1 //===- DataStructure.cpp - Implement the core data structure analysis -----===//
3 // This file implements the core data structure functionality.
5 //===----------------------------------------------------------------------===//
7 #include "llvm/Analysis/DSGraph.h"
8 #include "llvm/Function.h"
9 #include "llvm/iOther.h"
10 #include "llvm/DerivedTypes.h"
11 #include "llvm/Target/TargetData.h"
12 #include "Support/STLExtras.h"
13 #include "Support/Statistic.h"
14 #include "Support/Timer.h"
18 Statistic<> NumFolds ("dsnode", "Number of nodes completely folded");
19 Statistic<> NumCallNodesMerged("dsnode", "Number of call nodes merged");
22 namespace DS { // TODO: FIXME
27 //===----------------------------------------------------------------------===//
28 // DSNode Implementation
29 //===----------------------------------------------------------------------===//
31 DSNode::DSNode(enum NodeTy NT, const Type *T)
32 : Ty(Type::VoidTy), Size(0), NodeType(NT) {
33 // Add the type entry if it is specified...
34 if (T) mergeTypeInfo(T, 0);
37 // DSNode copy constructor... do not copy over the referrers list!
38 DSNode::DSNode(const DSNode &N)
39 : Links(N.Links), Globals(N.Globals), Ty(N.Ty), Size(N.Size),
40 NodeType(N.NodeType) {
43 void DSNode::removeReferrer(DSNodeHandle *H) {
44 // Search backwards, because we depopulate the list from the back for
45 // efficiency (because it's a vector).
46 std::vector<DSNodeHandle*>::reverse_iterator I =
47 std::find(Referrers.rbegin(), Referrers.rend(), H);
48 assert(I != Referrers.rend() && "Referrer not pointing to node!");
49 Referrers.erase(I.base()-1);
52 // addGlobal - Add an entry for a global value to the Globals list. This also
53 // marks the node with the 'G' flag if it does not already have it.
55 void DSNode::addGlobal(GlobalValue *GV) {
56 // Keep the list sorted.
57 std::vector<GlobalValue*>::iterator I =
58 std::lower_bound(Globals.begin(), Globals.end(), GV);
60 if (I == Globals.end() || *I != GV) {
61 //assert(GV->getType()->getElementType() == Ty);
62 Globals.insert(I, GV);
63 NodeType |= GlobalNode;
67 /// foldNodeCompletely - If we determine that this node has some funny
68 /// behavior happening to it that we cannot represent, we fold it down to a
69 /// single, completely pessimistic, node. This node is represented as a
70 /// single byte with a single TypeEntry of "void".
72 void DSNode::foldNodeCompletely() {
73 if (isNodeCompletelyFolded()) return;
77 // We are no longer typed at all...
82 // Loop over all of our referrers, making them point to our zero bytes of
84 for (std::vector<DSNodeHandle*>::iterator I = Referrers.begin(),
85 E = Referrers.end(); I != E; ++I)
88 // If we have links, merge all of our outgoing links together...
89 for (unsigned i = 1; i < Links.size(); ++i)
90 Links[0].mergeWith(Links[i]);
94 /// isNodeCompletelyFolded - Return true if this node has been completely
95 /// folded down to something that can never be expanded, effectively losing
96 /// all of the field sensitivity that may be present in the node.
98 bool DSNode::isNodeCompletelyFolded() const {
99 return getSize() == 1 && Ty == Type::VoidTy && isArray();
103 /// mergeTypeInfo - This method merges the specified type into the current node
104 /// at the specified offset. This may update the current node's type record if
105 /// this gives more information to the node, it may do nothing to the node if
106 /// this information is already known, or it may merge the node completely (and
107 /// return true) if the information is incompatible with what is already known.
109 /// This method returns true if the node is completely folded, otherwise false.
111 bool DSNode::mergeTypeInfo(const Type *NewTy, unsigned Offset) {
112 // Check to make sure the Size member is up-to-date. Size can be one of the
114 // Size = 0, Ty = Void: Nothing is known about this node.
115 // Size = 0, Ty = FnTy: FunctionPtr doesn't have a size, so we use zero
116 // Size = 1, Ty = Void, Array = 1: The node is collapsed
117 // Otherwise, sizeof(Ty) = Size
119 assert(((Size == 0 && Ty == Type::VoidTy && !isArray()) ||
120 (Size == 0 && !Ty->isSized() && !isArray()) ||
121 (Size == 1 && Ty == Type::VoidTy && isArray()) ||
122 (Size == 0 && !Ty->isSized() && !isArray()) ||
123 (TD.getTypeSize(Ty) == Size)) &&
124 "Size member of DSNode doesn't match the type structure!");
125 assert(NewTy != Type::VoidTy && "Cannot merge void type into DSNode!");
127 if (Offset == 0 && NewTy == Ty)
128 return false; // This should be a common case, handle it efficiently
130 // Return true immediately if the node is completely folded.
131 if (isNodeCompletelyFolded()) return true;
133 // If this is an array type, eliminate the outside arrays because they won't
134 // be used anyway. This greatly reduces the size of large static arrays used
135 // as global variables, for example.
137 bool WillBeArray = false;
138 while (const ArrayType *AT = dyn_cast<ArrayType>(NewTy)) {
139 // FIXME: we might want to keep small arrays, but must be careful about
140 // things like: [2 x [10000 x int*]]
141 NewTy = AT->getElementType();
145 // Figure out how big the new type we're merging in is...
146 unsigned NewTySize = NewTy->isSized() ? TD.getTypeSize(NewTy) : 0;
148 // Otherwise check to see if we can fold this type into the current node. If
149 // we can't, we fold the node completely, if we can, we potentially update our
152 if (Ty == Type::VoidTy) {
153 // If this is the first type that this node has seen, just accept it without
155 assert(Offset == 0 && "Cannot have an offset into a void node!");
156 assert(!isArray() && "This shouldn't happen!");
159 if (WillBeArray) NodeType |= Array;
162 // Calculate the number of outgoing links from this node.
163 Links.resize((Size+DS::PointerSize-1) >> DS::PointerShift);
167 // Handle node expansion case here...
168 if (Offset+NewTySize > Size) {
169 // It is illegal to grow this node if we have treated it as an array of
172 foldNodeCompletely();
176 if (Offset) { // We could handle this case, but we don't for now...
