}
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;
+}
+
//===----------------------------------------------------------------------===//
// DSNode Implementation
//===----------------------------------------------------------------------===//
-DSNode::DSNode(enum NodeTy NT, const Type *T)
- : Ty(Type::VoidTy), Size(0), NodeType(NT) {
+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)
- : Links(N.Links), Globals(N.Globals), Ty(N.Ty), Size(N.Size),
- NodeType(N.NodeType) {
+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!");
}
-void DSNode::removeReferrer(DSNodeHandle *H) {
- // Search backwards, because we depopulate the list from the back for
- // efficiency (because it's a vector).
- std::vector<DSNodeHandle*>::reverse_iterator I =
- std::find(Referrers.rbegin(), Referrers.rend(), H);
- assert(I != Referrers.rend() && "Referrer not pointing to node!");
- Referrers.erase(I.base()-1);
+/// 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
/// single byte with a single TypeEntry of "void".
///
void DSNode::foldNodeCompletely() {
- if (isNodeCompletelyFolded()) return;
+ assert(!hasNoReferrers() &&
+ "Why would we collapse a node with no referrers?");
+ if (isNodeCompletelyFolded()) return; // If this node is already folded...
++NumFolds;
- // We are no longer typed at all...
- Ty = Type::VoidTy;
- NodeType |= Array;
- Size = 1;
-
- // Loop over all of our referrers, making them point to our zero bytes of
- // space.
- for (std::vector<DSNodeHandle*>::iterator I = Referrers.begin(),
- E = Referrers.end(); I != E; ++I)
- (*I)->setOffset(0);
-
- // If we have links, merge all of our outgoing links together...
- for (unsigned i = 1, e = Links.size(); i < e; ++i)
- Links[0].mergeWith(Links[i]);
- Links.resize(1);
+ // 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);
+
+ // Start forwarding to the destination node...
+ forwardNode(DestNode, 0);
+
+ if (Links.size()) {
+ DestNode->Links.push_back(Links[0]);
+ DSNodeHandle NH(DestNode);
+
+ // 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);
+ }
}
/// isNodeCompletelyFolded - Return true if this node has been completely
///
/// This method returns true if the node is completely folded, otherwise false.
///
-bool DSNode::mergeTypeInfo(const Type *NewTy, unsigned Offset) {
+bool DSNode::mergeTypeInfo(const Type *NewTy, unsigned Offset,
+ bool FoldIfIncompatible) {
// 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.
// It is illegal to grow this node if we have treated it as an array of
// objects...
if (isArray()) {
- foldNodeCompletely();
+ if (FoldIfIncompatible) 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();
+ if (FoldIfIncompatible) foldNodeCompletely();
return true;
}
break;
}
default:
- assert(0 && "Unknown type!");
+ if (FoldIfIncompatible) foldNodeCompletely();
+ return true;
}
}
<< "\n due to:" << NewTy << " @ " << Offset << "!\n"
<< "SubType: " << SubType << "\n\n");
- foldNodeCompletely();
+ if (FoldIfIncompatible) foldNodeCompletely();
return true;
}
unsigned NSize = NH.getNode()->getSize();
// Merge the type entries of the two nodes together...
- if (NH.getNode()->Ty != Type::VoidTy) {
+ 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
if (CurNodeH.getNode()->isNodeCompletelyFolded()) {
if (!NH.getNode()->isNodeCompletelyFolded()) {
NH.getNode()->foldNodeCompletely();
- assert(NH.getOffset()==0 && "folding did not make offset 0?");
+ 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.getOffset()==0 && "folding did not make offset 0?");
+ assert(CurNodeH.getNode() && CurNodeH.getOffset() == 0 &&
+ "folding did not make offset 0?");
NOffset = NH.getOffset();
NSize = NH.getNode()->getSize();
assert(NOffset == 0 && NSize == 1);
}
- if (CurNodeH.getNode() == NH.getNode() || NH.getNode() == 0) return;
+ DSNode *N = NH.getNode();
+ if (CurNodeH.getNode() == N || N == 0) return;
assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
- // Remove all edges pointing at N, causing them to point to 'this' instead.
