-//===- DataStructure.cpp - Analysis for data structure identification -------=//
+//===- DataStructure.cpp - Implement the core data structure analysis -----===//
//
-// Implement the LLVM data structure analysis library.
+// This file implements the core data structure functionality.
//
//===----------------------------------------------------------------------===//
-#include "llvm/Analysis/DataStructure.h"
-#include "llvm/Module.h"
+#include "llvm/Analysis/DSGraph.h"
#include "llvm/Function.h"
-#include <fstream>
+#include "llvm/iOther.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Target/TargetData.h"
+#include "Support/STLExtras.h"
+#include "Support/Statistic.h"
+#include "Support/Timer.h"
#include <algorithm>
+namespace {
+ Statistic<> NumFolds ("dsnode", "Number of nodes completely folded");
+ Statistic<> NumCallNodesMerged("dsnode", "Number of call nodes merged");
+};
+
+namespace DS { // TODO: FIXME
+ extern TargetData TD;
+}
+using namespace DS;
+
+DSNode *DSNodeHandle::HandleForwarding() const {
+ assert(!N->ForwardNH.isNull() && "Can only be invoked if forwarding!");
+
+ // Handle node forwarding here!
+ DSNode *Next = N->ForwardNH.getNode(); // Cause recursive shrinkage
+ Offset += N->ForwardNH.getOffset();
+
+ if (--N->NumReferrers == 0) {
+ // Removing the last referrer to the node, sever the forwarding link
+ N->stopForwarding();
+ }
+
+ N = Next;
+ N->NumReferrers++;
+ if (N->Size <= Offset) {
+ assert(N->Size <= 1 && "Forwarded to shrunk but not collapsed node?");
+ Offset = 0;
+ }
+ return N;
+}
+
//===----------------------------------------------------------------------===//
-// DataStructure Class Implementation
+// DSNode Implementation
+//===----------------------------------------------------------------------===//
+
+DSNode::DSNode(unsigned NT, const Type *T, DSGraph *G)
+ : NumReferrers(0), Size(0), ParentGraph(G), Ty(Type::VoidTy), NodeType(NT) {
+ // Add the type entry if it is specified...
+ if (T) mergeTypeInfo(T, 0);
+ G->getNodes().push_back(this);
+}
+
+// DSNode copy constructor... do not copy over the referrers list!
+DSNode::DSNode(const DSNode &N, DSGraph *G)
+ : NumReferrers(0), Size(N.Size), ParentGraph(G), Ty(N.Ty),
+ Links(N.Links), Globals(N.Globals), NodeType(N.NodeType) {
+ G->getNodes().push_back(this);
+}
+
+void DSNode::assertOK() const {
+ assert((Ty != Type::VoidTy ||
+ Ty == Type::VoidTy && (Size == 0 ||
+ (NodeType & DSNode::Array))) &&
+ "Node not OK!");
+}
+
+/// forwardNode - Mark this node as being obsolete, and all references to it
+/// should be forwarded to the specified node and offset.
+///
+void DSNode::forwardNode(DSNode *To, unsigned Offset) {
+ assert(this != To && "Cannot forward a node to itself!");
+ assert(ForwardNH.isNull() && "Already forwarding from this node!");
+ if (To->Size <= 1) Offset = 0;
+ assert((Offset < To->Size || (Offset == To->Size && Offset == 0)) &&
+ "Forwarded offset is wrong!");
+ ForwardNH.setNode(To);
+ ForwardNH.setOffset(Offset);
+ NodeType = DEAD;
+ Size = 0;
+ Ty = Type::VoidTy;
+}
+
+// addGlobal - Add an entry for a global value to the Globals list. This also
+// marks the node with the 'G' flag if it does not already have it.
//
+void DSNode::addGlobal(GlobalValue *GV) {
+ // Keep the list sorted.
+ std::vector<GlobalValue*>::iterator I =
+ std::lower_bound(Globals.begin(), Globals.end(), GV);
+
+ if (I == Globals.end() || *I != GV) {
+ //assert(GV->getType()->getElementType() == Ty);
+ Globals.insert(I, GV);
+ NodeType |= GlobalNode;
+ }
+}
+
+/// foldNodeCompletely - If we determine that this node has some funny
+/// behavior happening to it that we cannot represent, we fold it down to a
+/// single, completely pessimistic, node. This node is represented as a
+/// single byte with a single TypeEntry of "void".
+///
+void DSNode::foldNodeCompletely() {
+ assert(!hasNoReferrers() &&
+ "Why would we collapse a node with no referrers?");
+ if (isNodeCompletelyFolded()) return; // If this node is already folded...
+
+ ++NumFolds;
+
+ // Create the node we are going to forward to...
+ DSNode *DestNode = new DSNode(NodeType|DSNode::Array, 0, ParentGraph);
+ DestNode->Ty = Type::VoidTy;
+ DestNode->Size = 1;
+ DestNode->Globals.swap(Globals);
-AnalysisID DataStructure::ID(AnalysisID::create<DataStructure>());
+ // Start forwarding to the destination node...
+ forwardNode(DestNode, 0);
+
+ if (Links.size()) {
+ DestNode->Links.push_back(Links[0]);
+ DSNodeHandle NH(DestNode);
-// releaseMemory - If the pass pipeline is done with this pass, we can release
-// our memory... here...
-void DataStructure::releaseMemory() {
- for (InfoMap::iterator I = DSInfo.begin(), E = DSInfo.end(); I != E; ++I) {
- delete I->second.first;
- delete I->second.second;
+ // If we have links, merge all of our outgoing links together...
+ for (unsigned i = Links.size()-1; i != 0; --i)
+ NH.getNode()->Links[0].mergeWith(Links[i]);
+ Links.clear();
+ } else {
+ DestNode->Links.resize(1);
}
+}
- // Empty map so next time memory is released, data structures are not
- // re-deleted.
- DSInfo.clear();
+/// isNodeCompletelyFolded - Return true if this node has been completely
+/// folded down to something that can never be expanded, effectively losing
+/// all of the field sensitivity that may be present in the node.
+///
+bool DSNode::isNodeCompletelyFolded() const {
+ return getSize() == 1 && Ty == Type::VoidTy && isArray();
}
-// FIXME REMOVE
-#include <sys/time.h>
-#include "Support/CommandLine.h"
-cl::Flag Time("t", "Print analysis time...");
+/// mergeTypeInfo - This method merges the specified type into the current node
+/// at the specified offset. This may update the current node's type record if
+/// this gives more information to the node, it may do nothing to the node if
+/// this information is already known, or it may merge the node completely (and
+/// return true) if the information is incompatible with what is already known.
+///
+/// This method returns true if the node is completely folded, otherwise false.
+///
+bool DSNode::mergeTypeInfo(const Type *NewTy, unsigned Offset) {
+ // Check to make sure the Size member is up-to-date. Size can be one of the
+ // following:
+ // Size = 0, Ty = Void: Nothing is known about this node.