177 DEBUG(std::cerr << "UNIMP: Trying to merge a growth type into "
178 << "offset != 0: Collapsing!\n");
179 foldNodeCompletely();
183 // Okay, the situation is nice and simple, we are trying to merge a type in
184 // at offset 0 that is bigger than our current type. Implement this by
185 // switching to the new type and then merge in the smaller one, which should
186 // hit the other code path here. If the other code path decides it's not
187 // ok, it will collapse the node as appropriate.
189 const Type *OldTy = Ty;
192 if (WillBeArray) NodeType |= Array;
195 // Must grow links to be the appropriate size...
196 Links.resize((Size+DS::PointerSize-1) >> DS::PointerShift);
198 // Merge in the old type now... which is guaranteed to be smaller than the
200 return mergeTypeInfo(OldTy, 0);
203 assert(Offset <= Size &&
204 "Cannot merge something into a part of our type that doesn't exist!");
206 // Find the section of Ty that NewTy overlaps with... first we find the
207 // type that starts at offset Offset.
210 const Type *SubType = Ty;
212 assert(Offset-O < TD.getTypeSize(SubType) && "Offset out of range!");
214 switch (SubType->getPrimitiveID()) {
215 case Type::StructTyID: {
216 const StructType *STy = cast<StructType>(SubType);
217 const StructLayout &SL = *TD.getStructLayout(STy);
219 unsigned i = 0, e = SL.MemberOffsets.size();
220 for (; i+1 < e && SL.MemberOffsets[i+1] <= Offset-O; ++i)
223 // The offset we are looking for must be in the i'th element...
224 SubType = STy->getElementTypes()[i];
225 O += SL.MemberOffsets[i];
228 case Type::ArrayTyID: {
229 SubType = cast<ArrayType>(SubType)->getElementType();
230 unsigned ElSize = TD.getTypeSize(SubType);
231 unsigned Remainder = (Offset-O) % ElSize;
232 O = Offset-Remainder;
236 foldNodeCompletely();
241 assert(O == Offset && "Could not achieve the correct offset!");
243 // If we found our type exactly, early exit
244 if (SubType == NewTy) return false;
246 // Okay, so we found the leader type at the offset requested. Search the list
247 // of types that starts at this offset. If SubType is currently an array or
248 // structure, the type desired may actually be the first element of the
251 unsigned SubTypeSize = SubType->isSized() ? TD.getTypeSize(SubType) : 0;
252 unsigned PadSize = SubTypeSize; // Size, including pad memory which is ignored
253 while (SubType != NewTy) {
254 const Type *NextSubType = 0;
255 unsigned NextSubTypeSize = 0;
256 unsigned NextPadSize = 0;
257 switch (SubType->getPrimitiveID()) {
258 case Type::StructTyID: {
259 const StructType *STy = cast<StructType>(SubType);
260 const StructLayout &SL = *TD.getStructLayout(STy);
261 if (SL.MemberOffsets.size() > 1)
262 NextPadSize = SL.MemberOffsets[1];
264 NextPadSize = SubTypeSize;
265 NextSubType = STy->getElementTypes()[0];
266 NextSubTypeSize = TD.getTypeSize(NextSubType);
269 case Type::ArrayTyID:
270 NextSubType = cast<ArrayType>(SubType)->getElementType();
271 NextSubTypeSize = TD.getTypeSize(NextSubType);
272 NextPadSize = NextSubTypeSize;
278 if (NextSubType == 0)
279 break; // In the default case, break out of the loop
281 if (NextPadSize < NewTySize)
282 break; // Don't allow shrinking to a smaller type than NewTySize
283 SubType = NextSubType;
284 SubTypeSize = NextSubTypeSize;
285 PadSize = NextPadSize;
288 // If we found the type exactly, return it...
289 if (SubType == NewTy)
292 // Check to see if we have a compatible, but different type...
293 if (NewTySize == SubTypeSize) {
294 // Check to see if this type is obviously convertable... int -> uint f.e.
295 if (NewTy->isLosslesslyConvertableTo(SubType))
298 // Check to see if we have a pointer & integer mismatch going on here,
299 // loading a pointer as a long, for example.
301 if (SubType->isInteger() && isa<PointerType>(NewTy) ||
302 NewTy->isInteger() && isa<PointerType>(SubType))
304 } else if (NewTySize > SubTypeSize && NewTySize <= PadSize) {
305 // We are accessing the field, plus some structure padding. Ignore the
306 // structure padding.
311 DEBUG(std::cerr << "MergeTypeInfo Folding OrigTy: " << Ty
312 << "\n due to:" << NewTy << " @ " << Offset << "!\n"
313 << "SubType: " << SubType << "\n\n");
315 foldNodeCompletely();
321 // addEdgeTo - Add an edge from the current node to the specified node. This
322 // can cause merging of nodes in the graph.
324 void DSNode::addEdgeTo(unsigned Offset, const DSNodeHandle &NH) {
325 if (NH.getNode() == 0) return; // Nothing to do
327 DSNodeHandle &ExistingEdge = getLink(Offset);
328 if (ExistingEdge.getNode()) {
329 // Merge the two nodes...
330 ExistingEdge.mergeWith(NH);
331 } else { // No merging to perform...
332 setLink(Offset, NH); // Just force a link in there...
337 // MergeSortedVectors - Efficiently merge a vector into another vector where
338 // duplicates are not allowed and both are sorted. This assumes that 'T's are
339 // efficiently copyable and have sane comparison semantics.
341 static void MergeSortedVectors(std::vector<GlobalValue*> &Dest,
342 const std::vector<GlobalValue*> &Src) {
343 // By far, the most common cases will be the simple ones. In these cases,
344 // avoid having to allocate a temporary vector...
346 if (Src.empty()) { // Nothing to merge in...
348 } else if (Dest.empty()) { // Just copy the result in...
350 } else if (Src.size() == 1) { // Insert a single element...
351 const GlobalValue *V = Src[0];
352 std::vector<GlobalValue*>::iterator I =
353 std::lower_bound(Dest.begin(), Dest.end(), V);
354 if (I == Dest.end() || *I != Src[0]) // If not already contained...
