#include "llvm/iOther.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Target/TargetData.h"
+#include "llvm/Assembly/Writer.h"
+#include "Support/Debug.h"
#include "Support/STLExtras.h"
#include "Support/Statistic.h"
#include "Support/Timer.h"
}
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(const Type *T, DSGraph *G)
+ : NumReferrers(0), Size(0), ParentGraph(G), Ty(Type::VoidTy), NodeType(0) {
// 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::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);
+void DSNode::assertOK() const {
+ assert((Ty != Type::VoidTy ||
+ Ty == Type::VoidTy && (Size == 0 ||
+ (NodeType & DSNode::Array))) &&
+ "Node not OK!");
+
+ assert(ParentGraph && "Node has no parent?");
+ const DSGraph::ScalarMapTy &SM = ParentGraph->getScalarMap();
+ for (unsigned i = 0, e = Globals.size(); i != e; ++i) {
+ assert(SM.find(Globals[i]) != SM.end());
+ assert(SM.find(Globals[i])->second.getNode() == this);
+ }
+}
+
+/// 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;
+ 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(0, ParentGraph);
+ DestNode->NodeType = NodeType|DSNode::Array;
+ 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
}
+namespace {
+ /// TypeElementWalker Class - Used for implementation of physical subtyping...
+ ///
+ class TypeElementWalker {
+ struct StackState {
+ const Type *Ty;
+ unsigned Offset;
+ unsigned Idx;
+ StackState(const Type *T, unsigned Off = 0)
+ : Ty(T), Offset(Off), Idx(0) {}
+ };
+
+ std::vector<StackState> Stack;
+ public:
+ TypeElementWalker(const Type *T) {
+ Stack.push_back(T);
+ StepToLeaf();
+ }
+
+ bool isDone() const { return Stack.empty(); }
+ const Type *getCurrentType() const { return Stack.back().Ty; }
+ unsigned getCurrentOffset() const { return Stack.back().Offset; }
+
+ void StepToNextType() {
+ PopStackAndAdvance();
+ StepToLeaf();
+ }
+
+ private:
+ /// PopStackAndAdvance - Pop the current element off of the stack and
+ /// advance the underlying element to the next contained member.
+ void PopStackAndAdvance() {
+ assert(!Stack.empty() && "Cannot pop an empty stack!");
+ Stack.pop_back();
+ while (!Stack.empty()) {
+ StackState &SS = Stack.back();
+ if (const StructType *ST = dyn_cast<StructType>(SS.Ty)) {
+ ++SS.Idx;
+ if (SS.Idx != ST->getElementTypes().size()) {
+ const StructLayout *SL = TD.getStructLayout(ST);
+ SS.Offset += SL->MemberOffsets[SS.Idx]-SL->MemberOffsets[SS.Idx-1];
+ return;
+ }
+ Stack.pop_back(); // At the end of the structure
+ } else {
+ const ArrayType *AT = cast<ArrayType>(SS.Ty);
+ ++SS.Idx;
+ if (SS.Idx != AT->getNumElements()) {
+ SS.Offset += TD.getTypeSize(AT->getElementType());
+ return;
+ }
+ Stack.pop_back(); // At the end of the array
+ }
+ }
+ }
+
+ /// StepToLeaf - Used by physical subtyping to move to the first leaf node
+ /// on the type stack.
+ void StepToLeaf() {
+ if (Stack.empty()) return;
+ while (!Stack.empty() && !Stack.back().Ty->isFirstClassType()) {
+ StackState &SS = Stack.back();
+ if (const StructType *ST = dyn_cast<StructType>(SS.Ty)) {
+ if (ST->getElementTypes().empty()) {
+ assert(SS.Idx == 0);
+ PopStackAndAdvance();
+ } else {
+ // Step into the structure...
+ assert(SS.Idx < ST->getElementTypes().size());
+ const StructLayout *SL = TD.getStructLayout(ST);
+ Stack.push_back(StackState(ST->getElementTypes()[SS.Idx],
+ SS.Offset+SL->MemberOffsets[SS.Idx]));
+ }
+ } else {
+ const ArrayType *AT = cast<ArrayType>(SS.Ty);
+ if (AT->getNumElements() == 0) {
+ assert(SS.Idx == 0);
+ PopStackAndAdvance();
+ } else {
+ // Step into the array...
+ assert(SS.Idx < AT->getNumElements());
+ Stack.push_back(StackState(AT->getElementType(),
+ SS.Offset+SS.Idx*
+ TD.getTypeSize(AT->getElementType())));
+ }
+ }
+ }
+ }
+ };
+}
+
+/// ElementTypesAreCompatible - Check to see if the specified types are
+/// "physically" compatible. If so, return true, else return false. We only
+/// have to check the fields in T1: T2 may be larger than T1.