- // Make sure to adjust their offset, not just the node pointer.
- // Also, be careful to use the DSNode* rather than NH since NH is one of
- // the referrers and once NH refers to CurNodeH.getNode() this will
- // become an infinite loop.
- DSNode* N = NH.getNode();
- unsigned OldNHOffset = NH.getOffset();
- while (!N->Referrers.empty()) {
- DSNodeHandle &Ref = *N->Referrers.back();
- Ref = DSNodeHandle(CurNodeH.getNode(), NOffset+Ref.getOffset());
- }
- NH = DSNodeHandle(N, OldNHOffset); // reset NH to point back to where it was
-
+ // 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 *NH now be outgoing links of
- // this. This can cause recursive merging!
- //
- for (unsigned i = 0; i < NH.getNode()->getSize(); i += DS::PointerSize) {
- DSNodeHandle &Link = NH.getNode()->getLink(i);
+ // 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
// recursive merging, we must make sure to merge in all remaining
// links at offset zero.
unsigned MergeOffset = 0;
- if (CurNodeH.getNode()->Size != 1)
- MergeOffset = (i+NOffset) % CurNodeH.getNode()->getSize();
- CurNodeH.getNode()->addEdgeTo(MergeOffset, Link);
+ 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.
- NH.getNode()->Links.clear();
- NH.getNode()->Size = 0;
- NH.getNode()->Ty = Type::VoidTy;
-
- // Merge the node types
- CurNodeH.getNode()->NodeType |= NH.getNode()->NodeType;
- NH.getNode()->NodeType = DEAD; // NH is now a dead node.
+ N->Links.clear();
// Merge the globals list...
- if (!NH.getNode()->Globals.empty()) {
- MergeSortedVectors(CurNodeH.getNode()->Globals, NH.getNode()->Globals);
+ if (!N->Globals.empty()) {
+ MergeSortedVectors(CurNodeH.getNode()->Globals, N->Globals);
// Delete the globals from the old node...
- NH.getNode()->Globals.clear();
+ std::vector<GlobalValue*>().swap(N->Globals);
}
}
DSGraph::DSGraph(const DSGraph &G) : Func(G.Func), GlobalsGraph(0) {
PrintAuxCalls = false;
- std::map<const DSNode*, DSNodeHandle> NodeMap;
+ hash_map<const DSNode*, DSNodeHandle> NodeMap;
RetNode = cloneInto(G, ScalarMap, NodeMap);
}
DSGraph::DSGraph(const DSGraph &G,
- std::map<const DSNode*, DSNodeHandle> &NodeMap)
+ hash_map<const DSNode*, DSNodeHandle> &NodeMap)
: Func(G.Func), GlobalsGraph(0) {
PrintAuxCalls = false;
RetNode = cloneInto(G, ScalarMap, NodeMap);
/// remapLinks - Change all of the Links in the current node according to the
/// specified mapping.
///
-void DSNode::remapLinks(std::map<const DSNode*, DSNodeHandle> &OldNodeMap) {
+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());
// calling function's graph.
//
DSNodeHandle DSGraph::cloneInto(const DSGraph &G,
- std::map<Value*, DSNodeHandle> &OldValMap,
- std::map<const DSNode*, DSNodeHandle> &OldNodeMap,
+ 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!");
// 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);
- New->NodeType &= ~DSNode::DEAD; // Clear dead flag...
- Nodes.push_back(New);
+ DSNode *New = new DSNode(*Old, this);
+ New->NodeType &= ~clearBits;
OldNodeMap[Old] = New;
}
for (unsigned i = FN, e = Nodes.size(); i != e; ++i)
Nodes[i]->remapLinks(OldNodeMap);
- // Remove alloca markers as specified
- if (CloneFlags & (StripAllocaBit | StripModRefBits)) {
- unsigned short clearBits = (CloneFlags & StripAllocaBit
- ? DSNode::AllocaNode : 0)
- | (CloneFlags & StripModRefBits
- ? (DSNode::Modified | DSNode::Read) : 0);
- for (unsigned i = FN, e = Nodes.size(); i != e; ++i)
- Nodes[i]->NodeType &= ~clearBits;
- }
-
- // Copy the value map... and merge all of the global nodes...