355 Dest.insert(I, Src[0]);
356 } else if (Dest.size() == 1) {
357 GlobalValue *Tmp = Dest[0]; // Save value in temporary...
358 Dest = Src; // Copy over list...
359 std::vector<GlobalValue*>::iterator I =
360 std::lower_bound(Dest.begin(), Dest.end(), Tmp);
361 if (I == Dest.end() || *I != Tmp) // If not already contained...
365 // Make a copy to the side of Dest...
366 std::vector<GlobalValue*> Old(Dest);
368 // Make space for all of the type entries now...
369 Dest.resize(Dest.size()+Src.size());
371 // Merge the two sorted ranges together... into Dest.
372 std::merge(Old.begin(), Old.end(), Src.begin(), Src.end(), Dest.begin());
374 // Now erase any duplicate entries that may have accumulated into the
375 // vectors (because they were in both of the input sets)
376 Dest.erase(std::unique(Dest.begin(), Dest.end()), Dest.end());
381 // MergeNodes() - Helper function for DSNode::mergeWith().
382 // This function does the hard work of merging two nodes, CurNodeH
383 // and NH after filtering out trivial cases and making sure that
384 // CurNodeH.offset >= NH.offset.
387 // Since merging may cause either node to go away, we must always
388 // use the node-handles to refer to the nodes. These node handles are
389 // automatically updated during merging, so will always provide access
390 // to the correct node after a merge.
392 void DSNode::MergeNodes(DSNodeHandle& CurNodeH, DSNodeHandle& NH) {
393 assert(CurNodeH.getOffset() >= NH.getOffset() &&
394 "This should have been enforced in the caller.");
396 // Now we know that Offset >= NH.Offset, so convert it so our "Offset" (with
397 // respect to NH.Offset) is now zero. NOffset is the distance from the base
398 // of our object that N starts from.
400 unsigned NOffset = CurNodeH.getOffset()-NH.getOffset();
401 unsigned NSize = NH.getNode()->getSize();
403 // Merge the type entries of the two nodes together...
404 if (NH.getNode()->Ty != Type::VoidTy) {
405 CurNodeH.getNode()->mergeTypeInfo(NH.getNode()->Ty, NOffset);
407 assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
409 // If we are merging a node with a completely folded node, then both nodes are
410 // now completely folded.
412 if (CurNodeH.getNode()->isNodeCompletelyFolded()) {
413 if (!NH.getNode()->isNodeCompletelyFolded()) {
414 NH.getNode()->foldNodeCompletely();
415 assert(NH.getOffset()==0 && "folding did not make offset 0?");
416 NOffset = NH.getOffset();
417 NSize = NH.getNode()->getSize();
418 assert(NOffset == 0 && NSize == 1);
420 } else if (NH.getNode()->isNodeCompletelyFolded()) {
421 CurNodeH.getNode()->foldNodeCompletely();
422 assert(CurNodeH.getOffset()==0 && "folding did not make offset 0?");
423 NOffset = NH.getOffset();
424 NSize = NH.getNode()->getSize();
425 assert(NOffset == 0 && NSize == 1);
428 if (CurNodeH.getNode() == NH.getNode() || NH.getNode() == 0) return;
429 assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
431 // Remove all edges pointing at N, causing them to point to 'this' instead.
432 // Make sure to adjust their offset, not just the node pointer.
433 // Also, be careful to use the DSNode* rather than NH since NH is one of
434 // the referrers and once NH refers to CurNodeH.getNode() this will
435 // become an infinite loop.
436 DSNode* N = NH.getNode();
437 unsigned OldNHOffset = NH.getOffset();
438 while (!N->Referrers.empty()) {
439 DSNodeHandle &Ref = *N->Referrers.back();
440 Ref = DSNodeHandle(CurNodeH.getNode(), NOffset+Ref.getOffset());
442 NH = DSNodeHandle(N, OldNHOffset); // reset NH to point back to where it was
444 assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
446 // Make all of the outgoing links of *NH now be outgoing links of
447 // this. This can cause recursive merging!
449 for (unsigned i = 0; i < NH.getNode()->getSize(); i += DS::PointerSize) {
450 DSNodeHandle &Link = NH.getNode()->getLink(i);
451 if (Link.getNode()) {
452 // Compute the offset into the current node at which to
453 // merge this link. In the common case, this is a linear
454 // relation to the offset in the original node (with
455 // wrapping), but if the current node gets collapsed due to
456 // recursive merging, we must make sure to merge in all remaining
457 // links at offset zero.
458 unsigned MergeOffset = 0;
459 if (CurNodeH.getNode()->Size != 1)
460 MergeOffset = (i+NOffset) % CurNodeH.getNode()->getSize();
461 CurNodeH.getNode()->addEdgeTo(MergeOffset, Link);
465 // Now that there are no outgoing edges, all of the Links are dead.
466 NH.getNode()->Links.clear();
467 NH.getNode()->Size = 0;
468 NH.getNode()->Ty = Type::VoidTy;
470 // Merge the node types
471 CurNodeH.getNode()->NodeType |= NH.getNode()->NodeType;
472 NH.getNode()->NodeType = DEAD; // NH is now a dead node.
474 // Merge the globals list...
475 if (!NH.getNode()->Globals.empty()) {
476 MergeSortedVectors(CurNodeH.getNode()->Globals, NH.getNode()->Globals);
478 // Delete the globals from the old node...
479 NH.getNode()->Globals.clear();
484 // mergeWith - Merge this node and the specified node, moving all links to and
485 // from the argument node into the current node, deleting the node argument.
486 // Offset indicates what offset the specified node is to be merged into the
489 // The specified node may be a null pointer (in which case, nothing happens).
491 void DSNode::mergeWith(const DSNodeHandle &NH, unsigned Offset) {
492 DSNode *N = NH.getNode();
493 if (N == 0 || (N == this && NH.getOffset() == Offset))
496 assert((N->NodeType & DSNode::DEAD) == 0);
497 assert((NodeType & DSNode::DEAD) == 0);
498 assert(!hasNoReferrers() && "Should not try to fold a useless node!");
501 // We cannot merge two pieces of the same node together, collapse the node
503 DEBUG(std::cerr << "Attempting to merge two chunks of"
504 << " the same node together!\n");
505 foldNodeCompletely();
509 // If both nodes are not at offset 0, make sure that we are merging the node
510 // at an later offset into the node with the zero offset.
