private MidExp SimplifyLabelExpImpl(
MidLabelExp labelExp,
MidLetExp letExp,
SimplifyEnv env)
{
// As long as the label doesn't occur in the
// bound expression, we can move it outside
// of the label's bounds.
if (!UsesLabel(letExp.Exp, labelExp.Label))
{
MidExp result = new MidLetExp(
letExp.Range,
letExp.Var,
letExp.Exp,
new MidLabelExp(
labelExp.Range,
labelExp.Label,
letExp.Body,
labelExp.Type));
result = SimplifyExp(result, env);
return(result);
}
return(labelExp);
}
private MidExp SimplifyLabelExpImpl(
MidLabelExp labelExp,
MidExp exp,
SimplifyEnv env)
{
if (!UsesLabel(exp, labelExp.Label))
{
return(exp);
}
return(labelExp);
}
private MidExp SimplifyLabelExpImpl(
MidLabelExp labelExp,
MidBreakExp breakExp,
SimplifyEnv env)
{
if (labelExp.Label == breakExp.Label)
{
return(breakExp.Value);
}
return(labelExp);
}
private EmitValHLSL EmitExpImpl(MidLabelExp exp, Span span)
{
if (_labels.ContainsKey(exp.Label))
{
return EmitExp(exp.Body, span);
}
// Try to resolve this label with
// loop nesting...
var resultType = EmitType(exp.Type);
var resultVar = resultType.CreateVal("__block_result");
DeclareLocal(resultVar, span);
Label newLabel = new BreakLabel(
exp.Label,
this,
resultVar);
_nestedLabels.Push(newLabel);
try
{
span.WriteLine("do {");
var innerSpan = span.IndentSpan();
var bodyVal = EmitExp(exp.Body, innerSpan);
if (bodyVal != null)
{
Assign(resultVar, bodyVal, innerSpan);
}
span.WriteLine("} while(false);");
}
finally
{
_nestedLabels.Pop();
}
return resultVar;
}
private MidExp SimplifyExpImpl(MidLabelExp exp, SimplifyEnv env)
{
return(SimplifyLabelExpImpl(exp, (dynamic)exp.Body, env));
}
private void TransformChildrenImpl(
MidLabelExp exp)
{
exp.Body = Transform(exp.Body);
}
public void PreEmitExpImpl(
MidLabelExp exp,
Span span)
{
PreEmitExp(exp.Body, span);
}
private MidExp SimplifyLabelExpImpl(
MidLabelExp labelExp,
MidExp exp,
SimplifyEnv env)
{
if (!UsesLabel(exp, labelExp.Label))
return exp;
return labelExp;
}
private MidExp SimplifyLabelExpImpl(
MidLabelExp labelExp,
MidBreakExp breakExp,
SimplifyEnv env)
{
if (labelExp.Label == breakExp.Label)
{
return breakExp.Value;
}
return labelExp;
}
private MidExp SimplifyLabelExpImpl(
MidLabelExp labelExp,
MidLetExp letExp,
SimplifyEnv env)
{
// As long as the label doesn't occur in the
// bound expression, we can move it outside
// of the label's bounds.
if (!UsesLabel(letExp.Exp, labelExp.Label))
{
MidExp result = new MidLetExp(
letExp.Range,
letExp.Var,
letExp.Exp,
new MidLabelExp(
labelExp.Range,
labelExp.Label,
letExp.Body,
labelExp.Type));
result = SimplifyExp(result, env);
return result;
}
return labelExp;
}
private MidExp SimplifyExpImpl(MidLabelExp exp, SimplifyEnv env)
{
return SimplifyLabelExpImpl(exp, (dynamic) exp.Body, env);
}
private void TransformChildrenImpl(
MidLabelExp exp)
{
exp.Body = Transform(exp.Body);
}