1 //===- DataStructure.cpp - Implement the core data structure analysis -----===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the core data structure functionality.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Analysis/DataStructure/DSGraphTraits.h"
15 #include "llvm/Function.h"
16 #include "llvm/GlobalVariable.h"
17 #include "llvm/Instructions.h"
18 #include "llvm/DerivedTypes.h"
19 #include "llvm/Target/TargetData.h"
20 #include "llvm/Assembly/Writer.h"
21 #include "Support/CommandLine.h"
22 #include "Support/Debug.h"
23 #include "Support/DepthFirstIterator.h"
24 #include "Support/STLExtras.h"
25 #include "Support/Statistic.h"
26 #include "Support/Timer.h"
31 Statistic<> NumFolds ("dsa", "Number of nodes completely folded");
32 Statistic<> NumCallNodesMerged("dsa", "Number of call nodes merged");
33 Statistic<> NumNodeAllocated ("dsa", "Number of nodes allocated");
34 Statistic<> NumDNE ("dsa", "Number of nodes removed by reachability");
35 Statistic<> NumTrivialDNE ("dsa", "Number of nodes trivially removed");
36 Statistic<> NumTrivialGlobalDNE("dsa", "Number of globals trivially removed");
40 #define TIME_REGION(VARNAME, DESC) \
41 NamedRegionTimer VARNAME(DESC)
43 #define TIME_REGION(VARNAME, DESC)
48 DSNode *DSNodeHandle::HandleForwarding() const {
49 assert(N->isForwarding() && "Can only be invoked if forwarding!");
51 // Handle node forwarding here!
52 DSNode *Next = N->ForwardNH.getNode(); // Cause recursive shrinkage
53 Offset += N->ForwardNH.getOffset();
55 if (--N->NumReferrers == 0) {
56 // Removing the last referrer to the node, sever the forwarding link
62 if (N->Size <= Offset) {
63 assert(N->Size <= 1 && "Forwarded to shrunk but not collapsed node?");
69 //===----------------------------------------------------------------------===//
70 // DSNode Implementation
71 //===----------------------------------------------------------------------===//
73 DSNode::DSNode(const Type *T, DSGraph *G)
74 : NumReferrers(0), Size(0), ParentGraph(G), Ty(Type::VoidTy), NodeType(0) {
75 // Add the type entry if it is specified...
76 if (T) mergeTypeInfo(T, 0);
77 if (G) G->addNode(this);
81 // DSNode copy constructor... do not copy over the referrers list!
82 DSNode::DSNode(const DSNode &N, DSGraph *G, bool NullLinks)
83 : NumReferrers(0), Size(N.Size), ParentGraph(G),
84 Ty(N.Ty), NodeType(N.NodeType) {
89 Links.resize(N.Links.size()); // Create the appropriate number of null links
94 /// getTargetData - Get the target data object used to construct this node.
96 const TargetData &DSNode::getTargetData() const {
97 return ParentGraph->getTargetData();
100 void DSNode::assertOK() const {
101 assert((Ty != Type::VoidTy ||
102 Ty == Type::VoidTy && (Size == 0 ||
103 (NodeType & DSNode::Array))) &&
106 assert(ParentGraph && "Node has no parent?");
107 const DSScalarMap &SM = ParentGraph->getScalarMap();
108 for (unsigned i = 0, e = Globals.size(); i != e; ++i) {
109 assert(SM.count(Globals[i]));
110 assert(SM.find(Globals[i])->second.getNode() == this);
114 /// forwardNode - Mark this node as being obsolete, and all references to it
115 /// should be forwarded to the specified node and offset.
117 void DSNode::forwardNode(DSNode *To, unsigned Offset) {
118 assert(this != To && "Cannot forward a node to itself!");
119 assert(ForwardNH.isNull() && "Already forwarding from this node!");
120 if (To->Size <= 1) Offset = 0;
121 assert((Offset < To->Size || (Offset == To->Size && Offset == 0)) &&
122 "Forwarded offset is wrong!");
123 ForwardNH.setTo(To, Offset);
128 // Remove this node from the parent graph's Nodes list.
129 ParentGraph->unlinkNode(this);
133 // addGlobal - Add an entry for a global value to the Globals list. This also
134 // marks the node with the 'G' flag if it does not already have it.
136 void DSNode::addGlobal(GlobalValue *GV) {
137 // Keep the list sorted.
138 std::vector<GlobalValue*>::iterator I =
139 std::lower_bound(Globals.begin(), Globals.end(), GV);
141 if (I == Globals.end() || *I != GV) {
142 //assert(GV->getType()->getElementType() == Ty);
143 Globals.insert(I, GV);
144 NodeType |= GlobalNode;
148 /// foldNodeCompletely - If we determine that this node has some funny
149 /// behavior happening to it that we cannot represent, we fold it down to a
150 /// single, completely pessimistic, node. This node is represented as a
151 /// single byte with a single TypeEntry of "void".
153 void DSNode::foldNodeCompletely() {
154 if (isNodeCompletelyFolded()) return; // If this node is already folded...
158 // If this node has a size that is <= 1, we don't need to create a forwarding
160 if (getSize() <= 1) {
161 NodeType |= DSNode::Array;
164 assert(Links.size() <= 1 && "Size is 1, but has more links?");
167 // Create the node we are going to forward to. This is required because
168 // some referrers may have an offset that is > 0. By forcing them to
169 // forward, the forwarder has the opportunity to correct the offset.
170 DSNode *DestNode = new DSNode(0, ParentGraph);
171 DestNode->NodeType = NodeType|DSNode::Array;
172 DestNode->Ty = Type::VoidTy;
174 DestNode->Globals.swap(Globals);
176 // Start forwarding to the destination node...
177 forwardNode(DestNode, 0);
179 if (!Links.empty()) {
180 DestNode->Links.reserve(1);
182 DSNodeHandle NH(DestNode);
183 DestNode->Links.push_back(Links[0]);
185 // If we have links, merge all of our outgoing links together...
186 for (unsigned i = Links.size()-1; i != 0; --i)
187 NH.getNode()->Links[0].mergeWith(Links[i]);
190 DestNode->Links.resize(1);
195 /// isNodeCompletelyFolded - Return true if this node has been completely
196 /// folded down to something that can never be expanded, effectively losing
197 /// all of the field sensitivity that may be present in the node.
199 bool DSNode::isNodeCompletelyFolded() const {
200 return getSize() == 1 && Ty == Type::VoidTy && isArray();
204 /// TypeElementWalker Class - Used for implementation of physical subtyping...
206 class TypeElementWalker {
211 StackState(const Type *T, unsigned Off = 0)
212 : Ty(T), Offset(Off), Idx(0) {}
215 std::vector<StackState> Stack;
216 const TargetData &TD;
218 TypeElementWalker(const Type *T, const TargetData &td) : TD(td) {
223 bool isDone() const { return Stack.empty(); }
224 const Type *getCurrentType() const { return Stack.back().Ty; }
225 unsigned getCurrentOffset() const { return Stack.back().Offset; }
227 void StepToNextType() {
228 PopStackAndAdvance();
233 /// PopStackAndAdvance - Pop the current element off of the stack and
234 /// advance the underlying element to the next contained member.
235 void PopStackAndAdvance() {
236 assert(!Stack.empty() && "Cannot pop an empty stack!");
238 while (!Stack.empty()) {
239 StackState &SS = Stack.back();
240 if (const StructType *ST = dyn_cast<StructType>(SS.Ty)) {
242 if (SS.Idx != ST->getNumElements()) {
243 const StructLayout *SL = TD.getStructLayout(ST);
244 SS.Offset += SL->MemberOffsets[SS.Idx]-SL->MemberOffsets[SS.Idx-1];
247 Stack.pop_back(); // At the end of the structure
249 const ArrayType *AT = cast<ArrayType>(SS.Ty);
251 if (SS.Idx != AT->getNumElements()) {
252 SS.Offset += TD.getTypeSize(AT->getElementType());
255 Stack.pop_back(); // At the end of the array
260 /// StepToLeaf - Used by physical subtyping to move to the first leaf node
261 /// on the type stack.
263 if (Stack.empty()) return;
264 while (!Stack.empty() && !Stack.back().Ty->isFirstClassType()) {
265 StackState &SS = Stack.back();
266 if (const StructType *ST = dyn_cast<StructType>(SS.Ty)) {
267 if (ST->getNumElements() == 0) {
269 PopStackAndAdvance();
271 // Step into the structure...
272 assert(SS.Idx < ST->getNumElements());
273 const StructLayout *SL = TD.getStructLayout(ST);
274 Stack.push_back(StackState(ST->getElementType(SS.Idx),
275 SS.Offset+SL->MemberOffsets[SS.Idx]));
278 const ArrayType *AT = cast<ArrayType>(SS.Ty);
279 if (AT->getNumElements() == 0) {
281 PopStackAndAdvance();
283 // Step into the array...
284 assert(SS.Idx < AT->getNumElements());
285 Stack.push_back(StackState(AT->getElementType(),
287 TD.getTypeSize(AT->getElementType())));
293 } // end anonymous namespace
295 /// ElementTypesAreCompatible - Check to see if the specified types are
296 /// "physically" compatible. If so, return true, else return false. We only
297 /// have to check the fields in T1: T2 may be larger than T1. If AllowLargerT1
298 /// is true, then we also allow a larger T1.