- for (std::map<Value*, DSNodeHandle>::const_iterator I = G.ScalarMap.begin(),
+ // 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.setNode(MappedNode.getNode());
H.setOffset(I->second.getOffset()+MappedNode.getOffset());
+ H.setNode(MappedNode.getNode());
if (isa<GlobalValue>(I->first)) { // Is this a global?
- std::map<Value*, DSNodeHandle>::iterator GVI = ScalarMap.find(I->first);
- if (GVI != ScalarMap.end()) { // Is the global value in this fn already?
+ 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 {
+ else
ScalarMap[I->first] = H; // Add global pointer to this graph
- }
}
}
///
void DSGraph::mergeInGraph(DSCallSite &CS, const DSGraph &Graph,
unsigned CloneFlags) {
- std::map<Value*, DSNodeHandle> OldValMap;
+ hash_map<Value*, DSNodeHandle> OldValMap;
DSNodeHandle RetVal;
- std::map<Value*, DSNodeHandle> *ScalarMap = &OldValMap;
+ 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.
- std::map<const DSNode*, DSNodeHandle> OldNodeMap;
+ 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
for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i, ++AI) {
// Advance the argument iterator to the first pointer argument...
- while (!isPointerType(AI->getType())) {
+ while (AI != F.aend() && !isPointerType(AI->getType())) {
++AI;
#ifndef NDEBUG
if (AI == F.aend())
std::cerr << "Bad call to Function: " << F.getName() << "\n";
#endif
- assert(AI != F.aend() && "# Args provided is not # Args required!");
}
+ 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));
}
}
-#if 0
-// cloneGlobalInto - Clone the given global node and all its target links
-// (and all their llinks, recursively).
-//
-DSNode *DSGraph::cloneGlobalInto(const DSNode *GNode) {
- if (GNode == 0 || GNode->getGlobals().size() == 0) return 0;
-
- // If a clone has already been created for GNode, return it.
- DSNodeHandle& ValMapEntry = ScalarMap[GNode->getGlobals()[0]];
- if (ValMapEntry != 0)
- return ValMapEntry;
-
- // Clone the node and update the ValMap.
- DSNode* NewNode = new DSNode(*GNode);
- ValMapEntry = NewNode; // j=0 case of loop below!
- Nodes.push_back(NewNode);
- for (unsigned j = 1, N = NewNode->getGlobals().size(); j < N; ++j)
- ScalarMap[NewNode->getGlobals()[j]] = NewNode;
-
- // Rewrite the links in the new node to point into the current graph.
- for (unsigned j = 0, e = GNode->getNumLinks(); j != e; ++j)
- NewNode->setLink(j, cloneGlobalInto(GNode->getLink(j)));
-
- return NewNode;
-}
-#endif
-
// markIncompleteNodes - Mark the specified node as having contents that are not
// known with the current analysis we have performed. Because a node makes all
//
void DSGraph::markIncompleteNodes(unsigned Flags) {
// Mark any incoming arguments as incomplete...
- if ((Flags & DSGraph::MarkFormalArgs) && Func)
+ 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());
markIncomplete(AuxFunctionCalls[i]);
- // Mark all of the nodes pointed to by global nodes as incomplete...
- for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
- if (Nodes[i]->NodeType & DSNode::GlobalNode) {
- DSNode *N = Nodes[i];
- for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
- if (DSNode *DSN = N->getLink(i).getNode())
- markIncompleteNode(DSN);
- }
-}
-
-// removeRefsToGlobal - Helper function that removes globals from the
-// ScalarMap so that the referrer count will go down to zero.