+ // Size = 0, Ty = FnTy: FunctionPtr doesn't have a size, so we use zero
+ // Size = 1, Ty = Void, Array = 1: The node is collapsed
+ // Otherwise, sizeof(Ty) = Size
+ //
+ assert(((Size == 0 && Ty == Type::VoidTy && !isArray()) ||
+ (Size == 0 && !Ty->isSized() && !isArray()) ||
+ (Size == 1 && Ty == Type::VoidTy && isArray()) ||
+ (Size == 0 && !Ty->isSized() && !isArray()) ||
+ (TD.getTypeSize(Ty) == Size)) &&
+ "Size member of DSNode doesn't match the type structure!");
+ assert(NewTy != Type::VoidTy && "Cannot merge void type into DSNode!");
+ if (Offset == 0 && NewTy == Ty)
+ return false; // This should be a common case, handle it efficiently
-// print - Print out the analysis results...
-void DataStructure::print(std::ostream &O, Module *M) const {
- if (Time) {
- timeval TV1, TV2;
- gettimeofday(&TV1, 0);
- for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
- if (!(*I)->isExternal()) {
- getDSGraph(*I);
- getClosedDSGraph(*I);
- }
- gettimeofday(&TV2, 0);
- cerr << "Analysis took "
- << (TV2.tv_sec-TV1.tv_sec)*1000000+(TV2.tv_usec-TV1.tv_usec)
- << " microseconds.\n";
+ // Return true immediately if the node is completely folded.
+ if (isNodeCompletelyFolded()) return true;
+
+ // If this is an array type, eliminate the outside arrays because they won't
+ // be used anyway. This greatly reduces the size of large static arrays used
+ // as global variables, for example.
+ //
+ bool WillBeArray = false;
+ while (const ArrayType *AT = dyn_cast<ArrayType>(NewTy)) {
+ // FIXME: we might want to keep small arrays, but must be careful about
+ // things like: [2 x [10000 x int*]]
+ NewTy = AT->getElementType();
+ WillBeArray = true;
}
- for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
- if (!(*I)->isExternal()) {
+ // Figure out how big the new type we're merging in is...
+ unsigned NewTySize = NewTy->isSized() ? TD.getTypeSize(NewTy) : 0;
- string Filename = "ds." + (*I)->getName() + ".dot";
- O << "Writing '" << Filename << "'...\n";
- ofstream F(Filename.c_str());
- if (F.good()) {
- F << "digraph DataStructures {\n"
- << "\tnode [shape=Mrecord];\n"
- << "\tedge [arrowtail=\"dot\"];\n"
- << "\tsize=\"10,7.5\";\n"
- << "\trotate=\"90\";\n";
+ // Otherwise check to see if we can fold this type into the current node. If
+ // we can't, we fold the node completely, if we can, we potentially update our
+ // internal state.
+ //
+ if (Ty == Type::VoidTy) {
+ // If this is the first type that this node has seen, just accept it without
+ // question....
+ assert(Offset == 0 && "Cannot have an offset into a void node!");
+ assert(!isArray() && "This shouldn't happen!");
+ Ty = NewTy;
+ NodeType &= ~Array;
+ if (WillBeArray) NodeType |= Array;
+ Size = NewTySize;
- getDSGraph(*I).printFunction(F, "Local");
- getClosedDSGraph(*I).printFunction(F, "Closed");
+ // Calculate the number of outgoing links from this node.
+ Links.resize((Size+DS::PointerSize-1) >> DS::PointerShift);
+ return false;
+ }
- F << "}\n";
- } else {
- O << " error opening file for writing!\n";
- }
-
- O << (*I)->getName() << " " << getDSGraph(*I).getGraphSize() << " "
- << getClosedDSGraph(*I).getGraphSize() << "\n";
+ // Handle node expansion case here...
+ if (Offset+NewTySize > Size) {
+ // It is illegal to grow this node if we have treated it as an array of
+ // objects...
+ if (isArray()) {
+ foldNodeCompletely();
+ return true;
+ }
+
+ if (Offset) { // We could handle this case, but we don't for now...
+ DEBUG(std::cerr << "UNIMP: Trying to merge a growth type into "
+ << "offset != 0: Collapsing!\n");
+ foldNodeCompletely();
+ return true;
+ }
+
+ // Okay, the situation is nice and simple, we are trying to merge a type in
+ // at offset 0 that is bigger than our current type. Implement this by
+ // switching to the new type and then merge in the smaller one, which should
+ // hit the other code path here. If the other code path decides it's not
+ // ok, it will collapse the node as appropriate.
+ //
+ const Type *OldTy = Ty;
+ Ty = NewTy;
+ NodeType &= ~Array;
+ if (WillBeArray) NodeType |= Array;
+ Size = NewTySize;
+
+ // Must grow links to be the appropriate size...
+ Links.resize((Size+DS::PointerSize-1) >> DS::PointerShift);
+
+ // Merge in the old type now... which is guaranteed to be smaller than the
+ // "current" type.
+ return mergeTypeInfo(OldTy, 0);
+ }
+
+ assert(Offset <= Size &&
+ "Cannot merge something into a part of our type that doesn't exist!");
+
+ // Find the section of Ty that NewTy overlaps with... first we find the
+ // type that starts at offset Offset.
+ //
+ unsigned O = 0;
+ const Type *SubType = Ty;
+ while (O < Offset) {
+ assert(Offset-O < TD.getTypeSize(SubType) && "Offset out of range!");
+
+ switch (SubType->getPrimitiveID()) {
+ case Type::StructTyID: {
+ const StructType *STy = cast<StructType>(SubType);
+ const StructLayout &SL = *TD.getStructLayout(STy);
+
+ unsigned i = 0, e = SL.MemberOffsets.size();
+ for (; i+1 < e && SL.MemberOffsets[i+1] <= Offset-O; ++i)
+ /* empty */;
+
+ // The offset we are looking for must be in the i'th element...
+ SubType = STy->getElementTypes()[i];
+ O += SL.MemberOffsets[i];
+ break;
+ }
+ case Type::ArrayTyID: {
+ SubType = cast<ArrayType>(SubType)->getElementType();
+ unsigned ElSize = TD.getTypeSize(SubType);
+ unsigned Remainder = (Offset-O) % ElSize;
+ O = Offset-Remainder;
+ break;
+ }
+ default:
+ foldNodeCompletely();
+ return true;
+ }
+ }
+
+ assert(O == Offset && "Could not achieve the correct offset!");
+
+ // If we found our type exactly, early exit
+ if (SubType == NewTy) return false;
+
+ // Okay, so we found the leader type at the offset requested. Search the list
+ // of types that starts at this offset. If SubType is currently an array or
+ // structure, the type desired may actually be the first element of the
+ // composite type...