300 static bool ElementTypesAreCompatible(const Type *T1, const Type *T2,
301 bool AllowLargerT1, const TargetData &TD){
302 TypeElementWalker T1W(T1, TD), T2W(T2, TD);
304 while (!T1W.isDone() && !T2W.isDone()) {
305 if (T1W.getCurrentOffset() != T2W.getCurrentOffset())
308 const Type *T1 = T1W.getCurrentType();
309 const Type *T2 = T2W.getCurrentType();
310 if (T1 != T2 && !T1->isLosslesslyConvertibleTo(T2))
313 T1W.StepToNextType();
314 T2W.StepToNextType();
317 return AllowLargerT1 || T1W.isDone();
321 /// mergeTypeInfo - This method merges the specified type into the current node
322 /// at the specified offset. This may update the current node's type record if
323 /// this gives more information to the node, it may do nothing to the node if
324 /// this information is already known, or it may merge the node completely (and
325 /// return true) if the information is incompatible with what is already known.
327 /// This method returns true if the node is completely folded, otherwise false.
329 bool DSNode::mergeTypeInfo(const Type *NewTy, unsigned Offset,
330 bool FoldIfIncompatible) {
331 const TargetData &TD = getTargetData();
332 // Check to make sure the Size member is up-to-date. Size can be one of the
334 // Size = 0, Ty = Void: Nothing is known about this node.
335 // Size = 0, Ty = FnTy: FunctionPtr doesn't have a size, so we use zero
336 // Size = 1, Ty = Void, Array = 1: The node is collapsed
337 // Otherwise, sizeof(Ty) = Size
339 assert(((Size == 0 && Ty == Type::VoidTy && !isArray()) ||
340 (Size == 0 && !Ty->isSized() && !isArray()) ||
341 (Size == 1 && Ty == Type::VoidTy && isArray()) ||
342 (Size == 0 && !Ty->isSized() && !isArray()) ||
343 (TD.getTypeSize(Ty) == Size)) &&
344 "Size member of DSNode doesn't match the type structure!");
345 assert(NewTy != Type::VoidTy && "Cannot merge void type into DSNode!");
347 if (Offset == 0 && NewTy == Ty)
348 return false; // This should be a common case, handle it efficiently
350 // Return true immediately if the node is completely folded.
351 if (isNodeCompletelyFolded()) return true;
353 // If this is an array type, eliminate the outside arrays because they won't
354 // be used anyway. This greatly reduces the size of large static arrays used
355 // as global variables, for example.
357 bool WillBeArray = false;
358 while (const ArrayType *AT = dyn_cast<ArrayType>(NewTy)) {
359 // FIXME: we might want to keep small arrays, but must be careful about
360 // things like: [2 x [10000 x int*]]
361 NewTy = AT->getElementType();
365 // Figure out how big the new type we're merging in is...
366 unsigned NewTySize = NewTy->isSized() ? TD.getTypeSize(NewTy) : 0;
368 // Otherwise check to see if we can fold this type into the current node. If
369 // we can't, we fold the node completely, if we can, we potentially update our
372 if (Ty == Type::VoidTy) {
373 // If this is the first type that this node has seen, just accept it without
375 assert(Offset == 0 && !isArray() &&
376 "Cannot have an offset into a void node!");
379 if (WillBeArray) NodeType |= Array;
382 // Calculate the number of outgoing links from this node.
383 Links.resize((Size+DS::PointerSize-1) >> DS::PointerShift);
387 // Handle node expansion case here...
388 if (Offset+NewTySize > Size) {
389 // It is illegal to grow this node if we have treated it as an array of
392 if (FoldIfIncompatible) foldNodeCompletely();
396 if (Offset) { // We could handle this case, but we don't for now...
397 std::cerr << "UNIMP: Trying to merge a growth type into "
398 << "offset != 0: Collapsing!\n";
399 if (FoldIfIncompatible) foldNodeCompletely();
403 // Okay, the situation is nice and simple, we are trying to merge a type in
404 // at offset 0 that is bigger than our current type. Implement this by
405 // switching to the new type and then merge in the smaller one, which should
406 // hit the other code path here. If the other code path decides it's not
407 // ok, it will collapse the node as appropriate.
409 const Type *OldTy = Ty;
412 if (WillBeArray) NodeType |= Array;
415 // Must grow links to be the appropriate size...
416 Links.resize((Size+DS::PointerSize-1) >> DS::PointerShift);
418 // Merge in the old type now... which is guaranteed to be smaller than the
420 return mergeTypeInfo(OldTy, 0);
423 assert(Offset <= Size &&
424 "Cannot merge something into a part of our type that doesn't exist!");
426 // Find the section of Ty that NewTy overlaps with... first we find the
427 // type that starts at offset Offset.
430 const Type *SubType = Ty;
432 assert(Offset-O < TD.getTypeSize(SubType) && "Offset out of range!");
434 switch (SubType->getTypeID()) {
435 case Type::StructTyID: {
436 const StructType *STy = cast<StructType>(SubType);
437 const StructLayout &SL = *TD.getStructLayout(STy);
439 unsigned i = 0, e = SL.MemberOffsets.size();
440 for (; i+1 < e && SL.MemberOffsets[i+1] <= Offset-O; ++i)
443 // The offset we are looking for must be in the i'th element...
444 SubType = STy->getElementType(i);
445 O += SL.MemberOffsets[i];
448 case Type::ArrayTyID: {
449 SubType = cast<ArrayType>(SubType)->getElementType();
450 unsigned ElSize = TD.getTypeSize(SubType);
451 unsigned Remainder = (Offset-O) % ElSize;
452 O = Offset-Remainder;
456 if (FoldIfIncompatible) foldNodeCompletely();
461 assert(O == Offset && "Could not achieve the correct offset!");
463 // If we found our type exactly, early exit
464 if (SubType == NewTy) return false;
466 // Differing function types don't require us to merge. They are not values
468 if (isa<FunctionType>(SubType) &&
469 isa<FunctionType>(NewTy)) return false;
471 unsigned SubTypeSize = SubType->isSized() ? TD.getTypeSize(SubType) : 0;
473 // Ok, we are getting desperate now. Check for physical subtyping, where we
474 // just require each element in the node to be compatible.
475 if (NewTySize <= SubTypeSize && NewTySize && NewTySize < 256 &&
476 SubTypeSize && SubTypeSize < 256 &&
477 ElementTypesAreCompatible(NewTy, SubType, !isArray(), TD))
480 // Okay, so we found the leader type at the offset requested. Search the list
481 // of types that starts at this offset. If SubType is currently an array or
482 // structure, the type desired may actually be the first element of the
485 unsigned PadSize = SubTypeSize; // Size, including pad memory which is ignored
486 while (SubType != NewTy) {
487 const Type *NextSubType = 0;
488 unsigned NextSubTypeSize = 0;
489 unsigned NextPadSize = 0;
490 switch (SubType->getTypeID()) {
491 case Type::StructTyID: {
492 const StructType *STy = cast<StructType>(SubType);
493 const StructLayout &SL = *TD.getStructLayout(STy);
494 if (SL.MemberOffsets.size() > 1)
495 NextPadSize = SL.MemberOffsets[1];
497 NextPadSize = SubTypeSize;
498 NextSubType = STy->getElementType(0);
499 NextSubTypeSize = TD.getTypeSize(NextSubType);
502 case Type::ArrayTyID:
503 NextSubType = cast<ArrayType>(SubType)->getElementType();
504 NextSubTypeSize = TD.getTypeSize(NextSubType);
505 NextPadSize = NextSubTypeSize;
511 if (NextSubType == 0)
512 break; // In the default case, break out of the loop
514 if (NextPadSize < NewTySize)
515 break; // Don't allow shrinking to a smaller type than NewTySize
516 SubType = NextSubType;
517 SubTypeSize = NextSubTypeSize;
518 PadSize = NextPadSize;
521 // If we found the type exactly, return it...
522 if (SubType == NewTy)
525 // Check to see if we have a compatible, but different type...
526 if (NewTySize == SubTypeSize) {
527 // Check to see if this type is obviously convertible... int -> uint f.e.
528 if (NewTy->isLosslesslyConvertibleTo(SubType))
531 // Check to see if we have a pointer & integer mismatch going on here,
532 // loading a pointer as a long, for example.
534 if (SubType->isInteger() && isa<PointerType>(NewTy) ||
535 NewTy->isInteger() && isa<PointerType>(SubType))
537 } else if (NewTySize > SubTypeSize && NewTySize <= PadSize) {
538 // We are accessing the field, plus some structure padding. Ignore the
539 // structure padding.
544 if (getParentGraph()->getReturnNodes().size())
545 M = getParentGraph()->getReturnNodes().begin()->first->getParent();
546 DEBUG(std::cerr << "MergeTypeInfo Folding OrigTy: ";
547 WriteTypeSymbolic(std::cerr, Ty, M) << "\n due to:";
548 WriteTypeSymbolic(std::cerr, NewTy, M) << " @ " << Offset << "!\n"
550 WriteTypeSymbolic(std::cerr, SubType, M) << "\n\n");
552 if (FoldIfIncompatible) foldNodeCompletely();
558 /// addEdgeTo - Add an edge from the current node to the specified node. This
559 /// can cause merging of nodes in the graph.
561 void DSNode::addEdgeTo(unsigned Offset, const DSNodeHandle &NH) {
562 if (NH.isNull()) return; // Nothing to do
564 DSNodeHandle &ExistingEdge = getLink(Offset);
565 if (!ExistingEdge.isNull()) {
566 // Merge the two nodes...
567 ExistingEdge.mergeWith(NH);
568 } else { // No merging to perform...
569 setLink(Offset, NH); // Just force a link in there...
574 /// MergeSortedVectors - Efficiently merge a vector into another vector where
575 /// duplicates are not allowed and both are sorted. This assumes that 'T's are
576 /// efficiently copyable and have sane comparison semantics.
578 static void MergeSortedVectors(std::vector<GlobalValue*> &Dest,
579 const std::vector<GlobalValue*> &Src) {
580 // By far, the most common cases will be the simple ones. In these cases,
581 // avoid having to allocate a temporary vector...
583 if (Src.empty()) { // Nothing to merge in...
585 } else if (Dest.empty()) { // Just copy the result in...
