @@ public class LoopInvariantMotion implements MethodOptimization {
         @Override
         public void visit(NullConstantInstruction insn) {
             var = program.createVariable();
-            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
+            var.setDebugName(insn.getReceiver().getDebugName());
             NullConstantInstruction copy = new NullConstantInstruction();
             copy.setReceiver(var);
             this.copy = copy;
@@ -244,7 +244,7 @@ public class LoopInvariantMotion implements MethodOptimization {
         @Override
         public void visit(IntegerConstantInstruction insn) {
             var = program.createVariable();
-            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
+            var.setDebugName(insn.getReceiver().getDebugName());
             IntegerConstantInstruction copy = new IntegerConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);
@@ -254,7 +254,7 @@ public class LoopInvariantMotion implements MethodOptimization {
         @Override
         public void visit(LongConstantInstruction insn) {
             var = program.createVariable();
-            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
+            var.setDebugName(insn.getReceiver().getDebugName());
             LongConstantInstruction copy = new LongConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);
@@ -264,7 +264,7 @@ public class LoopInvariantMotion implements MethodOptimization {
         @Override
         public void visit(FloatConstantInstruction insn) {
             var = program.createVariable();
-            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
+            var.setDebugName(insn.getReceiver().getDebugName());
             FloatConstantInstruction copy = new FloatConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);
@@ -274,7 +274,7 @@ public class LoopInvariantMotion implements MethodOptimization {
         @Override
         public void visit(DoubleConstantInstruction insn) {
             var = program.createVariable();
-            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
+            var.setDebugName(insn.getReceiver().getDebugName());
             DoubleConstantInstruction copy = new DoubleConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);
@@ -284,7 +284,7 @@ public class LoopInvariantMotion implements MethodOptimization {
         @Override
         public void visit(StringConstantInstruction insn) {
             var = program.createVariable();
-            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
+            var.setDebugName(insn.getReceiver().getDebugName());
             StringConstantInstruction copy = new StringConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);

core/src/main/java/org/teavm/model/util/AsyncProgramSplitter.java

@@ -193,7 +193,7 @@ public class AsyncProgramSplitter {
             copy.createVariable();
             Variable varCopy = copy.variableAt(i);
             varCopy.setRegister(var.getRegister());
-            varCopy.getDebugNames().addAll(var.getDebugNames());
+            varCopy.setDebugName(var.getDebugName());
         }
         return copy;
     }

core/src/main/java/org/teavm/model/util/ListingBuilder.java

@@ -28,16 +28,8 @@ public class ListingBuilder {
         for (int i = 0; i < program.variableCount(); ++i) {
             sb.append(prefix).append("var @").append(i);
             VariableReader var = program.variableAt(i);
-            if (var != null && !var.readDebugNames().isEmpty()) {
+            if (var != null && var.getDebugName() != null) {
-                sb.append(" as ");
+                sb.append(" as ").append(var.getDebugName());
-                boolean first = true;
-                for (String debugName : var.readDebugNames()) {
-                    if (!first) {
-                        sb.append(", ");
-                    }
-                    first = false;
-                    sb.append(debugName);
-                }
             }
             sb.append('\n');
         }

core/src/main/java/org/teavm/model/util/PhiUpdater.java

@@ -200,7 +200,7 @@ public class PhiUpdater {
 
             for (Phi phi : synthesizedPhis.get(index)) {
                 Variable var = program.createVariable();
-                var.getDebugNames().addAll(phi.getReceiver().getDebugNames());
+                var.setDebugName(phi.getReceiver().getDebugName());
                 variableMap[phi.getReceiver().getIndex()] = var;
                 phi.setReceiver(var);
             }
@@ -287,7 +287,7 @@ public class PhiUpdater {
                 incoming.setSource(currentBlock);
                 incoming.setValue(var);
                 phi.getIncomings().add(incoming);
-                phi.getReceiver().getDebugNames().addAll(var.getDebugNames());
+                phi.getReceiver().setDebugName(var.getDebugName());
             }
         }
     }

core/src/main/java/org/teavm/model/util/ProgramUtils.java

@@ -70,7 +70,7 @@ public final class ProgramUtils {
         Program copy = new Program();
         for (int i = 0; i < program.variableCount(); ++i) {
             Variable var = copy.createVariable();
-            var.getDebugNames().addAll(program.variableAt(i).readDebugNames());
+            var.setDebugName(program.variableAt(i).getDebugName());
         }
         for (int i = 0; i < program.basicBlockCount(); ++i) {
             copy.createBasicBlock();

