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/Constants.h"
16 #include "llvm/Function.h"
17 #include "llvm/GlobalVariable.h"
18 #include "llvm/Instructions.h"
19 #include "llvm/DerivedTypes.h"
20 #include "llvm/Target/TargetData.h"
21 #include "llvm/Assembly/Writer.h"
22 #include "llvm/Support/CommandLine.h"
23 #include "llvm/Support/Debug.h"
24 #include "llvm/ADT/DepthFirstIterator.h"
25 #include "llvm/ADT/STLExtras.h"
26 #include "llvm/ADT/Statistic.h"
27 #include "llvm/Support/Timer.h"
31 #define COLLAPSE_ARRAYS_AGGRESSIVELY 0
34 Statistic<> NumFolds ("dsa", "Number of nodes completely folded");
35 Statistic<> NumCallNodesMerged("dsa", "Number of call nodes merged");
36 Statistic<> NumNodeAllocated ("dsa", "Number of nodes allocated");
37 Statistic<> NumDNE ("dsa", "Number of nodes removed by reachability");
38 Statistic<> NumTrivialDNE ("dsa", "Number of nodes trivially removed");
39 Statistic<> NumTrivialGlobalDNE("dsa", "Number of globals trivially removed");
43 #define TIME_REGION(VARNAME, DESC) \
44 NamedRegionTimer VARNAME(DESC)
46 #define TIME_REGION(VARNAME, DESC)
51 /// isForwarding - Return true if this NodeHandle is forwarding to another
53 bool DSNodeHandle::isForwarding() const {
54 return N && N->isForwarding();
57 DSNode *DSNodeHandle::HandleForwarding() const {
58 assert(N->isForwarding() && "Can only be invoked if forwarding!");
60 // Handle node forwarding here!
61 DSNode *Next = N->ForwardNH.getNode(); // Cause recursive shrinkage
62 Offset += N->ForwardNH.getOffset();
64 if (--N->NumReferrers == 0) {
65 // Removing the last referrer to the node, sever the forwarding link
71 if (N->Size <= Offset) {
72 assert(N->Size <= 1 && "Forwarded to shrunk but not collapsed node?");
78 //===----------------------------------------------------------------------===//
79 // DSNode Implementation
80 //===----------------------------------------------------------------------===//
82 DSNode::DSNode(const Type *T, DSGraph *G)
83 : NumReferrers(0), Size(0), ParentGraph(G), Ty(Type::VoidTy), NodeType(0) {
84 // Add the type entry if it is specified...
85 if (T) mergeTypeInfo(T, 0);
86 if (G) G->addNode(this);
90 // DSNode copy constructor... do not copy over the referrers list!
91 DSNode::DSNode(const DSNode &N, DSGraph *G, bool NullLinks)
92 : NumReferrers(0), Size(N.Size), ParentGraph(G),
93 Ty(N.Ty), NodeType(N.NodeType) {
98 Links.resize(N.Links.size()); // Create the appropriate number of null links
103 /// getTargetData - Get the target data object used to construct this node.
105 const TargetData &DSNode::getTargetData() const {
106 return ParentGraph->getTargetData();
109 void DSNode::assertOK() const {
110 assert((Ty != Type::VoidTy ||
111 Ty == Type::VoidTy && (Size == 0 ||
112 (NodeType & DSNode::Array))) &&
115 assert(ParentGraph && "Node has no parent?");
116 const DSScalarMap &SM = ParentGraph->getScalarMap();
117 for (unsigned i = 0, e = Globals.size(); i != e; ++i) {
118 assert(SM.count(Globals[i]));
119 assert(SM.find(Globals[i])->second.getNode() == this);
123 /// forwardNode - Mark this node as being obsolete, and all references to it
124 /// should be forwarded to the specified node and offset.
126 void DSNode::forwardNode(DSNode *To, unsigned Offset) {
127 assert(this != To && "Cannot forward a node to itself!");
128 assert(ForwardNH.isNull() && "Already forwarding from this node!");
129 if (To->Size <= 1) Offset = 0;
130 assert((Offset < To->Size || (Offset == To->Size && Offset == 0)) &&
131 "Forwarded offset is wrong!");
132 ForwardNH.setTo(To, Offset);
137 // Remove this node from the parent graph's Nodes list.
138 ParentGraph->unlinkNode(this);
142 // addGlobal - Add an entry for a global value to the Globals list. This also
143 // marks the node with the 'G' flag if it does not already have it.
145 void DSNode::addGlobal(GlobalValue *GV) {
146 // Keep the list sorted.
147 std::vector<GlobalValue*>::iterator I =
148 std::lower_bound(Globals.begin(), Globals.end(), GV);
150 if (I == Globals.end() || *I != GV) {
151 Globals.insert(I, GV);
152 NodeType |= GlobalNode;
156 /// foldNodeCompletely - If we determine that this node has some funny
157 /// behavior happening to it that we cannot represent, we fold it down to a
158 /// single, completely pessimistic, node. This node is represented as a
159 /// single byte with a single TypeEntry of "void".
161 void DSNode::foldNodeCompletely() {
162 if (isNodeCompletelyFolded()) return; // If this node is already folded...
166 // If this node has a size that is <= 1, we don't need to create a forwarding
168 if (getSize() <= 1) {
169 NodeType |= DSNode::Array;
172 assert(Links.size() <= 1 && "Size is 1, but has more links?");
175 // Create the node we are going to forward to. This is required because
176 // some referrers may have an offset that is > 0. By forcing them to
177 // forward, the forwarder has the opportunity to correct the offset.
178 DSNode *DestNode = new DSNode(0, ParentGraph);
179 DestNode->NodeType = NodeType|DSNode::Array;
180 DestNode->Ty = Type::VoidTy;
182 DestNode->Globals.swap(Globals);
184 // Start forwarding to the destination node...
185 forwardNode(DestNode, 0);
187 if (!Links.empty()) {
188 DestNode->Links.reserve(1);
190 DSNodeHandle NH(DestNode);
191 DestNode->Links.push_back(Links[0]);
193 // If we have links, merge all of our outgoing links together...
194 for (unsigned i = Links.size()-1; i != 0; --i)
195 NH.getNode()->Links[0].mergeWith(Links[i]);
198 DestNode->Links.resize(1);
203 /// isNodeCompletelyFolded - Return true if this node has been completely
204 /// folded down to something that can never be expanded, effectively losing
205 /// all of the field sensitivity that may be present in the node.
207 bool DSNode::isNodeCompletelyFolded() const {
208 return getSize() == 1 && Ty == Type::VoidTy && isArray();
212 /// TypeElementWalker Class - Used for implementation of physical subtyping...
214 class TypeElementWalker {
219 StackState(const Type *T, unsigned Off = 0)
220 : Ty(T), Offset(Off), Idx(0) {}
223 std::vector<StackState> Stack;
224 const TargetData &TD;
226 TypeElementWalker(const Type *T, const TargetData &td) : TD(td) {
231 bool isDone() const { return Stack.empty(); }
232 const Type *getCurrentType() const { return Stack.back().Ty; }
233 unsigned getCurrentOffset() const { return Stack.back().Offset; }
235 void StepToNextType() {
236 PopStackAndAdvance();
241 /// PopStackAndAdvance - Pop the current element off of the stack and
242 /// advance the underlying element to the next contained member.
243 void PopStackAndAdvance() {
244 assert(!Stack.empty() && "Cannot pop an empty stack!");
246 while (!Stack.empty()) {
247 StackState &SS = Stack.back();
248 if (const StructType *ST = dyn_cast<StructType>(SS.Ty)) {
250 if (SS.Idx != ST->getNumElements()) {
251 const StructLayout *SL = TD.getStructLayout(ST);
253 unsigned(SL->MemberOffsets[SS.Idx]-SL->MemberOffsets[SS.Idx-1]);
256 Stack.pop_back(); // At the end of the structure
258 const ArrayType *AT = cast<ArrayType>(SS.Ty);
260 if (SS.Idx != AT->getNumElements()) {
261 SS.Offset += unsigned(TD.getTypeSize(AT->getElementType()));
264 Stack.pop_back(); // At the end of the array
269 /// StepToLeaf - Used by physical subtyping to move to the first leaf node
270 /// on the type stack.
272 if (Stack.empty()) return;
273 while (!Stack.empty() && !Stack.back().Ty->isFirstClassType()) {
274 StackState &SS = Stack.back();
275 if (const StructType *ST = dyn_cast<StructType>(SS.Ty)) {
276 if (ST->getNumElements() == 0) {
278 PopStackAndAdvance();
280 // Step into the structure...
281 assert(SS.Idx < ST->getNumElements());
282 const StructLayout *SL = TD.getStructLayout(ST);
283 Stack.push_back(StackState(ST->getElementType(SS.Idx),
284 SS.Offset+unsigned(SL->MemberOffsets[SS.Idx])));
287 const ArrayType *AT = cast<ArrayType>(SS.Ty);
288 if (AT->getNumElements() == 0) {
290 PopStackAndAdvance();
292 // Step into the array...
293 assert(SS.Idx < AT->getNumElements());
294 Stack.push_back(StackState(AT->getElementType(),
296 unsigned(TD.getTypeSize(AT->getElementType()))));
302 } // end anonymous namespace
304 /// ElementTypesAreCompatible - Check to see if the specified types are
305 /// "physically" compatible. If so, return true, else return false. We only
306 /// have to check the fields in T1: T2 may be larger than T1. If AllowLargerT1
307 /// is true, then we also allow a larger T1.
309 static bool ElementTypesAreCompatible(const Type *T1, const Type *T2,
310 bool AllowLargerT1, const TargetData &TD){
311 TypeElementWalker T1W(T1, TD), T2W(T2, TD);
313 while (!T1W.isDone() && !T2W.isDone()) {
314 if (T1W.getCurrentOffset() != T2W.getCurrentOffset())
317 const Type *T1 = T1W.getCurrentType();
318 const Type *T2 = T2W.getCurrentType();
319 if (T1 != T2 && !T1->isLosslesslyConvertibleTo(T2))
322 T1W.StepToNextType();
323 T2W.StepToNextType();
326 return AllowLargerT1 || T1W.isDone();
330 /// mergeTypeInfo - This method merges the specified type into the current node
331 /// at the specified offset. This may update the current node's type record if
332 /// this gives more information to the node, it may do nothing to the node if
333 /// this information is already known, or it may merge the node completely (and
334 /// return true) if the information is incompatible with what is already known.