587 } else if (Src.size() == 1) { // Insert a single element...
588 const GlobalValue *V = Src[0];
589 std::vector<GlobalValue*>::iterator I =
590 std::lower_bound(Dest.begin(), Dest.end(), V);
591 if (I == Dest.end() || *I != Src[0]) // If not already contained...
592 Dest.insert(I, Src[0]);
593 } else if (Dest.size() == 1) {
594 GlobalValue *Tmp = Dest[0]; // Save value in temporary...
595 Dest = Src; // Copy over list...
596 std::vector<GlobalValue*>::iterator I =
597 std::lower_bound(Dest.begin(), Dest.end(), Tmp);
598 if (I == Dest.end() || *I != Tmp) // If not already contained...
602 // Make a copy to the side of Dest...
603 std::vector<GlobalValue*> Old(Dest);
605 // Make space for all of the type entries now...
606 Dest.resize(Dest.size()+Src.size());
608 // Merge the two sorted ranges together... into Dest.
609 std::merge(Old.begin(), Old.end(), Src.begin(), Src.end(), Dest.begin());
611 // Now erase any duplicate entries that may have accumulated into the
612 // vectors (because they were in both of the input sets)
613 Dest.erase(std::unique(Dest.begin(), Dest.end()), Dest.end());
617 void DSNode::mergeGlobals(const std::vector<GlobalValue*> &RHS) {
618 MergeSortedVectors(Globals, RHS);
621 // MergeNodes - Helper function for DSNode::mergeWith().
622 // This function does the hard work of merging two nodes, CurNodeH
623 // and NH after filtering out trivial cases and making sure that
624 // CurNodeH.offset >= NH.offset.
627 // Since merging may cause either node to go away, we must always
628 // use the node-handles to refer to the nodes. These node handles are
629 // automatically updated during merging, so will always provide access
630 // to the correct node after a merge.
632 void DSNode::MergeNodes(DSNodeHandle& CurNodeH, DSNodeHandle& NH) {
633 assert(CurNodeH.getOffset() >= NH.getOffset() &&
634 "This should have been enforced in the caller.");
635 assert(CurNodeH.getNode()->getParentGraph()==NH.getNode()->getParentGraph() &&
636 "Cannot merge two nodes that are not in the same graph!");
638 // Now we know that Offset >= NH.Offset, so convert it so our "Offset" (with
639 // respect to NH.Offset) is now zero. NOffset is the distance from the base
640 // of our object that N starts from.
642 unsigned NOffset = CurNodeH.getOffset()-NH.getOffset();
643 unsigned NSize = NH.getNode()->getSize();
645 // If the two nodes are of different size, and the smaller node has the array
646 // bit set, collapse!
647 if (NSize != CurNodeH.getNode()->getSize()) {
648 if (NSize < CurNodeH.getNode()->getSize()) {
649 if (NH.getNode()->isArray())
650 NH.getNode()->foldNodeCompletely();
651 } else if (CurNodeH.getNode()->isArray()) {
652 NH.getNode()->foldNodeCompletely();
656 // Merge the type entries of the two nodes together...
657 if (NH.getNode()->Ty != Type::VoidTy)
658 CurNodeH.getNode()->mergeTypeInfo(NH.getNode()->Ty, NOffset);
659 assert(!CurNodeH.getNode()->isDeadNode());
661 // If we are merging a node with a completely folded node, then both nodes are
662 // now completely folded.
664 if (CurNodeH.getNode()->isNodeCompletelyFolded()) {
665 if (!NH.getNode()->isNodeCompletelyFolded()) {
666 NH.getNode()->foldNodeCompletely();
667 assert(NH.getNode() && NH.getOffset() == 0 &&
668 "folding did not make offset 0?");
669 NOffset = NH.getOffset();
670 NSize = NH.getNode()->getSize();
671 assert(NOffset == 0 && NSize == 1);
673 } else if (NH.getNode()->isNodeCompletelyFolded()) {
674 CurNodeH.getNode()->foldNodeCompletely();
675 assert(CurNodeH.getNode() && CurNodeH.getOffset() == 0 &&
676 "folding did not make offset 0?");
677 NOffset = NH.getOffset();
678 NSize = NH.getNode()->getSize();
679 assert(NOffset == 0 && NSize == 1);
682 DSNode *N = NH.getNode();
683 if (CurNodeH.getNode() == N || N == 0) return;
684 assert(!CurNodeH.getNode()->isDeadNode());
686 // Merge the NodeType information.
687 CurNodeH.getNode()->NodeType |= N->NodeType;
689 // Start forwarding to the new node!
690 N->forwardNode(CurNodeH.getNode(), NOffset);
691 assert(!CurNodeH.getNode()->isDeadNode());
693 // Make all of the outgoing links of N now be outgoing links of CurNodeH.
695 for (unsigned i = 0; i < N->getNumLinks(); ++i) {
696 DSNodeHandle &Link = N->getLink(i << DS::PointerShift);
697 if (Link.getNode()) {
698 // Compute the offset into the current node at which to
699 // merge this link. In the common case, this is a linear
700 // relation to the offset in the original node (with
701 // wrapping), but if the current node gets collapsed due to
702 // recursive merging, we must make sure to merge in all remaining
703 // links at offset zero.
704 unsigned MergeOffset = 0;
705 DSNode *CN = CurNodeH.getNode();
707 MergeOffset = ((i << DS::PointerShift)+NOffset) % CN->getSize();
708 CN->addEdgeTo(MergeOffset, Link);
712 // Now that there are no outgoing edges, all of the Links are dead.
715 // Merge the globals list...
716 if (!N->Globals.empty()) {
717 CurNodeH.getNode()->mergeGlobals(N->Globals);
719 // Delete the globals from the old node...
720 std::vector<GlobalValue*>().swap(N->Globals);
725 /// mergeWith - Merge this node and the specified node, moving all links to and
726 /// from the argument node into the current node, deleting the node argument.
727 /// Offset indicates what offset the specified node is to be merged into the
730 /// The specified node may be a null pointer (in which case, we update it to
731 /// point to this node).
733 void DSNode::mergeWith(const DSNodeHandle &NH, unsigned Offset) {
734 DSNode *N = NH.getNode();
735 if (N == this && NH.getOffset() == Offset)
738 // If the RHS is a null node, make it point to this node!
740 NH.mergeWith(DSNodeHandle(this, Offset));
744 assert(!N->isDeadNode() && !isDeadNode());
745 assert(!hasNoReferrers() && "Should not try to fold a useless node!");
748 // We cannot merge two pieces of the same node together, collapse the node
750 DEBUG(std::cerr << "Attempting to merge two chunks of"
751 << " the same node together!\n");
752 foldNodeCompletely();
756 // If both nodes are not at offset 0, make sure that we are merging the node
757 // at an later offset into the node with the zero offset.
759 if (Offset < NH.getOffset()) {
760 N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
762 } else if (Offset == NH.getOffset() && getSize() < N->getSize()) {
763 // If the offsets are the same, merge the smaller node into the bigger node
764 N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
768 // Ok, now we can merge the two nodes. Use a static helper that works with
769 // two node handles, since "this" may get merged away at intermediate steps.
770 DSNodeHandle CurNodeH(this, Offset);
771 DSNodeHandle NHCopy(NH);
772 DSNode::MergeNodes(CurNodeH, NHCopy);
776 //===----------------------------------------------------------------------===//
777 // ReachabilityCloner Implementation
778 //===----------------------------------------------------------------------===//
780 DSNodeHandle ReachabilityCloner::getClonedNH(const DSNodeHandle &SrcNH) {
781 if (SrcNH.isNull()) return DSNodeHandle();
782 const DSNode *SN = SrcNH.getNode();
784 DSNodeHandle &NH = NodeMap[SN];
785 if (!NH.isNull()) // Node already mapped?
786 return DSNodeHandle(NH.getNode(), NH.getOffset()+SrcNH.getOffset());
788 // If SrcNH has globals and the destination graph has one of the same globals,
789 // merge this node with the destination node, which is much more efficient.
790 if (SN->global_begin() != SN->global_end()) {
791 DSScalarMap &DestSM = Dest.getScalarMap();
792 for (DSNode::global_iterator I = SN->global_begin(), E = SN->global_end();
794 GlobalValue *GV = *I;
795 DSScalarMap::iterator GI = DestSM.find(GV);
796 if (GI != DestSM.end() && !GI->second.isNull()) {
797 // We found one, use merge instead!
798 merge(GI->second, Src.getNodeForValue(GV));
799 assert(!NH.isNull() && "Didn't merge node!");
800 return DSNodeHandle(NH.getNode(), NH.getOffset()+SrcNH.getOffset());
805 DSNode *DN = new DSNode(*SN, &Dest, true /* Null out all links */);
806 DN->maskNodeTypes(BitsToKeep);
809 // Next, recursively clone all outgoing links as necessary. Note that
810 // adding these links can cause the node to collapse itself at any time, and
811 // the current node may be merged with arbitrary other nodes. For this
812 // reason, we must always go through NH.
814 for (unsigned i = 0, e = SN->getNumLinks(); i != e; ++i) {
815 const DSNodeHandle &SrcEdge = SN->getLink(i << DS::PointerShift);
816 if (!SrcEdge.isNull()) {
817 const DSNodeHandle &DestEdge = getClonedNH(SrcEdge);
818 // Compute the offset into the current node at which to
819 // merge this link. In the common case, this is a linear
820 // relation to the offset in the original node (with
821 // wrapping), but if the current node gets collapsed due to
822 // recursive merging, we must make sure to merge in all remaining
823 // links at offset zero.
