private bool _AreEqual(VariableExpression a, VariableExpression b)
{
if (_aliases == null)
{
return(a.Name.Equals(b.Name));
}
// TODO currently only allowing one single alias. There are cases
// multiple are correct, but also where not. If loop dependence analysis
// supports branches, this has to be improved.
var aAliases = _aliases.GetAliasesOfVariableBefore(a.Name, _aNode).ToList();
if (aAliases.Count != 1)
{
return(false);
}
var bAliases = _aliases.GetAliasesOfVariableBefore(b.Name, _bNode).ToList();
if (bAliases.Count != 1)
{
return(false);
}
// TODO support nested expressions through aliasing?
return(aAliases.Single().Equals(bAliases.Single()));
}
private Expression _GetAliasTarget(string variableName, FlowNode node)
{
// TODO at this point this check is unnecessary and could be removed.
// because of the loop dependence analysis check beforehand which does not support
// multiple values of a variable, there should actually be exactly one alias.
var aliases = _aliasAnalysis.GetAliasesOfVariableBefore(variableName, node).ToList();
if (aliases.Count != 1)
{
// TODO it might be possible to support multiple distinct aliases in some cases
throw new UnsupportedSyntaxException($"detected multiple possible values for variable {variableName}: {aliases}");
}
return(aliases[0].Target);
}