+ //
+ unsigned SubTypeSize = SubType->isSized() ? TD.getTypeSize(SubType) : 0;
+ unsigned PadSize = SubTypeSize; // Size, including pad memory which is ignored
+ while (SubType != NewTy) {
+ const Type *NextSubType = 0;
+ unsigned NextSubTypeSize = 0;
+ unsigned NextPadSize = 0;
+ switch (SubType->getPrimitiveID()) {
+ case Type::StructTyID: {
+ const StructType *STy = cast<StructType>(SubType);
+ const StructLayout &SL = *TD.getStructLayout(STy);
+ if (SL.MemberOffsets.size() > 1)
+ NextPadSize = SL.MemberOffsets[1];
+ else
+ NextPadSize = SubTypeSize;
+ NextSubType = STy->getElementTypes()[0];
+ NextSubTypeSize = TD.getTypeSize(NextSubType);
+ break;
}
+ case Type::ArrayTyID:
+ NextSubType = cast<ArrayType>(SubType)->getElementType();
+ NextSubTypeSize = TD.getTypeSize(NextSubType);
+ NextPadSize = NextSubTypeSize;
+ break;
+ default: ;
+ // fall out
+ }
+
+ if (NextSubType == 0)
+ break; // In the default case, break out of the loop
+
+ if (NextPadSize < NewTySize)
+ break; // Don't allow shrinking to a smaller type than NewTySize
+ SubType = NextSubType;
+ SubTypeSize = NextSubTypeSize;
+ PadSize = NextPadSize;
+ }
+
+ // If we found the type exactly, return it...
+ if (SubType == NewTy)
+ return false;
+
+ // Check to see if we have a compatible, but different type...
+ if (NewTySize == SubTypeSize) {
+ // Check to see if this type is obviously convertable... int -> uint f.e.
+ if (NewTy->isLosslesslyConvertableTo(SubType))
+ return false;
+
+ // Check to see if we have a pointer & integer mismatch going on here,
+ // loading a pointer as a long, for example.
+ //
+ if (SubType->isInteger() && isa<PointerType>(NewTy) ||
+ NewTy->isInteger() && isa<PointerType>(SubType))
+ return false;
+ } else if (NewTySize > SubTypeSize && NewTySize <= PadSize) {
+ // We are accessing the field, plus some structure padding. Ignore the
+ // structure padding.
+ return false;
+ }
+
+
+ DEBUG(std::cerr << "MergeTypeInfo Folding OrigTy: " << Ty
+ << "\n due to:" << NewTy << " @ " << Offset << "!\n"
+ << "SubType: " << SubType << "\n\n");
+
+ foldNodeCompletely();
+ return true;
}
-//===----------------------------------------------------------------------===//
-// PointerVal Class Implementation
+
+// addEdgeTo - Add an edge from the current node to the specified node. This
+// can cause merging of nodes in the graph.
+//
+void DSNode::addEdgeTo(unsigned Offset, const DSNodeHandle &NH) {
+ if (NH.getNode() == 0) return; // Nothing to do
+
+ DSNodeHandle &ExistingEdge = getLink(Offset);
+ if (ExistingEdge.getNode()) {
+ // Merge the two nodes...
+ ExistingEdge.mergeWith(NH);
+ } else { // No merging to perform...
+ setLink(Offset, NH); // Just force a link in there...
+ }
+}
+
+
+// MergeSortedVectors - Efficiently merge a vector into another vector where
+// duplicates are not allowed and both are sorted. This assumes that 'T's are
+// efficiently copyable and have sane comparison semantics.
//
+static void MergeSortedVectors(std::vector<GlobalValue*> &Dest,
+ const std::vector<GlobalValue*> &Src) {
+ // By far, the most common cases will be the simple ones. In these cases,
+ // avoid having to allocate a temporary vector...
+ //
+ if (Src.empty()) { // Nothing to merge in...
+ return;
+ } else if (Dest.empty()) { // Just copy the result in...
+ Dest = Src;
+ } else if (Src.size() == 1) { // Insert a single element...
+ const GlobalValue *V = Src[0];
+ std::vector<GlobalValue*>::iterator I =
+ std::lower_bound(Dest.begin(), Dest.end(), V);
+ if (I == Dest.end() || *I != Src[0]) // If not already contained...
+ Dest.insert(I, Src[0]);
+ } else if (Dest.size() == 1) {
+ GlobalValue *Tmp = Dest[0]; // Save value in temporary...
+ Dest = Src; // Copy over list...
+ std::vector<GlobalValue*>::iterator I =
+ std::lower_bound(Dest.begin(), Dest.end(), Tmp);
+ if (I == Dest.end() || *I != Tmp) // If not already contained...
+ Dest.insert(I, Tmp);
-void PointerVal::print(std::ostream &O) const {
- if (Node) {
- O << " Node: " << Node->getCaption() << "[" << Index << "]\n";
} else {
- O << " NULL NODE\n";
+ // Make a copy to the side of Dest...
+ std::vector<GlobalValue*> Old(Dest);
+
+ // Make space for all of the type entries now...
+ Dest.resize(Dest.size()+Src.size());
+
+ // Merge the two sorted ranges together... into Dest.
+ std::merge(Old.begin(), Old.end(), Src.begin(), Src.end(), Dest.begin());
+
+ // Now erase any duplicate entries that may have accumulated into the
+ // vectors (because they were in both of the input sets)
+ Dest.erase(std::unique(Dest.begin(), Dest.end()), Dest.end());
+ }
+}
+
+
+// MergeNodes() - Helper function for DSNode::mergeWith().
+// This function does the hard work of merging two nodes, CurNodeH
+// and NH after filtering out trivial cases and making sure that
+// CurNodeH.offset >= NH.offset.
+//
+// ***WARNING***
+// Since merging may cause either node to go away, we must always
+// use the node-handles to refer to the nodes. These node handles are
+// automatically updated during merging, so will always provide access
+// to the correct node after a merge.
+//
+void DSNode::MergeNodes(DSNodeHandle& CurNodeH, DSNodeHandle& NH) {
+ assert(CurNodeH.getOffset() >= NH.getOffset() &&
+ "This should have been enforced in the caller.");
+
+ // Now we know that Offset >= NH.Offset, so convert it so our "Offset" (with
+ // respect to NH.Offset) is now zero. NOffset is the distance from the base
+ // of our object that N starts from.
+ //
+ unsigned NOffset = CurNodeH.getOffset()-NH.getOffset();
+ unsigned NSize = NH.getNode()->getSize();
+
+ // Merge the type entries of the two nodes together...
+ if (NH.getNode()->Ty != Type::VoidTy)
+ CurNodeH.getNode()->mergeTypeInfo(NH.getNode()->Ty, NOffset);
+ assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
+
+ // If we are merging a node with a completely folded node, then both nodes are
+ // now completely folded.