+///
+static bool ElementTypesAreCompatible(const Type *T1, const Type *T2) {
+ TypeElementWalker T1W(T1), T2W(T2);
+
+ while (!T1W.isDone() && !T2W.isDone()) {
+ if (T1W.getCurrentOffset() != T2W.getCurrentOffset())
+ return false;
+
+ const Type *T1 = T1W.getCurrentType();
+ const Type *T2 = T2W.getCurrentType();
+ if (T1 != T2 && !T1->isLosslesslyConvertibleTo(T2))
+ return false;
+
+ T1W.StepToNextType();
+ T2W.StepToNextType();
+ }
+
+ return T1W.isDone();
+}
+
+
/// 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 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();
+ std::cerr << "UNIMP: Trying to merge a growth type into "
+ << "offset != 0: Collapsing!\n";
+ if (FoldIfIncompatible) foldNodeCompletely();
return true;
}
break;
}
default:
- assert(0 && "Unknown type!");
+ if (FoldIfIncompatible) foldNodeCompletely();
+ return true;
}
}
// If we found our type exactly, early exit
if (SubType == NewTy) return false;
+ unsigned SubTypeSize = SubType->isSized() ? TD.getTypeSize(SubType) : 0;
+
+ // Ok, we are getting desperate now. Check for physical subtyping, where we
+ // just require each element in the node to be compatible.
+ if (NewTySize <= SubTypeSize && NewTySize && NewTySize < 256 &&
+ SubTypeSize && SubTypeSize < 256 &&
+ ElementTypesAreCompatible(NewTy, SubType))
+ 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;
// 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))
+ // Check to see if this type is obviously convertible... int -> uint f.e.
+ if (NewTy->isLosslesslyConvertibleTo(SubType))
return false;
// Check to see if we have a pointer & integer mismatch going on here,
return false;
}
+ Module *M = 0;
+ if (getParentGraph()->getReturnNodes().size())
+ M = getParentGraph()->getReturnNodes().begin()->first->getParent();
+ DEBUG(std::cerr << "MergeTypeInfo Folding OrigTy: ";
+ WriteTypeSymbolic(std::cerr, Ty, M) << "\n due to:";
+ WriteTypeSymbolic(std::cerr, NewTy, M) << " @ " << Offset << "!\n"
+ << "SubType: ";
+ WriteTypeSymbolic(std::cerr, SubType, M) << "\n\n");
- DEBUG(std::cerr << "MergeTypeInfo Folding OrigTy: " << Ty
- << "\n due to:" << NewTy << " @ " << Offset << "!\n"
- << "SubType: " << SubType << "\n\n");
-
- foldNodeCompletely();
+ if (FoldIfIncompatible) foldNodeCompletely();
return true;
}
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);
+ // If the two nodes are of different size, and the smaller node has the array
+ // bit set, collapse!
+ if (NSize != CurNodeH.getNode()->getSize()) {
+ if (NSize < CurNodeH.getNode()->getSize()) {
+ if (NH.getNode()->isArray())
+ NH.getNode()->foldNodeCompletely();
+ } else if (CurNodeH.getNode()->isArray()) {
+ NH.getNode()->foldNodeCompletely();
+ }
}
- assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
+
+ // 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()->isDeadNode());
// 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.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;
- 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
+ DSNode *N = NH.getNode();
+ if (CurNodeH.getNode() == N || N == 0) return;
+ assert(!CurNodeH.getNode()->isDeadNode());
- assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
+ // Merge the NodeType information...
+ CurNodeH.getNode()->NodeType |= N->NodeType;
- // 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);
+ // Start forwarding to the new node!
+ N->forwardNode(CurNodeH.getNode(), NOffset);
+ assert(!CurNodeH.getNode()->isDeadNode());
+
+ // 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);
}
}
if (N == 0 || (N == this && NH.getOffset() == Offset))
return; // Noop
- assert((N->NodeType & DSNode::DEAD) == 0);
- assert((NodeType & DSNode::DEAD) == 0);
+ assert(!N->isDeadNode() && !isDeadNode());
assert(!hasNoReferrers() && "Should not try to fold a useless node!");
if (N == this) {
// DSGraph Implementation
//===----------------------------------------------------------------------===//
-DSGraph::DSGraph(const DSGraph &G) : Func(G.Func), GlobalsGraph(0) {
+/// getFunctionNames - Return a space separated list of the name of the
+/// functions in this graph (if any)
+std::string DSGraph::getFunctionNames() const {
+ switch (getReturnNodes().size()) {
+ case 0: return "Globals graph";
+ case 1: return getReturnNodes().begin()->first->getName();
+ default:
+ std::string Return;
+ for (DSGraph::ReturnNodesTy::const_iterator I = getReturnNodes().begin();
+ I != getReturnNodes().end(); ++I)
+ Return += I->first->getName() + " ";
+ Return.erase(Return.end()-1, Return.end()); // Remove last space character
+ return Return;
+ }
+}
+
+
+DSGraph::DSGraph(const DSGraph &G) : GlobalsGraph(0) {
PrintAuxCalls = false;
- hash_map<const DSNode*, DSNodeHandle> NodeMap;
- RetNode = cloneInto(G, ScalarMap, NodeMap);
+ NodeMapTy NodeMap;
+ cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
+ InlinedGlobals.clear(); // clear set of "up-to-date" globals
}
-DSGraph::DSGraph(const DSGraph &G,
- hash_map<const DSNode*, DSNodeHandle> &NodeMap)
- : Func(G.Func), GlobalsGraph(0) {
+DSGraph::DSGraph(const DSGraph &G, NodeMapTy &NodeMap)
+ : GlobalsGraph(0) {
PrintAuxCalls = false;
- RetNode = cloneInto(G, ScalarMap, NodeMap);
+ cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
+ InlinedGlobals.clear(); // clear set of "up-to-date" globals
}
DSGraph::~DSGraph() {
FunctionCalls.clear();
AuxFunctionCalls.clear();
+ InlinedGlobals.clear();
ScalarMap.clear();
- RetNode.setNode(0);
+ ReturnNodes.clear();
// Drop all intra-node references, so that assertions don't fail...
