Continue for simple loops (while/for).

frog/leg/ssa/nodes.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 interface HVisitor<R> {
   R visitAdd(HAdd node);
   R visitBailoutTarget(HBailoutTarget node);
   R visitBitAnd(HBitAnd node);
   R visitBitNot(HBitNot node);
   R visitBitOr(HBitOr node);
   R visitBitXor(HBitXor node);
   R visitBoolify(HBoolify node);
   R visitBoundsCheck(HBoundsCheck node);
   R visitBreak(HBreak node);
   R visitConstant(HConstant node);
+  R visitContinue(HContinue node);
   R visitDivide(HDivide node);
   R visitEquals(HEquals node);
   R visitExit(HExit node);
   R visitFieldGet(HFieldGet node);
   R visitFieldSet(HFieldSet node);
   R visitForeign(HForeign node);
   R visitForeignNew(HForeignNew node);
   R visitGoto(HGoto node);
   R visitGreater(HGreater node);
   R visitGreaterEqual(HGreaterEqual node);
@@ skipping 223 matching lines @@
 
   visitAdd(HAdd node) => visitBinaryArithmetic(node);
   visitBitAnd(HBitAnd node) => visitBinaryBitOp(node);
   visitBitNot(HBitNot node) => visitInvokeUnary(node);
   visitBitOr(HBitOr node) => visitBinaryBitOp(node);
   visitBitXor(HBitXor node) => visitBinaryBitOp(node);
   visitBailoutTarget(HBailoutTarget node) => visitInstruction(node);
   visitBoolify(HBoolify node) => visitInstruction(node);
   visitBoundsCheck(HBoundsCheck node) => visitCheck(node);
   visitBreak(HBreak node) => visitGoto(node);
+  visitContinue(HContinue node) => visitGoto(node);
   visitCheck(HCheck node) => visitInstruction(node);
   visitConstant(HConstant node) => visitInstruction(node);
   visitDivide(HDivide node) => visitBinaryArithmetic(node);
   visitEquals(HEquals node) => visitRelational(node);
   visitExit(HExit node) => visitControlFlow(node);
   visitFieldGet(HFieldGet node) => visitInstruction(node);
   visitFieldSet(HFieldSet node) => visitInstruction(node);
   visitForeign(HForeign node) => visitInstruction(node);
   visitForeignNew(HForeignNew node) => visitForeign(node);
   visitGoto(HGoto node) => visitControlFlow(node);
@@ skipping 377 matching lines @@
   }
 
   bool isValid() {
     assert(isClosed());
     HValidator validator = new HValidator();
     validator.visitBasicBlock(this);
     return validator.isValid;
   }
 }
 
-class HBlockInformation {
-  // Just a marker class.
-}
-
-class HLabeledBlockInformation extends HBlockInformation {
+class HLabeledBlockInformation {
   final SubGraph body;
   final HBasicBlock joinBlock;
   final List<LabelElement> labels;
   final TargetElement target;
+  final bool isContinue;
 
   HLabeledBlockInformation(this.body, this.joinBlock,
-                           List<LabelElement> labels) :
+                           List<LabelElement> labels,
+                           [this.isContinue = false]) :
       this.labels = labels, this.target = labels[0].target;
 
-  // For creating block information when there are no explicit labels.
-  HLabeledBlockInformation.implicit(this.body, this.joinBlock, this.target) :
-      this.labels = const<LabelElement>[];
+  HLabeledBlockInformation.implicit(this.body,
+                                    this.joinBlock,
+                                    this.target,
+                                    [this.isContinue = false])
+      : this.labels = const<LabelElement>[];
 }
 
-class HLoopInformation extends HBlockInformation {
+class HLoopInformation {
   final HBasicBlock header;
   final List<HBasicBlock> blocks;
   final List<HBasicBlock> backEdges;
   final List<LabelElement> labels;
 
   HLoopInformation(this.header, this.labels)
       : blocks = new List<HBasicBlock>(),
         backEdges = new List<HBasicBlock>();
 
   void addBackEdge(HBasicBlock predecessor) {
@@ skipping 918 matching lines @@
   accept(HVisitor visitor) => visitor.visitExit(this);
 }
 
 class HGoto extends HControlFlow {
   HGoto() : super(const <HInstruction>[]);
   toString() => 'goto';
   accept(HVisitor visitor) => visitor.visitGoto(this);
 }
 
 class HBreak extends HGoto {
-  // Target is either a LabelElement or a TargetElement.
   final TargetElement target;
   final LabelElement label;
   HBreak(this.target) : label = null;
   HBreak.toLabel(LabelElement label) : label = label, target = label.target;
-  toString() => (target is LabelElement) ? 'break ${label.labelName}' : 'break';
+  toString() => (label !== null) ? 'break ${label.labelName}' : 'break';
   accept(HVisitor visitor) => visitor.visitBreak(this);
 }
 
+class HContinue extends HGoto {
+  final TargetElement target;
+  final LabelElement label;
+  HContinue(this.target) : label = null;
+  HContinue.toLabel(LabelElement label) : label = label, target = label.target;
+  toString() => (label !== null) ? 'continue ${label.labelName}' : 'continue';
+  accept(HVisitor visitor) => visitor.visitContinue(this);
+}
+
 class HTry extends HControlFlow {
   HParameterValue exception;
   HBasicBlock finallyBlock;
   HTry() : super(const <HInstruction>[]);
   toString() => 'try';
   accept(HVisitor visitor) => visitor.visitTry(this);
   HBasicBlock get joinBlock() => this.block.successors.last();
 }
 
 class HIf extends HConditionalBranch {
@@ skipping 500 matching lines @@
 class HIfBlockInformation {
   final HIf branch;
   final SubGraph thenGraph;
   final SubGraph elseGraph;
   final HBasicBlock joinBlock;
   HIfBlockInformation(this.branch,
                       this.thenGraph,
                       this.elseGraph,
                       this.joinBlock);
 }