+ //
+ if (CurNodeH.getNode()->isNodeCompletelyFolded()) {
+ if (!NH.getNode()->isNodeCompletelyFolded()) {
+ NH.getNode()->foldNodeCompletely();
+ assert(NH.getNode() && NH.getOffset() == 0 &&
+ "folding did not make offset 0?");
+ NOffset = NH.getOffset();
+ NSize = NH.getNode()->getSize();
+ assert(NOffset == 0 && NSize == 1);
+ }
+ } else if (NH.getNode()->isNodeCompletelyFolded()) {
+ CurNodeH.getNode()->foldNodeCompletely();
+ assert(CurNodeH.getNode() && CurNodeH.getOffset() == 0 &&
+ "folding did not make offset 0?");
+ NOffset = NH.getOffset();
+ NSize = NH.getNode()->getSize();
+ assert(NOffset == 0 && NSize == 1);
}
+
+ DSNode *N = NH.getNode();
+ if (CurNodeH.getNode() == N || N == 0) return;
+ assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
+
+ // Start forwarding to the new node!
+ CurNodeH.getNode()->NodeType |= N->NodeType;
+ N->forwardNode(CurNodeH.getNode(), NOffset);
+ assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
+
+ // Make all of the outgoing links of N now be outgoing links of CurNodeH.
+ //
+ for (unsigned i = 0; i < N->getNumLinks(); ++i) {
+ DSNodeHandle &Link = N->getLink(i << DS::PointerShift);
+ if (Link.getNode()) {
+ // Compute the offset into the current node at which to
+ // merge this link. In the common case, this is a linear
+ // relation to the offset in the original node (with
+ // wrapping), but if the current node gets collapsed due to
+ // recursive merging, we must make sure to merge in all remaining
+ // links at offset zero.
+ unsigned MergeOffset = 0;
+ DSNode *CN = CurNodeH.getNode();
+ if (CN->Size != 1)
+ MergeOffset = ((i << DS::PointerShift)+NOffset) % CN->getSize();
+ CN->addEdgeTo(MergeOffset, Link);
+ }
+ }
+
+ // Now that there are no outgoing edges, all of the Links are dead.
+ N->Links.clear();
+
+ // Merge the globals list...
+ if (!N->Globals.empty()) {
+ MergeSortedVectors(CurNodeH.getNode()->Globals, N->Globals);
+
+ // Delete the globals from the old node...
+ std::vector<GlobalValue*>().swap(N->Globals);
+ }
+}
+
+
+// mergeWith - Merge this node and the specified node, moving all links to and
+// from the argument node into the current node, deleting the node argument.
+// Offset indicates what offset the specified node is to be merged into the
+// current node.
+//
+// The specified node may be a null pointer (in which case, nothing happens).
+//
+void DSNode::mergeWith(const DSNodeHandle &NH, unsigned Offset) {
+ DSNode *N = NH.getNode();
+ if (N == 0 || (N == this && NH.getOffset() == Offset))
+ return; // Noop
+
+ assert((N->NodeType & DSNode::DEAD) == 0);
+ assert((NodeType & DSNode::DEAD) == 0);
+ assert(!hasNoReferrers() && "Should not try to fold a useless node!");
+
+ if (N == this) {
+ // We cannot merge two pieces of the same node together, collapse the node
+ // completely.
+ DEBUG(std::cerr << "Attempting to merge two chunks of"
+ << " the same node together!\n");
+ foldNodeCompletely();
+ return;
+ }
+
+ // If both nodes are not at offset 0, make sure that we are merging the node
+ // at an later offset into the node with the zero offset.
+ //
+ if (Offset < NH.getOffset()) {
+ N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
+ return;
+ } else if (Offset == NH.getOffset() && getSize() < N->getSize()) {
+ // If the offsets are the same, merge the smaller node into the bigger node
+ N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
+ return;
+ }
+
+ // Ok, now we can merge the two nodes. Use a static helper that works with
+ // two node handles, since "this" may get merged away at intermediate steps.
+ DSNodeHandle CurNodeH(this, Offset);
+ DSNodeHandle NHCopy(NH);
+ DSNode::MergeNodes(CurNodeH, NHCopy);
+}
+
+//===----------------------------------------------------------------------===//
+// DSCallSite Implementation
+//===----------------------------------------------------------------------===//
+
+// Define here to avoid including iOther.h and BasicBlock.h in DSGraph.h
+Function &DSCallSite::getCaller() const {
+ return *Inst->getParent()->getParent();
}
+
+//===----------------------------------------------------------------------===//
+// DSGraph Implementation
//===----------------------------------------------------------------------===//
-// PointerValSet Class Implementation
+
+DSGraph::DSGraph(const DSGraph &G) : Func(G.Func), GlobalsGraph(0) {
+ PrintAuxCalls = false;
+ hash_map<const DSNode*, DSNodeHandle> NodeMap;
+ RetNode = cloneInto(G, ScalarMap, NodeMap);
+}
+
+DSGraph::DSGraph(const DSGraph &G,
+ hash_map<const DSNode*, DSNodeHandle> &NodeMap)
+ : Func(G.Func), GlobalsGraph(0) {
+ PrintAuxCalls = false;
+ RetNode = cloneInto(G, ScalarMap, NodeMap);
+}
+
+DSGraph::~DSGraph() {
+ FunctionCalls.clear();
+ AuxFunctionCalls.clear();
+ ScalarMap.clear();
+ RetNode.setNode(0);
+
+ // Drop all intra-node references, so that assertions don't fail...
+ std::for_each(Nodes.begin(), Nodes.end(),
+ std::mem_fun(&DSNode::dropAllReferences));
+
+ // Delete all of the nodes themselves...
+ std::for_each(Nodes.begin(), Nodes.end(), deleter<DSNode>);
+}
+
+// dump - Allow inspection of graph in a debugger.
+void DSGraph::dump() const { print(std::cerr); }
+
+
+/// remapLinks - Change all of the Links in the current node according to the
+/// specified mapping.
+///
+void DSNode::remapLinks(hash_map<const DSNode*, DSNodeHandle> &OldNodeMap) {
+ for (unsigned i = 0, e = Links.size(); i != e; ++i) {
+ DSNodeHandle &H = OldNodeMap[Links[i].getNode()];
+ Links[i].setNode(H.getNode());
+ Links[i].setOffset(Links[i].getOffset()+H.getOffset());
+ }
+}
+
+
+// cloneInto - Clone the specified DSGraph into the current graph, returning the
+// Return node of the graph. The translated ScalarMap for the old function is
+// filled into the OldValMap member. If StripAllocas is set to true, Alloca
+// markers are removed from the graph, as the graph is being cloned into a
+// calling function's graph.
//
+DSNodeHandle DSGraph::cloneInto(const DSGraph &G,
+ hash_map<Value*, DSNodeHandle> &OldValMap,
+ hash_map<const DSNode*, DSNodeHandle> &OldNodeMap,
+ unsigned CloneFlags) {
+ assert(OldNodeMap.empty() && "Returned OldNodeMap should be empty!");
+ assert(&G != this && "Cannot clone graph into itself!");
+
+ unsigned FN = Nodes.size(); // First new node...
-void PointerValSet::addRefs() {
- for (unsigned i = 0, e = Vals.size(); i != e; ++i)
- Vals[i].Node->addReferrer(this);
+ // Duplicate all of the nodes, populating the node map...