512 if (Offset < NH.getOffset()) {
513 N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
515 } else if (Offset == NH.getOffset() && getSize() < N->getSize()) {
516 // If the offsets are the same, merge the smaller node into the bigger node
517 N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
521 // Ok, now we can merge the two nodes. Use a static helper that works with
522 // two node handles, since "this" may get merged away at intermediate steps.
523 DSNodeHandle CurNodeH(this, Offset);
524 DSNodeHandle NHCopy(NH);
525 DSNode::MergeNodes(CurNodeH, NHCopy);
528 //===----------------------------------------------------------------------===//
529 // DSCallSite Implementation
530 //===----------------------------------------------------------------------===//
532 // Define here to avoid including iOther.h and BasicBlock.h in DSGraph.h
533 Function &DSCallSite::getCaller() const {
534 return *Inst->getParent()->getParent();
538 //===----------------------------------------------------------------------===//
539 // DSGraph Implementation
540 //===----------------------------------------------------------------------===//
542 DSGraph::DSGraph(const DSGraph &G) : Func(G.Func), GlobalsGraph(0) {
543 PrintAuxCalls = false;
544 hash_map<const DSNode*, DSNodeHandle> NodeMap;
545 RetNode = cloneInto(G, ScalarMap, NodeMap);
548 DSGraph::DSGraph(const DSGraph &G,
549 hash_map<const DSNode*, DSNodeHandle> &NodeMap)
550 : Func(G.Func), GlobalsGraph(0) {
551 PrintAuxCalls = false;
552 RetNode = cloneInto(G, ScalarMap, NodeMap);
555 DSGraph::~DSGraph() {
556 FunctionCalls.clear();
557 AuxFunctionCalls.clear();
561 // Drop all intra-node references, so that assertions don't fail...
562 std::for_each(Nodes.begin(), Nodes.end(),
563 std::mem_fun(&DSNode::dropAllReferences));
565 // Delete all of the nodes themselves...
566 std::for_each(Nodes.begin(), Nodes.end(), deleter<DSNode>);
569 // dump - Allow inspection of graph in a debugger.
570 void DSGraph::dump() const { print(std::cerr); }
573 /// remapLinks - Change all of the Links in the current node according to the
574 /// specified mapping.
576 void DSNode::remapLinks(hash_map<const DSNode*, DSNodeHandle> &OldNodeMap) {
577 for (unsigned i = 0, e = Links.size(); i != e; ++i) {
578 DSNodeHandle &H = OldNodeMap[Links[i].getNode()];
579 Links[i].setNode(H.getNode());
580 Links[i].setOffset(Links[i].getOffset()+H.getOffset());
585 // cloneInto - Clone the specified DSGraph into the current graph, returning the
586 // Return node of the graph. The translated ScalarMap for the old function is
587 // filled into the OldValMap member. If StripAllocas is set to true, Alloca
588 // markers are removed from the graph, as the graph is being cloned into a
589 // calling function's graph.
591 DSNodeHandle DSGraph::cloneInto(const DSGraph &G,
592 hash_map<Value*, DSNodeHandle> &OldValMap,
593 hash_map<const DSNode*, DSNodeHandle> &OldNodeMap,
594 unsigned CloneFlags) {
595 assert(OldNodeMap.empty() && "Returned OldNodeMap should be empty!");
596 assert(&G != this && "Cannot clone graph into itself!");
598 unsigned FN = Nodes.size(); // First new node...
600 // Duplicate all of the nodes, populating the node map...
601 Nodes.reserve(FN+G.Nodes.size());
603 // Remove alloca or mod/ref bits as specified...
604 unsigned clearBits = (CloneFlags & StripAllocaBit ? DSNode::AllocaNode : 0)
605 | (CloneFlags & StripModRefBits ? (DSNode::Modified | DSNode::Read) : 0);
606 clearBits |= DSNode::DEAD; // Clear dead flag...
607 for (unsigned i = 0, e = G.Nodes.size(); i != e; ++i) {
608 DSNode *Old = G.Nodes[i];
609 DSNode *New = new DSNode(*Old);
610 New->NodeType &= ~clearBits;
611 Nodes.push_back(New);
612 OldNodeMap[Old] = New;
616 Timer::addPeakMemoryMeasurement();
619 // Rewrite the links in the new nodes to point into the current graph now.
620 for (unsigned i = FN, e = Nodes.size(); i != e; ++i)
621 Nodes[i]->remapLinks(OldNodeMap);
623 // Copy the scalar map... merging all of the global nodes...
624 for (hash_map<Value*, DSNodeHandle>::const_iterator I = G.ScalarMap.begin(),
625 E = G.ScalarMap.end(); I != E; ++I) {
626 DSNodeHandle &H = OldValMap[I->first];
627 DSNodeHandle &MappedNode = OldNodeMap[I->second.getNode()];
628 H.setNode(MappedNode.getNode());
629 H.setOffset(I->second.getOffset()+MappedNode.getOffset());
631 if (isa<GlobalValue>(I->first)) { // Is this a global?
632 hash_map<Value*, DSNodeHandle>::iterator GVI = ScalarMap.find(I->first);
633 if (GVI != ScalarMap.end()) // Is the global value in this fn already?
634 GVI->second.mergeWith(H);
636 ScalarMap[I->first] = H; // Add global pointer to this graph
640 if (!(CloneFlags & DontCloneCallNodes)) {
641 // Copy the function calls list...
642 unsigned FC = FunctionCalls.size(); // FirstCall
643 FunctionCalls.reserve(FC+G.FunctionCalls.size());
644 for (unsigned i = 0, ei = G.FunctionCalls.size(); i != ei; ++i)
645 FunctionCalls.push_back(DSCallSite(G.FunctionCalls[i], OldNodeMap));
648 if (!(CloneFlags & DontCloneAuxCallNodes)) {
649 // Copy the auxillary function calls list...
650 unsigned FC = AuxFunctionCalls.size(); // FirstCall
651 AuxFunctionCalls.reserve(FC+G.AuxFunctionCalls.size());
652 for (unsigned i = 0, ei = G.AuxFunctionCalls.size(); i != ei; ++i)
653 AuxFunctionCalls.push_back(DSCallSite(G.AuxFunctionCalls[i], OldNodeMap));
656 // Return the returned node pointer...
