WASM: porting jbox2d benchmark to WebAssembly

classlib/src/main/java/org/teavm/classlib/java/lang/TFloat.java

@@ -15,6 +15,7 @@
  */
 package org.teavm.classlib.java.lang;
 
+import org.teavm.interop.Import;
 import org.teavm.jso.JSBody;
 
 public class TFloat extends TNumber implements TComparable<TFloat> {
@@ -89,12 +90,19 @@ public class TFloat extends TNumber implements TComparable<TFloat> {
     }
 
     @JSBody(params = "v", script = "return isNaN(v);")
+    @Import(module = "runtime", name = "isNaN")
     public static native boolean isNaN(float v);
 
-    @JSBody(params = "v", script = "return !isFinite(v);")
+    public static boolean isInfinite(float v) {
-    public static native boolean isInfinite(float v);
+        return !isFinite(v);
+    }
+
+    @JSBody(params = "v", script = "return isFinite(v);")
+    @Import(module = "runtime", name = "isFinite")
+    private static native boolean isFinite(float v);
 
     @JSBody(params = {}, script = "return NaN;")
+    @Import(module = "runtime", name = "getNaN")
     private static native float getNaN();
 
     public static float parseFloat(TString string) throws TNumberFormatException {

classlib/src/main/java/org/teavm/classlib/java/lang/TMath.java

@@ -16,11 +16,8 @@
 package org.teavm.classlib.java.lang;
 
 import org.teavm.backend.javascript.spi.GeneratedBy;
+import org.teavm.interop.Import;
 
-/**
- *
- * @author Alexey Andreev
- */
 public final class TMath extends TObject {
     public static final double E = 2.71828182845904523536;
     public static final double PI = 3.14159265358979323846;
@@ -29,21 +26,27 @@ public final class TMath extends TObject {
     }
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "sin")
     public static native double sin(double a);
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "cos")
     public static native double cos(double a);
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "tan")
     public static native double tan(double a);
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "asin")
     public static native double asin(double a);
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "acos")
     public static native double acos(double a);
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "atan")
     public static native double atan(double a);
 
     public static double toRadians(double angdeg) {
@@ -55,9 +58,11 @@ public final class TMath extends TObject {
     }
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "exp")
     public static native double exp(double a);
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "log")
     public static native double log(double a);
 
     public static double log10(double a) {
@@ -65,6 +70,7 @@ public final class TMath extends TObject {
     }
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "sqrt")
     public static native double sqrt(double a);
 
     public static double cbrt(double a) {
@@ -77,12 +83,15 @@ public final class TMath extends TObject {
     }
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "ceil")
     public static native double ceil(double a);
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "floor")
     public static native double floor(double a);
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "pow")
     public static native double pow(double x, double y);
 
     public static double rint(double a) {
@@ -90,6 +99,7 @@ public final class TMath extends TObject {
     }
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "atan2")
     public static native double atan2(double y, double x);
 
     public static int round(float a) {
@@ -101,6 +111,7 @@ public final class TMath extends TObject {
     }
 
     @GeneratedBy(MathNativeGenerator.class)
+    @Import(module = "math", name = "random")
     public static native double random();
 
     public static int min(int a, int b) {

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

@@ -18,7 +18,6 @@ package org.teavm.backend.wasm.generate;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.Comparator;
 import java.util.Deque;
 import java.util.HashMap;
@@ -106,7 +105,6 @@ import org.teavm.backend.wasm.model.expression.WasmStoreInt64;
 import org.teavm.backend.wasm.model.expression.WasmSwitch;
 import org.teavm.backend.wasm.model.expression.WasmUnreachable;
 import org.teavm.interop.Address;
-import org.teavm.model.CallLocation;
 import org.teavm.model.FieldReference;
 import org.teavm.model.MethodReference;
 import org.teavm.model.TextLocation;
@@ -123,7 +121,6 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
     private WasmGenerationContext context;
     private WasmClassGenerator classGenerator;
     private WasmFunction function;
-    private MethodReference method;
     private int firstVariable;
     private IdentifiedStatement currentContinueTarget;
     private IdentifiedStatement currentBreakTarget;
@@ -135,11 +132,10 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
     WasmExpression result;
 