824 unsigned MergeOffset = 0;
825 DSNode *CN = NH.getNode();
826 if (CN->getSize() != 1)
827 MergeOffset = ((i << DS::PointerShift)+NH.getOffset()) % CN->getSize();
828 CN->addEdgeTo(MergeOffset, DestEdge);
832 // If this node contains any globals, make sure they end up in the scalar
833 // map with the correct offset.
834 for (DSNode::global_iterator I = SN->global_begin(), E = SN->global_end();
836 GlobalValue *GV = *I;
837 const DSNodeHandle &SrcGNH = Src.getNodeForValue(GV);
838 DSNodeHandle &DestGNH = NodeMap[SrcGNH.getNode()];
839 assert(DestGNH.getNode() == NH.getNode() &&"Global mapping inconsistent");
840 Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
841 DestGNH.getOffset()+SrcGNH.getOffset()));
843 if (CloneFlags & DSGraph::UpdateInlinedGlobals)
844 Dest.getInlinedGlobals().insert(GV);
846 NH.getNode()->mergeGlobals(SN->getGlobals());
848 return DSNodeHandle(NH.getNode(), NH.getOffset()+SrcNH.getOffset());
851 void ReachabilityCloner::merge(const DSNodeHandle &NH,
852 const DSNodeHandle &SrcNH) {
853 if (SrcNH.isNull()) return; // Noop
855 // If there is no destination node, just clone the source and assign the
856 // destination node to be it.
857 NH.mergeWith(getClonedNH(SrcNH));
861 // Okay, at this point, we know that we have both a destination and a source
862 // node that need to be merged. Check to see if the source node has already
864 const DSNode *SN = SrcNH.getNode();
865 DSNodeHandle &SCNH = NodeMap[SN]; // SourceClonedNodeHandle
866 if (!SCNH.isNull()) { // Node already cloned?
867 NH.mergeWith(DSNodeHandle(SCNH.getNode(),
868 SCNH.getOffset()+SrcNH.getOffset()));
870 return; // Nothing to do!
873 // Okay, so the source node has not already been cloned. Instead of creating
874 // a new DSNode, only to merge it into the one we already have, try to perform
875 // the merge in-place. The only case we cannot handle here is when the offset
876 // into the existing node is less than the offset into the virtual node we are
877 // merging in. In this case, we have to extend the existing node, which
878 // requires an allocation anyway.
879 DSNode *DN = NH.getNode(); // Make sure the Offset is up-to-date
880 if (NH.getOffset() >= SrcNH.getOffset()) {
881 if (!DN->isNodeCompletelyFolded()) {
882 // Make sure the destination node is folded if the source node is folded.
883 if (SN->isNodeCompletelyFolded()) {
884 DN->foldNodeCompletely();
886 } else if (SN->getSize() != DN->getSize()) {
887 // If the two nodes are of different size, and the smaller node has the
888 // array bit set, collapse!
889 if (SN->getSize() < DN->getSize()) {
891 DN->foldNodeCompletely();
894 } else if (DN->isArray()) {
895 DN->foldNodeCompletely();
900 // Merge the type entries of the two nodes together...
901 if (SN->getType() != Type::VoidTy && !DN->isNodeCompletelyFolded()) {
902 DN->mergeTypeInfo(SN->getType(), NH.getOffset()-SrcNH.getOffset());
907 assert(!DN->isDeadNode());
909 // Merge the NodeType information.
910 DN->mergeNodeFlags(SN->getNodeFlags() & BitsToKeep);
912 // Before we start merging outgoing links and updating the scalar map, make
913 // sure it is known that this is the representative node for the src node.
914 SCNH = DSNodeHandle(DN, NH.getOffset()-SrcNH.getOffset());
916 // If the source node contains any globals, make sure they end up in the
917 // scalar map with the correct offset.
918 if (SN->global_begin() != SN->global_end()) {
919 // Update the globals in the destination node itself.
920 DN->mergeGlobals(SN->getGlobals());
922 // Update the scalar map for the graph we are merging the source node
924 for (DSNode::global_iterator I = SN->global_begin(), E = SN->global_end();
926 GlobalValue *GV = *I;
927 const DSNodeHandle &SrcGNH = Src.getNodeForValue(GV);
928 DSNodeHandle &DestGNH = NodeMap[SrcGNH.getNode()];
929 assert(DestGNH.getNode()==NH.getNode() &&"Global mapping inconsistent");
930 Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
931 DestGNH.getOffset()+SrcGNH.getOffset()));
933 if (CloneFlags & DSGraph::UpdateInlinedGlobals)
934 Dest.getInlinedGlobals().insert(GV);
936 NH.getNode()->mergeGlobals(SN->getGlobals());
939 // We cannot handle this case without allocating a temporary node. Fall
940 // back on being simple.
941 DSNode *NewDN = new DSNode(*SN, &Dest, true /* Null out all links */);
942 NewDN->maskNodeTypes(BitsToKeep);
944 unsigned NHOffset = NH.getOffset();
945 NH.mergeWith(DSNodeHandle(NewDN, SrcNH.getOffset()));
947 assert(NH.getNode() &&
948 (NH.getOffset() > NHOffset ||
949 (NH.getOffset() == 0 && NH.getNode()->isNodeCompletelyFolded())) &&
950 "Merging did not adjust the offset!");
952 // Before we start merging outgoing links and updating the scalar map, make
953 // sure it is known that this is the representative node for the src node.
954 SCNH = DSNodeHandle(NH.getNode(), NH.getOffset()-SrcNH.getOffset());
956 // If the source node contained any globals, make sure to create entries
957 // in the scalar map for them!
958 for (DSNode::global_iterator I = SN->global_begin(), E = SN->global_end();
960 GlobalValue *GV = *I;
961 const DSNodeHandle &SrcGNH = Src.getNodeForValue(GV);
962 DSNodeHandle &DestGNH = NodeMap[SrcGNH.getNode()];
963 assert(DestGNH.getNode()==NH.getNode() &&"Global mapping inconsistent");
964 assert(SrcGNH.getNode() == SN && "Global mapping inconsistent");
965 Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
966 DestGNH.getOffset()+SrcGNH.getOffset()));
968 if (CloneFlags & DSGraph::UpdateInlinedGlobals)
969 Dest.getInlinedGlobals().insert(GV);
974 // Next, recursively merge all outgoing links as necessary. Note that
975 // adding these links can cause the destination node to collapse itself at
976 // any time, and the current node may be merged with arbitrary other nodes.
977 // For this reason, we must always go through NH.
979 for (unsigned i = 0, e = SN->getNumLinks(); i != e; ++i) {
980 const DSNodeHandle &SrcEdge = SN->getLink(i << DS::PointerShift);
981 if (!SrcEdge.isNull()) {
982 // Compute the offset into the current node at which to
983 // merge this link. In the common case, this is a linear
984 // relation to the offset in the original node (with
985 // wrapping), but if the current node gets collapsed due to
986 // recursive merging, we must make sure to merge in all remaining
987 // links at offset zero.
988 DSNode *CN = SCNH.getNode();
989 unsigned MergeOffset =
990 ((i << DS::PointerShift)+SCNH.getOffset()) % CN->getSize();
992 DSNodeHandle Tmp = CN->getLink(MergeOffset);
994 // Perform the recursive merging. Make sure to create a temporary NH,
995 // because the Link can disappear in the process of recursive merging.
998 Tmp.mergeWith(getClonedNH(SrcEdge));
999 // Merging this could cause all kinds of recursive things to happen,
1000 // culminating in the current node being eliminated. Since this is
1001 // possible, make sure to reaquire the link from 'CN'.
1003 unsigned MergeOffset = 0;
1004 CN = SCNH.getNode();
1005 MergeOffset = ((i << DS::PointerShift)+SCNH.getOffset()) %CN->getSize();
1006 CN->getLink(MergeOffset).mergeWith(Tmp);
1012 /// mergeCallSite - Merge the nodes reachable from the specified src call
1013 /// site into the nodes reachable from DestCS.
1014 void ReachabilityCloner::mergeCallSite(const DSCallSite &DestCS,
1015 const DSCallSite &SrcCS) {
1016 merge(DestCS.getRetVal(), SrcCS.getRetVal());
1017 unsigned MinArgs = DestCS.getNumPtrArgs();
1018 if (SrcCS.getNumPtrArgs() < MinArgs) MinArgs = SrcCS.getNumPtrArgs();
1020 for (unsigned a = 0; a != MinArgs; ++a)
1021 merge(DestCS.getPtrArg(a), SrcCS.getPtrArg(a));
1025 //===----------------------------------------------------------------------===//
1026 // DSCallSite Implementation
1027 //===----------------------------------------------------------------------===//
1029 // Define here to avoid including iOther.h and BasicBlock.h in DSGraph.h
1030 Function &DSCallSite::getCaller() const {
1031 return *Site.getInstruction()->getParent()->getParent();
1034 void DSCallSite::InitNH(DSNodeHandle &NH, const DSNodeHandle &Src,
1035 ReachabilityCloner &RC) {
1036 NH = RC.getClonedNH(Src);
1039 //===----------------------------------------------------------------------===//
1040 // DSGraph Implementation
1041 //===----------------------------------------------------------------------===//
1043 /// getFunctionNames - Return a space separated list of the name of the
1044 /// functions in this graph (if any)
1045 std::string DSGraph::getFunctionNames() const {
1046 switch (getReturnNodes().size()) {
1047 case 0: return "Globals graph";
1048 case 1: return getReturnNodes().begin()->first->getName();
1051 for (DSGraph::ReturnNodesTy::const_iterator I = getReturnNodes().begin();
1052 I != getReturnNodes().end(); ++I)
1053 Return += I->first->getName() + " ";
1054 Return.erase(Return.end()-1, Return.end()); // Remove last space character
1060 DSGraph::DSGraph(const DSGraph &G) : GlobalsGraph(0), TD(G.TD) {
1061 PrintAuxCalls = false;
1063 cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
1066 DSGraph::DSGraph(const DSGraph &G, NodeMapTy &NodeMap)
1067 : GlobalsGraph(0), TD(G.TD) {
1068 PrintAuxCalls = false;
1069 cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
1072 DSGraph::~DSGraph() {
1073 FunctionCalls.clear();
1074 AuxFunctionCalls.clear();
1075 InlinedGlobals.clear();
1077 ReturnNodes.clear();
1079 // Drop all intra-node references, so that assertions don't fail...