336 /// This method returns true if the node is completely folded, otherwise false.
338 bool DSNode::mergeTypeInfo(const Type *NewTy, unsigned Offset,
339 bool FoldIfIncompatible) {
340 const TargetData &TD = getTargetData();
341 // Check to make sure the Size member is up-to-date. Size can be one of the
343 // Size = 0, Ty = Void: Nothing is known about this node.
344 // Size = 0, Ty = FnTy: FunctionPtr doesn't have a size, so we use zero
345 // Size = 1, Ty = Void, Array = 1: The node is collapsed
346 // Otherwise, sizeof(Ty) = Size
348 assert(((Size == 0 && Ty == Type::VoidTy && !isArray()) ||
349 (Size == 0 && !Ty->isSized() && !isArray()) ||
350 (Size == 1 && Ty == Type::VoidTy && isArray()) ||
351 (Size == 0 && !Ty->isSized() && !isArray()) ||
352 (TD.getTypeSize(Ty) == Size)) &&
353 "Size member of DSNode doesn't match the type structure!");
354 assert(NewTy != Type::VoidTy && "Cannot merge void type into DSNode!");
356 if (Offset == 0 && NewTy == Ty)
357 return false; // This should be a common case, handle it efficiently
359 // Return true immediately if the node is completely folded.
360 if (isNodeCompletelyFolded()) return true;
362 // If this is an array type, eliminate the outside arrays because they won't
363 // be used anyway. This greatly reduces the size of large static arrays used
364 // as global variables, for example.
366 bool WillBeArray = false;
367 while (const ArrayType *AT = dyn_cast<ArrayType>(NewTy)) {
368 // FIXME: we might want to keep small arrays, but must be careful about
369 // things like: [2 x [10000 x int*]]
370 NewTy = AT->getElementType();
374 // Figure out how big the new type we're merging in is...
375 unsigned NewTySize = NewTy->isSized() ? (unsigned)TD.getTypeSize(NewTy) : 0;
377 // Otherwise check to see if we can fold this type into the current node. If
378 // we can't, we fold the node completely, if we can, we potentially update our
381 if (Ty == Type::VoidTy) {
382 // If this is the first type that this node has seen, just accept it without
384 assert(Offset == 0 && !isArray() &&
385 "Cannot have an offset into a void node!");
387 // If this node would have to have an unreasonable number of fields, just
388 // collapse it. This can occur for fortran common blocks, which have stupid
389 // things like { [100000000 x double], [1000000 x double] }.
390 unsigned NumFields = (NewTySize+DS::PointerSize-1) >> DS::PointerShift;
391 if (NumFields > 64) {
392 foldNodeCompletely();
398 if (WillBeArray) NodeType |= Array;
401 // Calculate the number of outgoing links from this node.
402 Links.resize(NumFields);
406 // Handle node expansion case here...
407 if (Offset+NewTySize > Size) {
408 // It is illegal to grow this node if we have treated it as an array of
411 if (FoldIfIncompatible) foldNodeCompletely();
415 if (Offset) { // We could handle this case, but we don't for now...
416 std::cerr << "UNIMP: Trying to merge a growth type into "
417 << "offset != 0: Collapsing!\n";
418 if (FoldIfIncompatible) foldNodeCompletely();
422 // Okay, the situation is nice and simple, we are trying to merge a type in
423 // at offset 0 that is bigger than our current type. Implement this by
424 // switching to the new type and then merge in the smaller one, which should
425 // hit the other code path here. If the other code path decides it's not
426 // ok, it will collapse the node as appropriate.
429 // If this node would have to have an unreasonable number of fields, just
430 // collapse it. This can occur for fortran common blocks, which have stupid
431 // things like { [100000000 x double], [1000000 x double] }.
432 unsigned NumFields = (NewTySize+DS::PointerSize-1) >> DS::PointerShift;
433 if (NumFields > 64) {
434 foldNodeCompletely();
438 const Type *OldTy = Ty;
441 if (WillBeArray) NodeType |= Array;
444 // Must grow links to be the appropriate size...
445 Links.resize(NumFields);
447 // Merge in the old type now... which is guaranteed to be smaller than the
449 return mergeTypeInfo(OldTy, 0);
452 assert(Offset <= Size &&
453 "Cannot merge something into a part of our type that doesn't exist!");
455 // Find the section of Ty that NewTy overlaps with... first we find the
456 // type that starts at offset Offset.
459 const Type *SubType = Ty;
461 assert(Offset-O < TD.getTypeSize(SubType) && "Offset out of range!");
463 switch (SubType->getTypeID()) {
464 case Type::StructTyID: {
465 const StructType *STy = cast<StructType>(SubType);
466 const StructLayout &SL = *TD.getStructLayout(STy);
467 unsigned i = SL.getElementContainingOffset(Offset-O);
469 // The offset we are looking for must be in the i'th element...
470 SubType = STy->getElementType(i);
471 O += (unsigned)SL.MemberOffsets[i];
474 case Type::ArrayTyID: {
475 SubType = cast<ArrayType>(SubType)->getElementType();
476 unsigned ElSize = (unsigned)TD.getTypeSize(SubType);
477 unsigned Remainder = (Offset-O) % ElSize;
478 O = Offset-Remainder;
482 if (FoldIfIncompatible) foldNodeCompletely();
487 assert(O == Offset && "Could not achieve the correct offset!");
489 // If we found our type exactly, early exit
490 if (SubType == NewTy) return false;
492 // Differing function types don't require us to merge. They are not values
494 if (isa<FunctionType>(SubType) &&
495 isa<FunctionType>(NewTy)) return false;
497 unsigned SubTypeSize = SubType->isSized() ?
498 (unsigned)TD.getTypeSize(SubType) : 0;
500 // Ok, we are getting desperate now. Check for physical subtyping, where we
501 // just require each element in the node to be compatible.
502 if (NewTySize <= SubTypeSize && NewTySize && NewTySize < 256 &&
503 SubTypeSize && SubTypeSize < 256 &&
504 ElementTypesAreCompatible(NewTy, SubType, !isArray(), TD))
507 // Okay, so we found the leader type at the offset requested. Search the list
508 // of types that starts at this offset. If SubType is currently an array or
509 // structure, the type desired may actually be the first element of the
512 unsigned PadSize = SubTypeSize; // Size, including pad memory which is ignored
513 while (SubType != NewTy) {
514 const Type *NextSubType = 0;
515 unsigned NextSubTypeSize = 0;
516 unsigned NextPadSize = 0;
517 switch (SubType->getTypeID()) {
518 case Type::StructTyID: {
519 const StructType *STy = cast<StructType>(SubType);
520 const StructLayout &SL = *TD.getStructLayout(STy);
521 if (SL.MemberOffsets.size() > 1)
522 NextPadSize = (unsigned)SL.MemberOffsets[1];
524 NextPadSize = SubTypeSize;
525 NextSubType = STy->getElementType(0);
526 NextSubTypeSize = (unsigned)TD.getTypeSize(NextSubType);
529 case Type::ArrayTyID:
530 NextSubType = cast<ArrayType>(SubType)->getElementType();
531 NextSubTypeSize = (unsigned)TD.getTypeSize(NextSubType);
532 NextPadSize = NextSubTypeSize;
538 if (NextSubType == 0)
539 break; // In the default case, break out of the loop
541 if (NextPadSize < NewTySize)
542 break; // Don't allow shrinking to a smaller type than NewTySize
543 SubType = NextSubType;
544 SubTypeSize = NextSubTypeSize;
545 PadSize = NextPadSize;
548 // If we found the type exactly, return it...
549 if (SubType == NewTy)
552 // Check to see if we have a compatible, but different type...
553 if (NewTySize == SubTypeSize) {
554 // Check to see if this type is obviously convertible... int -> uint f.e.
555 if (NewTy->isLosslesslyConvertibleTo(SubType))
558 // Check to see if we have a pointer & integer mismatch going on here,
559 // loading a pointer as a long, for example.
561 if (SubType->isInteger() && isa<PointerType>(NewTy) ||
562 NewTy->isInteger() && isa<PointerType>(SubType))
564 } else if (NewTySize > SubTypeSize && NewTySize <= PadSize) {
565 // We are accessing the field, plus some structure padding. Ignore the
566 // structure padding.
571 if (getParentGraph()->retnodes_begin() != getParentGraph()->retnodes_end())
572 M = getParentGraph()->retnodes_begin()->first->getParent();
573 DEBUG(std::cerr << "MergeTypeInfo Folding OrigTy: ";
574 WriteTypeSymbolic(std::cerr, Ty, M) << "\n due to:";
575 WriteTypeSymbolic(std::cerr, NewTy, M) << " @ " << Offset << "!\n"
577 WriteTypeSymbolic(std::cerr, SubType, M) << "\n\n");
579 if (FoldIfIncompatible) foldNodeCompletely();
585 /// addEdgeTo - Add an edge from the current node to the specified node. This
586 /// can cause merging of nodes in the graph.
588 void DSNode::addEdgeTo(unsigned Offset, const DSNodeHandle &NH) {
589 if (NH.isNull()) return; // Nothing to do
591 DSNodeHandle &ExistingEdge = getLink(Offset);
592 if (!ExistingEdge.isNull()) {
593 // Merge the two nodes...
594 ExistingEdge.mergeWith(NH);
595 } else { // No merging to perform...
596 setLink(Offset, NH); // Just force a link in there...
601 /// MergeSortedVectors - Efficiently merge a vector into another vector where
602 /// duplicates are not allowed and both are sorted. This assumes that 'T's are
603 /// efficiently copyable and have sane comparison semantics.
605 static void MergeSortedVectors(std::vector<GlobalValue*> &Dest,
606 const std::vector<GlobalValue*> &Src) {
607 // By far, the most common cases will be the simple ones. In these cases,
608 // avoid having to allocate a temporary vector...
610 if (Src.empty()) { // Nothing to merge in...
612 } else if (Dest.empty()) { // Just copy the result in...
614 } else if (Src.size() == 1) { // Insert a single element...
615 const GlobalValue *V = Src[0];
616 std::vector<GlobalValue*>::iterator I =
617 std::lower_bound(Dest.begin(), Dest.end(), V);
618 if (I == Dest.end() || *I != Src[0]) // If not already contained...
