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	* Do not demand a shadow node when resolving * Raise arbitrary inline limit git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2100 91177308-0d34-0410-b5e6-96231b3b80d8
		
			
				
	
	
		
			249 lines
		
	
	
		
			9.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			249 lines
		
	
	
		
			9.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| //===- ComputeClosure.cpp - Implement interprocedural closing of graphs ---===//
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| //
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| // Compute the interprocedural closure of a data structure graph
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| // DEBUG_IP_CLOSURE - Define this to debug the act of linking up graphs
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| //#define DEBUG_IP_CLOSURE 1
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| 
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| #include "llvm/Analysis/DataStructure.h"
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| #include "llvm/iOther.h"
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| #include "Support/STLExtras.h"
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| #include <algorithm>
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| #ifdef DEBUG_IP_CLOSURE
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| #include "llvm/Assembly/Writer.h"
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| #endif
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| 
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| // Make all of the pointers that point to Val also point to N.
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| //
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| static void copyEdgesFromTo(PointerVal Val, DSNode *N) {
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|   unsigned ValIdx = Val.Index;
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|   unsigned NLinks = N->getNumLinks();
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| 
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|   const vector<PointerValSet*> &PVSsToUpdate(Val.Node->getReferrers());
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|   for (unsigned i = 0, e = PVSsToUpdate.size(); i != e; ++i) {
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|     // Loop over all of the pointers pointing to Val...
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|     PointerValSet &PVS = *PVSsToUpdate[i];
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|     for (unsigned j = 0, je = PVS.size(); j != je; ++j) {
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|       if (PVS[j].Node == Val.Node && PVS[j].Index >= ValIdx && 
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|           PVS[j].Index < ValIdx+NLinks)
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|         PVS.add(PointerVal(N, PVS[j].Index-ValIdx));
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|     }
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|   }
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| }
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| 
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| static void ResolveNodesTo(const PointerVal &FromPtr,
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|                            const PointerValSet &ToVals) {
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|   assert(FromPtr.Index == 0 &&
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|          "Resolved node return pointer should be index 0!");
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|   DSNode *N = FromPtr.Node;
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| 
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|   // Make everything that pointed to the shadow node also point to the values in
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|   // ToVals...
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|   //
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|   for (unsigned i = 0, e = ToVals.size(); i != e; ++i)
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|     copyEdgesFromTo(ToVals[i], N);
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| 
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|   // Make everything that pointed to the shadow node now also point to the
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|   // values it is equivalent to...
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|   const vector<PointerValSet*> &PVSToUpdate(N->getReferrers());
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|   for (unsigned i = 0, e = PVSToUpdate.size(); i != e; ++i)
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|     PVSToUpdate[i]->add(ToVals);
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| }
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| 
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| 
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| // ResolveNodeTo - The specified node is now known to point to the set of values
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| // in ToVals, instead of the old shadow node subgraph that it was pointing to.
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| //
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| static void ResolveNodeTo(DSNode *Node, const PointerValSet &ToVals) {
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|   assert(Node->getNumLinks() == 1 && "Resolved node can only be a scalar!!");
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| 
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|   const PointerValSet &PVS = Node->getLink(0);
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| 
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|   // Only resolve the first pointer, although there many be many pointers here.
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|   // The problem is that the inlined function might return one of the arguments
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|   // to the function, and if so, extra values can be added to the arg or call
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|   // node that point to what the other one got resolved to.  Since these will
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|   // be added to the end of the PVS pointed in, we just ignore them.
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|   //
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|   ResolveNodesTo(PVS[0], ToVals);
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| }
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| 
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| // isResolvableCallNode - Return true if node is a call node and it is a call
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| // node that we can inline...
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| //
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| static bool isResolvableCallNode(CallDSNode *CN) {
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|   // Only operate on call nodes with direct method calls
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|   Function *F = CN->getCall()->getCalledFunction();
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|   if (F == 0) return false;
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| 
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|   // Only work on call nodes with direct calls to methods with bodies.
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|   return !F->isExternal();
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| }
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| 
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| 
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| // computeClosure - Replace all of the resolvable call nodes with the contents
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| // of their corresponding method data structure graph...
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| //
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| void FunctionDSGraph::computeClosure(const DataStructure &DS) {
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|   // Note that this cannot be a real vector because the keys will be changing
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|   // as nodes are eliminated!
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|   //
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|   typedef pair<vector<PointerValSet>, CallInst *> CallDescriptor;
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|   vector<pair<CallDescriptor, PointerValSet> > CallMap;
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| 
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|   unsigned NumInlines = 0;
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| 
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|   // Loop over the resolvable call nodes...
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|   vector<CallDSNode*>::iterator NI;
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|   NI = std::find_if(CallNodes.begin(), CallNodes.end(), isResolvableCallNode);
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|   while (NI != CallNodes.end()) {
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|     CallDSNode *CN = *NI;
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|     Function *F = CN->getCall()->getCalledFunction();
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| 
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|     if (NumInlines++ == 100) {      // CUTE hack huh?
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|       cerr << "Infinite (?) recursion halted\n";
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|       return;
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|     }
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| 
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|     CallNodes.erase(NI);                 // Remove the call node from the graph
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| 
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|     unsigned CallNodeOffset = NI-CallNodes.begin();
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| 
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|     // Find out if we have already incorporated this node... if so, it will be
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|     // in the CallMap...
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|     //
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|     
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| #if 0
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|     cerr << "\nSearching for: " << (void*)CN->getCall() << ": ";
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|     for (unsigned X = 0; X != CN->getArgs().size(); ++X) {
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|       cerr << " " << X << " is\n";
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|       CN->getArgs().first[X].print(cerr);
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|     }
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| #endif
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| 
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|     const vector<PointerValSet> &Args = CN->getArgs();
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|     PointerValSet *CMI = 0;