1080 for (node_iterator NI = node_begin(), E = node_end(); NI != E; ++NI)
1081 (*NI)->dropAllReferences();
1083 // Free all of the nodes.
1087 // dump - Allow inspection of graph in a debugger.
1088 void DSGraph::dump() const { print(std::cerr); }
1091 /// remapLinks - Change all of the Links in the current node according to the
1092 /// specified mapping.
1094 void DSNode::remapLinks(DSGraph::NodeMapTy &OldNodeMap) {
1095 for (unsigned i = 0, e = Links.size(); i != e; ++i)
1096 if (DSNode *N = Links[i].getNode()) {
1097 DSGraph::NodeMapTy::const_iterator ONMI = OldNodeMap.find(N);
1098 if (ONMI != OldNodeMap.end())
1099 Links[i].setTo(ONMI->second.getNode(),
1100 Links[i].getOffset()+ONMI->second.getOffset());
1104 /// updateFromGlobalGraph - This function rematerializes global nodes and
1105 /// nodes reachable from them from the globals graph into the current graph.
1106 /// It uses the vector InlinedGlobals to avoid cloning and merging globals that
1107 /// are already up-to-date in the current graph. In practice, in the TD pass,
1108 /// this is likely to be a large fraction of the live global nodes in each
1109 /// function (since most live nodes are likely to have been brought up-to-date
1110 /// in at _some_ caller or callee).
1112 void DSGraph::updateFromGlobalGraph() {
1113 TIME_REGION(X, "updateFromGlobalGraph");
1114 ReachabilityCloner RC(*this, *GlobalsGraph, 0);
1116 // Clone the non-up-to-date global nodes into this graph.
1117 for (DSScalarMap::global_iterator I = getScalarMap().global_begin(),
1118 E = getScalarMap().global_end(); I != E; ++I)
1119 if (InlinedGlobals.count(*I) == 0) { // GNode is not up-to-date
1120 DSScalarMap::iterator It = GlobalsGraph->ScalarMap.find(*I);
1121 if (It != GlobalsGraph->ScalarMap.end())
1122 RC.merge(getNodeForValue(*I), It->second);
1126 /// cloneInto - Clone the specified DSGraph into the current graph. The
1127 /// translated ScalarMap for the old function is filled into the OldValMap
1128 /// member, and the translated ReturnNodes map is returned into ReturnNodes.
1130 /// The CloneFlags member controls various aspects of the cloning process.
1132 void DSGraph::cloneInto(const DSGraph &G, DSScalarMap &OldValMap,
1133 ReturnNodesTy &OldReturnNodes, NodeMapTy &OldNodeMap,
1134 unsigned CloneFlags) {
1135 TIME_REGION(X, "cloneInto");
1136 assert(OldNodeMap.empty() && "Returned OldNodeMap should be empty!");
1137 assert(&G != this && "Cannot clone graph into itself!");
1139 // Remove alloca or mod/ref bits as specified...
1140 unsigned BitsToClear = ((CloneFlags & StripAllocaBit)? DSNode::AllocaNode : 0)
1141 | ((CloneFlags & StripModRefBits)? (DSNode::Modified | DSNode::Read) : 0)
1142 | ((CloneFlags & StripIncompleteBit)? DSNode::Incomplete : 0);
1143 BitsToClear |= DSNode::DEAD; // Clear dead flag...
1145 for (node_iterator I = G.node_begin(), E = G.node_end(); I != E; ++I) {
1146 assert(!(*I)->isForwarding() &&
1147 "Forward nodes shouldn't be in node list!");
1148 DSNode *New = new DSNode(**I, this);
1149 New->maskNodeTypes(~BitsToClear);
1150 OldNodeMap[*I] = New;
1154 Timer::addPeakMemoryMeasurement();
1157 // Rewrite the links in the new nodes to point into the current graph now.
1158 // Note that we don't loop over the node's list to do this. The problem is
1159 // that remaping links can cause recursive merging to happen, which means
1160 // that node_iterator's can get easily invalidated! Because of this, we
1161 // loop over the OldNodeMap, which contains all of the new nodes as the
1162 // .second element of the map elements. Also note that if we remap a node
1163 // more than once, we won't break anything.
1164 for (NodeMapTy::iterator I = OldNodeMap.begin(), E = OldNodeMap.end();
1166 I->second.getNode()->remapLinks(OldNodeMap);
1168 // Copy the scalar map... merging all of the global nodes...
1169 for (DSScalarMap::const_iterator I = G.ScalarMap.begin(),
1170 E = G.ScalarMap.end(); I != E; ++I) {
1171 DSNodeHandle &MappedNode = OldNodeMap[I->second.getNode()];
1172 DSNodeHandle &H = OldValMap[I->first];
1173 H.mergeWith(DSNodeHandle(MappedNode.getNode(),
1174 I->second.getOffset()+MappedNode.getOffset()));
1176 // If this is a global, add the global to this fn or merge if already exists
1177 if (GlobalValue* GV = dyn_cast<GlobalValue>(I->first)) {
1178 ScalarMap[GV].mergeWith(H);
1179 if (CloneFlags & DSGraph::UpdateInlinedGlobals)
1180 InlinedGlobals.insert(GV);
1184 if (!(CloneFlags & DontCloneCallNodes)) {
1185 // Copy the function calls list...
1186 unsigned FC = FunctionCalls.size(); // FirstCall
1187 FunctionCalls.reserve(FC+G.FunctionCalls.size());
1188 for (unsigned i = 0, ei = G.FunctionCalls.size(); i != ei; ++i)
1189 FunctionCalls.push_back(DSCallSite(G.FunctionCalls[i], OldNodeMap));
1192 if (!(CloneFlags & DontCloneAuxCallNodes)) {
1193 // Copy the auxiliary function calls list...
1194 unsigned FC = AuxFunctionCalls.size(); // FirstCall
1195 AuxFunctionCalls.reserve(FC+G.AuxFunctionCalls.size());
1196 for (unsigned i = 0, ei = G.AuxFunctionCalls.size(); i != ei; ++i)
1197 AuxFunctionCalls.push_back(DSCallSite(G.AuxFunctionCalls[i], OldNodeMap));
1200 // Map the return node pointers over...
1201 for (ReturnNodesTy::const_iterator I = G.getReturnNodes().begin(),
1202 E = G.getReturnNodes().end(); I != E; ++I) {
1203 const DSNodeHandle &Ret = I->second;
1204 DSNodeHandle &MappedRet = OldNodeMap[Ret.getNode()];
1205 OldReturnNodes.insert(std::make_pair(I->first,
1206 DSNodeHandle(MappedRet.getNode(),
1207 MappedRet.getOffset()+Ret.getOffset())));
1211 static bool PathExistsToClonedNode(const DSNode *N, ReachabilityCloner &RC) {
1213 for (df_iterator<const DSNode*> I = df_begin(N), E = df_end(N); I != E; ++I)
1214 if (RC.hasClonedNode(*I))
1219 static bool PathExistsToClonedNode(const DSCallSite &CS,
1220 ReachabilityCloner &RC) {
1221 if (PathExistsToClonedNode(CS.getRetVal().getNode(), RC))
1223 for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i)
1224 if (PathExistsToClonedNode(CS.getPtrArg(i).getNode(), RC))
1229 /// mergeInGraph - The method is used for merging graphs together. If the
1230 /// argument graph is not *this, it makes a clone of the specified graph, then
1231 /// merges the nodes specified in the call site with the formal arguments in the
1234 void DSGraph::mergeInGraph(const DSCallSite &CS, Function &F,
1235 const DSGraph &Graph, unsigned CloneFlags) {
1236 TIME_REGION(X, "mergeInGraph");
1238 // Fastpath for a noop inline.
1239 if (CS.getNumPtrArgs() == 0 && CS.getRetVal().isNull())
1242 // If this is not a recursive call, clone the graph into this graph...
1243 if (&Graph != this) {
1244 // Clone the callee's graph into the current graph, keeping track of where
1245 // scalars in the old graph _used_ to point, and of the new nodes matching
1246 // nodes of the old graph.
1247 ReachabilityCloner RC(*this, Graph, CloneFlags);
1249 // Set up argument bindings
1250 Function::aiterator AI = F.abegin();
1251 for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i, ++AI) {
1252 // Advance the argument iterator to the first pointer argument...
1253 while (AI != F.aend() && !isPointerType(AI->getType())) {
1255 #ifndef NDEBUG // FIXME: We should merge vararg arguments!
1256 if (AI == F.aend() && !F.getFunctionType()->isVarArg())
1257 std::cerr << "Bad call to Function: " << F.getName() << "\n";
1260 if (AI == F.aend()) break;
1262 // Add the link from the argument scalar to the provided value.
1263 RC.merge(CS.getPtrArg(i), Graph.getNodeForValue(AI));
1266 // Map the return node pointer over.
1267 if (!CS.getRetVal().isNull())
1268 RC.merge(CS.getRetVal(), Graph.getReturnNodeFor(F));
1270 // If requested, copy all of the calls.
1271 if (!(CloneFlags & DontCloneCallNodes)) {
1272 // Copy the function calls list...
1273 FunctionCalls.reserve(FunctionCalls.size()+Graph.FunctionCalls.size());
1274 for (unsigned i = 0, ei = Graph.FunctionCalls.size(); i != ei; ++i)
1275 FunctionCalls.push_back(DSCallSite(Graph.FunctionCalls[i], RC));
1278 // If the user has us copying aux calls (the normal case), set up a data
1279 // structure to keep track of which ones we've copied over.