619 Dest.insert(I, Src[0]);
620 } else if (Dest.size() == 1) {
621 GlobalValue *Tmp = Dest[0]; // Save value in temporary...
622 Dest = Src; // Copy over list...
623 std::vector<GlobalValue*>::iterator I =
624 std::lower_bound(Dest.begin(), Dest.end(), Tmp);
625 if (I == Dest.end() || *I != Tmp) // If not already contained...
629 // Make a copy to the side of Dest...
630 std::vector<GlobalValue*> Old(Dest);
632 // Make space for all of the type entries now...
633 Dest.resize(Dest.size()+Src.size());
635 // Merge the two sorted ranges together... into Dest.
636 std::merge(Old.begin(), Old.end(), Src.begin(), Src.end(), Dest.begin());
638 // Now erase any duplicate entries that may have accumulated into the
639 // vectors (because they were in both of the input sets)
640 Dest.erase(std::unique(Dest.begin(), Dest.end()), Dest.end());
644 void DSNode::mergeGlobals(const std::vector<GlobalValue*> &RHS) {
645 MergeSortedVectors(Globals, RHS);
648 // MergeNodes - Helper function for DSNode::mergeWith().
649 // This function does the hard work of merging two nodes, CurNodeH
650 // and NH after filtering out trivial cases and making sure that
651 // CurNodeH.offset >= NH.offset.
654 // Since merging may cause either node to go away, we must always
655 // use the node-handles to refer to the nodes. These node handles are
656 // automatically updated during merging, so will always provide access
657 // to the correct node after a merge.
659 void DSNode::MergeNodes(DSNodeHandle& CurNodeH, DSNodeHandle& NH) {
660 assert(CurNodeH.getOffset() >= NH.getOffset() &&
661 "This should have been enforced in the caller.");
662 assert(CurNodeH.getNode()->getParentGraph()==NH.getNode()->getParentGraph() &&
663 "Cannot merge two nodes that are not in the same graph!");
665 // Now we know that Offset >= NH.Offset, so convert it so our "Offset" (with
666 // respect to NH.Offset) is now zero. NOffset is the distance from the base
667 // of our object that N starts from.
669 unsigned NOffset = CurNodeH.getOffset()-NH.getOffset();
670 unsigned NSize = NH.getNode()->getSize();
672 // If the two nodes are of different size, and the smaller node has the array
673 // bit set, collapse!
674 if (NSize != CurNodeH.getNode()->getSize()) {
675 #if COLLAPSE_ARRAYS_AGGRESSIVELY
676 if (NSize < CurNodeH.getNode()->getSize()) {
677 if (NH.getNode()->isArray())
678 NH.getNode()->foldNodeCompletely();
679 } else if (CurNodeH.getNode()->isArray()) {
680 NH.getNode()->foldNodeCompletely();
685 // Merge the type entries of the two nodes together...
686 if (NH.getNode()->Ty != Type::VoidTy)
687 CurNodeH.getNode()->mergeTypeInfo(NH.getNode()->Ty, NOffset);
688 assert(!CurNodeH.getNode()->isDeadNode());
690 // If we are merging a node with a completely folded node, then both nodes are
691 // now completely folded.
693 if (CurNodeH.getNode()->isNodeCompletelyFolded()) {
694 if (!NH.getNode()->isNodeCompletelyFolded()) {
695 NH.getNode()->foldNodeCompletely();
696 assert(NH.getNode() && NH.getOffset() == 0 &&
697 "folding did not make offset 0?");
698 NOffset = NH.getOffset();
699 NSize = NH.getNode()->getSize();
700 assert(NOffset == 0 && NSize == 1);
702 } else if (NH.getNode()->isNodeCompletelyFolded()) {
703 CurNodeH.getNode()->foldNodeCompletely();
704 assert(CurNodeH.getNode() && CurNodeH.getOffset() == 0 &&
705 "folding did not make offset 0?");
706 NSize = NH.getNode()->getSize();
707 NOffset = NH.getOffset();
708 assert(NOffset == 0 && NSize == 1);
711 DSNode *N = NH.getNode();
712 if (CurNodeH.getNode() == N || N == 0) return;
713 assert(!CurNodeH.getNode()->isDeadNode());
715 // Merge the NodeType information.
716 CurNodeH.getNode()->NodeType |= N->NodeType;
718 // Start forwarding to the new node!
719 N->forwardNode(CurNodeH.getNode(), NOffset);
720 assert(!CurNodeH.getNode()->isDeadNode());
722 // Make all of the outgoing links of N now be outgoing links of CurNodeH.
724 for (unsigned i = 0; i < N->getNumLinks(); ++i) {
725 DSNodeHandle &Link = N->getLink(i << DS::PointerShift);
726 if (Link.getNode()) {
727 // Compute the offset into the current node at which to
728 // merge this link. In the common case, this is a linear
729 // relation to the offset in the original node (with
730 // wrapping), but if the current node gets collapsed due to
731 // recursive merging, we must make sure to merge in all remaining
732 // links at offset zero.
733 unsigned MergeOffset = 0;
734 DSNode *CN = CurNodeH.getNode();
736 MergeOffset = ((i << DS::PointerShift)+NOffset) % CN->getSize();
737 CN->addEdgeTo(MergeOffset, Link);
741 // Now that there are no outgoing edges, all of the Links are dead.
744 // Merge the globals list...
745 if (!N->Globals.empty()) {
746 CurNodeH.getNode()->mergeGlobals(N->Globals);
748 // Delete the globals from the old node...
749 std::vector<GlobalValue*>().swap(N->Globals);
754 /// mergeWith - Merge this node and the specified node, moving all links to and
755 /// from the argument node into the current node, deleting the node argument.
756 /// Offset indicates what offset the specified node is to be merged into the
759 /// The specified node may be a null pointer (in which case, we update it to
760 /// point to this node).
762 void DSNode::mergeWith(const DSNodeHandle &NH, unsigned Offset) {
763 DSNode *N = NH.getNode();
764 if (N == this && NH.getOffset() == Offset)
767 // If the RHS is a null node, make it point to this node!
769 NH.mergeWith(DSNodeHandle(this, Offset));
773 assert(!N->isDeadNode() && !isDeadNode());
774 assert(!hasNoReferrers() && "Should not try to fold a useless node!");
777 // We cannot merge two pieces of the same node together, collapse the node
779 DEBUG(std::cerr << "Attempting to merge two chunks of"
780 << " the same node together!\n");
781 foldNodeCompletely();
785 // If both nodes are not at offset 0, make sure that we are merging the node
786 // at an later offset into the node with the zero offset.
788 if (Offset < NH.getOffset()) {
789 N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
791 } else if (Offset == NH.getOffset() && getSize() < N->getSize()) {
792 // If the offsets are the same, merge the smaller node into the bigger node
793 N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
797 // Ok, now we can merge the two nodes. Use a static helper that works with
798 // two node handles, since "this" may get merged away at intermediate steps.
799 DSNodeHandle CurNodeH(this, Offset);
800 DSNodeHandle NHCopy(NH);
801 DSNode::MergeNodes(CurNodeH, NHCopy);
805 //===----------------------------------------------------------------------===//
806 // ReachabilityCloner Implementation
807 //===----------------------------------------------------------------------===//
809 DSNodeHandle ReachabilityCloner::getClonedNH(const DSNodeHandle &SrcNH) {
810 if (SrcNH.isNull()) return DSNodeHandle();
811 const DSNode *SN = SrcNH.getNode();
813 DSNodeHandle &NH = NodeMap[SN];
814 if (!NH.isNull()) { // Node already mapped?
815 DSNode *NHN = NH.getNode();
816 return DSNodeHandle(NHN, NH.getOffset()+SrcNH.getOffset());
819 // If SrcNH has globals and the destination graph has one of the same globals,
820 // merge this node with the destination node, which is much more efficient.
821 if (SN->global_begin() != SN->global_end()) {
822 DSScalarMap &DestSM = Dest.getScalarMap();
823 for (DSNode::global_iterator I = SN->global_begin(), E = SN->global_end();
825 GlobalValue *GV = *I;
826 DSScalarMap::iterator GI = DestSM.find(GV);
827 if (GI != DestSM.end() && !GI->second.isNull()) {
828 // We found one, use merge instead!
829 merge(GI->second, Src.getNodeForValue(GV));
830 assert(!NH.isNull() && "Didn't merge node!");
831 DSNode *NHN = NH.getNode();
832 return DSNodeHandle(NHN, NH.getOffset()+SrcNH.getOffset());
837 DSNode *DN = new DSNode(*SN, &Dest, true /* Null out all links */);
838 DN->maskNodeTypes(BitsToKeep);
841 // Next, recursively clone all outgoing links as necessary. Note that
842 // adding these links can cause the node to collapse itself at any time, and
843 // the current node may be merged with arbitrary other nodes. For this
844 // reason, we must always go through NH.
846 for (unsigned i = 0, e = SN->getNumLinks(); i != e; ++i) {
847 const DSNodeHandle &SrcEdge = SN->getLink(i << DS::PointerShift);
848 if (!SrcEdge.isNull()) {
849 const DSNodeHandle &DestEdge = getClonedNH(SrcEdge);
850 // Compute the offset into the current node at which to
851 // merge this link. In the common case, this is a linear
852 // relation to the offset in the original node (with
853 // wrapping), but if the current node gets collapsed due to
854 // recursive merging, we must make sure to merge in all remaining
855 // links at offset zero.
856 unsigned MergeOffset = 0;
857 DSNode *CN = NH.getNode();
858 if (CN->getSize() != 1)
859 MergeOffset = ((i << DS::PointerShift)+NH.getOffset()) % CN->getSize();
860 CN->addEdgeTo(MergeOffset, DestEdge);
864 // If this node contains any globals, make sure they end up in the scalar
865 // map with the correct offset.
866 for (DSNode::global_iterator I = SN->global_begin(), E = SN->global_end();
868 GlobalValue *GV = *I;
869 const DSNodeHandle &SrcGNH = Src.getNodeForValue(GV);
870 DSNodeHandle &DestGNH = NodeMap[SrcGNH.getNode()];
871 assert(DestGNH.getNode() == NH.getNode() &&"Global mapping inconsistent");
872 Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
873 DestGNH.getOffset()+SrcGNH.getOffset()));
875 if (CloneFlags & DSGraph::UpdateInlinedGlobals)
876 Dest.getInlinedGlobals().insert(GV);
878 NH.getNode()->mergeGlobals(SN->getGlobals());
880 return DSNodeHandle(NH.getNode(), NH.getOffset()+SrcNH.getOffset());
883 void ReachabilityCloner::merge(const DSNodeHandle &NH,
884 const DSNodeHandle &SrcNH) {
885 if (SrcNH.isNull()) return; // Noop
887 // If there is no destination node, just clone the source and assign the
888 // destination node to be it.