-static void removeRefsToGlobal(DSNode* N,
- std::map<Value*, DSNodeHandle> &ScalarMap) {
- while (!N->getGlobals().empty()) {
- GlobalValue *GV = N->getGlobals().back();
- N->getGlobals().pop_back();
- ScalarMap.erase(GV);
- }
-}
-
-
-// isNodeDead - This method checks to see if a node is dead, and if it isn't, it
-// checks to see if there are simple transformations that it can do to make it
-// dead.
-//
-bool DSGraph::isNodeDead(DSNode *N) {
- // Is it a trivially dead shadow node?
- return N->getReferrers().empty() && (N->NodeType & ~DSNode::DEAD) == 0;
+ // 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 && Nodes[i]->getNumLinks())
+ markIncompleteNode(Nodes[i]);
}
static inline void killIfUselessEdge(DSNodeHandle &Edge) {
if (DSNode *N = Edge.getNode()) // Is there an edge?
- if (N->getReferrers().size() == 1) // Does it point to a lonely node?
+ 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!
std::sort(Calls.begin(), Calls.end()); // Sort by callee as primary key!
// Scan the call list cleaning it up as necessary...
- DSNode *LastCalleeNode = 0;
+ DSNode *LastCalleeNode = 0;
+ Function *LastCalleeFunc = 0;
unsigned NumDuplicateCalls = 0;
bool LastCalleeContainsExternalFunction = false;
for (unsigned i = 0; i != Calls.size(); ++i) {
// If the Callee is a useless edge, this must be an unreachable call site,
// eliminate it.
- killIfUselessEdge(CS.getCallee());
- if (CS.getCallee().getNode() == 0) {
+ 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;
// never be resolved. Merge the arguments of the call node because no
// information will be lost.
//
- if (CS.getCallee().getNode() == LastCalleeNode) {
+ if ((CS.isDirectCall() && CS.getCalleeFunc() == LastCalleeFunc) ||
+ (CS.isIndirectCall() && CS.getCalleeNode() == LastCalleeNode)) {
++NumDuplicateCalls;
if (NumDuplicateCalls == 1) {
- LastCalleeContainsExternalFunction =
- nodeContainsExternalFunction(LastCalleeNode);
+ if (LastCalleeNode)
+ LastCalleeContainsExternalFunction =
+ nodeContainsExternalFunction(LastCalleeNode);
+ else
+ LastCalleeContainsExternalFunction = LastCalleeFunc->isExternal();
}
if (LastCalleeContainsExternalFunction ||
OCS = CS;
}
} else {
- LastCalleeNode = CS.getCallee().getNode();
+ if (CS.isDirectCall()) {
+ LastCalleeFunc = CS.getCalleeFunc();
+ LastCalleeNode = 0;
+ } else {
+ LastCalleeNode = CS.getCalleeNode();
+ LastCalleeFunc = 0;
+ }
NumDuplicateCalls = 0;
}
}
removeIdenticalCalls(FunctionCalls, Func ? Func->getName() : "");
removeIdenticalCalls(AuxFunctionCalls, Func ? Func->getName() : "");
- for (unsigned i = 0; i != Nodes.size(); ++i)
- if (isNodeDead(Nodes[i])) { // This node is dead!
- delete Nodes[i]; // Free memory...
- Nodes.erase(Nodes.begin()+i--); // Remove from node list...
+ 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...
