C# Implementation.ComputePredecessorsForBlocks方法代码示例

 private Graph<Block> ComputeYieldingLoopHeaders(Implementation impl, out HashSet<Block> yieldingHeaders)
 {
     Graph<Block> graph;
     impl.PruneUnreachableBlocks();
     impl.ComputePredecessorsForBlocks();
     graph = Program.GraphFromImpl(impl);
     graph.ComputeLoops();
     if (!graph.Reducible)
     {
         throw new Exception("Irreducible flow graphs are unsupported.");
     }
     yieldingHeaders = new HashSet<Block>();
     IEnumerable<Block> sortedHeaders = graph.SortHeadersByDominance();
     foreach (Block header in sortedHeaders)
     {
         if (yieldingHeaders.Any(x => graph.DominatorMap.DominatedBy(x, header)))
         {
             yieldingHeaders.Add(header);
         }
         else if (IsYieldingHeader(graph, header))
         {
             yieldingHeaders.Add(header);
         }
         else
         {
             continue;
         }
     }
     return graph;
 }

    public Graph<Block> ProcessLoops(Implementation impl) {
      while (true) {
        impl.PruneUnreachableBlocks();
        impl.ComputePredecessorsForBlocks();
        Graph<Block/*!*/>/*!*/ g = GraphFromImpl(impl);
        g.ComputeLoops();
        if (g.Reducible) {
          return g;
        }
        throw new IrreducibleLoopException();
#if USED_CODE
        System.Diagnostics.Debug.Assert(g.SplitCandidates.Count > 0);
        Block splitCandidate = null;
        foreach (Block b in g.SplitCandidates) {
          if (b.Predecessors.Length > 1) {
            splitCandidate = b;
            break;
          }
        }
        System.Diagnostics.Debug.Assert(splitCandidate != null);
        int count = 0;
        foreach (Block b in splitCandidate.Predecessors) {
          GotoCmd gotoCmd = (GotoCmd)b.TransferCmd;
          gotoCmd.labelNames.Remove(splitCandidate.Label);
          gotoCmd.labelTargets.Remove(splitCandidate);

          CodeCopier codeCopier = new CodeCopier(new Hashtable(), new Hashtable());
          List<Cmd> newCmdSeq = codeCopier.CopyCmdSeq(splitCandidate.Cmds);
          TransferCmd newTransferCmd;
          GotoCmd splitGotoCmd = splitCandidate.TransferCmd as GotoCmd;
          if (splitGotoCmd == null) {
            newTransferCmd = new ReturnCmd(splitCandidate.tok);
          }
          else {
            List<String> newLabelNames = new List<String>();
            newLabelNames.AddRange(splitGotoCmd.labelNames);
            List<Block> newLabelTargets = new List<Block>();
            newLabelTargets.AddRange(splitGotoCmd.labelTargets);
            newTransferCmd = new GotoCmd(splitCandidate.tok, newLabelNames, newLabelTargets);
          }
          Block copy = new Block(splitCandidate.tok, splitCandidate.Label + count++, newCmdSeq, newTransferCmd);

          impl.Blocks.Add(copy);
          gotoCmd.AddTarget(copy);
        }
#endif
      }
    }

        public override Implementation VisitImplementation(Implementation node)
        {
            node.PruneUnreachableBlocks();
            node.ComputePredecessorsForBlocks();
            GraphUtil.Graph<Block> graph = Program.GraphFromImpl(node);
            graph.ComputeLoops();

            HashSet<Variable> start = new HashSet<Variable>(globalVarToDomainName.Keys);
            for (int i = 0; i < node.InParams.Count; i++)
            {
                Variable v = node.Proc.InParams[i];
                string domainName = FindDomainName(v);
                if (domainName != null)
                {
                    var kind = FindLinearKind(v);
                    inParamToLinearQualifier[node.InParams[i]] = new LinearQualifier(domainName, kind);
                    if (kind == LinearKind.LINEAR || kind == LinearKind.LINEAR_IN)
                    {
                        start.Add(node.InParams[i]);
                    }
                }
            }
            for (int i = 0; i < node.OutParams.Count; i++)
            {
                string domainName = FindDomainName(node.Proc.OutParams[i]);
                if (domainName != null)
                {
                    outParamToDomainName[node.OutParams[i]] = domainName;
                }
            }
            
            var oldErrorCount = this.errorCount;
            var impl = base.VisitImplementation(node);
            if (oldErrorCount < this.errorCount)
                return impl;

