Exemplo n.º 1
0
        /// <summary>
        /// This callback is called from the SccFinder, which passes it a list
        /// of Procedures that form a SCC.
        /// </summary>
        /// <param name="procs"></param>
        private void UntangleProcedureScc(IList <Procedure> procs)
        {
            this.sccProcs = procs.ToHashSet();
            flow.CreateFlowsFor(procs);

            // Convert all procedures in the SCC to SSA form and perform
            // value propagation.
            var ssts = procs.Select(ConvertToSsa).ToArray();

            this.ssts.AddRange(ssts);
            DumpWatchedProcedure("After extra stack vars", ssts);

            // At this point, the computation of ProcedureFlow is possible.
            var trf = new TrashedRegisterFinder(program, flow, ssts, this.eventListener);

            trf.Compute();

            // New stack based variables may be available now.
            foreach (var sst in ssts)
            {
                var vp = new ValuePropagator(program.SegmentMap, sst.SsaState, program.CallGraph, dynamicLinker, this.eventListener);
                vp.Transform();
                sst.RenameFrameAccesses = true;
                sst.Transform();
                DumpWatchedProcedure("After extra stack vars", sst.SsaState.Procedure);
            }

            foreach (var ssa in ssts.Select(sst => sst.SsaState))
            {
                RemoveImplicitRegistersFromHellNodes(ssa);
                var sac = new SegmentedAccessClassifier(ssa);
                sac.Classify();
                var prj = new ProjectionPropagator(ssa, sac);
                prj.Transform();
                DumpWatchedProcedure("After projection propagation", ssa.Procedure);
            }

            var uid = new UsedRegisterFinder(flow, procs, this.eventListener);

            foreach (var sst in ssts)
            {
                var ssa = sst.SsaState;
                RemovePreservedUseInstructions(ssa);
                DeadCode.Eliminate(ssa);
                uid.ComputeLiveIn(ssa, true);
                var procFlow = flow[ssa.Procedure];
                RemoveDeadArgumentsFromCalls(ssa.Procedure, procFlow, ssts);
                DumpWatchedProcedure("After dead call argument removal", ssa.Procedure);
            }
            eventListener.Advance(procs.Count);
        }
Exemplo n.º 2
0
        /// <summary>
        /// Finds all interprocedural register dependencies (in- and out-parameters) and
        /// abstracts them away by rewriting as calls.
        /// </summary>
        /// <returns>A RegisterLiveness object that summarizes the interprocedural register
        /// liveness analysis. This information can be used to generate SSA form.
        /// </returns>
        public void UntangleProcedures()
        {
            eventListener.ShowStatus("Eliminating intra-block dead registers.");
            IntraBlockDeadRegisters.Apply(program);
            eventListener.ShowStatus("Finding terminating procedures.");
            var term = new TerminationAnalysis(flow);

            term.Analyze(program);
            eventListener.ShowStatus("Finding trashed registers.");
            var trf = new TrashedRegisterFinder(program, program.Procedures.Values, flow, eventListener);

            trf.Compute();
            eventListener.ShowStatus("Rewriting affine expressions.");
            trf.RewriteBasicBlocks();
            eventListener.ShowStatus("Computing register liveness.");
            var rl = RegisterLiveness.Compute(program, flow, eventListener);

            eventListener.ShowStatus("Rewriting calls.");
            GlobalCallRewriter.Rewrite(program, flow);
        }
Exemplo n.º 3
0
        /// <summary>
        /// Finds all interprocedural register dependencies (in- and out-parameters) and
        /// abstracts them away by rewriting as calls.
        /// </summary>
        /// <returns>A RegisterLiveness object that summarizes the interprocedural register
        /// liveness analysis. This information can be used to generate SSA form.
        /// </returns>
        public void UntangleProcedures()
        {
            eventListener.ShowStatus("Eliminating intra-block dead registers.");
            var usb = new UserSignatureBuilder(program);

            usb.BuildSignatures(eventListener);
            CallRewriter.Rewrite(program, eventListener);
            IntraBlockDeadRegisters.Apply(program, eventListener);
            AdjacentBranchCollector.Transform(program, eventListener);
            eventListener.ShowStatus("Finding terminating procedures.");
            var term = new TerminationAnalysis(flow, eventListener);

            term.Analyze(program);
            eventListener.ShowStatus("Finding trashed registers.");
            var trf = new TrashedRegisterFinder(program, program.Procedures.Values, flow, eventListener);

            trf.Compute();
            eventListener.ShowStatus("Rewriting affine expressions.");
            trf.RewriteBasicBlocks();
            eventListener.ShowStatus("Computing register liveness.");
            RegisterLiveness.Compute(program, flow, eventListener);
            eventListener.ShowStatus("Rewriting calls.");
            GlobalCallRewriter.Rewrite(program, flow, eventListener);
        }