+ Nodes.reserve(FN+G.Nodes.size());
+
+ // Remove alloca or mod/ref bits as specified...
+ unsigned clearBits = (CloneFlags & StripAllocaBit ? DSNode::AllocaNode : 0)
+ | (CloneFlags & StripModRefBits ? (DSNode::Modified | DSNode::Read) : 0);
+ clearBits |= DSNode::DEAD; // Clear dead flag...
+ for (unsigned i = 0, e = G.Nodes.size(); i != e; ++i) {
+ DSNode *Old = G.Nodes[i];
+ DSNode *New = new DSNode(*Old, this);
+ New->NodeType &= ~clearBits;
+ OldNodeMap[Old] = New;
+ }
+
+#ifndef NDEBUG
+ Timer::addPeakMemoryMeasurement();
+#endif
+
+ // Rewrite the links in the new nodes to point into the current graph now.
+ for (unsigned i = FN, e = Nodes.size(); i != e; ++i)
+ Nodes[i]->remapLinks(OldNodeMap);
+
+ // Copy the scalar map... merging all of the global nodes...
+ for (hash_map<Value*, DSNodeHandle>::const_iterator I = G.ScalarMap.begin(),
+ E = G.ScalarMap.end(); I != E; ++I) {
+ DSNodeHandle &H = OldValMap[I->first];
+ DSNodeHandle &MappedNode = OldNodeMap[I->second.getNode()];
+ H.setOffset(I->second.getOffset()+MappedNode.getOffset());
+ H.setNode(MappedNode.getNode());
+
+ if (isa<GlobalValue>(I->first)) { // Is this a global?
+ hash_map<Value*, DSNodeHandle>::iterator GVI = ScalarMap.find(I->first);
+ if (GVI != ScalarMap.end()) // Is the global value in this fn already?
+ GVI->second.mergeWith(H);
+ else
+ ScalarMap[I->first] = H; // Add global pointer to this graph
+ }
+ }
+
+ if (!(CloneFlags & DontCloneCallNodes)) {
+ // Copy the function calls list...
+ unsigned FC = FunctionCalls.size(); // FirstCall
+ FunctionCalls.reserve(FC+G.FunctionCalls.size());
+ for (unsigned i = 0, ei = G.FunctionCalls.size(); i != ei; ++i)
+ FunctionCalls.push_back(DSCallSite(G.FunctionCalls[i], OldNodeMap));
+ }
+
+ if (!(CloneFlags & DontCloneAuxCallNodes)) {
+ // Copy the auxillary function calls list...
+ unsigned FC = AuxFunctionCalls.size(); // FirstCall
+ AuxFunctionCalls.reserve(FC+G.AuxFunctionCalls.size());
+ for (unsigned i = 0, ei = G.AuxFunctionCalls.size(); i != ei; ++i)
+ AuxFunctionCalls.push_back(DSCallSite(G.AuxFunctionCalls[i], OldNodeMap));
+ }
+
+ // Return the returned node pointer...
+ DSNodeHandle &MappedRet = OldNodeMap[G.RetNode.getNode()];
+ return DSNodeHandle(MappedRet.getNode(),
+ MappedRet.getOffset()+G.RetNode.getOffset());
}
-void PointerValSet::dropRefs() {
- for (unsigned i = 0, e = Vals.size(); i != e; ++i)
- Vals[i].Node->removeReferrer(this);
+/// mergeInGraph - The method is used for merging graphs together. If the
+/// argument graph is not *this, it makes a clone of the specified graph, then
+/// merges the nodes specified in the call site with the formal arguments in the
+/// graph.
+///
+void DSGraph::mergeInGraph(DSCallSite &CS, const DSGraph &Graph,
+ unsigned CloneFlags) {
+ hash_map<Value*, DSNodeHandle> OldValMap;
+ DSNodeHandle RetVal;
+ hash_map<Value*, DSNodeHandle> *ScalarMap = &OldValMap;
+
+ // If this is not a recursive call, clone the graph into this graph...
+ if (&Graph != this) {
+ // Clone the callee's graph into the current graph, keeping
+ // track of where scalars in the old graph _used_ to point,
+ // and of the new nodes matching nodes of the old graph.
+ hash_map<const DSNode*, DSNodeHandle> OldNodeMap;
+
+ // The clone call may invalidate any of the vectors in the data
+ // structure graph. Strip locals and don't copy the list of callers
+ RetVal = cloneInto(Graph, OldValMap, OldNodeMap, CloneFlags);
+ ScalarMap = &OldValMap;
+ } else {
+ RetVal = getRetNode();
+ ScalarMap = &getScalarMap();
+ }
+
+ // Merge the return value with the return value of the context...
+ RetVal.mergeWith(CS.getRetVal());
+
+ // Resolve all of the function arguments...
+ Function &F = Graph.getFunction();
+ Function::aiterator AI = F.abegin();
+
+ for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i, ++AI) {
+ // Advance the argument iterator to the first pointer argument...
+ while (AI != F.aend() && !isPointerType(AI->getType())) {
+ ++AI;
+#ifndef NDEBUG
+ if (AI == F.aend())
+ std::cerr << "Bad call to Function: " << F.getName() << "\n";
+#endif
+ }
+ if (AI == F.aend()) break;
+
+ // Add the link from the argument scalar to the provided value
+ assert(ScalarMap->count(AI) && "Argument not in scalar map?");
+ DSNodeHandle &NH = (*ScalarMap)[AI];
+ assert(NH.getNode() && "Pointer argument without scalarmap entry?");
+ NH.mergeWith(CS.getPtrArg(i));
+ }
}
-const PointerValSet &PointerValSet::operator=(const PointerValSet &PVS) {
- dropRefs();
- Vals.clear();
- Vals = PVS.Vals;
- addRefs();
- return *this;
+
+// markIncompleteNodes - Mark the specified node as having contents that are not
+// known with the current analysis we have performed. Because a node makes all
+// of the nodes it can reach imcomplete if the node itself is incomplete, we
+// must recursively traverse the data structure graph, marking all reachable
+// nodes as incomplete.
+//
+static void markIncompleteNode(DSNode *N) {
+ // Stop recursion if no node, or if node already marked...
+ if (N == 0 || (N->NodeType & DSNode::Incomplete)) return;
+
+ // Actually mark the node
+ N->NodeType |= DSNode::Incomplete;
+
+ // Recusively process children...
+ for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
+ if (DSNode *DSN = N->getLink(i).getNode())
+ markIncompleteNode(DSN);
}
-// operator< - Allow insertion into a map...
-bool PointerValSet::operator<(const PointerValSet &PVS) const {
- if (Vals.size() < PVS.Vals.size()) return true;
- if (Vals.size() > PVS.Vals.size()) return false;
- if (Vals.size() == 1) return Vals[0] < PVS.Vals[0]; // Most common case
+static void markIncomplete(DSCallSite &Call) {
+ // Then the return value is certainly incomplete!
