Esempio n. 1
0
            /// <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 &amp; 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);
            }