889 NH.mergeWith(getClonedNH(SrcNH));
893 // Okay, at this point, we know that we have both a destination and a source
894 // node that need to be merged. Check to see if the source node has already
896 const DSNode *SN = SrcNH.getNode();
897 DSNodeHandle &SCNH = NodeMap[SN]; // SourceClonedNodeHandle
898 if (!SCNH.isNull()) { // Node already cloned?
899 DSNode *SCNHN = SCNH.getNode();
900 NH.mergeWith(DSNodeHandle(SCNHN,
901 SCNH.getOffset()+SrcNH.getOffset()));
902 return; // Nothing to do!
905 // Okay, so the source node has not already been cloned. Instead of creating
906 // a new DSNode, only to merge it into the one we already have, try to perform
907 // the merge in-place. The only case we cannot handle here is when the offset
908 // into the existing node is less than the offset into the virtual node we are
909 // merging in. In this case, we have to extend the existing node, which
910 // requires an allocation anyway.
911 DSNode *DN = NH.getNode(); // Make sure the Offset is up-to-date
912 if (NH.getOffset() >= SrcNH.getOffset()) {
913 if (!DN->isNodeCompletelyFolded()) {
914 // Make sure the destination node is folded if the source node is folded.
915 if (SN->isNodeCompletelyFolded()) {
916 DN->foldNodeCompletely();
918 } else if (SN->getSize() != DN->getSize()) {
919 // If the two nodes are of different size, and the smaller node has the
920 // array bit set, collapse!
921 #if COLLAPSE_ARRAYS_AGGRESSIVELY
922 if (SN->getSize() < DN->getSize()) {
924 DN->foldNodeCompletely();
927 } else if (DN->isArray()) {
928 DN->foldNodeCompletely();
934 // Merge the type entries of the two nodes together...
935 if (SN->getType() != Type::VoidTy && !DN->isNodeCompletelyFolded()) {
936 DN->mergeTypeInfo(SN->getType(), NH.getOffset()-SrcNH.getOffset());
941 assert(!DN->isDeadNode());
943 // Merge the NodeType information.
944 DN->mergeNodeFlags(SN->getNodeFlags() & BitsToKeep);
946 // Before we start merging outgoing links and updating the scalar map, make
947 // sure it is known that this is the representative node for the src node.
948 SCNH = DSNodeHandle(DN, NH.getOffset()-SrcNH.getOffset());
950 // If the source node contains any globals, make sure they end up in the
951 // scalar map with the correct offset.
952 if (SN->global_begin() != SN->global_end()) {
953 // Update the globals in the destination node itself.
954 DN->mergeGlobals(SN->getGlobals());
956 // Update the scalar map for the graph we are merging the source node
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 Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
965 DestGNH.getOffset()+SrcGNH.getOffset()));
967 if (CloneFlags & DSGraph::UpdateInlinedGlobals)
968 Dest.getInlinedGlobals().insert(GV);
970 NH.getNode()->mergeGlobals(SN->getGlobals());
973 // We cannot handle this case without allocating a temporary node. Fall
974 // back on being simple.
975 DSNode *NewDN = new DSNode(*SN, &Dest, true /* Null out all links */);
976 NewDN->maskNodeTypes(BitsToKeep);
978 unsigned NHOffset = NH.getOffset();
979 NH.mergeWith(DSNodeHandle(NewDN, SrcNH.getOffset()));
981 assert(NH.getNode() &&
982 (NH.getOffset() > NHOffset ||
983 (NH.getOffset() == 0 && NH.getNode()->isNodeCompletelyFolded())) &&
984 "Merging did not adjust the offset!");
986 // Before we start merging outgoing links and updating the scalar map, make
987 // sure it is known that this is the representative node for the src node.
988 SCNH = DSNodeHandle(NH.getNode(), NH.getOffset()-SrcNH.getOffset());
990 // If the source node contained any globals, make sure to create entries
991 // in the scalar map for them!
992 for (DSNode::global_iterator I = SN->global_begin(), E = SN->global_end();
994 GlobalValue *GV = *I;
995 const DSNodeHandle &SrcGNH = Src.getNodeForValue(GV);
996 DSNodeHandle &DestGNH = NodeMap[SrcGNH.getNode()];
997 assert(DestGNH.getNode()==NH.getNode() &&"Global mapping inconsistent");
998 assert(SrcGNH.getNode() == SN && "Global mapping inconsistent");
999 Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
1000 DestGNH.getOffset()+SrcGNH.getOffset()));
1002 if (CloneFlags & DSGraph::UpdateInlinedGlobals)
1003 Dest.getInlinedGlobals().insert(GV);
1008 // Next, recursively merge all outgoing links as necessary. Note that
1009 // adding these links can cause the destination node to collapse itself at
1010 // any time, and the current node may be merged with arbitrary other nodes.
1011 // For this reason, we must always go through NH.
1013 for (unsigned i = 0, e = SN->getNumLinks(); i != e; ++i) {
1014 const DSNodeHandle &SrcEdge = SN->getLink(i << DS::PointerShift);
1015 if (!SrcEdge.isNull()) {
1016 // Compute the offset into the current node at which to
1017 // merge this link. In the common case, this is a linear
1018 // relation to the offset in the original node (with
1019 // wrapping), but if the current node gets collapsed due to
1020 // recursive merging, we must make sure to merge in all remaining
1021 // links at offset zero.
1022 DSNode *CN = SCNH.getNode();
1023 unsigned MergeOffset =
1024 ((i << DS::PointerShift)+SCNH.getOffset()) % CN->getSize();
1026 DSNodeHandle Tmp = CN->getLink(MergeOffset);
1027 if (!Tmp.isNull()) {
1028 // Perform the recursive merging. Make sure to create a temporary NH,
1029 // because the Link can disappear in the process of recursive merging.
1030 merge(Tmp, SrcEdge);
1032 Tmp.mergeWith(getClonedNH(SrcEdge));
1033 // Merging this could cause all kinds of recursive things to happen,
1034 // culminating in the current node being eliminated. Since this is
1035 // possible, make sure to reaquire the link from 'CN'.
1037 unsigned MergeOffset = 0;
1038 CN = SCNH.getNode();
1039 MergeOffset = ((i << DS::PointerShift)+SCNH.getOffset()) %CN->getSize();
1040 CN->getLink(MergeOffset).mergeWith(Tmp);
1046 /// mergeCallSite - Merge the nodes reachable from the specified src call
1047 /// site into the nodes reachable from DestCS.
1048 void ReachabilityCloner::mergeCallSite(const DSCallSite &DestCS,
1049 const DSCallSite &SrcCS) {
1050 merge(DestCS.getRetVal(), SrcCS.getRetVal());
1051 unsigned MinArgs = DestCS.getNumPtrArgs();
1052 if (SrcCS.getNumPtrArgs() < MinArgs) MinArgs = SrcCS.getNumPtrArgs();
1054 for (unsigned a = 0; a != MinArgs; ++a)
1055 merge(DestCS.getPtrArg(a), SrcCS.getPtrArg(a));
1059 //===----------------------------------------------------------------------===//
1060 // DSCallSite Implementation
1061 //===----------------------------------------------------------------------===//
1063 // Define here to avoid including iOther.h and BasicBlock.h in DSGraph.h
1064 Function &DSCallSite::getCaller() const {
1065 return *Site.getInstruction()->getParent()->getParent();
1068 void DSCallSite::InitNH(DSNodeHandle &NH, const DSNodeHandle &Src,
1069 ReachabilityCloner &RC) {
1070 NH = RC.getClonedNH(Src);
1073 //===----------------------------------------------------------------------===//
1074 // DSGraph Implementation
1075 //===----------------------------------------------------------------------===//
1077 /// getFunctionNames - Return a space separated list of the name of the
1078 /// functions in this graph (if any)
1079 std::string DSGraph::getFunctionNames() const {
1080 switch (getReturnNodes().size()) {
1081 case 0: return "Globals graph";
1082 case 1: return retnodes_begin()->first->getName();
1085 for (DSGraph::retnodes_iterator I = retnodes_begin();
1086 I != retnodes_end(); ++I)
1087 Return += I->first->getName() + " ";
1088 Return.erase(Return.end()-1, Return.end()); // Remove last space character
1094 DSGraph::DSGraph(const DSGraph &G) : GlobalsGraph(0), TD(G.TD) {
1095 PrintAuxCalls = false;
1097 cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
1100 DSGraph::DSGraph(const DSGraph &G, NodeMapTy &NodeMap)
1101 : GlobalsGraph(0), TD(G.TD) {
1102 PrintAuxCalls = false;
1103 cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
1106 DSGraph::~DSGraph() {
1107 FunctionCalls.clear();
1108 AuxFunctionCalls.clear();
1109 InlinedGlobals.clear();
1111 ReturnNodes.clear();
1113 // Drop all intra-node references, so that assertions don't fail...
1114 for (node_iterator NI = node_begin(), E = node_end(); NI != E; ++NI)
1115 NI->dropAllReferences();
1117 // Free all of the nodes.
1121 // dump - Allow inspection of graph in a debugger.
1122 void DSGraph::dump() const { print(std::cerr); }
1125 /// remapLinks - Change all of the Links in the current node according to the
1126 /// specified mapping.
1128 void DSNode::remapLinks(DSGraph::NodeMapTy &OldNodeMap) {
1129 for (unsigned i = 0, e = Links.size(); i != e; ++i)
1130 if (DSNode *N = Links[i].getNode()) {
1131 DSGraph::NodeMapTy::const_iterator ONMI = OldNodeMap.find(N);
1132 if (ONMI != OldNodeMap.end()) {
1133 DSNode *ONMIN = ONMI->second.getNode();
1134 Links[i].setTo(ONMIN, Links[i].getOffset()+ONMI->second.getOffset());
1139 /// updateFromGlobalGraph - This function rematerializes global nodes and
1140 /// nodes reachable from them from the globals graph into the current graph.
