While eliminator

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

@@ -0,0 +1,111 @@
+/*
+ *  Copyright 2014 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.List;
+import org.teavm.javascript.ast.*;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+class BreakToContinueReplacer implements StatementVisitor {
+    private IdentifiedStatement replacedBreak;
+    private IdentifiedStatement replacement;
+    private ContinueStatement replaceBy;
+
+    public BreakToContinueReplacer(IdentifiedStatement replacedBreak, IdentifiedStatement replacement) {
+        this.replacedBreak = replacedBreak;
+        this.replacement = replacement;
+    }
+
+    @Override
+    public void visit(AssignmentStatement statement) {
+    }
+
+    public void visitSequence(List<Statement> statements) {
+        for (int i = 0; i < statements.size(); ++i) {
+            Statement stmt = statements.get(i);
+            stmt.acceptVisitor(this);
+            if (replaceBy != null) {
+                statements.set(i, replaceBy);
+                replaceBy = null;
+            }
+        }
+    }
+
+    @Override
+    public void visit(SequentialStatement statement) {
+        visitSequence(statement.getSequence());
+    }
+
+    @Override
+    public void visit(ConditionalStatement statement) {
+        visitSequence(statement.getConsequent());
+        visitSequence(statement.getAlternative());
+    }
+
+    @Override
+    public void visit(SwitchStatement statement) {
+        for (SwitchClause clause : statement.getClauses()) {
+            visitSequence(clause.getBody());
+        }
+        visitSequence(statement.getDefaultClause());
+    }
+
+    @Override
+    public void visit(WhileStatement statement) {
+        visitSequence(statement.getBody());
+    }
+
+    @Override
+    public void visit(BlockStatement statement) {
+        visitSequence(statement.getBody());
+    }
+
+    @Override
+    public void visit(ForStatement statement) {
+    }
+
+    @Override
+    public void visit(BreakStatement statement) {
+        if (statement.getTarget() == replacedBreak) {
+            replaceBy = new ContinueStatement();
+            replaceBy.setTarget(replacement);
+        }
+    }
+
+    @Override
+    public void visit(ContinueStatement statement) {
+    }
+
+    @Override
+    public void visit(ReturnStatement statement) {
+    }
+
+    @Override
+    public void visit(ThrowStatement statement) {
+    }
+
+    @Override
+    public void visit(IncrementStatement statement) {
+    }
+
+    @Override
+    public void visit(InitClassStatement statement) {
+    }
+
+}

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

@@ -447,6 +447,13 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
 
     @Override
     public void visit(WhileStatement statement) {
+        if (statement.getBody().size() == 1 && statement.getBody().get(0) instanceof WhileStatement) {
+            WhileStatement innerLoop = (WhileStatement)statement.getBody().get(0);
+            BreakToContinueReplacer replacer = new BreakToContinueReplacer(innerLoop, statement);
+            replacer.visitSequence(innerLoop.getBody());
+            statement.getBody().clear();
+            statement.getBody().addAll(innerLoop.getBody());
+        }
         List<Statement> statements = processSequence(statement.getBody(), true);
         statement.getBody().clear();
         statement.getBody().addAll(statements);
@@ -454,6 +461,25 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
             statement.getCondition().acceptVisitor(this);
             statement.setCondition(resultExpr);
         }
+        while (true) {
+            if (!statement.getBody().isEmpty() && statement.getBody().get(0) instanceof ConditionalStatement) {
+                ConditionalStatement cond = (ConditionalStatement)statement.getBody().get(0);
+                if (cond.getConsequent().size() == 1 && cond.getConsequent().get(0) instanceof BreakStatement) {
+                    BreakStatement breakStmt = (BreakStatement)cond.getConsequent().get(0);
+                    if (breakStmt.getTarget() == statement) {
+                        statement.getBody().remove(0);
+                        if (statement.getCondition() != null) {
+                            statement.setCondition(Expr.binary(BinaryOperation.AND, statement.getCondition(),
+                                    ExprOptimizer.invert(cond.getCondition())));
+                        } else {
+                            statement.setCondition(ExprOptimizer.invert(cond.getCondition()));
+                        }
+                        continue;
+                    }
+                }
+            }
+            break;
+        }
         resultStmt = statement;
     }