+ }
+ }
}
/// 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(std::set<DSNode*> &ReachableNodes) {
+void DSNode::markReachableNodes(hash_set<DSNode*> &ReachableNodes) {
if (this == 0) return;
- std::set<DSNode*>::iterator I = ReachableNodes.lower_bound(this);
- if (I != ReachableNodes.end() && *I == this)
- return; // Already marked reachable
- ReachableNodes.insert(I, this); // Is reachable now
+ 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(std::set<DSNode*> &Nodes) {
+void DSCallSite::markReachableNodes(hash_set<DSNode*> &Nodes) {
getRetVal().getNode()->markReachableNodes(Nodes);
- getCallee().getNode()->markReachableNodes(Nodes);
+ if (isIndirectCall()) getCalleeNode()->markReachableNodes(Nodes);
- for (unsigned j = 0, e = getNumPtrArgs(); j != e; ++j)
- getPtrArg(j).getNode()->markReachableNodes(Nodes);
+ for (unsigned i = 0, e = getNumPtrArgs(); i != e; ++i)
+ getPtrArg(i).getNode()->markReachableNodes(Nodes);
}
-// markAliveIfCanReachAlive - Simple graph walker that recursively traverses the
-// graph looking for a node that is marked alive. If the node is marked alive,
-// the recursive unwind marks node alive that can point to the alive node. This
-// is basically just a post-order traversal.
-//
-// This function returns true if the specified node is alive.
+// 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 markAliveIfCanReachAlive(DSNode *N, std::set<DSNode*> &Alive,
- std::set<DSNode*> &Visited) {
+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.
- std::set<DSNode*>::iterator VI = Visited.lower_bound(N);
- if (VI != Visited.end() && *VI == N) return false; // Found a cycle
- // No recursion, insert into Visited...
- Visited.insert(VI, N);
-
- if (N->NodeType & DSNode::GlobalNode)
- return false; // Global nodes will be marked on their own
-
- bool ChildrenAreAlive = false;
+ 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)
- ChildrenAreAlive |= markAliveIfCanReachAlive(N->getLink(i).getNode(),
- Alive, Visited);
- if (ChildrenAreAlive)
- N->markReachableNodes(Alive);
- return ChildrenAreAlive;
-}
-
-static bool CallSiteUsesAliveArgs(DSCallSite &CS, std::set<DSNode*> &Alive,
- std::set<DSNode*> &Visited) {
- if (markAliveIfCanReachAlive(CS.getRetVal().getNode(), Alive, Visited) ||
- markAliveIfCanReachAlive(CS.getCallee().getNode(), Alive, Visited))
- return true;
- for (unsigned j = 0, e = CS.getNumPtrArgs(); j != e; ++j)
- if (markAliveIfCanReachAlive(CS.getPtrArg(j).getNode(), Alive, Visited))
+ if (CanReachAliveNodes(N->getLink(i).getNode(), Alive, Visited)) {
+ N->markReachableNodes(Alive);
return true;
+ }
return false;
}
-// GlobalIsAlivenessRoot - Return true if the specified global node is
-// intrinsically alive in the context of the current graph (ie, it is a root of
-// aliveness). For TD graphs, no globals are. For the BU graphs all are unless
-// they are trivial globals...
+// CallSiteUsesAliveArgs - Return true if the specified call site can reach any
+// alive nodes.
//
-static bool GlobalIsAlivenessRoot(DSNode *N, unsigned Flags) {
- if (Flags & DSGraph::RemoveUnreachableGlobals)
- return false; // If we are to remove all globals, go for it.
-
- // Ok, we are keeping globals... hrm, we can still delete it if it has no
- // links, and no mod/ref or other info... If it is not modified, it can't
- // have links...
- //
- if ((N->NodeType & ~(DSNode::Composition | DSNode::Array)) == 0)
- return false;
- return true;
+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
// inlining graphs.
//
void DSGraph::removeDeadNodes(unsigned Flags) {
- // Reduce the amount of work we have to do...
+ // 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.
- std::set<DSNode*> Alive;
+ hash_set<DSNode*> Alive;
std::vector<std::pair<Value*, DSNode*> > GlobalNodes;
// Mark all nodes reachable by (non-global) scalar nodes as alive...
- for (std::map<Value*, DSNodeHandle>::iterator I = ScalarMap.begin(),
- E = ScalarMap.end(); I != E; ++I)
- if (!isa<GlobalValue>(I->first) ||
- GlobalIsAlivenessRoot(I->second.getNode(), Flags))
- I->second.getNode()->markReachableNodes(Alive);
- else // Keep track of global nodes
+ 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);
- // If any global nodes points to a non-global that is "alive", the global is
- // "alive" as well...