1141 /// It uses the vector InlinedGlobals to avoid cloning and merging globals that
1142 /// are already up-to-date in the current graph. In practice, in the TD pass,
1143 /// this is likely to be a large fraction of the live global nodes in each
1144 /// function (since most live nodes are likely to have been brought up-to-date
1145 /// in at _some_ caller or callee).
1147 void DSGraph::updateFromGlobalGraph() {
1148 TIME_REGION(X, "updateFromGlobalGraph");
1149 ReachabilityCloner RC(*this, *GlobalsGraph, 0);
1151 // Clone the non-up-to-date global nodes into this graph.
1152 for (DSScalarMap::global_iterator I = getScalarMap().global_begin(),
1153 E = getScalarMap().global_end(); I != E; ++I)
1154 if (InlinedGlobals.count(*I) == 0) { // GNode is not up-to-date
1155 DSScalarMap::iterator It = GlobalsGraph->ScalarMap.find(*I);
1156 if (It != GlobalsGraph->ScalarMap.end())
1157 RC.merge(getNodeForValue(*I), It->second);
1161 /// addObjectToGraph - This method can be used to add global, stack, and heap
1162 /// objects to the graph. This can be used when updating DSGraphs due to the
1163 /// introduction of new temporary objects. The new object is not pointed to
1164 /// and does not point to any other objects in the graph.
1165 DSNode *DSGraph::addObjectToGraph(Value *Ptr, bool UseDeclaredType) {
1166 assert(isa<PointerType>(Ptr->getType()) && "Ptr is not a pointer!");
1167 const Type *Ty = cast<PointerType>(Ptr->getType())->getElementType();
1168 DSNode *N = new DSNode(UseDeclaredType ? Ty : 0, this);
1169 assert(ScalarMap[Ptr].isNull() && "Object already in this graph!");
1172 if (GlobalValue *GV = dyn_cast<GlobalValue>(Ptr)) {
1174 } else if (MallocInst *MI = dyn_cast<MallocInst>(Ptr)) {
1175 N->setHeapNodeMarker();
1176 } else if (AllocaInst *AI = dyn_cast<AllocaInst>(Ptr)) {
1177 N->setAllocaNodeMarker();
1179 assert(0 && "Illegal memory object input!");
1185 /// cloneInto - Clone the specified DSGraph into the current graph. The
1186 /// translated ScalarMap for the old function is filled into the OldValMap
1187 /// member, and the translated ReturnNodes map is returned into ReturnNodes.
1189 /// The CloneFlags member controls various aspects of the cloning process.
1191 void DSGraph::cloneInto(const DSGraph &G, DSScalarMap &OldValMap,
1192 ReturnNodesTy &OldReturnNodes, NodeMapTy &OldNodeMap,
1193 unsigned CloneFlags) {
1194 TIME_REGION(X, "cloneInto");
1195 assert(OldNodeMap.empty() && "Returned OldNodeMap should be empty!");
1196 assert(&G != this && "Cannot clone graph into itself!");
1198 // Remove alloca or mod/ref bits as specified...
1199 unsigned BitsToClear = ((CloneFlags & StripAllocaBit)? DSNode::AllocaNode : 0)
1200 | ((CloneFlags & StripModRefBits)? (DSNode::Modified | DSNode::Read) : 0)
1201 | ((CloneFlags & StripIncompleteBit)? DSNode::Incomplete : 0);
1202 BitsToClear |= DSNode::DEAD; // Clear dead flag...
1204 for (node_const_iterator I = G.node_begin(), E = G.node_end(); I != E; ++I) {
1205 assert(!I->isForwarding() &&
1206 "Forward nodes shouldn't be in node list!");
1207 DSNode *New = new DSNode(*I, this);
1208 New->maskNodeTypes(~BitsToClear);
1209 OldNodeMap[I] = New;
1213 Timer::addPeakMemoryMeasurement();
1216 // Rewrite the links in the new nodes to point into the current graph now.
1217 // Note that we don't loop over the node's list to do this. The problem is
1218 // that remaping links can cause recursive merging to happen, which means
1219 // that node_iterator's can get easily invalidated! Because of this, we
1220 // loop over the OldNodeMap, which contains all of the new nodes as the
1221 // .second element of the map elements. Also note that if we remap a node
1222 // more than once, we won't break anything.
1223 for (NodeMapTy::iterator I = OldNodeMap.begin(), E = OldNodeMap.end();
1225 I->second.getNode()->remapLinks(OldNodeMap);
1227 // Copy the scalar map... merging all of the global nodes...
1228 for (DSScalarMap::const_iterator I = G.ScalarMap.begin(),
1229 E = G.ScalarMap.end(); I != E; ++I) {
1230 DSNodeHandle &MappedNode = OldNodeMap[I->second.getNode()];
1231 DSNodeHandle &H = OldValMap[I->first];
1232 DSNode *MappedNodeN = MappedNode.getNode();
1233 H.mergeWith(DSNodeHandle(MappedNodeN,
1234 I->second.getOffset()+MappedNode.getOffset()));
1236 // If this is a global, add the global to this fn or merge if already exists
1237 if (GlobalValue* GV = dyn_cast<GlobalValue>(I->first)) {
1238 ScalarMap[GV].mergeWith(H);
1239 if (CloneFlags & DSGraph::UpdateInlinedGlobals)
1240 InlinedGlobals.insert(GV);
1244 if (!(CloneFlags & DontCloneCallNodes)) {
1245 // Copy the function calls list.
1246 for (fc_iterator I = G.fc_begin(), E = G.fc_end(); I != E; ++I)
1247 FunctionCalls.push_back(DSCallSite(*I, OldNodeMap));
1250 if (!(CloneFlags & DontCloneAuxCallNodes)) {
1251 // Copy the auxiliary function calls list.
1252 for (afc_iterator I = G.afc_begin(), E = G.afc_end(); I != E; ++I)
1253 AuxFunctionCalls.push_back(DSCallSite(*I, OldNodeMap));
1256 // Map the return node pointers over...
1257 for (retnodes_iterator I = G.retnodes_begin(),
1258 E = G.retnodes_end(); I != E; ++I) {
1259 const DSNodeHandle &Ret = I->second;
1260 DSNodeHandle &MappedRet = OldNodeMap[Ret.getNode()];
1261 DSNode *MappedRetN = MappedRet.getNode();
1262 OldReturnNodes.insert(std::make_pair(I->first,
1263 DSNodeHandle(MappedRetN,
1264 MappedRet.getOffset()+Ret.getOffset())));
1268 static bool PathExistsToClonedNode(const DSNode *N, ReachabilityCloner &RC) {
1270 for (df_iterator<const DSNode*> I = df_begin(N), E = df_end(N); I != E; ++I)
1271 if (RC.hasClonedNode(*I))
1276 static bool PathExistsToClonedNode(const DSCallSite &CS,
1277 ReachabilityCloner &RC) {
1278 if (PathExistsToClonedNode(CS.getRetVal().getNode(), RC))
1280 for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i)
1281 if (PathExistsToClonedNode(CS.getPtrArg(i).getNode(), RC))
1286 /// getFunctionArgumentsForCall - Given a function that is currently in this
1287 /// graph, return the DSNodeHandles that correspond to the pointer-compatible
1288 /// function arguments. The vector is filled in with the return value (or
1289 /// null if it is not pointer compatible), followed by all of the
1290 /// pointer-compatible arguments.
1291 void DSGraph::getFunctionArgumentsForCall(Function *F,
1292 std::vector<DSNodeHandle> &Args) const {
1293 Args.push_back(getReturnNodeFor(*F));
1294 for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end(); AI != E; ++AI)
1295 if (isPointerType(AI->getType())) {
1296 Args.push_back(getNodeForValue(AI));
1297 assert(!Args.back().isNull() && "Pointer argument w/o scalarmap entry!?");
1301 /// mergeInCallFromOtherGraph - This graph merges in the minimal number of
1302 /// nodes from G2 into 'this' graph, merging the bindings specified by the
1303 /// call site (in this graph) with the bindings specified by the vector in G2.
1304 /// The two DSGraphs must be different.
1306 void DSGraph::mergeInGraph(const DSCallSite &CS,
1307 std::vector<DSNodeHandle> &Args,
1308 const DSGraph &Graph, unsigned CloneFlags) {
1309 TIME_REGION(X, "mergeInGraph");
1311 // If this is not a recursive call, clone the graph into this graph...
1312 if (&Graph != this) {
1313 // Clone the callee's graph into the current graph, keeping track of where
1314 // scalars in the old graph _used_ to point, and of the new nodes matching
1315 // nodes of the old graph.
1316 ReachabilityCloner RC(*this, Graph, CloneFlags);
1318 // Map the return node pointer over.
1319 if (!CS.getRetVal().isNull())
1320 RC.merge(CS.getRetVal(), Args[0]);
1322 // Map over all of the arguments.
1323 for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i) {
1324 if (i == Args.size()-1)
1327 // Add the link from the argument scalar to the provided value.
1328 RC.merge(CS.getPtrArg(i), Args[i+1]);
1331 // If requested, copy all of the calls.
1332 if (!(CloneFlags & DontCloneCallNodes)) {
1333 // Copy the function calls list.
1334 for (fc_iterator I = Graph.fc_begin(), E = Graph.fc_end(); I != E; ++I)
1335 FunctionCalls.push_back(DSCallSite(*I, RC));
1338 // If the user has us copying aux calls (the normal case), set up a data
1339 // structure to keep track of which ones we've copied over.
1340 std::set<const DSCallSite*> CopiedAuxCall;
1342 // Clone over all globals that appear in the caller and callee graphs.
1343 hash_set<GlobalVariable*> NonCopiedGlobals;
1344 for (DSScalarMap::global_iterator GI = Graph.getScalarMap().global_begin(),
1345 E = Graph.getScalarMap().global_end(); GI != E; ++GI)
1346 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(*GI))
1347 if (ScalarMap.count(GV))
1348 RC.merge(ScalarMap[GV], Graph.getNodeForValue(GV));
1350 NonCopiedGlobals.insert(GV);
1352 // If the global does not appear in the callers graph we generally don't
1353 // want to copy the node. However, if there is a path from the node global
1354 // node to a node that we did copy in the graph, we *must* copy it to
1355 // maintain the connection information. Every time we decide to include a
1356 // new global, this might make other globals live, so we must iterate
1358 bool MadeChange = true;
1359 while (MadeChange) {
1361 for (hash_set<GlobalVariable*>::iterator I = NonCopiedGlobals.begin();
1362 I != NonCopiedGlobals.end();) {
1363 DSNode *GlobalNode = Graph.getNodeForValue(*I).getNode();
1364 if (RC.hasClonedNode(GlobalNode)) {
1365 // Already cloned it, remove from set.
