EntryAndExitPoints.cs

var tree = CSharpSyntaxTree.ParseText(@"
class C
{
    void M(int x)
    {
        L1: ; // 1
        if (x == 0) goto L1;    //firstIf
        if (x == 1) goto L2;
        if (x == 3) goto L3;
        L3: ;                   //label3
        L2: ; // 2
        if(x == 4) goto L3;
    }
}
");

var Mscorlib = PortableExecutableReference.CreateFromAssembly(typeof(object).Assembly);
var compilation = CSharpCompilation.Create("MyCompilation",
syntaxTrees: new[] { tree }, references: new[] { Mscorlib });
var model = compilation.GetSemanticModel(tree);

//Choose first and last statements
var firstIf = tree.GetRoot().DescendantNodes().OfType<IfStatementSyntax>().First();
var label3 = tree.GetRoot().DescendantNodes().OfType<LabeledStatementSyntax>().Skip(1).Take(1).Single();

ControlFlowAnalysis result = model.AnalyzeControlFlow(firstIf, label3);
Console.WriteLine(result.EntryPoints);      //1 - Label 3 is a candidate entry point within these statements
Console.WriteLine(result.ExitPoints);       //2 - goto L1 and goto L2 and candidate exit points