/// <summary>
/// Perform data-flow analysis to get dead definitions for each basic block.
/// </summary>
/// <param name="Graph">HlGraph.</param>
/// <returns>Data flow results.</returns>
/// <remarks>Dead definitions is an all-paths reverse data flow problem described by the
/// following equations:
///
/// <code>
/// InitFn(n) := ( (n == CanonicalExit) ? ALL_STACK | ALL_LOCAL | ALL_ARG : TOP, TOP )
/// NodeFn(n, l) := l + n.DAD - n.UEU
/// EdgeFn(s, t, l) := l
/// MergeFn(l, r) := (l & r)
/// </code>
/// </remarks>
public static DataFlow <LocationList> .Result DoDF(HlGraph Graph)
{
DataFlow <LocationList> .Result DfResult = DataFlow <LocationList> .Reverse(
Graph.BasicBlocks,
delegate(BasicBlock BasicBlock, out LocationList Entry, out LocationList Exit)
{
if (Graph.CanonicalExitBlock == BasicBlock)
{
Entry = new LocationList();
for (int i = 0; i < Graph.m_MaxStack; i++)
{
Entry.Add(new StackLocation(i));
}
foreach (LocalVariableLocation LocVar in Graph.LocalVariables)
{
Entry.Add(LocVar);
}
foreach (ArgumentLocation Arg in Graph.Arguments)
{
Entry.Add(Arg);
}
Exit = null;
}
else
{
Entry = Exit = null;
}
},
delegate(BasicBlock BasicBlock, LocationList DeadDefinitionList)
{
return(BeforeInstruction(BasicBlock, 0, DeadDefinitionList));
},
delegate(BasicBlock Source, BasicBlock Target, LocationList DeadDefinitionList)
{
return(DeadDefinitionList);
},
LocationList.MergeInlineAnd
);
return(DfResult);
}