657 DSNodeHandle &MappedRet = OldNodeMap[G.RetNode.getNode()];
658 return DSNodeHandle(MappedRet.getNode(),
659 MappedRet.getOffset()+G.RetNode.getOffset());
662 /// mergeInGraph - The method is used for merging graphs together. If the
663 /// argument graph is not *this, it makes a clone of the specified graph, then
664 /// merges the nodes specified in the call site with the formal arguments in the
667 void DSGraph::mergeInGraph(DSCallSite &CS, const DSGraph &Graph,
668 unsigned CloneFlags) {
669 hash_map<Value*, DSNodeHandle> OldValMap;
671 hash_map<Value*, DSNodeHandle> *ScalarMap = &OldValMap;
673 // If this is not a recursive call, clone the graph into this graph...
674 if (&Graph != this) {
675 // Clone the callee's graph into the current graph, keeping
676 // track of where scalars in the old graph _used_ to point,
677 // and of the new nodes matching nodes of the old graph.
678 hash_map<const DSNode*, DSNodeHandle> OldNodeMap;
680 // The clone call may invalidate any of the vectors in the data
681 // structure graph. Strip locals and don't copy the list of callers
682 RetVal = cloneInto(Graph, OldValMap, OldNodeMap, CloneFlags);
683 ScalarMap = &OldValMap;
685 RetVal = getRetNode();
686 ScalarMap = &getScalarMap();
689 // Merge the return value with the return value of the context...
690 RetVal.mergeWith(CS.getRetVal());
692 // Resolve all of the function arguments...
693 Function &F = Graph.getFunction();
694 Function::aiterator AI = F.abegin();
696 for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i, ++AI) {
697 // Advance the argument iterator to the first pointer argument...
698 while (AI != F.aend() && !isPointerType(AI->getType())) {
702 std::cerr << "Bad call to Function: " << F.getName() << "\n";
705 if (AI == F.aend()) break;
707 // Add the link from the argument scalar to the provided value
708 DSNodeHandle &NH = (*ScalarMap)[AI];
709 assert(NH.getNode() && "Pointer argument without scalarmap entry?");
710 NH.mergeWith(CS.getPtrArg(i));
715 // markIncompleteNodes - Mark the specified node as having contents that are not
716 // known with the current analysis we have performed. Because a node makes all
717 // of the nodes it can reach imcomplete if the node itself is incomplete, we
718 // must recursively traverse the data structure graph, marking all reachable
719 // nodes as incomplete.
721 static void markIncompleteNode(DSNode *N) {
722 // Stop recursion if no node, or if node already marked...
723 if (N == 0 || (N->NodeType & DSNode::Incomplete)) return;
725 // Actually mark the node
726 N->NodeType |= DSNode::Incomplete;
728 // Recusively process children...
729 for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
730 if (DSNode *DSN = N->getLink(i).getNode())
731 markIncompleteNode(DSN);
734 static void markIncomplete(DSCallSite &Call) {
735 // Then the return value is certainly incomplete!
736 markIncompleteNode(Call.getRetVal().getNode());
738 // All objects pointed to by function arguments are incomplete!
739 for (unsigned i = 0, e = Call.getNumPtrArgs(); i != e; ++i)
740 markIncompleteNode(Call.getPtrArg(i).getNode());
743 // markIncompleteNodes - Traverse the graph, identifying nodes that may be
744 // modified by other functions that have not been resolved yet. This marks
745 // nodes that are reachable through three sources of "unknownness":
747 // Global Variables, Function Calls, and Incoming Arguments
749 // For any node that may have unknown components (because something outside the
750 // scope of current analysis may have modified it), the 'Incomplete' flag is
751 // added to the NodeType.
753 void DSGraph::markIncompleteNodes(unsigned Flags) {
754 // Mark any incoming arguments as incomplete...
755 if ((Flags & DSGraph::MarkFormalArgs) && Func && Func->getName() != "main")
756 for (Function::aiterator I = Func->abegin(), E = Func->aend(); I != E; ++I)
757 if (isPointerType(I->getType()) && ScalarMap.find(I) != ScalarMap.end())
758 markIncompleteNode(ScalarMap[I].getNode());
760 // Mark stuff passed into functions calls as being incomplete...
761 if (!shouldPrintAuxCalls())
762 for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
763 markIncomplete(FunctionCalls[i]);
765 for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
766 markIncomplete(AuxFunctionCalls[i]);
769 // Mark all global nodes as incomplete...
770 if ((Flags & DSGraph::IgnoreGlobals) == 0)
771 for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
772 if (Nodes[i]->NodeType & DSNode::GlobalNode)
773 markIncompleteNode(Nodes[i]);
776 static inline void killIfUselessEdge(DSNodeHandle &Edge) {
777 if (DSNode *N = Edge.getNode()) // Is there an edge?
778 if (N->getReferrers().size() == 1) // Does it point to a lonely node?
779 if ((N->NodeType & ~DSNode::Incomplete) == 0 && // No interesting info?
780 N->getType() == Type::VoidTy && !N->isNodeCompletelyFolded())
781 Edge.setNode(0); // Kill the edge!
784 static inline bool nodeContainsExternalFunction(const DSNode *N) {
785 const std::vector<GlobalValue*> &Globals = N->getGlobals();
786 for (unsigned i = 0, e = Globals.size(); i != e; ++i)
787 if (Globals[i]->isExternal())
792 static void removeIdenticalCalls(std::vector<DSCallSite> &Calls,
793 const std::string &where) {
794 // Remove trivially identical function calls
795 unsigned NumFns = Calls.size();
796 std::sort(Calls.begin(), Calls.end()); // Sort by callee as primary key!
798 // Scan the call list cleaning it up as necessary...
799 DSNode *LastCalleeNode = 0;
800 Function *LastCalleeFunc = 0;
801 unsigned NumDuplicateCalls = 0;
802 bool LastCalleeContainsExternalFunction = false;
803 for (unsigned i = 0; i != Calls.size(); ++i) {
804 DSCallSite &CS = Calls[i];
806 // If the Callee is a useless edge, this must be an unreachable call site,
808 if (CS.isIndirectCall() && CS.getCalleeNode()->getReferrers().size() == 1 &&
809 CS.getCalleeNode()->NodeType == 0) { // No useful info?
810 std::cerr << "WARNING: Useless call site found??\n";
811 CS.swap(Calls.back());
815 // If the return value or any arguments point to a void node with no
816 // information at all in it, and the call node is the only node to point
817 // to it, remove the edge to the node (killing the node).