     WasmGenerationVisitor(WasmGenerationContext context, WasmClassGenerator classGenerator,
-            WasmFunction function, MethodReference method, int firstVariable) {
+            WasmFunction function, int firstVariable) {
         this.context = context;
         this.classGenerator = classGenerator;
         this.function = function;
-        this.method = method;
         this.firstVariable = firstVariable;
         int typeCount = WasmType.values().length;
         for (int i = 0; i < typeCount; ++i) {
@@ -862,15 +858,7 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
             int vtableOffset = classGenerator.getClassSize(RuntimeClass.class.getName());
             VirtualTableEntry vtableEntry = context.getVirtualTableProvider().lookup(expr.getMethod());
             if (vtableEntry == null) {
-                result = new WasmInt32Constant(0);
+                result = new WasmUnreachable();
-                TextLocation insnLocation = null;
-                if (expr.getLocation() != null) {
-                    insnLocation = new TextLocation(expr.getLocation().getFileName(),
-                            expr.getLocation().getLine());
-                }
-                CallLocation location = new CallLocation(method, insnLocation);
-                context.getDiagnostics().error(location, "Can't generate WebAssembly to call {{m0}} method",
-                        expr.getMethod());
                 return;
             }
             WasmExpression methodIndex = new WasmIntBinary(WasmIntType.INT32, WasmIntBinaryOperation.ADD,
@@ -1160,7 +1148,7 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
         if (expr.getType() instanceof ValueType.Object) {
             ValueType.Object cls = (ValueType.Object) expr.getType();
             List<TagRegistry.Range> ranges = context.getTagRegistry().getRanges(cls.getClassName());
-            Collections.sort(ranges, Comparator.comparingInt(range -> range.lower));
+            ranges.sort(Comparator.comparingInt(range -> range.lower));
 
             WasmBlock block = new WasmBlock(false);
             block.setLocation(expr.getLocation());
@@ -1187,11 +1175,11 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
                         WasmIntBinaryOperation.GT_SIGNED, new WasmGetLocal(tagVar),
                         new WasmInt32Constant(ranges.get(i - 1).upper));
                 WasmConditional conditional = new WasmConditional(upperThanExcluded);
-                WasmExpression lowerThanExluded = new WasmIntBinary(WasmIntType.INT32,
+                WasmExpression lowerThanExcluded = new WasmIntBinary(WasmIntType.INT32,
                         WasmIntBinaryOperation.LT_SIGNED, new WasmGetLocal(tagVar),
                         new WasmInt32Constant(ranges.get(i).lower));
 
-                WasmBranch branch = new WasmBranch(lowerThanExluded, block);
+                WasmBranch branch = new WasmBranch(lowerThanExcluded, block);
                 branch.setResult(new WasmInt32Constant(0));
                 conditional.getThenBlock().getBody().add(branch);
 

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

@@ -21,6 +21,8 @@ import org.teavm.ast.decompilation.Decompiler;
 import org.teavm.backend.wasm.model.WasmFunction;
 import org.teavm.backend.wasm.model.WasmLocal;
 import org.teavm.backend.wasm.model.WasmType;
+import org.teavm.interop.Export;
+import org.teavm.model.AnnotationReader;
 import org.teavm.model.ClassHolder;
 import org.teavm.model.ClassHolderSource;
 import org.teavm.model.ElementModifier;
@@ -64,11 +66,16 @@ public class WasmGenerator {
             function.setResult(WasmGeneratorUtil.mapType(methodReference.getReturnType()));
         }
 
-        WasmGenerationVisitor visitor = new WasmGenerationVisitor(context, classGenerator, function, methodReference,
+        WasmGenerationVisitor visitor = new WasmGenerationVisitor(context, classGenerator, function,
                 firstVariable);
         methodAst.getBody().acceptVisitor(visitor);
         function.getBody().add(visitor.result);
 
+        AnnotationReader exportAnnot = method.getAnnotations().get(Export.class.getName());
+        if (exportAnnot != null) {
+            function.setExportName(exportAnnot.getValue("name").getString());
+        }
+
         return function;
     }
 