core/src/main/java/org/teavm/model/util/RegisterAllocator.java

@@ -257,14 +257,13 @@ public class RegisterAllocator {
             BasicBlock block = program.basicBlockAt(i);
             mapper.apply(block);
         }
-        String[][] originalNames = new String[program.variableCount()][];
+        String[] originalNames = new String[program.variableCount()];
         for (int i = 0; i < program.variableCount(); ++i) {
             Variable var = program.variableAt(i);
-            originalNames[i] = var.getDebugNames().toArray(new String[0]);
+            originalNames[i] = var.getDebugName();
-            var.getDebugNames().clear();
         }
         for (int i = 0; i < program.variableCount(); ++i) {
-            program.variableAt(varMap[i]).getDebugNames().addAll(Arrays.asList(originalNames[i]));
+            program.variableAt(varMap[i]).setDebugName(originalNames[i]);
         }
     }
 

core/src/main/java/org/teavm/vm/TeaVM.java

@@ -20,6 +20,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
@@ -113,6 +114,7 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
     private final Properties properties = new Properties();
     private ProgramCache programCache;
     private boolean incremental;
+    private TeaVMOptimizationLevel optimizationLevel = TeaVMOptimizationLevel.SIMPLE;
     private TeaVMProgressListener progressListener;
     private boolean cancelled;
     private ListableClassHolderSource writtenClasses;
@@ -202,6 +204,14 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
         this.incremental = incremental;
     }
 
+    public TeaVMOptimizationLevel getOptimizationLevel() {
+        return optimizationLevel;
+    }
+
+    public void setOptimizationLevel(TeaVMOptimizationLevel optimizationLevel) {
+        this.optimizationLevel = optimizationLevel;
+    }
+
     public TeaVMProgressListener getProgressListener() {
         return progressListener;
     }
@@ -359,12 +369,13 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
                 return;
             }
 
-            //inline(classSet);
+            inline(classSet);
             if (wasCancelled()) {
                 return;
             }
         }
 
+        removeDebugNames(classSet);
         optimize(classSet);
         if (wasCancelled()) {
             return;
@@ -423,10 +434,13 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
     }
 
     private void inline(ListableClassHolderSource classes) {
+        if (optimizationLevel != TeaVMOptimizationLevel.FULL) {
+            return;
+        }
         Inlining inlining = new Inlining();
         for (String className : classes.getClassNames()) {
             ClassHolder cls = classes.get(className);
-            for (final MethodHolder method : cls.getMethods()) {
+            for (MethodHolder method : cls.getMethods()) {
                 if (method.getProgram() != null) {
                     inlining.apply(method.getProgram(), classes);
                 }
@@ -437,6 +451,25 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
         }
     }
 
+    private void removeDebugNames(ListableClassHolderSource classes) {
+        if (optimizationLevel == TeaVMOptimizationLevel.SIMPLE) {
+            return;
+        }
+        for (String className : classes.getClassNames()) {
+            ClassHolder cls = classes.get(className);
+            for (MethodHolder method : cls.getMethods()) {
+                if (method.getProgram() != null) {
+                    for (int i = 0; i < method.getProgram().variableCount(); ++i) {
+                        method.getProgram().variableAt(i).setDebugName(null);
+                    }
+                }
+            }
+            if (wasCancelled()) {
+                return;
+            }
+        }
+    }
+
     private void optimize(ListableClassHolderSource classSource) {
         for (String className : classSource.getClassNames()) {
             ClassHolder cls = classSource.get(className);
@@ -481,17 +514,22 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
     }
 
     private List<MethodOptimization> getOptimizations() {
-        return Arrays.asList(
+        List<MethodOptimization> optimizations = new ArrayList<>();
-                new RedundantJumpElimination(),
+        optimizations.add(new RedundantJumpElimination());
-                new ArrayUnwrapMotion(),
+        optimizations.add(new ArrayUnwrapMotion());
-                new LoopInversion(),
+        if (optimizationLevel.ordinal() >= TeaVMOptimizationLevel.ADVANCED.ordinal()) {
-                new LoopInvariantMotion(),
+            optimizations.add(new LoopInversion());
-                new GlobalValueNumbering(),
+            optimizations.add(new LoopInvariantMotion());
-                new ConstantConditionElimination(),
+        }
-                new RedundantJumpElimination(),
+        optimizations.add(new GlobalValueNumbering());
-                new UnusedVariableElimination(),
+        if (optimizationLevel.ordinal() >= TeaVMOptimizationLevel.ADVANCED.ordinal()) {
-                new ClassInitElimination(),
+            optimizations.add(new ConstantConditionElimination());
-                new UnreachableBasicBlockElimination());
+            optimizations.add(new RedundantJumpElimination());
+            optimizations.add(new UnusedVariableElimination());
+        }
+        optimizations.add(new ClassInitElimination());
+        optimizations.add(new UnreachableBasicBlockElimination());
+        return optimizations;
     }
 
     public void build(File dir, String fileName) {

core/src/main/java/org/teavm/vm/TeaVMOptimizationLevel.java

@@ -0,0 +1,22 @@
+/*
+ *  Copyright 2016 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.vm;
+
+public enum TeaVMOptimizationLevel {
+    SIMPLE,
+    ADVANCED,
+    FULL
+}

