public override Value?Visit(ConditionalExpression conditionalExpression)
{
conditionalExpression.ValidateNotNull(nameof(conditionalExpression));
var result = LookupVariable(conditionalExpression.ResultVariable.Name);
EmitLocation(conditionalExpression);
var condition = conditionalExpression.Condition.Accept(this);
if (condition == null)
{
return(null);
}
EmitLocation(conditionalExpression);
var condBool = InstructionBuilder.Compare(RealPredicate.OrderedAndNotEqual, condition, Context.CreateConstant(0.0))
.RegisterName("ifcond");
var function = InstructionBuilder.InsertFunction;
if (function is null)
{
throw new InternalCodeGeneratorException("ICE: expected block that is attached to a function at this point");
}
var thenBlock = function.AppendBasicBlock("then");
var elseBlock = function.AppendBasicBlock("else");
var continueBlock = function.AppendBasicBlock("ifcont");
InstructionBuilder.Branch(condBool, thenBlock, elseBlock);
// generate then block instructions
InstructionBuilder.PositionAtEnd(thenBlock);
// InstructionBuilder.InserBlock after this point is !null
Debug.Assert(InstructionBuilder.InsertBlock != null, "expected non-null InsertBlock");
var thenValue = conditionalExpression.ThenExpression.Accept(this);
if (thenValue == null)
{
return(null);
}
InstructionBuilder.Store(thenValue, result);
InstructionBuilder.Branch(continueBlock);
// generate else block
InstructionBuilder.PositionAtEnd(elseBlock);
var elseValue = conditionalExpression.ElseExpression.Accept(this);
if (elseValue == null)
{
return(null);
}
InstructionBuilder.Store(elseValue, result);
InstructionBuilder.Branch(continueBlock);
// generate continue block
InstructionBuilder.PositionAtEnd(continueBlock);
// since the Alloca is created as a non-opaque pointer it is OK to just use the
// ElementType. If full opaque pointer support was used, then the Lookup map
// would need to include the type of the value allocated.
return(InstructionBuilder.Load(result.ElementType, result)
.RegisterName("ifresult"));
}