1366 NonCopiedGlobals.erase(I++);
1368 } else if (PathExistsToClonedNode(GlobalNode, RC)) {
1369 RC.getClonedNH(Graph.getNodeForValue(*I));
1370 NonCopiedGlobals.erase(I++);
1377 // If requested, copy any aux calls that can reach copied nodes.
1378 if (!(CloneFlags & DontCloneAuxCallNodes)) {
1379 for (afc_iterator I = Graph.afc_begin(), E = Graph.afc_end(); I!=E; ++I)
1380 if (CopiedAuxCall.insert(&*I).second &&
1381 PathExistsToClonedNode(*I, RC)) {
1382 AuxFunctionCalls.push_back(DSCallSite(*I, RC));
1389 // Merge the return value with the return value of the context.
1390 Args[0].mergeWith(CS.getRetVal());
1392 // Resolve all of the function arguments.
1393 for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i) {
1394 if (i == Args.size()-1)
1397 // Add the link from the argument scalar to the provided value.
1398 Args[i+1].mergeWith(CS.getPtrArg(i));
1405 /// mergeInGraph - The method is used for merging graphs together. If the
1406 /// argument graph is not *this, it makes a clone of the specified graph, then
1407 /// merges the nodes specified in the call site with the formal arguments in the
1410 void DSGraph::mergeInGraph(const DSCallSite &CS, Function &F,
1411 const DSGraph &Graph, unsigned CloneFlags) {
1412 // Fastpath for a noop inline.
1413 if (CS.getNumPtrArgs() == 0 && CS.getRetVal().isNull())
1416 // Set up argument bindings.
1417 std::vector<DSNodeHandle> Args;
1418 Graph.getFunctionArgumentsForCall(&F, Args);
1420 mergeInGraph(CS, Args, Graph, CloneFlags);
1423 /// getCallSiteForArguments - Get the arguments and return value bindings for
1424 /// the specified function in the current graph.
1426 DSCallSite DSGraph::getCallSiteForArguments(Function &F) const {
1427 std::vector<DSNodeHandle> Args;
1429 for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I)
1430 if (isPointerType(I->getType()))
1431 Args.push_back(getNodeForValue(I));
1433 return DSCallSite(CallSite(), getReturnNodeFor(F), &F, Args);
1436 /// getDSCallSiteForCallSite - Given an LLVM CallSite object that is live in
1437 /// the context of this graph, return the DSCallSite for it.
1438 DSCallSite DSGraph::getDSCallSiteForCallSite(CallSite CS) const {
1439 DSNodeHandle RetVal;
1440 Instruction *I = CS.getInstruction();
1441 if (isPointerType(I->getType()))
1442 RetVal = getNodeForValue(I);
1444 std::vector<DSNodeHandle> Args;
1445 Args.reserve(CS.arg_end()-CS.arg_begin());
1447 // Calculate the arguments vector...
1448 for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); I != E; ++I)
1449 if (isPointerType((*I)->getType()))
1450 if (isa<ConstantPointerNull>(*I))
1451 Args.push_back(DSNodeHandle());
1453 Args.push_back(getNodeForValue(*I));
1455 // Add a new function call entry...
1456 if (Function *F = CS.getCalledFunction())
1457 return DSCallSite(CS, RetVal, F, Args);
1459 return DSCallSite(CS, RetVal,
1460 getNodeForValue(CS.getCalledValue()).getNode(), Args);
1465 // markIncompleteNodes - Mark the specified node as having contents that are not
1466 // known with the current analysis we have performed. Because a node makes all
1467 // of the nodes it can reach incomplete if the node itself is incomplete, we
1468 // must recursively traverse the data structure graph, marking all reachable
1469 // nodes as incomplete.
1471 static void markIncompleteNode(DSNode *N) {
1472 // Stop recursion if no node, or if node already marked...
1473 if (N == 0 || N->isIncomplete()) return;
1475 // Actually mark the node
1476 N->setIncompleteMarker();
1478 // Recursively process children...
1479 for (DSNode::edge_iterator I = N->edge_begin(),E = N->edge_end(); I != E; ++I)
1480 if (DSNode *DSN = I->getNode())
1481 markIncompleteNode(DSN);
1484 static void markIncomplete(DSCallSite &Call) {
1485 // Then the return value is certainly incomplete!
1486 markIncompleteNode(Call.getRetVal().getNode());
1488 // All objects pointed to by function arguments are incomplete!
1489 for (unsigned i = 0, e = Call.getNumPtrArgs(); i != e; ++i)
1490 markIncompleteNode(Call.getPtrArg(i).getNode());
1493 // markIncompleteNodes - Traverse the graph, identifying nodes that may be
1494 // modified by other functions that have not been resolved yet. This marks
1495 // nodes that are reachable through three sources of "unknownness":
1497 // Global Variables, Function Calls, and Incoming Arguments
1499 // For any node that may have unknown components (because something outside the
1500 // scope of current analysis may have modified it), the 'Incomplete' flag is
1501 // added to the NodeType.
1503 void DSGraph::markIncompleteNodes(unsigned Flags) {
1504 // Mark any incoming arguments as incomplete.
1505 if (Flags & DSGraph::MarkFormalArgs)
1506 for (ReturnNodesTy::iterator FI = ReturnNodes.begin(), E =ReturnNodes.end();
1508 Function &F = *FI->first;
1509 for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I)
1510 if (isPointerType(I->getType()))
1511 markIncompleteNode(getNodeForValue(I).getNode());
1512 markIncompleteNode(FI->second.getNode());
1515 // Mark stuff passed into functions calls as being incomplete.
1516 if (!shouldPrintAuxCalls())
1517 for (std::list<DSCallSite>::iterator I = FunctionCalls.begin(),
1518 E = FunctionCalls.end(); I != E; ++I)
1521 for (std::list<DSCallSite>::iterator I = AuxFunctionCalls.begin(),
1522 E = AuxFunctionCalls.end(); I != E; ++I)
1525 // Mark all global nodes as incomplete.
1526 for (DSScalarMap::global_iterator I = ScalarMap.global_begin(),
1527 E = ScalarMap.global_end(); I != E; ++I)
1528 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(*I))
1529 if (!GV->hasInitializer() || // Always mark external globals incomp.
1530 (!GV->isConstant() && (Flags & DSGraph::IgnoreGlobals) == 0))
1531 markIncompleteNode(ScalarMap[GV].getNode());
1534 static inline void killIfUselessEdge(DSNodeHandle &Edge) {
1535 if (DSNode *N = Edge.getNode()) // Is there an edge?
1536 if (N->getNumReferrers() == 1) // Does it point to a lonely node?
1537 // No interesting info?
1538 if ((N->getNodeFlags() & ~DSNode::Incomplete) == 0 &&
1539 N->getType() == Type::VoidTy && !N->isNodeCompletelyFolded())
1540 Edge.setTo(0, 0); // Kill the edge!
1543 static inline bool nodeContainsExternalFunction(const DSNode *N) {
1544 const std::vector<GlobalValue*> &Globals = N->getGlobals();
1545 for (unsigned i = 0, e = Globals.size(); i != e; ++i)
1546 if (Globals[i]->isExternal() && isa<Function>(Globals[i]))
1551 static void removeIdenticalCalls(std::list<DSCallSite> &Calls) {
1552 // Remove trivially identical function calls
1553 Calls.sort(); // Sort by callee as primary key!
1555 // Scan the call list cleaning it up as necessary...
1556 DSNode *LastCalleeNode = 0;
1557 Function *LastCalleeFunc = 0;
1558 unsigned NumDuplicateCalls = 0;
1559 bool LastCalleeContainsExternalFunction = false;
1561 unsigned NumDeleted = 0;
1562 for (std::list<DSCallSite>::iterator I = Calls.begin(), E = Calls.end();
1564 DSCallSite &CS = *I;
1565 std::list<DSCallSite>::iterator OldIt = I++;
1567 // If the Callee is a useless edge, this must be an unreachable call site,
1569 if (CS.isIndirectCall() && CS.getCalleeNode()->getNumReferrers() == 1 &&
1570 CS.getCalleeNode()->isComplete() &&
1571 CS.getCalleeNode()->getGlobals().empty()) { // No useful info?
1573 std::cerr << "WARNING: Useless call site found.\n";
1580 // If the return value or any arguments point to a void node with no
1581 // information at all in it, and the call node is the only node to point
1582 // to it, remove the edge to the node (killing the node).
1584 killIfUselessEdge(CS.getRetVal());
1585 for (unsigned a = 0, e = CS.getNumPtrArgs(); a != e; ++a)
1586 killIfUselessEdge(CS.getPtrArg(a));
1589 // If this call site calls the same function as the last call site, and if
1590 // the function pointer contains an external function, this node will
1591 // never be resolved. Merge the arguments of the call node because no
1592 // information will be lost.
1594 if ((CS.isDirectCall() && CS.getCalleeFunc() == LastCalleeFunc) ||
1595 (CS.isIndirectCall() && CS.getCalleeNode() == LastCalleeNode)) {
1596 ++NumDuplicateCalls;
1597 if (NumDuplicateCalls == 1) {
1599 LastCalleeContainsExternalFunction =
1600 nodeContainsExternalFunction(LastCalleeNode);
1602 LastCalleeContainsExternalFunction = LastCalleeFunc->isExternal();
1605 // It is not clear why, but enabling this code makes DSA really
1606 // sensitive to node forwarding. Basically, with this enabled, DSA
1607 // performs different number of inlinings based on which nodes are
1608 // forwarding or not. This is clearly a problem, so this code is
1609 // disabled until this can be resolved.
1611 if (LastCalleeContainsExternalFunction
1614 // This should be more than enough context sensitivity!
1615 // FIXME: Evaluate how many times this is tripped!
1616 NumDuplicateCalls > 20
1620 std::list<DSCallSite>::iterator PrevIt = OldIt;
1622 PrevIt->mergeWith(CS);
1624 // No need to keep this call anymore.