- //
- std::set<DSNode*> Visited;
- for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i)
- markAliveIfCanReachAlive(GlobalNodes[i].second, Alive, Visited);
-
- std::vector<bool> FCallsAlive(FunctionCalls.size());
+ // Mark any nodes reachable by primary calls as alive...
for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
- if (!(Flags & DSGraph::RemoveUnreachableGlobals) ||
- CallSiteUsesAliveArgs(FunctionCalls[i], Alive, Visited)) {
- FunctionCalls[i].markReachableNodes(Alive);
- FCallsAlive[i] = true;
- }
-
- std::vector<bool> AuxFCallsAlive(AuxFunctionCalls.size());
- for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
- if (CallSiteUsesAliveArgs(AuxFunctionCalls[i], Alive, Visited)) {
- AuxFunctionCalls[i].markReachableNodes(Alive);
- AuxFCallsAlive[i] = true;
- }
+ 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;
+ }
- // Remove all dead function calls...
- unsigned CurIdx = 0;
- for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
- if (FCallsAlive[i])
- FunctionCalls[CurIdx++].swap(FunctionCalls[i]);
- // Crop all the bad ones out...
- FunctionCalls.erase(FunctionCalls.begin()+CurIdx, FunctionCalls.end());
+ 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...
- CurIdx = 0;
+ unsigned CurIdx = 0;
for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
if (AuxFCallsAlive[i])
AuxFunctionCalls[CurIdx++].swap(AuxFunctionCalls[i]);
- // Crop all the bad ones out...
+ 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());
-
- // Remove all unreachable globals from the ScalarMap
- for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i)
- if (!Alive.count(GlobalNodes[i].second))
- ScalarMap.erase(GlobalNodes[i].first);
-
- // Loop over all unreachable nodes, dropping their references...
+ // 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()); // Only one allocation is allowed.
+ DeadNodes.reserve(Nodes.size());
for (unsigned i = 0; i != Nodes.size(); ++i)
if (!Alive.count(Nodes[i])) {
DSNode *N = Nodes[i];
- Nodes.erase(Nodes.begin()+i--); // Erase node from alive list.
- DeadNodes.push_back(N); // Add node to our list of dead nodes
- N->dropAllReferences(); // Drop all outgoing edges
+ 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?");
}
-
- // Delete all dead nodes...
- std::for_each(DeadNodes.begin(), DeadNodes.end(), deleter<DSNode>);
-}
-#if 0
-//===----------------------------------------------------------------------===//
-// GlobalDSGraph Implementation
-//===----------------------------------------------------------------------===//
-
-#if 0
-// Bits used in the next function
-static const char ExternalTypeBits = DSNode::GlobalNode | DSNode::HeapNode;
-
-
-// GlobalDSGraph::cloneNodeInto - Clone a global node and all its externally
-// visible target links (and recursively their such links) into this graph.
-// NodeCache maps the node being cloned to its clone in the Globals graph,
-// in order to track cycles.
-// GlobalsAreFinal is a flag that says whether it is safe to assume that
-// an existing global node is complete. This is important to avoid
-// reinserting all globals when inserting Calls to functions.
-// This is a helper function for cloneGlobals and cloneCalls.
-//
-DSNode* GlobalDSGraph::cloneNodeInto(DSNode *OldNode,
- std::map<const DSNode*, DSNode*> &NodeCache,
- bool GlobalsAreFinal) {
- if (OldNode == 0) return 0;
-
- // The caller should check this is an external node. Just more efficient...
- assert((OldNode->NodeType & ExternalTypeBits) && "Non-external node");
-
- // If a clone has already been created for OldNode, return it.
- DSNode*& CacheEntry = NodeCache[OldNode];
- if (CacheEntry != 0)
- return CacheEntry;
-
- // The result value...
- DSNode* NewNode = 0;
-
- // If nodes already exist for any of the globals of OldNode,
- // merge all such nodes together since they are merged in OldNode.