1280 std::vector<bool> CopiedAuxCall;
1281 if (!(CloneFlags & DontCloneAuxCallNodes)) {
1282 AuxFunctionCalls.reserve(AuxFunctionCalls.size()+
1283 Graph.AuxFunctionCalls.size());
1284 CopiedAuxCall.resize(Graph.AuxFunctionCalls.size());
1287 // Clone over all globals that appear in the caller and callee graphs.
1288 hash_set<GlobalVariable*> NonCopiedGlobals;
1289 for (DSScalarMap::global_iterator GI = Graph.getScalarMap().global_begin(),
1290 E = Graph.getScalarMap().global_end(); GI != E; ++GI)
1291 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(*GI))
1292 if (ScalarMap.count(GV))
1293 RC.merge(ScalarMap[GV], Graph.getNodeForValue(GV));
1295 NonCopiedGlobals.insert(GV);
1297 // If the global does not appear in the callers graph we generally don't
1298 // want to copy the node. However, if there is a path from the node global
1299 // node to a node that we did copy in the graph, we *must* copy it to
1300 // maintain the connection information. Every time we decide to include a
1301 // new global, this might make other globals live, so we must iterate
1303 bool MadeChange = true;
1304 while (MadeChange) {
1306 for (hash_set<GlobalVariable*>::iterator I = NonCopiedGlobals.begin();
1307 I != NonCopiedGlobals.end();) {
1308 DSNode *GlobalNode = Graph.getNodeForValue(*I).getNode();
1309 if (RC.hasClonedNode(GlobalNode)) {
1310 // Already cloned it, remove from set.
1311 NonCopiedGlobals.erase(I++);
1313 } else if (PathExistsToClonedNode(GlobalNode, RC)) {
1314 RC.getClonedNH(Graph.getNodeForValue(*I));
1315 NonCopiedGlobals.erase(I++);
1322 // If requested, copy any aux calls that can reach copied nodes.
1323 if (!(CloneFlags & DontCloneAuxCallNodes)) {
1324 for (unsigned i = 0, ei = Graph.AuxFunctionCalls.size(); i != ei; ++i)
1325 if (!CopiedAuxCall[i] &&
1326 PathExistsToClonedNode(Graph.AuxFunctionCalls[i], RC)) {
1327 AuxFunctionCalls.push_back(DSCallSite(Graph.AuxFunctionCalls[i],
1329 CopiedAuxCall[i] = true;
1336 DSNodeHandle RetVal = getReturnNodeFor(F);
1338 // Merge the return value with the return value of the context...
1339 RetVal.mergeWith(CS.getRetVal());
1341 // Resolve all of the function arguments...
1342 Function::aiterator AI = F.abegin();
1344 for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i, ++AI) {
1345 // Advance the argument iterator to the first pointer argument...
1346 while (AI != F.aend() && !isPointerType(AI->getType())) {
1348 #ifndef NDEBUG // FIXME: We should merge varargs arguments!!
1349 if (AI == F.aend() && !F.getFunctionType()->isVarArg())
1350 std::cerr << "Bad call to Function: " << F.getName() << "\n";
1353 if (AI == F.aend()) break;
1355 // Add the link from the argument scalar to the provided value
1356 DSNodeHandle &NH = getNodeForValue(AI);
1357 assert(NH.getNode() && "Pointer argument without scalarmap entry?");
1358 NH.mergeWith(CS.getPtrArg(i));
1363 /// getCallSiteForArguments - Get the arguments and return value bindings for
1364 /// the specified function in the current graph.
1366 DSCallSite DSGraph::getCallSiteForArguments(Function &F) const {
1367 std::vector<DSNodeHandle> Args;
1369 for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I)
1370 if (isPointerType(I->getType()))
1371 Args.push_back(getNodeForValue(I));
1373 return DSCallSite(CallSite(), getReturnNodeFor(F), &F, Args);
1376 /// getDSCallSiteForCallSite - Given an LLVM CallSite object that is live in
1377 /// the context of this graph, return the DSCallSite for it.
1378 DSCallSite DSGraph::getDSCallSiteForCallSite(CallSite CS) const {
1379 DSNodeHandle RetVal;
1380 Instruction *I = CS.getInstruction();
1381 if (isPointerType(I->getType()))
1382 RetVal = getNodeForValue(I);
1384 std::vector<DSNodeHandle> Args;
1385 Args.reserve(CS.arg_end()-CS.arg_begin());
1387 // Calculate the arguments vector...
1388 for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); I != E; ++I)
1389 if (isPointerType((*I)->getType()))
1390 Args.push_back(getNodeForValue(*I));
1392 // Add a new function call entry...
1393 if (Function *F = CS.getCalledFunction())
1394 return DSCallSite(CS, RetVal, F, Args);
1396 return DSCallSite(CS, RetVal,
1397 getNodeForValue(CS.getCalledValue()).getNode(), Args);
1402 // markIncompleteNodes - Mark the specified node as having contents that are not
1403 // known with the current analysis we have performed. Because a node makes all
1404 // of the nodes it can reach incomplete if the node itself is incomplete, we
1405 // must recursively traverse the data structure graph, marking all reachable
1406 // nodes as incomplete.
1408 static void markIncompleteNode(DSNode *N) {
1409 // Stop recursion if no node, or if node already marked...
1410 if (N == 0 || N->isIncomplete()) return;
1412 // Actually mark the node
1413 N->setIncompleteMarker();
1415 // Recursively process children...
1416 for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
1417 if (DSNode *DSN = N->getLink(i).getNode())
1418 markIncompleteNode(DSN);
1421 static void markIncomplete(DSCallSite &Call) {
1422 // Then the return value is certainly incomplete!
1423 markIncompleteNode(Call.getRetVal().getNode());
1425 // All objects pointed to by function arguments are incomplete!
1426 for (unsigned i = 0, e = Call.getNumPtrArgs(); i != e; ++i)
1427 markIncompleteNode(Call.getPtrArg(i).getNode());
1430 // markIncompleteNodes - Traverse the graph, identifying nodes that may be
1431 // modified by other functions that have not been resolved yet. This marks
1432 // nodes that are reachable through three sources of "unknownness":
1434 // Global Variables, Function Calls, and Incoming Arguments
1436 // For any node that may have unknown components (because something outside the
1437 // scope of current analysis may have modified it), the 'Incomplete' flag is
1438 // added to the NodeType.
1440 void DSGraph::markIncompleteNodes(unsigned Flags) {
1441 // Mark any incoming arguments as incomplete...
1442 if (Flags & DSGraph::MarkFormalArgs)
1443 for (ReturnNodesTy::iterator FI = ReturnNodes.begin(), E =ReturnNodes.end();
1445 Function &F = *FI->first;
1446 if (F.getName() != "main")
1447 for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I)
1448 if (isPointerType(I->getType()))
1449 markIncompleteNode(getNodeForValue(I).getNode());
1452 // Mark stuff passed into functions calls as being incomplete...
1453 if (!shouldPrintAuxCalls())
1454 for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
1455 markIncomplete(FunctionCalls[i]);
1457 for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
1458 markIncomplete(AuxFunctionCalls[i]);
1461 // Mark all global nodes as incomplete...
1462 if ((Flags & DSGraph::IgnoreGlobals) == 0)
1463 for (DSScalarMap::global_iterator I = ScalarMap.global_begin(),
1464 E = ScalarMap.global_end(); I != E; ++I)
1465 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(*I))
1466 if (!GV->isConstant() || !GV->hasInitializer())
1467 markIncompleteNode(ScalarMap[GV].getNode());
1470 static inline void killIfUselessEdge(DSNodeHandle &Edge) {
1471 if (DSNode *N = Edge.getNode()) // Is there an edge?
1472 if (N->getNumReferrers() == 1) // Does it point to a lonely node?
1473 // No interesting info?
1474 if ((N->getNodeFlags() & ~DSNode::Incomplete) == 0 &&
1475 N->getType() == Type::VoidTy && !N->isNodeCompletelyFolded())
1476 Edge.setTo(0, 0); // Kill the edge!
1479 static inline bool nodeContainsExternalFunction(const DSNode *N) {
1480 const std::vector<GlobalValue*> &Globals = N->getGlobals();
1481 for (unsigned i = 0, e = Globals.size(); i != e; ++i)
1482 if (Globals[i]->isExternal())
1487 static void removeIdenticalCalls(std::vector<DSCallSite> &Calls) {
1488 // Remove trivially identical function calls
1489 unsigned NumFns = Calls.size();
1490 std::sort(Calls.begin(), Calls.end()); // Sort by callee as primary key!
1493 // Scan the call list cleaning it up as necessary...
1494 DSNode *LastCalleeNode = 0;
1495 Function *LastCalleeFunc = 0;
1496 unsigned NumDuplicateCalls = 0;
1497 bool LastCalleeContainsExternalFunction = false;
1498 for (unsigned i = 0; i != Calls.size(); ++i) {
1499 DSCallSite &CS = Calls[i];
1501 // If the Callee is a useless edge, this must be an unreachable call site,
1503 if (CS.isIndirectCall() && CS.getCalleeNode()->getNumReferrers() == 1 &&
1504 CS.getCalleeNode()->isComplete() &&
1505 CS.getCalleeNode()->getGlobals().empty()) { // No useful info?
1507 std::cerr << "WARNING: Useless call site found.\n";
1509 CS.swap(Calls.back());
1513 // If the return value or any arguments point to a void node with no
1514 // information at all in it, and the call node is the only node to point
1515 // to it, remove the edge to the node (killing the node).