+ markIncompleteNode(Call.getRetVal().getNode());
- vector<PointerVal> S1(Vals), S2(PVS.Vals);
- sort(S1.begin(), S1.end());
- sort(S2.begin(), S2.end());
- return S1 < S2;
+ // All objects pointed to by function arguments are incomplete!
+ for (unsigned i = 0, e = Call.getNumPtrArgs(); i != e; ++i)
+ markIncompleteNode(Call.getPtrArg(i).getNode());
}
-bool PointerValSet::operator==(const PointerValSet &PVS) const {
- if (Vals.size() != PVS.Vals.size()) return false;
- if (Vals.size() == 1) return Vals[0] == PVS.Vals[0]; // Most common case...
+// markIncompleteNodes - Traverse the graph, identifying nodes that may be
+// modified by other functions that have not been resolved yet. This marks
+// nodes that are reachable through three sources of "unknownness":
+//
+// Global Variables, Function Calls, and Incoming Arguments
+//
+// For any node that may have unknown components (because something outside the
+// scope of current analysis may have modified it), the 'Incomplete' flag is
+// added to the NodeType.
+//
+void DSGraph::markIncompleteNodes(unsigned Flags) {
+ // Mark any incoming arguments as incomplete...
+ if ((Flags & DSGraph::MarkFormalArgs) && Func && Func->getName() != "main")
+ for (Function::aiterator I = Func->abegin(), E = Func->aend(); I != E; ++I)
+ if (isPointerType(I->getType()) && ScalarMap.find(I) != ScalarMap.end())
+ markIncompleteNode(ScalarMap[I].getNode());
+
+ // Mark stuff passed into functions calls as being incomplete...
+ if (!shouldPrintAuxCalls())
+ for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
+ markIncomplete(FunctionCalls[i]);
+ else
+ for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
+ markIncomplete(AuxFunctionCalls[i]);
+
- vector<PointerVal> S1(Vals), S2(PVS.Vals);
- sort(S1.begin(), S1.end());
- sort(S2.begin(), S2.end());
- return S1 == S2;
+ // Mark all global nodes as incomplete...
+ if ((Flags & DSGraph::IgnoreGlobals) == 0)
+ for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
+ if (Nodes[i]->NodeType & DSNode::GlobalNode)
+ markIncompleteNode(Nodes[i]);
}
+static inline void killIfUselessEdge(DSNodeHandle &Edge) {
+ if (DSNode *N = Edge.getNode()) // Is there an edge?
+ if (N->getNumReferrers() == 1) // Does it point to a lonely node?
+ if ((N->NodeType & ~DSNode::Incomplete) == 0 && // No interesting info?
+ N->getType() == Type::VoidTy && !N->isNodeCompletelyFolded())
+ Edge.setNode(0); // Kill the edge!
+}
-bool PointerValSet::add(const PointerVal &PV, Value *Pointer) {
- if (std::find(Vals.begin(), Vals.end(), PV) != Vals.end())
- return false;
- Vals.push_back(PV);
- if (Pointer) PV.Node->addPointer(Pointer);
- PV.Node->addReferrer(this);
- return true;
+static inline bool nodeContainsExternalFunction(const DSNode *N) {
+ const std::vector<GlobalValue*> &Globals = N->getGlobals();
+ for (unsigned i = 0, e = Globals.size(); i != e; ++i)
+ if (Globals[i]->isExternal())
+ return true;
+ return false;
}
-// removePointerTo - Remove a single pointer val that points to the specified
-// node...
-void PointerValSet::removePointerTo(DSNode *Node) {
- vector<PointerVal>::iterator I = std::find(Vals.begin(), Vals.end(), Node);
- assert(I != Vals.end() && "Couldn't remove nonexistent edge!");
- Vals.erase(I);
- Node->removeReferrer(this);
+static void removeIdenticalCalls(std::vector<DSCallSite> &Calls,
+ const std::string &where) {
+ // Remove trivially identical function calls
+ unsigned NumFns = Calls.size();
+ std::sort(Calls.begin(), Calls.end()); // Sort by callee as primary key!
+
+ // Scan the call list cleaning it up as necessary...
+ DSNode *LastCalleeNode = 0;
+ Function *LastCalleeFunc = 0;
+ unsigned NumDuplicateCalls = 0;
+ bool LastCalleeContainsExternalFunction = false;
+ for (unsigned i = 0; i != Calls.size(); ++i) {
+ DSCallSite &CS = Calls[i];
+
+ // If the Callee is a useless edge, this must be an unreachable call site,
+ // eliminate it.
+ if (CS.isIndirectCall() && CS.getCalleeNode()->getNumReferrers() == 1 &&
+ CS.getCalleeNode()->NodeType == 0) { // No useful info?
+ std::cerr << "WARNING: Useless call site found??\n";
+ CS.swap(Calls.back());
+ Calls.pop_back();
+ --i;
+ } else {
+ // If the return value or any arguments point to a void node with no
+ // information at all in it, and the call node is the only node to point
+ // to it, remove the edge to the node (killing the node).
+ //
+ killIfUselessEdge(CS.getRetVal());
+ for (unsigned a = 0, e = CS.getNumPtrArgs(); a != e; ++a)
+ killIfUselessEdge(CS.getPtrArg(a));
+
+ // If this call site calls the same function as the last call site, and if
+ // the function pointer contains an external function, this node will
+ // never be resolved. Merge the arguments of the call node because no
+ // information will be lost.
+ //
+ if ((CS.isDirectCall() && CS.getCalleeFunc() == LastCalleeFunc) ||
+ (CS.isIndirectCall() && CS.getCalleeNode() == LastCalleeNode)) {
+ ++NumDuplicateCalls;
+ if (NumDuplicateCalls == 1) {
+ if (LastCalleeNode)
+ LastCalleeContainsExternalFunction =
+ nodeContainsExternalFunction(LastCalleeNode);
+ else
+ LastCalleeContainsExternalFunction = LastCalleeFunc->isExternal();
+ }
+
+ if (LastCalleeContainsExternalFunction ||
+ // This should be more than enough context sensitivity!
+ // FIXME: Evaluate how many times this is tripped!
+ NumDuplicateCalls > 20) {
+ DSCallSite &OCS = Calls[i-1];
+ OCS.mergeWith(CS);
+
+ // The node will now be eliminated as a duplicate!
+ if (CS.getNumPtrArgs() < OCS.getNumPtrArgs())
+ CS = OCS;
+ else if (CS.getNumPtrArgs() > OCS.getNumPtrArgs())
+ OCS = CS;
+ }
+ } else {
+ if (CS.isDirectCall()) {
+ LastCalleeFunc = CS.getCalleeFunc();
+ LastCalleeNode = 0;
+ } else {
+ LastCalleeNode = CS.getCalleeNode();
+ LastCalleeFunc = 0;
+ }
+ NumDuplicateCalls = 0;
+ }
+ }
+ }
+
+ Calls.erase(std::unique(Calls.begin(), Calls.end()),
+ Calls.end());
+
+ // Track the number of call nodes merged away...