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

@@ -155,7 +155,7 @@ public class WasmBinaryRenderer {
 
         section.writeLEB(module.getMemorySize());
         section.writeLEB(module.getMemorySize());
-        section.writeByte(0);
+        section.writeByte(1);
 
         writeSection("memory", section.getData());
     }

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

@@ -398,10 +398,10 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
                 append("i32.load");
                 break;
         }
-        append(" align=" + expression.getAlignment());
         if (expression.getOffset() > 0) {
             append(" offset=" + expression.getOffset());
         }
+        append(" align=" + expression.getAlignment());
         line(expression.getIndex());
         close();
     }
@@ -432,30 +432,32 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
                 append("i64.load");
                 break;
         }
-        append(" align=" + expression.getAlignment());
         if (expression.getOffset() > 0) {
             append(" offset=" + expression.getOffset());
         }
+        append(" align=" + expression.getAlignment());
         line(expression.getIndex());
         close();
     }
 
     @Override
     public void visit(WasmLoadFloat32 expression) {
-        open().append("f32.load align=" + expression.getAlignment());
+        open().append("f32.load");
         if (expression.getOffset() > 0) {
             append(" offset=" + expression.getOffset());
         }
+        append(" align=" + expression.getAlignment());
         line(expression.getIndex());
         close();
     }
 
     @Override
     public void visit(WasmLoadFloat64 expression) {
-        open().append("f64.load align=" + expression.getAlignment());
+        open().append("f64.load");
         if (expression.getOffset() > 0) {
             append(" offset=" + expression.getOffset());
         }
+        append(" align=" + expression.getAlignment());
         line(expression.getIndex());
         close();
     }
@@ -476,10 +478,10 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
                 append("i32.store");
                 break;
         }
-        append(" align=" + expression.getAlignment());
         if (expression.getOffset() > 0) {
             append(" offset=" + expression.getOffset());
         }
+        append(" align=" + expression.getAlignment());
         line(expression.getIndex());
         line(expression.getValue());
         close();
@@ -505,10 +507,10 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
                 append("i64.store");
                 break;
         }
-        append(" align=" + expression.getAlignment());
         if (expression.getOffset() > 0) {
             append(" offset=" + expression.getOffset());
         }
+        append(" align=" + expression.getAlignment());
         line(expression.getIndex());
         line(expression.getValue());
         close();
@@ -516,10 +518,11 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
 
     @Override
     public void visit(WasmStoreFloat32 expression) {
-        open().append("f32.store align=" + expression.getAlignment());
+        open().append("f32.store");
         if (expression.getOffset() > 0) {
             append(" offset=" + expression.getOffset());
         }
+        append(" align=" + expression.getAlignment());
         line(expression.getIndex());
         line(expression.getValue());
         close();
@@ -527,10 +530,11 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
 
     @Override
     public void visit(WasmStoreFloat64 expression) {
-        open().append("f64.store align=" + expression.getAlignment());
+        open().append("f64.store");
         if (expression.getOffset() > 0) {
             append(" offset=" + expression.getOffset());
         }
+        append(" align=" + expression.getAlignment());
         line(expression.getIndex());
         line(expression.getValue());
         close();

core/src/main/java/org/teavm/model/classes/VirtualTableProvider.java

@@ -38,12 +38,17 @@ public class VirtualTableProvider {
         this.classSource = classSource;
         interfaceMapping = new InterfaceToClassMapping(classSource);
 
+        Set<String> classNames = new HashSet<>(classSource.getClassNames());
         for (MethodReference virtualMethod : virtualMethods) {
             String cls = interfaceMapping.mapClass(virtualMethod.getClassName());
+            if (cls == null) {
+                cls = virtualMethod.getClassName();
+            }
+            classNames.add(cls);
             virtualMethodMap.computeIfAbsent(cls, c -> new HashSet<>()).add(virtualMethod.getDescriptor());
         }
 
-        for (String className : classSource.getClassNames()) {
+        for (String className : classNames) {
             fillClass(className);
         }
     }