            Stack<Block> dfsStack = new Stack<Block>();
            HashSet<Block> dfsStackAsSet = new HashSet<Block>();
            availableLinearVars[node.Blocks[0]] = start;
            dfsStack.Push(node.Blocks[0]);
            dfsStackAsSet.Add(node.Blocks[0]);
            while (dfsStack.Count > 0)
            {
                Block b = dfsStack.Pop();
                dfsStackAsSet.Remove(b);
                HashSet<Variable> end = PropagateAvailableLinearVarsAcrossBlock(b);
                if (b.TransferCmd is ReturnCmd)
                {
                    foreach (GlobalVariable g in globalVarToDomainName.Keys.Except(end))
                    {
                        Error(b.TransferCmd, string.Format("Global variable {0} must be available at a return", g.Name));
                    } 
                    foreach (Variable v in node.InParams)
                    {
                        if (FindDomainName(v) == null || FindLinearKind(v) == LinearKind.LINEAR_IN || end.Contains(v)) continue;
                        Error(b.TransferCmd, string.Format("Input variable {0} must be available at a return", v.Name));
                    }
                    foreach (Variable v in node.OutParams)
                    {
                        if (FindDomainName(v) == null || end.Contains(v)) continue;
                        Error(b.TransferCmd, string.Format("Output variable {0} must be available at a return", v.Name));
                    }
                    continue;
                }
                GotoCmd gotoCmd = b.TransferCmd as GotoCmd;
                foreach (Block target in gotoCmd.labelTargets)
                {
                    if (!availableLinearVars.ContainsKey(target))
                    {
                        availableLinearVars[target] = new HashSet<Variable>(end);
                        dfsStack.Push(target);
                        dfsStackAsSet.Add(target);
                    }
                    else
                    {
                        var savedAvailableVars = new HashSet<Variable>(availableLinearVars[target]);
                        availableLinearVars[target].IntersectWith(end);
                        if (savedAvailableVars.IsProperSupersetOf(availableLinearVars[target]) && !dfsStackAsSet.Contains(target))
                        {
                            dfsStack.Push(target);
                            dfsStackAsSet.Add(target);
                        }
                    }
                }
            }

            if (graph.Reducible)
            {
                foreach (Block header in graph.Headers)
                {
                    foreach (GlobalVariable g in globalVarToDomainName.Keys.Except(availableLinearVars[header]))
                    {
                        Error(header, string.Format("Global variable {0} must be available at a loop head", g.Name));
                    }
                }
            }
            return impl;
        }

        private void TransformImpl(Implementation impl)
        {
            if (!QKeyValue.FindBoolAttribute(impl.Proc.Attributes, "yields")) return;

            // Find the yielding loop headers
            impl.PruneUnreachableBlocks();
            impl.ComputePredecessorsForBlocks();
            GraphUtil.Graph<Block> graph = Program.GraphFromImpl(impl);
            graph.ComputeLoops();
            if (!graph.Reducible)
            {
                throw new Exception("Irreducible flow graphs are unsupported.");
            }
            HashSet<Block> yieldingHeaders = new HashSet<Block>();
            IEnumerable<Block> sortedHeaders = graph.SortHeadersByDominance();
            foreach (Block header in sortedHeaders)
            {
                if (yieldingHeaders.Any(x => graph.DominatorMap.DominatedBy(x, header)))
                {
                    yieldingHeaders.Add(header);
                }
                else if (IsYieldingHeader(graph, header))
                {
                    yieldingHeaders.Add(header);
                }
                else
                {
                    continue;
                }
            }

            Program program = linearTypeChecker.program;
            Dictionary<Variable, Expr> map = new Dictionary<Variable, Expr>();
            foreach (Variable local in impl.LocVars)
            {
                var copy = new LocalVariable(Token.NoToken, new TypedIdent(Token.NoToken, local.Name, local.TypedIdent.Type));
                map[local] = new IdentifierExpr(Token.NoToken, copy);
            }
            Dictionary<Variable, Variable> ogOldGlobalMap = new Dictionary<Variable, Variable>();
            foreach (IdentifierExpr ie in globalMods)
            {
                Variable g = ie.Decl;
                LocalVariable l = new LocalVariable(Token.NoToken, new TypedIdent(Token.NoToken, string.Format("og_global_old_{0}", g.Name), g.TypedIdent.Type));
                ogOldGlobalMap[g] = l;
                impl.LocVars.Add(l);
            }
            Dictionary<string, Variable> domainNameToInputVar = new Dictionary<string, Variable>();
            Dictionary<string, Variable> domainNameToLocalVar = new Dictionary<string, Variable>();
            {
                int i = impl.InParams.Count - linearTypeChecker.linearDomains.Count;
                foreach (string domainName in linearTypeChecker.linearDomains.Keys)
                {
                    Variable inParam = impl.InParams[i];
                    domainNameToInputVar[domainName] = inParam;
                    Variable l = new LocalVariable(Token.NoToken, new TypedIdent(Token.NoToken, inParam.Name + "_local", inParam.TypedIdent.Type));
                    domainNameToLocalVar[domainName] = l;
                    impl.LocVars.Add(l);
                    i++;
                }
            }

            // Collect the yield predicates and desugar yields
            List<List<Cmd>> yields = new List<List<Cmd>>();
            List<Cmd> cmds = new List<Cmd>();
            foreach (Block b in impl.Blocks)
            {
                YieldCmd yieldCmd = null;
                List<Cmd> newCmds = new List<Cmd>();
                for (int i = 0; i < b.Cmds.Count; i++)
                {
                    Cmd cmd = b.Cmds[i];
                    if (cmd is YieldCmd)
                    {
                        yieldCmd = (YieldCmd)cmd;
                        continue;
                    }
                    if (yieldCmd != null)
                    {
                        PredicateCmd pcmd = cmd as PredicateCmd;
                        if (pcmd == null)
                        {
                            DesugarYield(yieldCmd, cmds, newCmds, ogOldGlobalMap, domainNameToInputVar, domainNameToLocalVar);
                            if (cmds.Count > 0)
                            {
                                yields.Add(cmds);
                                cmds = new List<Cmd>();
                            }
                            yieldCmd = null;
                        }
                        else
                        {
                            cmds.Add(pcmd);
                        }
                    }

                    if (cmd is CallCmd)
                    {
                        CallCmd callCmd = cmd as CallCmd;
                        if (callCmd.IsAsync || QKeyValue.FindBoolAttribute(callCmd.Proc.Attributes, "yields"))
                        {
//.........这里部分代码省略.........