+ NumCallNodesMerged += NumFns-Calls.size();
+
+ DEBUG(if (NumFns != Calls.size())
+ std::cerr << "Merged " << (NumFns-Calls.size())
+ << " call nodes in " << where << "\n";);
}
-void PointerValSet::print(std::ostream &O) const {
- for (unsigned i = 0, e = Vals.size(); i != e; ++i)
- Vals[i].print(O);
+// removeTriviallyDeadNodes - After the graph has been constructed, this method
+// removes all unreachable nodes that are created because they got merged with
+// other nodes in the graph. These nodes will all be trivially unreachable, so
+// we don't have to perform any non-trivial analysis here.
+//
+void DSGraph::removeTriviallyDeadNodes() {
+ removeIdenticalCalls(FunctionCalls, Func ? Func->getName() : "");
+ removeIdenticalCalls(AuxFunctionCalls, Func ? Func->getName() : "");
+
+ for (unsigned i = 0; i != Nodes.size(); ++i) {
+ DSNode *Node = Nodes[i];
+ if (!(Node->NodeType & ~(DSNode::Composition | DSNode::Array |
+ DSNode::DEAD))) {
+ // This is a useless node if it has no mod/ref info (checked above),
+ // outgoing edges (which it cannot, as it is not modified in this
+ // context), and it has no incoming edges. If it is a global node it may
+ // have all of these properties and still have incoming edges, due to the
+ // scalar map, so we check those now.
+ //
+ if (Node->getNumReferrers() == Node->getGlobals().size()) {
+ std::vector<GlobalValue*> &Globals = Node->getGlobals();
+
+ // Loop through and make sure all of the globals are referring directly
+ // to the node...
+ for (unsigned j = 0, e = Globals.size(); j != e; ++j) {
+ DSNode *N = ScalarMap.find(Globals[j])->second.getNode();
+ assert(N == Node && "ScalarMap doesn't match globals list!");
+ }
+
+ // Make sure numreferrers still agrees, if so, the node is truely dead.
+ if (Node->getNumReferrers() == Globals.size()) {
+ for (unsigned j = 0, e = Globals.size(); j != e; ++j)
+ ScalarMap.erase(Globals[j]);
+
+ Globals.clear();
+ assert(Node->hasNoReferrers() && "Shouldn't have refs now!");
+
+ Node->NodeType = DSNode::DEAD;
+ }
+ }
+ }
+
+ if ((Node->NodeType & ~DSNode::DEAD) == 0 && Node->hasNoReferrers()) {
+ // This node is dead!
+ delete Node; // Free memory...
+ Nodes[i--] = Nodes.back();
+ Nodes.pop_back(); // Remove from node list...
+ }
+ }
+}
+
+
+/// markReachableNodes - This method recursively traverses the specified
+/// DSNodes, marking any nodes which are reachable. All reachable nodes it adds
+/// to the set, which allows it to only traverse visited nodes once.
+///
+void DSNode::markReachableNodes(hash_set<DSNode*> &ReachableNodes) {
+ if (this == 0) return;
+ assert(getForwardNode() == 0 && "Cannot mark a forwarded node!");
+ if (ReachableNodes.count(this)) return; // Already marked reachable
+ ReachableNodes.insert(this); // Is reachable now
+
+ for (unsigned i = 0, e = getSize(); i < e; i += DS::PointerSize)
+ getLink(i).getNode()->markReachableNodes(ReachableNodes);
+}
+
+void DSCallSite::markReachableNodes(hash_set<DSNode*> &Nodes) {
+ getRetVal().getNode()->markReachableNodes(Nodes);
+ if (isIndirectCall()) getCalleeNode()->markReachableNodes(Nodes);
+
+ for (unsigned i = 0, e = getNumPtrArgs(); i != e; ++i)
+ getPtrArg(i).getNode()->markReachableNodes(Nodes);
+}
+
+// CanReachAliveNodes - Simple graph walker that recursively traverses the graph
+// looking for a node that is marked alive. If an alive node is found, return
+// true, otherwise return false. If an alive node is reachable, this node is
+// marked as alive...
+//
+static bool CanReachAliveNodes(DSNode *N, hash_set<DSNode*> &Alive,
+ hash_set<DSNode*> &Visited) {
+ if (N == 0) return false;
+ assert(N->getForwardNode() == 0 && "Cannot mark a forwarded node!");
+
+ // If we know that this node is alive, return so!
+ if (Alive.count(N)) return true;
+
+ // Otherwise, we don't think the node is alive yet, check for infinite
+ // recursion.
+ if (Visited.count(N)) return false; // Found a cycle
+ Visited.insert(N); // No recursion, insert into Visited...
+
+ for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
+ if (CanReachAliveNodes(N->getLink(i).getNode(), Alive, Visited)) {
+ N->markReachableNodes(Alive);
+ return true;
+ }
+ return false;
+}
+
+// CallSiteUsesAliveArgs - Return true if the specified call site can reach any
+// alive nodes.
+//
+static bool CallSiteUsesAliveArgs(DSCallSite &CS, hash_set<DSNode*> &Alive,
+ hash_set<DSNode*> &Visited) {
+ if (CanReachAliveNodes(CS.getRetVal().getNode(), Alive, Visited))
+ return true;
+ if (CS.isIndirectCall() &&
+ CanReachAliveNodes(CS.getCalleeNode(), Alive, Visited))
+ return true;
+ for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i)
+ if (CanReachAliveNodes(CS.getPtrArg(i).getNode(), Alive, Visited))
+ return true;
+ return false;
+}
+
+// removeDeadNodes - Use a more powerful reachability analysis to eliminate
+// subgraphs that are unreachable. This often occurs because the data
+// structure doesn't "escape" into it's caller, and thus should be eliminated
+// from the caller's graph entirely. This is only appropriate to use when
+// inlining graphs.
+//
+void DSGraph::removeDeadNodes(unsigned Flags) {
+ // Reduce the amount of work we have to do... remove dummy nodes left over by
+ // merging...
+ removeTriviallyDeadNodes();
+
+ // FIXME: Merge nontrivially identical call nodes...
+
+ // Alive - a set that holds all nodes found to be reachable/alive.
+ hash_set<DSNode*> Alive;
+ std::vector<std::pair<Value*, DSNode*> > GlobalNodes;
+
+ // Mark all nodes reachable by (non-global) scalar nodes as alive...
+ for (hash_map<Value*, DSNodeHandle>::iterator I = ScalarMap.begin(),
+ E = ScalarMap.end(); I != E; )
+ if (isa<GlobalValue>(I->first)) { // Keep track of global nodes
+ assert(I->second.getNode() && "Null global node?");
+ GlobalNodes.push_back(std::make_pair(I->first, I->second.getNode()));
+ ++I;
+ } else {
+ // Check to see if this is a worthless node generated for non-pointer
+ // values, such as integers. Consider an addition of long types: A+B.