- // If ValueCacheIsFinal==true, look for an existing node that has
- // an identical list of globals and return it if it exists.
+ // Now that the nodes have either been deleted or moved to the globals graph,
+ // loop over the scalarmap, updating the entries for globals...
//
- for (unsigned j = 0, N = OldNode->getGlobals().size(); j != N; ++j)
- if (DSNode *PrevNode = ScalarMap[OldNode->getGlobals()[j]].getNode()) {
- if (NewNode == 0) {
- NewNode = PrevNode; // first existing node found
- if (GlobalsAreFinal && j == 0)
- if (OldNode->getGlobals() == PrevNode->getGlobals()) {
- CacheEntry = NewNode;
- return NewNode;
- }
- }
- else if (NewNode != PrevNode) { // found another, different from prev
- // update ValMap *before* merging PrevNode into NewNode
- for (unsigned k = 0, NK = PrevNode->getGlobals().size(); k < NK; ++k)
- ScalarMap[PrevNode->getGlobals()[k]] = NewNode;
- NewNode->mergeWith(PrevNode);
- }
- } else if (NewNode != 0) {
- ScalarMap[OldNode->getGlobals()[j]] = NewNode; // add the merged node
+ 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);
}
- // If no existing node was found, clone the node and update the ValMap.
- if (NewNode == 0) {
- NewNode = new DSNode(*OldNode);
- Nodes.push_back(NewNode);
- for (unsigned j = 0, e = NewNode->getNumLinks(); j != e; ++j)
- NewNode->setLink(j, 0);
- for (unsigned j = 0, N = NewNode->getGlobals().size(); j < N; ++j)
- ScalarMap[NewNode->getGlobals()[j]] = NewNode;
- }
- else
- NewNode->NodeType |= OldNode->NodeType; // Markers may be different!
-
- // Add the entry to NodeCache
- CacheEntry = NewNode;
-
- // Rewrite the links in the new node to point into the current graph,
- // but only for links to external nodes. Set other links to NULL.
- for (unsigned j = 0, e = OldNode->getNumLinks(); j != e; ++j) {
- DSNode* OldTarget = OldNode->getLink(j);
- if (OldTarget && (OldTarget->NodeType & ExternalTypeBits)) {
- DSNode* NewLink = this->cloneNodeInto(OldTarget, NodeCache);
- if (NewNode->getLink(j))
- NewNode->getLink(j)->mergeWith(NewLink);
- else
- NewNode->setLink(j, NewLink);
- }
+ // 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);
}
- // Remove all local markers
- NewNode->NodeType &= ~(DSNode::AllocaNode | DSNode::ScalarNode);
+ // 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];
- return NewNode;
+ DEBUG(AssertGraphOK(); GlobalsGraph->AssertGraphOK());
}
-
-// GlobalDSGraph::cloneCalls - Clone function calls and their visible target
-// links (and recursively their such links) into this graph.
-//
-void GlobalDSGraph::cloneCalls(DSGraph& Graph) {
- std::map<const DSNode*, DSNode*> NodeCache;
- std::vector<DSCallSite >& FromCalls =Graph.FunctionCalls;
-
- FunctionCalls.reserve(FunctionCalls.size() + FromCalls.size());
-
- for (int i = 0, ei = FromCalls.size(); i < ei; ++i) {
- DSCallSite& callCopy = FunctionCalls.back();
- callCopy.reserve(FromCalls[i].size());
- for (unsigned j = 0, ej = FromCalls[i].size(); j != ej; ++j)
- callCopy.push_back
- ((FromCalls[i][j] && (FromCalls[i][j]->NodeType & ExternalTypeBits))
- ? cloneNodeInto(FromCalls[i][j], NodeCache, true)
- : 0);
+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);
+ }
}
-
- // remove trivially identical function calls
- removeIdenticalCalls(FunctionCalls, "Globals Graph");
+ AssertCallNodesInGraph();
+ AssertAuxCallNodesInGraph();
}
-#endif
-
-#endif
projects / oota-llvm.git / blobdiff