1517 killIfUselessEdge(CS.getRetVal());
1518 for (unsigned a = 0, e = CS.getNumPtrArgs(); a != e; ++a)
1519 killIfUselessEdge(CS.getPtrArg(a));
1521 // If this call site calls the same function as the last call site, and if
1522 // the function pointer contains an external function, this node will
1523 // never be resolved. Merge the arguments of the call node because no
1524 // information will be lost.
1526 if ((CS.isDirectCall() && CS.getCalleeFunc() == LastCalleeFunc) ||
1527 (CS.isIndirectCall() && CS.getCalleeNode() == LastCalleeNode)) {
1528 ++NumDuplicateCalls;
1529 if (NumDuplicateCalls == 1) {
1531 LastCalleeContainsExternalFunction =
1532 nodeContainsExternalFunction(LastCalleeNode);
1534 LastCalleeContainsExternalFunction = LastCalleeFunc->isExternal();
1537 // It is not clear why, but enabling this code makes DSA really
1538 // sensitive to node forwarding. Basically, with this enabled, DSA
1539 // performs different number of inlinings based on which nodes are
1540 // forwarding or not. This is clearly a problem, so this code is
1541 // disabled until this can be resolved.
1543 if (LastCalleeContainsExternalFunction
1546 // This should be more than enough context sensitivity!
1547 // FIXME: Evaluate how many times this is tripped!
1548 NumDuplicateCalls > 20
1551 DSCallSite &OCS = Calls[i-1];
1554 // The node will now be eliminated as a duplicate!
1555 if (CS.getNumPtrArgs() < OCS.getNumPtrArgs())
1557 else if (CS.getNumPtrArgs() > OCS.getNumPtrArgs())
1562 if (CS.isDirectCall()) {
1563 LastCalleeFunc = CS.getCalleeFunc();
1566 LastCalleeNode = CS.getCalleeNode();
1569 NumDuplicateCalls = 0;
1574 Calls.erase(std::unique(Calls.begin(), Calls.end()), Calls.end());
1576 // Track the number of call nodes merged away...
1577 NumCallNodesMerged += NumFns-Calls.size();
1579 DEBUG(if (NumFns != Calls.size())
1580 std::cerr << "Merged " << (NumFns-Calls.size()) << " call nodes.\n";);
1584 // removeTriviallyDeadNodes - After the graph has been constructed, this method
1585 // removes all unreachable nodes that are created because they got merged with
1586 // other nodes in the graph. These nodes will all be trivially unreachable, so
1587 // we don't have to perform any non-trivial analysis here.
1589 void DSGraph::removeTriviallyDeadNodes() {
1590 TIME_REGION(X, "removeTriviallyDeadNodes");
1593 /// NOTE: This code is disabled. This slows down DSA on 177.mesa
1596 // Loop over all of the nodes in the graph, calling getNode on each field.
1597 // This will cause all nodes to update their forwarding edges, causing
1598 // forwarded nodes to be delete-able.
1599 { TIME_REGION(X, "removeTriviallyDeadNodes:node_iterate");
1600 for (node_iterator NI = node_begin(), E = node_end(); NI != E; ++NI) {
1602 for (unsigned l = 0, e = N->getNumLinks(); l != e; ++l)
1603 N->getLink(l*N->getPointerSize()).getNode();
1607 // NOTE: This code is disabled. Though it should, in theory, allow us to
1608 // remove more nodes down below, the scan of the scalar map is incredibly
1609 // expensive for certain programs (with large SCCs). In the future, if we can
1610 // make the scalar map scan more efficient, then we can reenable this.
1611 { TIME_REGION(X, "removeTriviallyDeadNodes:scalarmap");
1613 // Likewise, forward any edges from the scalar nodes. While we are at it,
1614 // clean house a bit.
1615 for (DSScalarMap::iterator I = ScalarMap.begin(),E = ScalarMap.end();I != E;){
1616 I->second.getNode();
1621 bool isGlobalsGraph = !GlobalsGraph;
1623 for (NodeListTy::iterator NI = Nodes.begin(), E = Nodes.end(); NI != E; ) {
1626 // Do not remove *any* global nodes in the globals graph.
1627 // This is a special case because such nodes may not have I, M, R flags set.
1628 if (Node.isGlobalNode() && isGlobalsGraph) {
1633 if (Node.isComplete() && !Node.isModified() && !Node.isRead()) {
1634 // This is a useless node if it has no mod/ref info (checked above),
1635 // outgoing edges (which it cannot, as it is not modified in this
1636 // context), and it has no incoming edges. If it is a global node it may
1637 // have all of these properties and still have incoming edges, due to the
1638 // scalar map, so we check those now.
1640 if (Node.getNumReferrers() == Node.getGlobals().size()) {
1641 const std::vector<GlobalValue*> &Globals = Node.getGlobals();
1643 // Loop through and make sure all of the globals are referring directly
1645 for (unsigned j = 0, e = Globals.size(); j != e; ++j) {
1646 DSNode *N = getNodeForValue(Globals[j]).getNode();
1647 assert(N == &Node && "ScalarMap doesn't match globals list!");
1650 // Make sure NumReferrers still agrees, if so, the node is truly dead.
1651 if (Node.getNumReferrers() == Globals.size()) {
1652 for (unsigned j = 0, e = Globals.size(); j != e; ++j)
1653 ScalarMap.erase(Globals[j]);
1654 Node.makeNodeDead();
1655 ++NumTrivialGlobalDNE;
1660 if (Node.getNodeFlags() == 0 && Node.hasNoReferrers()) {
1661 // This node is dead!
1662 NI = Nodes.erase(NI); // Erase & remove from node list.
1669 removeIdenticalCalls(FunctionCalls);
1670 removeIdenticalCalls(AuxFunctionCalls);
1674 /// markReachableNodes - This method recursively traverses the specified
1675 /// DSNodes, marking any nodes which are reachable. All reachable nodes it adds
1676 /// to the set, which allows it to only traverse visited nodes once.
1678 void DSNode::markReachableNodes(hash_set<DSNode*> &ReachableNodes) {
1679 if (this == 0) return;
1680 assert(getForwardNode() == 0 && "Cannot mark a forwarded node!");
1681 if (ReachableNodes.insert(this).second) // Is newly reachable?
1682 for (unsigned i = 0, e = getSize(); i < e; i += DS::PointerSize)
1683 getLink(i).getNode()->markReachableNodes(ReachableNodes);
1686 void DSCallSite::markReachableNodes(hash_set<DSNode*> &Nodes) {
1687 getRetVal().getNode()->markReachableNodes(Nodes);
1688 if (isIndirectCall()) getCalleeNode()->markReachableNodes(Nodes);
1690 for (unsigned i = 0, e = getNumPtrArgs(); i != e; ++i)
1691 getPtrArg(i).getNode()->markReachableNodes(Nodes);
1694 // CanReachAliveNodes - Simple graph walker that recursively traverses the graph
1695 // looking for a node that is marked alive. If an alive node is found, return
1696 // true, otherwise return false. If an alive node is reachable, this node is
1697 // marked as alive...
1699 static bool CanReachAliveNodes(DSNode *N, hash_set<DSNode*> &Alive,
1700 hash_set<DSNode*> &Visited,
1701 bool IgnoreGlobals) {
1702 if (N == 0) return false;
1703 assert(N->getForwardNode() == 0 && "Cannot mark a forwarded node!");
1705 // If this is a global node, it will end up in the globals graph anyway, so we
1706 // don't need to worry about it.
1707 if (IgnoreGlobals && N->isGlobalNode()) return false;
1709 // If we know that this node is alive, return so!
1710 if (Alive.count(N)) return true;
1712 // Otherwise, we don't think the node is alive yet, check for infinite
1714 if (Visited.count(N)) return false; // Found a cycle
1715 Visited.insert(N); // No recursion, insert into Visited...
1717 for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
1718 if (CanReachAliveNodes(N->getLink(i).getNode(), Alive, Visited,
1720 N->markReachableNodes(Alive);
1726 // CallSiteUsesAliveArgs - Return true if the specified call site can reach any
1729 static bool CallSiteUsesAliveArgs(DSCallSite &CS, hash_set<DSNode*> &Alive,
1730 hash_set<DSNode*> &Visited,
1731 bool IgnoreGlobals) {
1732 if (CanReachAliveNodes(CS.getRetVal().getNode(), Alive, Visited,
1735 if (CS.isIndirectCall() &&
1736 CanReachAliveNodes(CS.getCalleeNode(), Alive, Visited, IgnoreGlobals))
1738 for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i)
1739 if (CanReachAliveNodes(CS.getPtrArg(i).getNode(), Alive, Visited,
1745 // removeDeadNodes - Use a more powerful reachability analysis to eliminate
1746 // subgraphs that are unreachable. This often occurs because the data
1747 // structure doesn't "escape" into it's caller, and thus should be eliminated
1748 // from the caller's graph entirely. This is only appropriate to use when
1751 void DSGraph::removeDeadNodes(unsigned Flags) {
1752 DEBUG(AssertGraphOK(); if (GlobalsGraph) GlobalsGraph->AssertGraphOK());
1754 // Reduce the amount of work we have to do... remove dummy nodes left over by
1756 removeTriviallyDeadNodes();
1758 TIME_REGION(X, "removeDeadNodes");
1760 // FIXME: Merge non-trivially identical call nodes...
1762 // Alive - a set that holds all nodes found to be reachable/alive.
1763 hash_set<DSNode*> Alive;
1764 std::vector<std::pair<Value*, DSNode*> > GlobalNodes;
1766 // Copy and merge all information about globals to the GlobalsGraph if this is
1767 // not a final pass (where unreachable globals are removed).
1769 // Strip all alloca bits since the current function is only for the BU pass.
1770 // Strip all incomplete bits since they are short-lived properties and they
1771 // will be correctly computed when rematerializing nodes into the functions.