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|     for (unsigned i = 0, e = CallMap.size(); i != e; ++i) {
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| #if 0
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|       cerr << "Found: " << (void*)CallMap[i].first.second << ": ";
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|       for (unsigned X = 0; X != CallMap[i].first.first.size(); ++X) {
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|         cerr << " " << X << " is\n"; CallMap[i].first.first[X].print(cerr);
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|       }
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| #endif
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| 
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|       // Look to see if the function call takes a superset of the values we are
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|       // providing as input
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|       // 
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|       CallDescriptor &CD = CallMap[i].first;
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|       if (CD.second == CN->getCall() && CD.first.size() == Args.size()) {
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|         bool FoundMismatch = false;
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|         for (unsigned j = 0, je = Args.size(); j != je; ++j) {
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|           PointerValSet ArgSet = CD.first[j];
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|           if (ArgSet.add(Args[j])) {
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|             FoundMismatch = true; break;
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|           }            
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|         }
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| 
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|         if (!FoundMismatch) { CMI = &CallMap[i].second; break; }
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|       }
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|     }
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| 
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|     // Hold the set of values that correspond to the incorporated methods
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|     // return set.
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|     //
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|     PointerValSet RetVals;
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| 
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|     if (CMI) {
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|       // We have already inlined an identical function call!
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|       RetVals = *CMI;
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|     } else {
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|       // Get the datastructure graph for the new method.  Note that we are not
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|       // allowed to modify this graph because it will be the cached graph that
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|       // is returned by other users that want the local datastructure graph for
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|       // a method.
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|       //
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|       const FunctionDSGraph &NewFunction = DS.getDSGraph(F);
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| 
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|       // StartNode - The first node of the incorporated graph, last node of the
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|       // preexisting data structure graph...
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|       //
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|       unsigned StartArgNode   = ArgNodes.size();
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|       unsigned StartAllocNode = AllocNodes.size();
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| 
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|       // Incorporate a copy of the called function graph into the current graph,
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|       // allowing us to do local transformations to local graph to link
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|       // arguments to call values, and call node to return value...
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|       //
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|       RetVals = cloneFunctionIntoSelf(NewFunction, false);
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|       CallMap.push_back(make_pair(CallDescriptor(CN->getArgs(), CN->getCall()),
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|                                   RetVals));
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| 
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|       // If the call node has arguments, process them now!
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|       if (CN->getNumArgs()) {
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|         // The ArgNodes of the incorporated graph should be the nodes starting
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|         // at StartNode, ordered the same way as the call arguments.  The arg
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|         // nodes are seperated by a single shadow node, but that shadow node
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|         // might get eliminated in the process of optimization.
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|         //
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|         for (unsigned i = 0, e = CN->getNumArgs(); i != e; ++i) {
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|           // Get the arg node of the incorporated method...
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|           ArgDSNode *ArgNode = ArgNodes[StartArgNode];
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|           
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|           // Now we make all of the nodes inside of the incorporated method
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|           // point to the real arguments values, not to the shadow nodes for the
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|           // argument.
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|           //
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|           ResolveNodeTo(ArgNode, CN->getArgValues(i));
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|           
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|           // Remove the argnode from the set of nodes in this method...
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|           ArgNodes.erase(ArgNodes.begin()+StartArgNode);
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|             
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|           // ArgNode is no longer useful, delete now!
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|           delete ArgNode;
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|         }
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|       }
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| 
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|       // Loop through the nodes, deleting alloca nodes in the inlined function.
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|       // Since the memory has been released, we cannot access their pointer
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|       // fields (with defined results at least), so it is not possible to use
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|       // any pointers to the alloca.  Drop them now, and remove the alloca's
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|       // since they are dead (we just removed all links to them).
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|       //
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|       for (unsigned i = StartAllocNode; i != AllocNodes.size(); ++i)
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|         if (AllocNodes[i]->isAllocaNode()) {
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|           AllocDSNode *NDS = AllocNodes[i];
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|           NDS->removeAllIncomingEdges();          // These edges are invalid now
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|           delete NDS;                             // Node is dead
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|           AllocNodes.erase(AllocNodes.begin()+i); // Remove slot in Nodes array
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|           --i;                                    // Don't skip the next node
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|         }
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|     }
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| 
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|     // If the function returns a pointer value...  Resolve values pointing to
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|     // the shadow nodes pointed to by CN to now point the values in RetVals...
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|     //
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|     if (CN->getNumLinks()) ResolveNodeTo(CN, RetVals);
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| 
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|     // Now the call node is completely destructable.  Eliminate it now.
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|     delete CN;
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| 
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|     bool Changed = true;
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|     while (Changed) {
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|       // Eliminate shadow nodes that are not distinguishable from some other
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|       // node in the graph...
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|       //
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|       Changed = UnlinkUndistinguishableNodes();
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| 
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|       // Eliminate shadow nodes that are now extraneous due to linking...
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|       Changed |= RemoveUnreachableNodes();
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|     }
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| 
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|     //if (F == Func) return;  // Only do one self inlining
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|     
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|     // Move on to the next call node...
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|     NI = std::find_if(CallNodes.begin(), CallNodes.end(), isResolvableCallNode);
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|   }
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| }
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