819 killIfUselessEdge(CS.getRetVal());
820 for (unsigned a = 0, e = CS.getNumPtrArgs(); a != e; ++a)
821 killIfUselessEdge(CS.getPtrArg(a));
823 // If this call site calls the same function as the last call site, and if
824 // the function pointer contains an external function, this node will
825 // never be resolved. Merge the arguments of the call node because no
826 // information will be lost.
828 if ((CS.isDirectCall() && CS.getCalleeFunc() == LastCalleeFunc) ||
829 (CS.isIndirectCall() && CS.getCalleeNode() == LastCalleeNode)) {
831 if (NumDuplicateCalls == 1) {
833 LastCalleeContainsExternalFunction =
834 nodeContainsExternalFunction(LastCalleeNode);
836 LastCalleeContainsExternalFunction = LastCalleeFunc->isExternal();
839 if (LastCalleeContainsExternalFunction ||
840 // This should be more than enough context sensitivity!
841 // FIXME: Evaluate how many times this is tripped!
842 NumDuplicateCalls > 20) {
843 DSCallSite &OCS = Calls[i-1];
846 // The node will now be eliminated as a duplicate!
847 if (CS.getNumPtrArgs() < OCS.getNumPtrArgs())
849 else if (CS.getNumPtrArgs() > OCS.getNumPtrArgs())
853 if (CS.isDirectCall()) {
854 LastCalleeFunc = CS.getCalleeFunc();
857 LastCalleeNode = CS.getCalleeNode();
860 NumDuplicateCalls = 0;
865 Calls.erase(std::unique(Calls.begin(), Calls.end()),
868 // Track the number of call nodes merged away...
869 NumCallNodesMerged += NumFns-Calls.size();
871 DEBUG(if (NumFns != Calls.size())
872 std::cerr << "Merged " << (NumFns-Calls.size())
873 << " call nodes in " << where << "\n";);
877 // removeTriviallyDeadNodes - After the graph has been constructed, this method
878 // removes all unreachable nodes that are created because they got merged with
879 // other nodes in the graph. These nodes will all be trivially unreachable, so
880 // we don't have to perform any non-trivial analysis here.
882 void DSGraph::removeTriviallyDeadNodes() {
883 removeIdenticalCalls(FunctionCalls, Func ? Func->getName() : "");
884 removeIdenticalCalls(AuxFunctionCalls, Func ? Func->getName() : "");
886 for (unsigned i = 0; i != Nodes.size(); ++i) {
887 DSNode *Node = Nodes[i];
888 if (!(Node->NodeType & ~(DSNode::Composition | DSNode::Array |
890 // This is a useless node if it has no mod/ref info (checked above),
891 // outgoing edges (which it cannot, as it is not modified in this
892 // context), and it has no incoming edges. If it is a global node it may
893 // have all of these properties and still have incoming edges, due to the
894 // scalar map, so we check those now.
896 if (Node->getReferrers().size() == Node->getGlobals().size()) {
897 std::vector<GlobalValue*> &Globals = Node->getGlobals();
898 for (unsigned j = 0, e = Globals.size(); j != e; ++j)
899 ScalarMap.erase(Globals[j]);
902 Node->NodeType = DSNode::DEAD;
906 if ((Node->NodeType & ~DSNode::DEAD) == 0 && Node->hasNoReferrers()) {
907 // This node is dead!
908 delete Node; // Free memory...
909 Nodes.erase(Nodes.begin()+i--); // Remove from node list...
915 /// markReachableNodes - This method recursively traverses the specified
916 /// DSNodes, marking any nodes which are reachable. All reachable nodes it adds
917 /// to the set, which allows it to only traverse visited nodes once.
919 void DSNode::markReachableNodes(hash_set<DSNode*> &ReachableNodes) {
920 if (this == 0) return;
921 if (ReachableNodes.count(this)) return; // Already marked reachable
922 ReachableNodes.insert(this); // Is reachable now
924 for (unsigned i = 0, e = getSize(); i < e; i += DS::PointerSize)
925 getLink(i).getNode()->markReachableNodes(ReachableNodes);
928 void DSCallSite::markReachableNodes(hash_set<DSNode*> &Nodes) {
929 getRetVal().getNode()->markReachableNodes(Nodes);
930 if (isIndirectCall()) getCalleeNode()->markReachableNodes(Nodes);
932 for (unsigned i = 0, e = getNumPtrArgs(); i != e; ++i)
933 getPtrArg(i).getNode()->markReachableNodes(Nodes);
936 // CanReachAliveNodes - Simple graph walker that recursively traverses the graph
937 // looking for a node that is marked alive. If an alive node is found, return
938 // true, otherwise return false. If an alive node is reachable, this node is
939 // marked as alive...
941 static bool CanReachAliveNodes(DSNode *N, hash_set<DSNode*> &Alive,
942 hash_set<DSNode*> &Visited) {
943 if (N == 0) return false;
945 // If we know that this node is alive, return so!
946 if (Alive.count(N)) return true;
948 // Otherwise, we don't think the node is alive yet, check for infinite
950 if (Visited.count(N)) return false; // Found a cycle
951 Visited.insert(N); // No recursion, insert into Visited...
953 for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
954 if (CanReachAliveNodes(N->getLink(i).getNode(), Alive, Visited)) {
955 N->markReachableNodes(Alive);
961 // CallSiteUsesAliveArgs - Return true if the specified call site can reach any
964 static bool CallSiteUsesAliveArgs(DSCallSite &CS, hash_set<DSNode*> &Alive,
965 hash_set<DSNode*> &Visited) {
966 if (CanReachAliveNodes(CS.getRetVal().getNode(), Alive, Visited))
968 if (CS.isIndirectCall() &&
969 CanReachAliveNodes(CS.getCalleeNode(), Alive, Visited))
971 for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i)
972 if (CanReachAliveNodes(CS.getPtrArg(i).getNode(), Alive, Visited))
977 // removeDeadNodes - Use a more powerful reachability analysis to eliminate
978 // subgraphs that are unreachable. This often occurs because the data
979 // structure doesn't "escape" into it's caller, and thus should be eliminated
980 // from the caller's graph entirely. This is only appropriate to use when
983 void DSGraph::removeDeadNodes(unsigned Flags) {
984 // Reduce the amount of work we have to do... remove dummy nodes left over by
986 removeTriviallyDeadNodes();
988 // FIXME: Merge nontrivially identical call nodes...