1631 if (CS.isDirectCall()) {
1632 LastCalleeFunc = CS.getCalleeFunc();
1635 LastCalleeNode = CS.getCalleeNode();
1638 NumDuplicateCalls = 0;
1642 if (I != Calls.end() && CS == *I) {
1649 // Resort now that we simplified things.
1652 // Now that we are in sorted order, eliminate duplicates.
1653 std::list<DSCallSite>::iterator CI = Calls.begin(), CE = Calls.end();
1656 std::list<DSCallSite>::iterator OldIt = CI++;
1657 if (CI == CE) break;
1659 // If this call site is now the same as the previous one, we can delete it
1661 if (*OldIt == *CI) {
1668 //Calls.erase(std::unique(Calls.begin(), Calls.end()), Calls.end());
1670 // Track the number of call nodes merged away...
1671 NumCallNodesMerged += NumDeleted;
1673 DEBUG(if (NumDeleted)
1674 std::cerr << "Merged " << NumDeleted << " call nodes.\n";);
1678 // removeTriviallyDeadNodes - After the graph has been constructed, this method
1679 // removes all unreachable nodes that are created because they got merged with
1680 // other nodes in the graph. These nodes will all be trivially unreachable, so
1681 // we don't have to perform any non-trivial analysis here.
1683 void DSGraph::removeTriviallyDeadNodes() {
1684 TIME_REGION(X, "removeTriviallyDeadNodes");
1687 /// NOTE: This code is disabled. This slows down DSA on 177.mesa
1690 // Loop over all of the nodes in the graph, calling getNode on each field.
1691 // This will cause all nodes to update their forwarding edges, causing
1692 // forwarded nodes to be delete-able.
1693 { TIME_REGION(X, "removeTriviallyDeadNodes:node_iterate");
1694 for (node_iterator NI = node_begin(), E = node_end(); NI != E; ++NI) {
1696 for (unsigned l = 0, e = N.getNumLinks(); l != e; ++l)
1697 N.getLink(l*N.getPointerSize()).getNode();
1701 // NOTE: This code is disabled. Though it should, in theory, allow us to
1702 // remove more nodes down below, the scan of the scalar map is incredibly
1703 // expensive for certain programs (with large SCCs). In the future, if we can
1704 // make the scalar map scan more efficient, then we can reenable this.
1705 { TIME_REGION(X, "removeTriviallyDeadNodes:scalarmap");
1707 // Likewise, forward any edges from the scalar nodes. While we are at it,
1708 // clean house a bit.
1709 for (DSScalarMap::iterator I = ScalarMap.begin(),E = ScalarMap.end();I != E;){
1710 I->second.getNode();
1715 bool isGlobalsGraph = !GlobalsGraph;
1717 for (NodeListTy::iterator NI = Nodes.begin(), E = Nodes.end(); NI != E; ) {
1720 // Do not remove *any* global nodes in the globals graph.
1721 // This is a special case because such nodes may not have I, M, R flags set.
1722 if (Node.isGlobalNode() && isGlobalsGraph) {
1727 if (Node.isComplete() && !Node.isModified() && !Node.isRead()) {
1728 // This is a useless node if it has no mod/ref info (checked above),
1729 // outgoing edges (which it cannot, as it is not modified in this
1730 // context), and it has no incoming edges. If it is a global node it may
1731 // have all of these properties and still have incoming edges, due to the
1732 // scalar map, so we check those now.
1734 if (Node.getNumReferrers() == Node.getGlobals().size()) {
1735 const std::vector<GlobalValue*> &Globals = Node.getGlobals();
1737 // Loop through and make sure all of the globals are referring directly
1739 for (unsigned j = 0, e = Globals.size(); j != e; ++j) {
1740 DSNode *N = getNodeForValue(Globals[j]).getNode();
1741 assert(N == &Node && "ScalarMap doesn't match globals list!");
1744 // Make sure NumReferrers still agrees, if so, the node is truly dead.
1745 if (Node.getNumReferrers() == Globals.size()) {
1746 for (unsigned j = 0, e = Globals.size(); j != e; ++j)
1747 ScalarMap.erase(Globals[j]);
1748 Node.makeNodeDead();
1749 ++NumTrivialGlobalDNE;
1754 if (Node.getNodeFlags() == 0 && Node.hasNoReferrers()) {
1755 // This node is dead!
1756 NI = Nodes.erase(NI); // Erase & remove from node list.
1763 removeIdenticalCalls(FunctionCalls);
1764 removeIdenticalCalls(AuxFunctionCalls);
1768 /// markReachableNodes - This method recursively traverses the specified
1769 /// DSNodes, marking any nodes which are reachable. All reachable nodes it adds
1770 /// to the set, which allows it to only traverse visited nodes once.
1772 void DSNode::markReachableNodes(hash_set<const DSNode*> &ReachableNodes) const {
1773 if (this == 0) return;
1774 assert(getForwardNode() == 0 && "Cannot mark a forwarded node!");
1775 if (ReachableNodes.insert(this).second) // Is newly reachable?
1776 for (DSNode::const_edge_iterator I = edge_begin(), E = edge_end();
1778 I->getNode()->markReachableNodes(ReachableNodes);
1781 void DSCallSite::markReachableNodes(hash_set<const DSNode*> &Nodes) const {
1782 getRetVal().getNode()->markReachableNodes(Nodes);
1783 if (isIndirectCall()) getCalleeNode()->markReachableNodes(Nodes);
1785 for (unsigned i = 0, e = getNumPtrArgs(); i != e; ++i)
1786 getPtrArg(i).getNode()->markReachableNodes(Nodes);
1789 // CanReachAliveNodes - Simple graph walker that recursively traverses the graph
1790 // looking for a node that is marked alive. If an alive node is found, return
1791 // true, otherwise return false. If an alive node is reachable, this node is
1792 // marked as alive...
1794 static bool CanReachAliveNodes(DSNode *N, hash_set<const DSNode*> &Alive,
1795 hash_set<const DSNode*> &Visited,
1796 bool IgnoreGlobals) {
1797 if (N == 0) return false;
1798 assert(N->getForwardNode() == 0 && "Cannot mark a forwarded node!");
1800 // If this is a global node, it will end up in the globals graph anyway, so we
1801 // don't need to worry about it.
1802 if (IgnoreGlobals && N->isGlobalNode()) return false;
1804 // If we know that this node is alive, return so!
1805 if (Alive.count(N)) return true;
1807 // Otherwise, we don't think the node is alive yet, check for infinite
1809 if (Visited.count(N)) return false; // Found a cycle
1810 Visited.insert(N); // No recursion, insert into Visited...
1812 for (DSNode::edge_iterator I = N->edge_begin(),E = N->edge_end(); I != E; ++I)
1813 if (CanReachAliveNodes(I->getNode(), Alive, Visited, IgnoreGlobals)) {
1814 N->markReachableNodes(Alive);
1820 // CallSiteUsesAliveArgs - Return true if the specified call site can reach any
1823 static bool CallSiteUsesAliveArgs(const DSCallSite &CS,
1824 hash_set<const DSNode*> &Alive,
1825 hash_set<const DSNode*> &Visited,
1826 bool IgnoreGlobals) {
1827 if (CanReachAliveNodes(CS.getRetVal().getNode(), Alive, Visited,
1830 if (CS.isIndirectCall() &&
1831 CanReachAliveNodes(CS.getCalleeNode(), Alive, Visited, IgnoreGlobals))
1833 for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i)
1834 if (CanReachAliveNodes(CS.getPtrArg(i).getNode(), Alive, Visited,
1840 // removeDeadNodes - Use a more powerful reachability analysis to eliminate
1841 // subgraphs that are unreachable. This often occurs because the data
1842 // structure doesn't "escape" into it's caller, and thus should be eliminated
1843 // from the caller's graph entirely. This is only appropriate to use when
1846 void DSGraph::removeDeadNodes(unsigned Flags) {
1847 DEBUG(AssertGraphOK(); if (GlobalsGraph) GlobalsGraph->AssertGraphOK());
1849 // Reduce the amount of work we have to do... remove dummy nodes left over by
1851 removeTriviallyDeadNodes();
1853 TIME_REGION(X, "removeDeadNodes");
1855 // FIXME: Merge non-trivially identical call nodes...
1857 // Alive - a set that holds all nodes found to be reachable/alive.
1858 hash_set<const DSNode*> Alive;
1859 std::vector<std::pair<Value*, DSNode*> > GlobalNodes;
1861 // Copy and merge all information about globals to the GlobalsGraph if this is
1862 // not a final pass (where unreachable globals are removed).
1864 // Strip all alloca bits since the current function is only for the BU pass.
1865 // Strip all incomplete bits since they are short-lived properties and they
1866 // will be correctly computed when rematerializing nodes into the functions.
1868 ReachabilityCloner GGCloner(*GlobalsGraph, *this, DSGraph::StripAllocaBit |
1869 DSGraph::StripIncompleteBit);
1871 // Mark all nodes reachable by (non-global) scalar nodes as alive...
1872 { TIME_REGION(Y, "removeDeadNodes:scalarscan");
1873 for (DSScalarMap::iterator I = ScalarMap.begin(), E = ScalarMap.end(); I !=E;)
1874 if (isa<GlobalValue>(I->first)) { // Keep track of global nodes
1875 assert(!I->second.isNull() && "Null global node?");
1876 assert(I->second.getNode()->isGlobalNode() && "Should be a global node!");
1877 GlobalNodes.push_back(std::make_pair(I->first, I->second.getNode()));
1879 // Make sure that all globals are cloned over as roots.
1880 if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
1881 DSGraph::ScalarMapTy::iterator SMI =
1882 GlobalsGraph->getScalarMap().find(I->first);
1883 if (SMI != GlobalsGraph->getScalarMap().end())
1884 GGCloner.merge(SMI->second, I->second);
1886 GGCloner.getClonedNH(I->second);
1890 DSNode *N = I->second.getNode();
1892 // Check to see if this is a worthless node generated for non-pointer
1893 // values, such as integers. Consider an addition of long types: A+B.
1894 // Assuming we can track all uses of the value in this context, and it is
1895 // NOT used as a pointer, we can delete the node. We will be able to
1896 // detect this situation if the node pointed to ONLY has Unknown bit set
1897 // in the node. In this case, the node is not incomplete, does not point
1898 // to any other nodes (no mod/ref bits set), and is therefore
1899 // uninteresting for data structure analysis. If we run across one of
1900 // these, prune the scalar pointing to it.