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

@@ -153,29 +153,6 @@ public class TypeInferer {
         }
     }
 
-    VariableType convert(ArrayElementType type) {
-        switch (type) {
-            case BYTE:
-                return VariableType.BYTE_ARRAY;
-            case CHAR:
-                return VariableType.CHAR_ARRAY;
-            case SHORT:
-                return VariableType.SHORT_ARRAY;
-            case INT:
-                return VariableType.INT_ARRAY;
-            case LONG:
-                return VariableType.LONG_ARRAY;
-            case FLOAT:
-                return VariableType.FLOAT_ARRAY;
-            case DOUBLE:
-                return VariableType.DOUBLE_ARRAY;
-            case OBJECT:
-                return VariableType.OBJECT_ARRAY;
-            default:
-                throw new AssertionError();
-        }
-    }
-
     VariableType convert(NumericOperandType type) {
         switch (type) {
             case INT:
@@ -396,7 +373,15 @@ public class TypeInferer {
         @Override
         public void binary(BinaryOperation op, VariableReader receiver, VariableReader first, VariableReader second,
                 NumericOperandType type) {
+            switch (op) {
+                case COMPARE:
+                    types[receiver.getIndex()] = VariableType.INT;
+                    break;
+                default:
                     types[receiver.getIndex()] = convert(type);
+                    break;
+            }
+
         }
 
         @Override

core/src/main/java/org/teavm/runtime/ExceptionHandling.java

@@ -16,6 +16,7 @@
 package org.teavm.runtime;
 
 import org.teavm.interop.Address;
+import org.teavm.interop.Export;
 import org.teavm.interop.StaticInit;
 import org.teavm.interop.Structure;
 import org.teavm.interop.Unmanaged;
@@ -30,6 +31,7 @@ public final class ExceptionHandling {
 
     private static Throwable thrownException;
 
+    @Export(name = "sys$catchException")
     public static Throwable catchException() {
         Throwable exception = thrownException;
         thrownException = null;

interop/core/src/main/java/org/teavm/interop/Export.java

@@ -0,0 +1,27 @@
+/*
+ *  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.interop;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface Export {
+    String name();
+}

samples/benchmark/pom.xml

@@ -45,6 +45,12 @@
       <version>${project.version}</version>
       <scope>provided</scope>
     </dependency>
+    <dependency>
+      <groupId>org.teavm</groupId>
+      <artifactId>teavm-interop</artifactId>
+      <version>${project.version}</version>
+      <scope>provided</scope>
+    </dependency>
     <dependency>
       <groupId>org.jbox2d</groupId>
       <artifactId>jbox2d-library</artifactId>
@@ -144,6 +150,19 @@
               <optimizationLevel>FULL</optimizationLevel>
             </configuration>
           </execution>
+          <execution>
+            <id>wasm-client</id>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+            <configuration>
+              <targetDirectory>${project.build.directory}/generated/wasm/teavm-wasm</targetDirectory>
+              <mainClass>org.teavm.samples.benchmark.teavm.WasmBenchmarkStarter</mainClass>
+              <debugInformationGenerated>true</debugInformationGenerated>
+              <targetType>WEBASSEMBLY</targetType>
+              <optimizationLevel>FULL</optimizationLevel>
+            </configuration>
+          </execution>
         </executions>
       </plugin>
       <plugin>

samples/benchmark/src/main/java/org/teavm/samples/benchmark/teavm/BenchmarkStarter.java

@@ -30,10 +30,6 @@ import org.teavm.jso.dom.html.HTMLDocument;
 import org.teavm.jso.dom.html.HTMLElement;
 import org.teavm.samples.benchmark.shared.Scene;
 
-/**
- *
- * @author Alexey Andreev
- */
 public final class BenchmarkStarter {
     private static HTMLDocument document = Window.current().getDocument();
     private static HTMLCanvasElement canvas = (HTMLCanvasElement) document.getElementById("benchmark-canvas");

samples/benchmark/src/main/java/org/teavm/samples/benchmark/teavm/WasmBenchmarkStarter.java