990 // Alive - a set that holds all nodes found to be reachable/alive.
991 hash_set<DSNode*> Alive;
992 std::vector<std::pair<Value*, DSNode*> > GlobalNodes;
994 // Mark all nodes reachable by (non-global) scalar nodes as alive...
995 for (hash_map<Value*, DSNodeHandle>::iterator I = ScalarMap.begin(),
996 E = ScalarMap.end(); I != E; ++I)
997 if (!isa<GlobalValue>(I->first))
998 I->second.getNode()->markReachableNodes(Alive);
999 else { // Keep track of global nodes
1000 GlobalNodes.push_back(std::make_pair(I->first, I->second.getNode()));
1001 assert(I->second.getNode() && "Null global node?");
1004 // The return value is alive as well...
1005 RetNode.getNode()->markReachableNodes(Alive);
1007 // Mark any nodes reachable by primary calls as alive...
1008 for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
1009 FunctionCalls[i].markReachableNodes(Alive);
1012 hash_set<DSNode*> Visited;
1013 std::vector<unsigned char> AuxFCallsAlive(AuxFunctionCalls.size());
1016 // If any global nodes points to a non-global that is "alive", the global is
1017 // "alive" as well... Remov it from the GlobalNodes list so we only have
1018 // unreachable globals in the list.
1021 for (unsigned i = 0; i != GlobalNodes.size(); ++i)
1022 if (CanReachAliveNodes(GlobalNodes[i].second, Alive, Visited)) {
1023 std::swap(GlobalNodes[i--], GlobalNodes.back()); // Move to end to erase
1024 GlobalNodes.pop_back(); // Erase efficiently
1028 for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
1029 if (!AuxFCallsAlive[i] &&
1030 CallSiteUsesAliveArgs(AuxFunctionCalls[i], Alive, Visited)) {
1031 AuxFunctionCalls[i].markReachableNodes(Alive);
1032 AuxFCallsAlive[i] = true;
1037 // Remove all dead aux function calls...
1038 unsigned CurIdx = 0;
1039 for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
1040 if (AuxFCallsAlive[i])
1041 AuxFunctionCalls[CurIdx++].swap(AuxFunctionCalls[i]);
1042 if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
1043 assert(GlobalsGraph && "No globals graph available??");
1044 // Move the unreachable call nodes to the globals graph...
1045 GlobalsGraph->AuxFunctionCalls.insert(GlobalsGraph->AuxFunctionCalls.end(),
1046 AuxFunctionCalls.begin()+CurIdx,
1047 AuxFunctionCalls.end());
1049 // Crop all the useless ones out...
1050 AuxFunctionCalls.erase(AuxFunctionCalls.begin()+CurIdx,
1051 AuxFunctionCalls.end());
1053 // At this point, any nodes which are visited, but not alive, are nodes which
1054 // should be moved to the globals graph. Loop over all nodes, eliminating
1055 // completely unreachable nodes, and moving visited nodes to the globals graph
1057 for (unsigned i = 0; i != Nodes.size(); ++i)
1058 if (!Alive.count(Nodes[i])) {
1059 DSNode *N = Nodes[i];
1060 std::swap(Nodes[i--], Nodes.back()); // move node to end of vector
1061 Nodes.pop_back(); // Erase node from alive list.
1062 if (!(Flags & DSGraph::RemoveUnreachableGlobals) && // Not in TD pass
1063 Visited.count(N)) { // Visited but not alive?
1064 GlobalsGraph->Nodes.push_back(N); // Move node to globals graph
1065 } else { // Otherwise, delete the node
1066 assert(((N->NodeType & DSNode::GlobalNode) == 0 ||
1067 (Flags & DSGraph::RemoveUnreachableGlobals))
1068 && "Killing a global?");
1069 while (!N->hasNoReferrers()) // Rewrite referrers
1070 N->getReferrers().back()->setNode(0);
1071 delete N; // Usecount is zero
1075 // Now that the nodes have either been deleted or moved to the globals graph,
1076 // loop over the scalarmap, updating the entries for globals...
1078 if (!(Flags & DSGraph::RemoveUnreachableGlobals)) { // Not in the TD pass?
1079 // In this array we start the remapping, which can cause merging. Because
1080 // of this, the DSNode pointers in GlobalNodes may be invalidated, so we
1081 // must always go through the ScalarMap (which contains DSNodeHandles [which
1082 // cannot be invalidated by merging]).
1084 for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i) {
1085 Value *G = GlobalNodes[i].first;
1086 hash_map<Value*, DSNodeHandle>::iterator I = ScalarMap.find(G);
1087 assert(I != ScalarMap.end() && "Global not in scalar map anymore?");
1088 assert(I->second.getNode() && "Global not pointing to anything?");
1089 assert(!Alive.count(I->second.getNode()) && "Node is alive??");
1090 GlobalsGraph->ScalarMap[G].mergeWith(I->second);
1091 assert(GlobalsGraph->ScalarMap[G].getNode() &&
1092 "Global not pointing to anything?");
1096 // Merging leaves behind silly nodes, we remove them to avoid polluting the
1098 GlobalsGraph->removeTriviallyDeadNodes();
1100 // If we are in the top-down pass, remove all unreachable globals from the
1102 for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i)
1103 ScalarMap.erase(GlobalNodes[i].first);
1106 DEBUG(AssertGraphOK(); GlobalsGraph->AssertGraphOK());
1109 void DSGraph::AssertGraphOK() const {
1110 for (hash_map<Value*, DSNodeHandle>::const_iterator I = ScalarMap.begin(),
1111 E = ScalarMap.end(); I != E; ++I) {
1112 assert(I->second.getNode() && "Null node in scalarmap!");
1113 AssertNodeInGraph(I->second.getNode());
1114 if (GlobalValue *GV = dyn_cast<GlobalValue>(I->first)) {
1115 assert((I->second.getNode()->NodeType & DSNode::GlobalNode) &&
1116 "Global points to node, but node isn't global?");
1117 AssertNodeContainsGlobal(I->second.getNode(), GV);
1120 AssertCallNodesInGraph();
1121 AssertAuxCallNodesInGraph();
1126 //===----------------------------------------------------------------------===//
1127 // GlobalDSGraph Implementation
1128 //===----------------------------------------------------------------------===//
1131 // Bits used in the next function
1132 static const char ExternalTypeBits = DSNode::GlobalNode | DSNode::HeapNode;
1134 // cloneGlobalInto - Clone the given global node and all its target links
1135 // (and all their llinks, recursively).