1902 if (N->getNodeFlags() == DSNode::UnknownNode && !isa<Argument>(I->first))
1903 ScalarMap.erase(I++);
1906 N->markReachableNodes(Alive);
1912 // The return values are alive as well.
1913 for (ReturnNodesTy::iterator I = ReturnNodes.begin(), E = ReturnNodes.end();
1915 I->second.getNode()->markReachableNodes(Alive);
1917 // Mark any nodes reachable by primary calls as alive...
1918 for (fc_iterator I = fc_begin(), E = fc_end(); I != E; ++I)
1919 I->markReachableNodes(Alive);
1922 // Now find globals and aux call nodes that are already live or reach a live
1923 // value (which makes them live in turn), and continue till no more are found.
1926 hash_set<const DSNode*> Visited;
1927 hash_set<const DSCallSite*> AuxFCallsAlive;
1930 // If any global node points to a non-global that is "alive", the global is
1931 // "alive" as well... Remove it from the GlobalNodes list so we only have
1932 // unreachable globals in the list.
1935 if (!(Flags & DSGraph::RemoveUnreachableGlobals))
1936 for (unsigned i = 0; i != GlobalNodes.size(); ++i)
1937 if (CanReachAliveNodes(GlobalNodes[i].second, Alive, Visited,
1938 Flags & DSGraph::RemoveUnreachableGlobals)) {
1939 std::swap(GlobalNodes[i--], GlobalNodes.back()); // Move to end to...
1940 GlobalNodes.pop_back(); // erase efficiently
1944 // Mark only unresolvable call nodes for moving to the GlobalsGraph since
1945 // call nodes that get resolved will be difficult to remove from that graph.
1946 // The final unresolved call nodes must be handled specially at the end of
1947 // the BU pass (i.e., in main or other roots of the call graph).
1948 for (afc_iterator CI = afc_begin(), E = afc_end(); CI != E; ++CI)
1949 if (!AuxFCallsAlive.count(&*CI) &&
1950 (CI->isIndirectCall()
1951 || CallSiteUsesAliveArgs(*CI, Alive, Visited,
1952 Flags & DSGraph::RemoveUnreachableGlobals))) {
1953 CI->markReachableNodes(Alive);
1954 AuxFCallsAlive.insert(&*CI);
1959 // Move dead aux function calls to the end of the list
1960 unsigned CurIdx = 0;
1961 for (std::list<DSCallSite>::iterator CI = AuxFunctionCalls.begin(),
1962 E = AuxFunctionCalls.end(); CI != E; )
1963 if (AuxFCallsAlive.count(&*CI))
1966 // Copy and merge global nodes and dead aux call nodes into the
1967 // GlobalsGraph, and all nodes reachable from those nodes. Update their
1968 // target pointers using the GGCloner.
1970 if (!(Flags & DSGraph::RemoveUnreachableGlobals))
1971 GlobalsGraph->AuxFunctionCalls.push_back(DSCallSite(*CI, GGCloner));
1973 AuxFunctionCalls.erase(CI++);
1976 // We are finally done with the GGCloner so we can destroy it.
1979 // At this point, any nodes which are visited, but not alive, are nodes
1980 // which can be removed. Loop over all nodes, eliminating completely
1981 // unreachable nodes.
1983 std::vector<DSNode*> DeadNodes;
1984 DeadNodes.reserve(Nodes.size());
1985 for (NodeListTy::iterator NI = Nodes.begin(), E = Nodes.end(); NI != E;) {
1987 assert(!N->isForwarding() && "Forwarded node in nodes list?");
1989 if (!Alive.count(N)) {
1991 assert(!N->isForwarding() && "Cannot remove a forwarding node!");
1992 DeadNodes.push_back(N);
1993 N->dropAllReferences();
1998 // Remove all unreachable globals from the ScalarMap.
1999 // If flag RemoveUnreachableGlobals is set, GlobalNodes has only dead nodes.
2000 // In either case, the dead nodes will not be in the set Alive.
2001 for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i)
2002 if (!Alive.count(GlobalNodes[i].second))
2003 ScalarMap.erase(GlobalNodes[i].first);
2005 assert((Flags & DSGraph::RemoveUnreachableGlobals) && "non-dead global");
2007 // Delete all dead nodes now since their referrer counts are zero.
2008 for (unsigned i = 0, e = DeadNodes.size(); i != e; ++i)
2009 delete DeadNodes[i];
2011 DEBUG(AssertGraphOK(); GlobalsGraph->AssertGraphOK());
2014 void DSGraph::AssertNodeContainsGlobal(const DSNode *N, GlobalValue *GV) const {
2015 assert(std::find(N->getGlobals().begin(), N->getGlobals().end(), GV) !=
2016 N->getGlobals().end() && "Global value not in node!");
2019 void DSGraph::AssertCallSiteInGraph(const DSCallSite &CS) const {
2020 if (CS.isIndirectCall()) {
2021 AssertNodeInGraph(CS.getCalleeNode());
2023 if (CS.getNumPtrArgs() && CS.getCalleeNode() == CS.getPtrArg(0).getNode() &&
2024 CS.getCalleeNode() && CS.getCalleeNode()->getGlobals().empty())
2025 std::cerr << "WARNING: WEIRD CALL SITE FOUND!\n";
2028 AssertNodeInGraph(CS.getRetVal().getNode());
2029 for (unsigned j = 0, e = CS.getNumPtrArgs(); j != e; ++j)
2030 AssertNodeInGraph(CS.getPtrArg(j).getNode());
2033 void DSGraph::AssertCallNodesInGraph() const {
2034 for (fc_iterator I = fc_begin(), E = fc_end(); I != E; ++I)
2035 AssertCallSiteInGraph(*I);
2037 void DSGraph::AssertAuxCallNodesInGraph() const {
2038 for (afc_iterator I = afc_begin(), E = afc_end(); I != E; ++I)
2039 AssertCallSiteInGraph(*I);
2042 void DSGraph::AssertGraphOK() const {
2043 for (node_const_iterator NI = node_begin(), E = node_end(); NI != E; ++NI)
2046 for (ScalarMapTy::const_iterator I = ScalarMap.begin(),
2047 E = ScalarMap.end(); I != E; ++I) {
2048 assert(!I->second.isNull() && "Null node in scalarmap!");
2049 AssertNodeInGraph(I->second.getNode());
2050 if (GlobalValue *GV = dyn_cast<GlobalValue>(I->first)) {
2051 assert(I->second.getNode()->isGlobalNode() &&
2052 "Global points to node, but node isn't global?");
2053 AssertNodeContainsGlobal(I->second.getNode(), GV);
2056 AssertCallNodesInGraph();
2057 AssertAuxCallNodesInGraph();
2059 // Check that all pointer arguments to any functions in this graph have
2061 for (ReturnNodesTy::const_iterator RI = ReturnNodes.begin(),
2062 E = ReturnNodes.end();
2064 Function &F = *RI->first;
2065 for (Function::arg_iterator AI = F.arg_begin(); AI != F.arg_end(); ++AI)
2066 if (isPointerType(AI->getType()))
2067 assert(!getNodeForValue(AI).isNull() &&
2068 "Pointer argument must be in the scalar map!");
2072 /// computeNodeMapping - Given roots in two different DSGraphs, traverse the
2073 /// nodes reachable from the two graphs, computing the mapping of nodes from the
2074 /// first to the second graph. This mapping may be many-to-one (i.e. the first
2075 /// graph may have multiple nodes representing one node in the second graph),
2076 /// but it will not work if there is a one-to-many or many-to-many mapping.
2078 void DSGraph::computeNodeMapping(const DSNodeHandle &NH1,
2079 const DSNodeHandle &NH2, NodeMapTy &NodeMap,
2080 bool StrictChecking) {
2081 DSNode *N1 = NH1.getNode(), *N2 = NH2.getNode();
2082 if (N1 == 0 || N2 == 0) return;
2084 DSNodeHandle &Entry = NodeMap[N1];
2085 if (!Entry.isNull()) {
2086 // Termination of recursion!
2087 if (StrictChecking) {
2088 assert(Entry.getNode() == N2 && "Inconsistent mapping detected!");
2089 assert((Entry.getOffset() == (NH2.getOffset()-NH1.getOffset()) ||
2090 Entry.getNode()->isNodeCompletelyFolded()) &&
2091 "Inconsistent mapping detected!");
2096 Entry.setTo(N2, NH2.getOffset()-NH1.getOffset());
2098 // Loop over all of the fields that N1 and N2 have in common, recursively
2099 // mapping the edges together now.
2100 int N2Idx = NH2.getOffset()-NH1.getOffset();
2101 unsigned N2Size = N2->getSize();
2102 if (N2Size == 0) return; // No edges to map to.
2104 for (unsigned i = 0, e = N1->getSize(); i < e; i += DS::PointerSize) {
2105 const DSNodeHandle &N1NH = N1->getLink(i);
2106 // Don't call N2->getLink if not needed (avoiding crash if N2Idx is not
2108 if (!N1NH.isNull()) {
2109 if (unsigned(N2Idx)+i < N2Size)
2110 computeNodeMapping(N1NH, N2->getLink(N2Idx+i), NodeMap);
2112 computeNodeMapping(N1NH,
2113 N2->getLink(unsigned(N2Idx+i) % N2Size), NodeMap);
2119 /// computeGToGGMapping - Compute the mapping of nodes in the global graph to
2120 /// nodes in this graph.
2121 void DSGraph::computeGToGGMapping(NodeMapTy &NodeMap) {
2122 DSGraph &GG = *getGlobalsGraph();
2124 DSScalarMap &SM = getScalarMap();
2125 for (DSScalarMap::global_iterator I = SM.global_begin(),
2126 E = SM.global_end(); I != E; ++I)
2127 DSGraph::computeNodeMapping(SM[*I], GG.getNodeForValue(*I), NodeMap);
2130 /// computeGGToGMapping - Compute the mapping of nodes in the global graph to
2131 /// nodes in this graph. Note that any uses of this method are probably bugs,
2132 /// unless it is known that the globals graph has been merged into this graph!
2133 void DSGraph::computeGGToGMapping(InvNodeMapTy &InvNodeMap) {
2135 computeGToGGMapping(NodeMap);
2137 while (!NodeMap.empty()) {
2138 InvNodeMap.insert(std::make_pair(NodeMap.begin()->second,
2139 NodeMap.begin()->first));
2140 NodeMap.erase(NodeMap.begin());