jso/impl/src/main/java/org/teavm/jso/impl/JSClassProcessor.java

@@ -170,8 +170,7 @@ class JSClassProcessor {
                 InstructionVariableMapper variableMapper = new InstructionVariableMapper(var ->
                          program.variableAt(var.getIndex() + 1));
                 for (int i = program.variableCount() - 1; i > 0; --i) {
-                    program.variableAt(i).getDebugNames().addAll(program.variableAt(i - 1).getDebugNames());
+                    program.variableAt(i).setDebugName(program.variableAt(i - 1).getDebugName());
-                    program.variableAt(i - 1).getDebugNames().clear();
                 }
                 for (int i = 0; i < program.basicBlockCount(); ++i) {
                     BasicBlock block = program.basicBlockAt(i);

tools/cli/src/main/java/org/teavm/cli/TeaVMRunner.java

@@ -24,6 +24,7 @@ import org.teavm.tooling.RuntimeCopyOperation;
 import org.teavm.tooling.TeaVMTargetType;
 import org.teavm.tooling.TeaVMTool;
 import org.teavm.tooling.TeaVMToolException;
+import org.teavm.vm.TeaVMOptimizationLevel;
 import org.teavm.vm.TeaVMPhase;
 import org.teavm.vm.TeaVMProgressFeedback;
 import org.teavm.vm.TeaVMProgressListener;
@@ -61,6 +62,9 @@ public final class TeaVMRunner {
                 .withDescription("causes TeaVM to generate minimized JavaScript file")
                 .withLongOpt("minify")
                 .create("m"));
+        options.addOption(OptionBuilder
+                .withDescription("optimization level (1-3)")
+                .create("O"));
         options.addOption(OptionBuilder
                 .withArgName("separate|merge|none")
                 .hasArg()
@@ -160,6 +164,33 @@ public final class TeaVMRunner {
         if (commandLine.hasOption('D')) {
             tool.setDebugInformationGenerated(true);
         }
+
+        if (commandLine.hasOption("O")) {
+            int level;
+            try {
+                level = Integer.parseInt(commandLine.getOptionValue("O"));
+            } catch (NumberFormatException e) {
+                System.err.print("Wrong optimization level");
+                printUsage(options);
+                return;
+            }
+            switch (level) {
+                case 1:
+                    tool.setOptimizationLevel(TeaVMOptimizationLevel.SIMPLE);
+                    break;
+                case 2:
+                    tool.setOptimizationLevel(TeaVMOptimizationLevel.ADVANCED);
+                    break;
+                case 3:
+                    tool.setOptimizationLevel(TeaVMOptimizationLevel.FULL);
+                    break;
+                default:
+                    System.err.print("Wrong optimization level");
+                    printUsage(options);
+                    return;
+            }
+        }
+
         if (commandLine.hasOption('S')) {
             tool.setSourceMapsFileGenerated(true);
         }
@@ -174,6 +205,7 @@ public final class TeaVMRunner {
         if (commandLine.hasOption('p')) {
             classPath = commandLine.getOptionValues('p');
         }
+
         boolean interactive = commandLine.hasOption('w');
         args = commandLine.getArgs();
         if (args.length > 1) {

tools/core/src/main/java/org/teavm/tooling/TeaVMTool.java

@@ -62,6 +62,7 @@ import org.teavm.vm.DirectoryBuildTarget;
 import org.teavm.vm.TeaVM;
 import org.teavm.vm.TeaVMBuilder;
 import org.teavm.vm.TeaVMEntryPoint;
+import org.teavm.vm.TeaVMOptimizationLevel;
 import org.teavm.vm.TeaVMProgressListener;
 import org.teavm.vm.TeaVMTarget;
 import org.teavm.vm.spi.AbstractRendererListener;
@@ -93,6 +94,7 @@ public class TeaVMTool implements BaseTeaVMTool {
     private boolean cancelled;
     private TeaVMProgressListener progressListener;
     private TeaVM vm;
+    private TeaVMOptimizationLevel optimizationLevel = TeaVMOptimizationLevel.SIMPLE;
     private List<SourceFileProvider> sourceFileProviders = new ArrayList<>();
     private DebugInformationBuilder debugEmitter;
     private JavaScriptTarget javaScriptTarget;
@@ -227,6 +229,14 @@ public class TeaVMTool implements BaseTeaVMTool {
         this.targetType = targetType;
     }
 
+    public TeaVMOptimizationLevel getOptimizationLevel() {
+        return optimizationLevel;
+    }
+
+    public void setOptimizationLevel(TeaVMOptimizationLevel optimizationLevel) {
+        this.optimizationLevel = optimizationLevel;
+    }
+
     public ClassLoader getClassLoader() {
         return classLoader;
     }
@@ -361,6 +371,7 @@ public class TeaVMTool implements BaseTeaVMTool {
             vm.setProperties(properties);
             vm.setProgramCache(programCache);
             vm.setIncremental(incremental);
+            vm.setOptimizationLevel(optimizationLevel);
 
             vm.installPlugins();
             for (ClassHolderTransformer transformer : transformers) {