+ // Assuming we can track all uses of the value in this context, and it is
+ // NOT used as a pointer, we can delete the node. We will be able to
+ // detect this situation if the node pointed to ONLY has Unknown bit set
+ // in the node. In this case, the node is not incomplete, does not point
+ // to any other nodes (no mod/ref bits set), and is therefore
+ // uninteresting for data structure analysis. If we run across one of
+ // these, prune the scalar pointing to it.
+ //
+ DSNode *N = I->second.getNode();
+ if (N->NodeType == DSNode::UnknownNode && !isa<Argument>(I->first)) {
+ ScalarMap.erase(I++);
+ } else {
+ I->second.getNode()->markReachableNodes(Alive);
+ ++I;
+ }
+ }
+
+ // The return value is alive as well...
+ RetNode.getNode()->markReachableNodes(Alive);
+
+ // Mark any nodes reachable by primary calls as alive...
+ for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
+ FunctionCalls[i].markReachableNodes(Alive);
+
+ bool Iterate;
+ hash_set<DSNode*> Visited;
+ std::vector<unsigned char> AuxFCallsAlive(AuxFunctionCalls.size());
+ do {
+ Visited.clear();
+ // If any global nodes points to a non-global that is "alive", the global is
+ // "alive" as well... Remove it from the GlobalNodes list so we only have
+ // unreachable globals in the list.
+ //
+ Iterate = false;
+ for (unsigned i = 0; i != GlobalNodes.size(); ++i)
+ if (CanReachAliveNodes(GlobalNodes[i].second, Alive, Visited)) {
+ std::swap(GlobalNodes[i--], GlobalNodes.back()); // Move to end to erase
+ GlobalNodes.pop_back(); // Erase efficiently
+ Iterate = true;
+ }
+
+ for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
+ if (!AuxFCallsAlive[i] &&
+ CallSiteUsesAliveArgs(AuxFunctionCalls[i], Alive, Visited)) {
+ AuxFunctionCalls[i].markReachableNodes(Alive);
+ AuxFCallsAlive[i] = true;
+ Iterate = true;
+ }
+ } while (Iterate);
+
+ // Remove all dead aux function calls...
+ unsigned CurIdx = 0;
+ for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
+ if (AuxFCallsAlive[i])
+ AuxFunctionCalls[CurIdx++].swap(AuxFunctionCalls[i]);
+ if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
+ assert(GlobalsGraph && "No globals graph available??");
+ // Move the unreachable call nodes to the globals graph...
+ GlobalsGraph->AuxFunctionCalls.insert(GlobalsGraph->AuxFunctionCalls.end(),
+ AuxFunctionCalls.begin()+CurIdx,
+ AuxFunctionCalls.end());
+ }
+ // Crop all the useless ones out...
+ AuxFunctionCalls.erase(AuxFunctionCalls.begin()+CurIdx,
+ AuxFunctionCalls.end());
+
+ // At this point, any nodes which are visited, but not alive, are nodes which
+ // should be moved to the globals graph. Loop over all nodes, eliminating
+ // completely unreachable nodes, and moving visited nodes to the globals graph
+ //
+ std::vector<DSNode*> DeadNodes;
+ DeadNodes.reserve(Nodes.size());
+ for (unsigned i = 0; i != Nodes.size(); ++i)
+ if (!Alive.count(Nodes[i])) {
+ DSNode *N = Nodes[i];
+ Nodes[i--] = Nodes.back(); // move node to end of vector
+ Nodes.pop_back(); // Erase node from alive list.
+ if (!(Flags & DSGraph::RemoveUnreachableGlobals) && // Not in TD pass
+ Visited.count(N)) { // Visited but not alive?
+ GlobalsGraph->Nodes.push_back(N); // Move node to globals graph
+ N->setParentGraph(GlobalsGraph);
+ } else { // Otherwise, delete the node
+ assert(((N->NodeType & DSNode::GlobalNode) == 0 ||
+ (Flags & DSGraph::RemoveUnreachableGlobals))
+ && "Killing a global?");
+ //std::cerr << "[" << i+1 << "/" << DeadNodes.size()
+ // << "] Node is dead: "; N->dump();
+ DeadNodes.push_back(N);
+ N->dropAllReferences();
+ }
+ } else {
+ assert(Nodes[i]->getForwardNode() == 0 && "Alive forwarded node?");
+ }
+
+ // Now that the nodes have either been deleted or moved to the globals graph,
+ // loop over the scalarmap, updating the entries for globals...
+ //
+ if (!(Flags & DSGraph::RemoveUnreachableGlobals)) { // Not in the TD pass?
+ // In this array we start the remapping, which can cause merging. Because
+ // of this, the DSNode pointers in GlobalNodes may be invalidated, so we
+ // must always go through the ScalarMap (which contains DSNodeHandles [which
+ // cannot be invalidated by merging]).
+ //
+ for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i) {
+ Value *G = GlobalNodes[i].first;
+ hash_map<Value*, DSNodeHandle>::iterator I = ScalarMap.find(G);
+ assert(I != ScalarMap.end() && "Global not in scalar map anymore?");
+ assert(I->second.getNode() && "Global not pointing to anything?");
+ assert(!Alive.count(I->second.getNode()) && "Node is alive??");
+ GlobalsGraph->ScalarMap[G].mergeWith(I->second);
+ assert(GlobalsGraph->ScalarMap[G].getNode() &&
+ "Global not pointing to anything?");
+ ScalarMap.erase(I);
+ }
+
+ // Merging leaves behind silly nodes, we remove them to avoid polluting the
+ // globals graph.
+ if (!GlobalNodes.empty())
+ GlobalsGraph->removeTriviallyDeadNodes();
+ } else {
+ // If we are in the top-down pass, remove all unreachable globals from the
+ // ScalarMap...
+ for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i)
+ ScalarMap.erase(GlobalNodes[i].first);
+ }
+
+ // Loop over all of the dead nodes now, deleting them since their referrer
+ // count is zero.
+ for (unsigned i = 0, e = DeadNodes.size(); i != e; ++i)
+ delete DeadNodes[i];
+
+ DEBUG(AssertGraphOK(); GlobalsGraph->AssertGraphOK());
}
+void DSGraph::AssertGraphOK() const {
+ for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
+ Nodes[i]->assertOK();
+ return; // FIXME: remove
+ for (hash_map<Value*, DSNodeHandle>::const_iterator I = ScalarMap.begin(),
+ E = ScalarMap.end(); I != E; ++I) {
+ assert(I->second.getNode() && "Null node in scalarmap!");
+ AssertNodeInGraph(I->second.getNode());
+ if (GlobalValue *GV = dyn_cast<GlobalValue>(I->first)) {
+ assert((I->second.getNode()->NodeType & DSNode::GlobalNode) &&
+ "Global points to node, but node isn't global?");
+ AssertNodeContainsGlobal(I->second.getNode(), GV);
+ }
+ }
+ AssertCallNodesInGraph();
+ AssertAuxCallNodesInGraph();
+}
projects / oota-llvm.git / blobdiff