protected internal override void VisitAST(ForStmtAST node)
{
this.Visit(node.PreRun); // init
var(postLabel, endLabel) = OpenLoop();
var beginLabel = Ins.CreateLabel();
GenCode.Add(Ins.Label(beginLabel));
this.Visit(node.InfLoop.Cond);
// repeat's logic is opposite to for
if (node.NodeType == ASTType.Repeat)
{
GenCode.Add(Ins.Not());
}
GenCode.Add(Ins.Fjp(endLabel));
// body
this.Visit(node.InfLoop.Body);
// post run
GenCode.Add(Ins.Label(postLabel));
this.Visit(node.PostRun);
// jump to cond
GenCode.Add(Ins.Ujp(beginLabel));
GenCode.Add(Ins.Label(endLabel));
CloseLoop();
}
protected internal override void VisitAST(IfStmtAST node)
{
var elseLabel = Ins.CreateLabel();
var endLabel = Ins.CreateLabel();
Branch ifBranch = node.Branches.First();
this.Visit(ifBranch.Cond);
GenCode.Add(Ins.Fjp(elseLabel));
this.Visit(ifBranch.Body);
GenCode.Add(Ins.Ujp(endLabel));
GenCode.Add(Ins.Label(elseLabel));
this.Visit(node.ElseBranch?.Body);
GenCode.Add(Ins.Label(endLabel));
}
protected internal override void VisitAST(RepeatStmtAST node)
{
var(beginLabel, endLabel) = OpenLoop();
GenCode.Add(Ins.Label(beginLabel));
this.Visit(node.InfLoop.Body);
// repeat's logic is opposite to for
this.Visit(node.InfLoop.Cond);
GenCode.Add(Ins.Not());
GenCode.Add(Ins.Fjp(endLabel));
GenCode.Add(Ins.Ujp(beginLabel));
GenCode.Add(Ins.Label(endLabel));
CloseLoop();
}