1137 DSNode *DSGraph::cloneGlobalInto(const DSNode *GNode) {
1138 if (GNode == 0 || GNode->getGlobals().size() == 0) return 0;
1140 // If a clone has already been created for GNode, return it.
1141 DSNodeHandle& ValMapEntry = ScalarMap[GNode->getGlobals()[0]];
1142 if (ValMapEntry != 0)
1145 // Clone the node and update the ValMap.
1146 DSNode* NewNode = new DSNode(*GNode);
1147 ValMapEntry = NewNode; // j=0 case of loop below!
1148 Nodes.push_back(NewNode);
1149 for (unsigned j = 1, N = NewNode->getGlobals().size(); j < N; ++j)
1150 ScalarMap[NewNode->getGlobals()[j]] = NewNode;
1152 // Rewrite the links in the new node to point into the current graph.
1153 for (unsigned j = 0, e = GNode->getNumLinks(); j != e; ++j)
1154 NewNode->setLink(j, cloneGlobalInto(GNode->getLink(j)));
1159 // GlobalDSGraph::cloneNodeInto - Clone a global node and all its externally
1160 // visible target links (and recursively their such links) into this graph.
1161 // NodeCache maps the node being cloned to its clone in the Globals graph,
1162 // in order to track cycles.
1163 // GlobalsAreFinal is a flag that says whether it is safe to assume that
1164 // an existing global node is complete. This is important to avoid
1165 // reinserting all globals when inserting Calls to functions.
1166 // This is a helper function for cloneGlobals and cloneCalls.
1168 DSNode* GlobalDSGraph::cloneNodeInto(DSNode *OldNode,
1169 hash_map<const DSNode*, DSNode*> &NodeCache,
1170 bool GlobalsAreFinal) {
1171 if (OldNode == 0) return 0;
1173 // The caller should check this is an external node. Just more efficient...
1174 assert((OldNode->NodeType & ExternalTypeBits) && "Non-external node");
1176 // If a clone has already been created for OldNode, return it.
1177 DSNode*& CacheEntry = NodeCache[OldNode];
1178 if (CacheEntry != 0)
1181 // The result value...
1182 DSNode* NewNode = 0;
1184 // If nodes already exist for any of the globals of OldNode,
1185 // merge all such nodes together since they are merged in OldNode.
1186 // If ValueCacheIsFinal==true, look for an existing node that has
1187 // an identical list of globals and return it if it exists.
1189 for (unsigned j = 0, N = OldNode->getGlobals().size(); j != N; ++j)
1190 if (DSNode *PrevNode = ScalarMap[OldNode->getGlobals()[j]].getNode()) {
1192 NewNode = PrevNode; // first existing node found
1193 if (GlobalsAreFinal && j == 0)
1194 if (OldNode->getGlobals() == PrevNode->getGlobals()) {
1195 CacheEntry = NewNode;
1199 else if (NewNode != PrevNode) { // found another, different from prev
1200 // update ValMap *before* merging PrevNode into NewNode
1201 for (unsigned k = 0, NK = PrevNode->getGlobals().size(); k < NK; ++k)
1202 ScalarMap[PrevNode->getGlobals()[k]] = NewNode;
1203 NewNode->mergeWith(PrevNode);
1205 } else if (NewNode != 0) {
1206 ScalarMap[OldNode->getGlobals()[j]] = NewNode; // add the merged node
1209 // If no existing node was found, clone the node and update the ValMap.
1211 NewNode = new DSNode(*OldNode);
1212 Nodes.push_back(NewNode);
1213 for (unsigned j = 0, e = NewNode->getNumLinks(); j != e; ++j)
1214 NewNode->setLink(j, 0);
1215 for (unsigned j = 0, N = NewNode->getGlobals().size(); j < N; ++j)
1216 ScalarMap[NewNode->getGlobals()[j]] = NewNode;
1219 NewNode->NodeType |= OldNode->NodeType; // Markers may be different!
1221 // Add the entry to NodeCache
1222 CacheEntry = NewNode;
1224 // Rewrite the links in the new node to point into the current graph,
1225 // but only for links to external nodes. Set other links to NULL.
1226 for (unsigned j = 0, e = OldNode->getNumLinks(); j != e; ++j) {
1227 DSNode* OldTarget = OldNode->getLink(j);
1228 if (OldTarget && (OldTarget->NodeType & ExternalTypeBits)) {
1229 DSNode* NewLink = this->cloneNodeInto(OldTarget, NodeCache);
1230 if (NewNode->getLink(j))
1231 NewNode->getLink(j)->mergeWith(NewLink);
1233 NewNode->setLink(j, NewLink);
1237 // Remove all local markers
1238 NewNode->NodeType &= ~(DSNode::AllocaNode | DSNode::ScalarNode);
1244 // GlobalDSGraph::cloneCalls - Clone function calls and their visible target
1245 // links (and recursively their such links) into this graph.
1247 void GlobalDSGraph::cloneCalls(DSGraph& Graph) {
1248 hash_map<const DSNode*, DSNode*> NodeCache;
1249 std::vector<DSCallSite >& FromCalls =Graph.FunctionCalls;
1251 FunctionCalls.reserve(FunctionCalls.size() + FromCalls.size());
1253 for (int i = 0, ei = FromCalls.size(); i < ei; ++i) {
1254 DSCallSite& callCopy = FunctionCalls.back();
1255 callCopy.reserve(FromCalls[i].size());
1256 for (unsigned j = 0, ej = FromCalls[i].size(); j != ej; ++j)
1258 ((FromCalls[i][j] && (FromCalls[i][j]->NodeType & ExternalTypeBits))
1259 ? cloneNodeInto(FromCalls[i][j], NodeCache, true)
1263 // remove trivially identical function calls
1264 removeIdenticalCalls(FunctionCalls, "Globals Graph");