1773 ReachabilityCloner GGCloner(*GlobalsGraph, *this, DSGraph::StripAllocaBit |
1774 DSGraph::StripIncompleteBit);
1776 // Mark all nodes reachable by (non-global) scalar nodes as alive...
1777 { TIME_REGION(Y, "removeDeadNodes:scalarscan");
1778 for (DSScalarMap::iterator I = ScalarMap.begin(), E = ScalarMap.end(); I !=E;)
1779 if (isa<GlobalValue>(I->first)) { // Keep track of global nodes
1780 assert(I->second.getNode() && "Null global node?");
1781 assert(I->second.getNode()->isGlobalNode() && "Should be a global node!");
1782 GlobalNodes.push_back(std::make_pair(I->first, I->second.getNode()));
1784 // Make sure that all globals are cloned over as roots.
1785 if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
1786 DSGraph::ScalarMapTy::iterator SMI =
1787 GlobalsGraph->getScalarMap().find(I->first);
1788 if (SMI != GlobalsGraph->getScalarMap().end())
1789 GGCloner.merge(SMI->second, I->second);
1791 GGCloner.getClonedNH(I->second);
1795 DSNode *N = I->second.getNode();
1797 // Check to see if this is a worthless node generated for non-pointer
1798 // values, such as integers. Consider an addition of long types: A+B.
1799 // Assuming we can track all uses of the value in this context, and it is
1800 // NOT used as a pointer, we can delete the node. We will be able to
1801 // detect this situation if the node pointed to ONLY has Unknown bit set
1802 // in the node. In this case, the node is not incomplete, does not point
1803 // to any other nodes (no mod/ref bits set), and is therefore
1804 // uninteresting for data structure analysis. If we run across one of
1805 // these, prune the scalar pointing to it.
1807 if (N->getNodeFlags() == DSNode::UnknownNode && !isa<Argument>(I->first))
1808 ScalarMap.erase(I++);
1811 N->markReachableNodes(Alive);
1817 // The return values are alive as well.
1818 for (ReturnNodesTy::iterator I = ReturnNodes.begin(), E = ReturnNodes.end();
1820 I->second.getNode()->markReachableNodes(Alive);
1822 // Mark any nodes reachable by primary calls as alive...
1823 for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
1824 FunctionCalls[i].markReachableNodes(Alive);
1827 // Now find globals and aux call nodes that are already live or reach a live
1828 // value (which makes them live in turn), and continue till no more are found.
1831 hash_set<DSNode*> Visited;
1832 std::vector<unsigned char> AuxFCallsAlive(AuxFunctionCalls.size());
1835 // If any global node points to a non-global that is "alive", the global is
1836 // "alive" as well... Remove it from the GlobalNodes list so we only have
1837 // unreachable globals in the list.
1840 if (!(Flags & DSGraph::RemoveUnreachableGlobals))
1841 for (unsigned i = 0; i != GlobalNodes.size(); ++i)
1842 if (CanReachAliveNodes(GlobalNodes[i].second, Alive, Visited,
1843 Flags & DSGraph::RemoveUnreachableGlobals)) {
1844 std::swap(GlobalNodes[i--], GlobalNodes.back()); // Move to end to...
1845 GlobalNodes.pop_back(); // erase efficiently
1849 // Mark only unresolvable call nodes for moving to the GlobalsGraph since
1850 // call nodes that get resolved will be difficult to remove from that graph.
1851 // The final unresolved call nodes must be handled specially at the end of
1852 // the BU pass (i.e., in main or other roots of the call graph).
1853 for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
1854 if (!AuxFCallsAlive[i] &&
1855 (AuxFunctionCalls[i].isIndirectCall()
1856 || CallSiteUsesAliveArgs(AuxFunctionCalls[i], Alive, Visited,
1857 Flags & DSGraph::RemoveUnreachableGlobals))) {
1858 AuxFunctionCalls[i].markReachableNodes(Alive);
1859 AuxFCallsAlive[i] = true;
1864 // Move dead aux function calls to the end of the list
1865 unsigned CurIdx = 0;
1866 for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
1867 if (AuxFCallsAlive[i])
1868 AuxFunctionCalls[CurIdx++].swap(AuxFunctionCalls[i]);
1870 // Copy and merge all global nodes and dead aux call nodes into the
1871 // GlobalsGraph, and all nodes reachable from those nodes
1873 if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
1874 // Copy the unreachable call nodes to the globals graph, updating their
1875 // target pointers using the GGCloner
1876 for (unsigned i = CurIdx, e = AuxFunctionCalls.size(); i != e; ++i)
1877 GlobalsGraph->AuxFunctionCalls.push_back(DSCallSite(AuxFunctionCalls[i],
1880 // Crop all the useless ones out...
1881 AuxFunctionCalls.erase(AuxFunctionCalls.begin()+CurIdx,
1882 AuxFunctionCalls.end());
1884 // We are finally done with the GGCloner so we can destroy it.
1887 // At this point, any nodes which are visited, but not alive, are nodes
1888 // which can be removed. Loop over all nodes, eliminating completely
1889 // unreachable nodes.
1891 std::vector<DSNode*> DeadNodes;
1892 DeadNodes.reserve(Nodes.size());
1893 for (NodeListTy::iterator NI = Nodes.begin(), E = Nodes.end(); NI != E;) {
1895 assert(!N->isForwarding() && "Forwarded node in nodes list?");
1897 if (!Alive.count(N)) {
1899 assert(!N->isForwarding() && "Cannot remove a forwarding node!");
1900 DeadNodes.push_back(N);
1901 N->dropAllReferences();
1906 // Remove all unreachable globals from the ScalarMap.
1907 // If flag RemoveUnreachableGlobals is set, GlobalNodes has only dead nodes.
1908 // In either case, the dead nodes will not be in the set Alive.
1909 for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i)
1910 if (!Alive.count(GlobalNodes[i].second))
1911 ScalarMap.erase(GlobalNodes[i].first);
1913 assert((Flags & DSGraph::RemoveUnreachableGlobals) && "non-dead global");
1915 // Delete all dead nodes now since their referrer counts are zero.
1916 for (unsigned i = 0, e = DeadNodes.size(); i != e; ++i)
1917 delete DeadNodes[i];
1919 DEBUG(AssertGraphOK(); GlobalsGraph->AssertGraphOK());
1922 void DSGraph::AssertCallSiteInGraph(const DSCallSite &CS) const {
1923 if (CS.isIndirectCall()) {
1924 AssertNodeInGraph(CS.getCalleeNode());
1926 if (CS.getNumPtrArgs() && CS.getCalleeNode() == CS.getPtrArg(0).getNode() &&
1927 CS.getCalleeNode() && CS.getCalleeNode()->getGlobals().empty())
1928 std::cerr << "WARNING: WIERD CALL SITE FOUND!\n";
1931 AssertNodeInGraph(CS.getRetVal().getNode());
1932 for (unsigned j = 0, e = CS.getNumPtrArgs(); j != e; ++j)
1933 AssertNodeInGraph(CS.getPtrArg(j).getNode());
1936 void DSGraph::AssertCallNodesInGraph() const {
1937 for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
1938 AssertCallSiteInGraph(FunctionCalls[i]);
1940 void DSGraph::AssertAuxCallNodesInGraph() const {
1941 for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
1942 AssertCallSiteInGraph(AuxFunctionCalls[i]);
1945 void DSGraph::AssertGraphOK() const {
1946 for (node_iterator NI = node_begin(), E = node_end(); NI != E; ++NI)
1949 for (ScalarMapTy::const_iterator I = ScalarMap.begin(),
1950 E = ScalarMap.end(); I != E; ++I) {
1951 assert(I->second.getNode() && "Null node in scalarmap!");
1952 AssertNodeInGraph(I->second.getNode());
1953 if (GlobalValue *GV = dyn_cast<GlobalValue>(I->first)) {
1954 assert(I->second.getNode()->isGlobalNode() &&
1955 "Global points to node, but node isn't global?");
1956 AssertNodeContainsGlobal(I->second.getNode(), GV);
1959 AssertCallNodesInGraph();
1960 AssertAuxCallNodesInGraph();
1963 /// computeNodeMapping - Given roots in two different DSGraphs, traverse the
1964 /// nodes reachable from the two graphs, computing the mapping of nodes from
1965 /// the first to the second graph.
1967 void DSGraph::computeNodeMapping(const DSNodeHandle &NH1,
1968 const DSNodeHandle &NH2, NodeMapTy &NodeMap,
1969 bool StrictChecking) {
1970 DSNode *N1 = NH1.getNode(), *N2 = NH2.getNode();
1971 if (N1 == 0 || N2 == 0) return;
1973 DSNodeHandle &Entry = NodeMap[N1];
1974 if (Entry.getNode()) {
1975 // Termination of recursion!
1976 if (StrictChecking) {
1977 assert(Entry.getNode() == N2 && "Inconsistent mapping detected!");
1978 assert((Entry.getOffset() == (NH2.getOffset()-NH1.getOffset()) ||
1979 Entry.getNode()->isNodeCompletelyFolded()) &&
1980 "Inconsistent mapping detected!");
1985 Entry.setTo(N2, NH2.getOffset()-NH1.getOffset());
1987 // Loop over all of the fields that N1 and N2 have in common, recursively
1988 // mapping the edges together now.
1989 int N2Idx = NH2.getOffset()-NH1.getOffset();
1990 unsigned N2Size = N2->getSize();
1991 for (unsigned i = 0, e = N1->getSize(); i < e; i += DS::PointerSize)
1992 if (unsigned(N2Idx)+i < N2Size)
1993 computeNodeMapping(N1->getLink(i), N2->getLink(N2Idx+i), NodeMap);
1995 computeNodeMapping(N1->getLink(i),
1996 N2->getLink(unsigned(N2Idx+i) % N2Size), NodeMap);