Attempting to increase performance of AST processing

teavm-core/src/main/java/org/teavm/javascript/AllBlocksCountVisitor.java

@@ -0,0 +1,134 @@
+/*
+ *  Copyright 2015 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.javascript;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import org.teavm.javascript.ast.*;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+class AllBlocksCountVisitor implements StatementVisitor {
+    private Map<IdentifiedStatement, Integer> blocksCount = new HashMap<>();
+    private IdentifiedStatement currentBlock;
+
+    public void visit(List<Statement> statements) {
+        if (statements == null) {
+            return;
+        }
+        for (Statement part : statements) {
+            part.acceptVisitor(this);
+        }
+    }
+
+    public int getCount(IdentifiedStatement statement) {
+        Integer result = blocksCount.get(statement);
+        return result != null ? result : 0;
+    }
+
+    @Override
+    public void visit(AssignmentStatement statement) {
+    }
+
+    @Override
+    public void visit(SequentialStatement statement) {
+        visit(statement.getSequence());
+    }
+
+    @Override
+    public void visit(ConditionalStatement statement) {
+        visit(statement.getConsequent());
+        visit(statement.getAlternative());
+    }
+
+    @Override
+    public void visit(SwitchStatement statement) {
+        IdentifiedStatement oldCurrentBlock = currentBlock;
+        currentBlock = statement;
+        for (SwitchClause clause : statement.getClauses()) {
+            visit(clause.getBody());
+        }
+        visit(statement.getDefaultClause());
+        currentBlock = oldCurrentBlock;
+    }
+
+    @Override
+    public void visit(WhileStatement statement) {
+        IdentifiedStatement oldCurrentBlock = currentBlock;
+        currentBlock = statement;
+        visit(statement.getBody());
+        currentBlock = oldCurrentBlock;
+    }
+
+    @Override
+    public void visit(BlockStatement statement) {
+        IdentifiedStatement oldCurrentBlock = currentBlock;
+        currentBlock = statement;
+        visit(statement.getBody());
+        currentBlock = oldCurrentBlock;
+    }
+
+    @Override
+    public void visit(BreakStatement statement) {
+        IdentifiedStatement target = statement.getTarget();
+        if (target == null) {
+            target = currentBlock;
+        }
+        blocksCount.put(target, getCount(target) + 1);
+    }
+
+    @Override
+    public void visit(ContinueStatement statement) {
+        IdentifiedStatement target = statement.getTarget();
+        if (target == null) {
+            target = currentBlock;
+        }
+        blocksCount.put(target, getCount(target) + 1);
+    }
+
+    @Override
+    public void visit(ReturnStatement statement) {
+    }
+
+    @Override
+    public void visit(ThrowStatement statement) {
+    }
+
+    @Override
+    public void visit(InitClassStatement statement) {
+    }
+
+    @Override
+    public void visit(TryCatchStatement statement) {
+        visit(statement.getProtectedBody());
+        visit(statement.getHandler());
+    }
+
+    @Override
+    public void visit(GotoPartStatement statement) {
+    }
+
+    @Override
+    public void visit(MonitorEnterStatement statement) {
+    }
+
+    @Override
+    public void visit(MonitorExitStatement statement) {
+    }
+}

teavm-core/src/main/java/org/teavm/javascript/BreakEliminator.java

@@ -28,6 +28,13 @@ class BreakEliminator implements StatementVisitor {
     private List<Statement> currentSequence;
     private boolean sequenceEscapes;
     private int currentIndex;
+    private AllBlocksCountVisitor usageCounter;
+
+    public void eliminate(Statement statement) {
+        usageCounter = new AllBlocksCountVisitor();
+        statement.acceptVisitor(usageCounter);
+        statement.acceptVisitor(this);
+    }
 
     private void processSequence(List<Statement> statements) {
         List<Statement> oldSequence = currentSequence;
@@ -97,10 +104,7 @@ class BreakEliminator implements StatementVisitor {
     @Override
     public void visit(BreakStatement statement) {
         if (blockSuccessors.containsKey(statement.getTarget())) {
-            BlockCountVisitor usageCounter = new BlockCountVisitor(
+            if (usageCounter.getCount(statement.getTarget()) == 1) {
-                    (BlockStatement)statement.getTarget());
-            statement.getTarget().acceptVisitor(usageCounter);
-            if (usageCounter.getCount() == 1) {
                 currentSequence.subList(currentIndex, currentSequence.size()).clear();
                 List<Statement> successors = blockSuccessors.remove(statement.getTarget());
                 currentSequence.addAll(successors);

teavm-core/src/main/java/org/teavm/javascript/Optimizer.java

@@ -36,7 +36,7 @@ public class Optimizer {
             }
         }
         BreakEliminator breakEliminator = new BreakEliminator();
-        method.getBody().acceptVisitor(breakEliminator);
+        breakEliminator.eliminate(method.getBody());
         OptimizingVisitor optimizer = new OptimizingVisitor(preservedVars, stats.reads);
         method.getBody().acceptVisitor(optimizer);
         method.setBody(optimizer.resultStmt);
@@ -67,7 +67,7 @@ public class Optimizer {
         for (int i = 0; i < splitter.size(); ++i) {
             AsyncMethodPart part = method.getBody().get(i);
             BreakEliminator breakEliminator = new BreakEliminator();
-            part.getStatement().acceptVisitor(breakEliminator);
+            breakEliminator.eliminate(part.getStatement());
             OptimizingVisitor optimizer = new OptimizingVisitor(preservedVars, readFrequencies[i]);
             part.getStatement().acceptVisitor(optimizer);
             part.setStatement(optimizer.resultStmt);

teavm-core/src/main/java/org/teavm/javascript/OptimizingVisitor.java

@@ -370,13 +370,10 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
             return;
         }
         Statement last = statements.get(statements.size() - 1);
-        if (last instanceof BreakStatement) {
+        if (last instanceof BreakStatement && exit != null) {
-            BreakStatement breakStmt = (BreakStatement)last;
+            IdentifiedStatement target = ((BreakStatement)last).getTarget();
-            if (exit != null) {
+            if (exit == target) {
-                IdentifiedStatement target = breakStmt.getTarget();
+                statements.remove(statements.size() - 1);
-                if (exit == target) {
-                    statements.remove(statements.size() - 1);
-                }
             }
         }
         if (statements.isEmpty()) {
@@ -453,6 +450,7 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
         }
     }
 
+
     private void normalizeConditional(ConditionalStatement stmt) {
         if (stmt.getConsequent().isEmpty()) {
             stmt.getConsequent().addAll(stmt.getAlternative());
@@ -566,7 +564,6 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
     public void visit(BlockStatement statement) {
         List<Statement> statements = processSequence(statement.getBody());
         eliminateRedundantBreaks(statements, statement);
-        statements = processSequence(statements);
         BlockCountVisitor usageCounter = new BlockCountVisitor(statement);
         usageCounter.visit(statements);
         if (usageCounter.getCount() == 0) {

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

@@ -292,7 +292,7 @@ public class TeaVMTool {
             }
             targetDirectory.mkdirs();
             try (Writer writer = new OutputStreamWriter(new BufferedOutputStream(
-                    new FileOutputStream(new File(targetDirectory, targetFileName))), "UTF-8")) {
+                    new FileOutputStream(new File(targetDirectory, targetFileName)), 65536), "UTF-8")) {
                 if (runtime == RuntimeCopyOperation.MERGED) {
                     vm.add(runtimeInjector);
                 }