@@ -0,0 +1,105 @@
+/*
+ *  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.samples.benchmark.teavm;
+
+import org.jbox2d.collision.shapes.CircleShape;
+import org.jbox2d.collision.shapes.PolygonShape;
+import org.jbox2d.collision.shapes.Shape;
+import org.jbox2d.collision.shapes.ShapeType;
+import org.jbox2d.common.Vec2;
+import org.jbox2d.dynamics.Body;
+import org.jbox2d.dynamics.Fixture;
+import org.teavm.interop.Export;
+import org.teavm.interop.Import;
+import org.teavm.samples.benchmark.shared.Scene;
+
+public final class WasmBenchmarkStarter {
+    private static Scene scene = new Scene();
+    private static int currentSecond;
+    private static long startMillisecond;
+    private static int timeSpentCalculating;
+
+    private WasmBenchmarkStarter() {
+    }
+
+    public static void main(String[] args) {
+        startMillisecond = System.currentTimeMillis();
+        tick();
+    }
+
+    @Export(name = "tick")
+    public static void tick() {
+        double start = performanceTime();
+        System.out.println("About to calculate frame");
+        scene.calculate();
+        System.out.println("Frame calculated successfully");
+        double end = performanceTime();
+        int second = (int) ((System.currentTimeMillis() - startMillisecond) / 1000);
+        if (second > currentSecond) {
+            reportPerformance(second, timeSpentCalculating);
+            timeSpentCalculating = 0;
+            currentSecond = second;
+        }
+        timeSpentCalculating += (int) (end - start);
+        render();
+        repeatAfter(scene.timeUntilNextStep());
+    }
+
+    private static void render() {
+        WasmCanvas.save();
+        setupCanvas();
+        for (Body body = scene.getWorld().getBodyList(); body != null; body = body.getNext()) {
+            Vec2 center = body.getPosition();
+            WasmCanvas.save();
+            WasmCanvas.translate(center.x, center.y);
+            WasmCanvas.rotate(body.getAngle());
+            for (Fixture fixture = body.getFixtureList(); fixture != null; fixture = fixture.getNext()) {
+                Shape shape = fixture.getShape();
+                if (shape.getType() == ShapeType.CIRCLE) {
+                    CircleShape circle = (CircleShape) shape;
+                    WasmCanvas.beginPath();
+                    WasmCanvas.arc(circle.m_p.x, circle.m_p.y, circle.getRadius(), 0, Math.PI * 2, true);
+                    WasmCanvas.closePath();
+                    WasmCanvas.stroke();
+                } else if (shape.getType() == ShapeType.POLYGON) {
+                    PolygonShape poly = (PolygonShape) shape;
+                    Vec2[] vertices = poly.getVertices();
+                    WasmCanvas.beginPath();
+                    WasmCanvas.moveTo(vertices[0].x, vertices[0].y);
+                    for (int i = 1; i < poly.getVertexCount(); ++i) {
+                        WasmCanvas.lineTo(vertices[i].x, vertices[i].y);
+                    }
+                    WasmCanvas.closePath();
+                    WasmCanvas.stroke();
+                }
+            }
+            WasmCanvas.restore();
+        }
+        WasmCanvas.restore();
+    }
+
+    @Import(module = "benchmark", name = "setupCanvas")
+    private static native void setupCanvas();
+
+    @Import(module = "benchmark", name = "performanceTime")
+    private static native double performanceTime();
+
+    @Import(module = "benchmark", name = "reportPerformance")
+    private static native void reportPerformance(int second, int timeSpentCalculating);
+
+    @Import(module = "benchmark", name = "repeatAfter")
+    private static native void repeatAfter(int seconds);
+}

samples/benchmark/src/main/java/org/teavm/samples/benchmark/teavm/WasmCanvas.java

@@ -0,0 +1,56 @@
+/*
+ *  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.samples.benchmark.teavm;
+
+import org.teavm.interop.Import;
+import org.teavm.interop.StaticInit;
+
+@StaticInit
+public final class WasmCanvas {
+    private WasmCanvas() {
+    }
+
+    @Import(module = "canvas", name = "save")
+    public static native void save();
+
+    @Import(module = "canvas", name = "restore")
+    public static native void restore();
+
+    @Import(module = "canvas", name = "translate")
+    public static native void translate(double x, double y);
+
+    @Import(module = "canvas", name = "rotate")
+    public static native void rotate(double angle);
+
+    @Import(module = "canvas", name = "beginPath")
+    public static native void beginPath();
+
+    @Import(module = "canvas", name = "closePath")
+    public static native void closePath();
+
+    @Import(module = "canvas", name = "stroke")
+    public static native void stroke();
+
+    @Import(module = "canvas", name = "arc")
+    public static native void arc(double cx, double cy, double radius, double startAngle, double endAngle,
+            boolean counterClockwise);
+
+    @Import(module = "canvas", name = "moveTo")
+    public static native void moveTo(double x, double y);
+
+    @Import(module = "canvas", name = "lineTo")
+    public static native void lineTo(double x, double y);
+}

samples/benchmark/src/main/webapp/teavm-wasm.html

@@ -0,0 +1,46 @@
+<!--
+  ~  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.
+  -->
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
+    <title>TeaVM WebAssembly jbox2d benchmark</title>
+    <script src="teavm-wasm.js" type="text/javascript"></script>
+  </head>
+  <body>
+    <h1>TeaVM performance</h1>
+    <div>
+      <canvas id="benchmark-canvas" width="600" height="600"></canvas>
+    </div>
+    <table>
+      <thead>
+        <tr>
+          <th>Second</th>
+          <th>Time spent computing, ms</th>
+        </tr>
+      </thead>
+      <tbody id="result-table-body">
+      </tbody>
+    </table>
+    <script>
+        var canvas = document.getElementById("benchmark-canvas");
+        document.body.onload = function() {
+            var benchmark = new Benchmark(canvas.getContext("2d"));
+            benchmark.runAll();
+        }
+    </script>
+  </body>
+</html>

samples/benchmark/src/main/webapp/teavm-wasm.js

@@ -0,0 +1,104 @@
+/*
+ *  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.
+ */
+
+var Benchmark = function() {
+    function Benchmark(canvas) {
+        this.canvas = canvas;
+        this.module = null;
+        this.line = "";
+    }
+    Benchmark.prototype.runAll = function() {
+        load(this, function() { this.module.exports.main(); }.bind(this));
+    }
+
+    function tick(benchmark) {
+        var exports = benchmark.module.exports;
+        exports.tick();
+        console.log("tick");
+        var exception = exports.sys$catchException();
+        if (exception != null) {
+            console.log("Exception: " + exception);
+        }
+    }
+
+    function currentTimeMillis() {
+        return new Date().getTime();
+    }
+
+    function putchar(benchmark, charCode) {
+        if (charCode == 10) {
+            console.log(benchmark.line);
+            benchmark.line = "";
+        } else {
+            benchmark.line += String.fromCharCode(charCode);
+        }
+    }
+
+    function load(benchmark, callback) {
+        var xhr = new XMLHttpRequest();
+        xhr.open("GET", "teavm-wasm/classes.wasm");
+        xhr.onreadystatechange = function() {
+            var response = xhr.response;
+            if (!response) {
+                return;
+            }
+            var importObj = {
+                runtime: {
+                    currentTimeMillis: currentTimeMillis,
+                    isNaN: isNaN,
+                    isFinite: isFinite,
+                    getNaN: function() { return NaN; },
+                    putchar: function() { putchar(benchmark); }
+                },
+                benchmark: {
+                    performanceTime: function() { return window.performance.now() || 0; },
+                    reportPerformance: function(second, timeSpentComputing) {
+                        console.log("Second: " + second + ", time: " + timeSpentComputing);
+                    },
+                    repeatAfter: function(time) {
+                        console.log("repeatAfter");
+                        setTimeout(tick.bind(benchmark), time);
+                    },
+                    setupCanvas: function() {
+                        var canvas = benchmark.canvas;
+                        canvas.setFillStyle("white");
+                        context.setStrokeStyle("grey");
+                        canvas.fillRect(0, 0, 600, 600);
+                        canvas.translate(0, 600);
+                        canvas.scale(1, -1);
+                        canvas.scale(100, 100);
+                        canvas.setLineWidth(0.01);
+                    }
+                },
+                canvas: benchmark.canvas,
+                math: Math,
+                debug: {
+                    traceMemoryAccess: function(callSite, address) {
+                        if (address >= 63 * 65536) {
+                            console.log("Memory access #" + callSite + " at " + address);
+                        }
+                        return address;
+                    }
+                }
+            };
+            benchmark.module = Wasm.instantiateModule(new Uint8Array(response), importObj)
+            callback();
+        };
+        xhr.send();
+    }
+
+    return Benchmark;
+}();