std::for_each(Nodes.begin(), Nodes.end(),
/// remapLinks - Change all of the Links in the current node according to the
/// specified mapping.
///
-void DSNode::remapLinks(hash_map<const DSNode*, DSNodeHandle> &OldNodeMap) {
+void DSNode::remapLinks(DSGraph::NodeMapTy &OldNodeMap) {
for (unsigned i = 0, e = Links.size(); i != e; ++i) {
DSNodeHandle &H = OldNodeMap[Links[i].getNode()];
Links[i].setNode(H.getNode());
}
-// 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) {
+/// cloneReachableNodes - Clone all reachable nodes from *Node into the
+/// current graph. This is a recursive function. The map OldNodeMap is a
+/// map from the original nodes to their clones.
+///
+void DSGraph::cloneReachableNodes(const DSNode* Node,
+ unsigned BitsToClear,
+ NodeMapTy& OldNodeMap,
+ NodeMapTy& CompletedNodeMap) {
+ if (CompletedNodeMap.find(Node) != CompletedNodeMap.end())
+ return;
+
+ DSNodeHandle& NH = OldNodeMap[Node];
+ if (NH.getNode() != NULL)
+ return;
+
+ // else Node has not yet been cloned: clone it and clear the specified bits
+ NH = new DSNode(*Node, this); // enters in OldNodeMap
+ NH.getNode()->maskNodeTypes(~BitsToClear);
+
+ // now recursively clone nodes pointed to by this node
+ for (unsigned i = 0, e = Node->getNumLinks(); i != e; ++i) {
+ const DSNodeHandle &Link = Node->getLink(i << DS::PointerShift);
+ if (const DSNode* nextNode = Link.getNode())
+ cloneReachableNodes(nextNode, BitsToClear, OldNodeMap, CompletedNodeMap);
+ }
+}
+
+void DSGraph::cloneReachableSubgraph(const DSGraph& G,
+ const hash_set<const DSNode*>& RootNodes,
+ NodeMapTy& OldNodeMap,
+ NodeMapTy& CompletedNodeMap,
+ unsigned CloneFlags) {
+ if (RootNodes.empty())
+ return;
+
+ assert(OldNodeMap.empty() && "Returned OldNodeMap should be empty!");
+ assert(&G != this && "Cannot clone graph into itself!");
+ assert((*RootNodes.begin())->getParentGraph() == &G &&
+ "Root nodes do not belong to this graph!");
+
+ // Remove alloca or mod/ref bits as specified...
+ unsigned BitsToClear = ((CloneFlags & StripAllocaBit)? DSNode::AllocaNode : 0)
+ | ((CloneFlags & StripModRefBits)? (DSNode::Modified | DSNode::Read) : 0)
+ | ((CloneFlags & StripIncompleteBit)? DSNode::Incomplete : 0);
+ BitsToClear |= DSNode::DEAD; // Clear dead flag...
+
+ // Clone all nodes reachable from each root node, using a recursive helper
+ for (hash_set<const DSNode*>::const_iterator I = RootNodes.begin(),
+ E = RootNodes.end(); I != E; ++I)
+ cloneReachableNodes(*I, BitsToClear, OldNodeMap, CompletedNodeMap);
+
+ // Merge the map entries in OldNodeMap and CompletedNodeMap to remap links
+ NodeMapTy MergedMap(OldNodeMap);
+ MergedMap.insert(CompletedNodeMap.begin(), CompletedNodeMap.end());
+
+ // Rewrite the links in the newly created nodes (the nodes in OldNodeMap)
+ // to point into the current graph. MergedMap gives the full mapping.
+ for (NodeMapTy::iterator I=OldNodeMap.begin(), E=OldNodeMap.end(); I!= E; ++I)
+ I->second.getNode()->remapLinks(MergedMap);
+
+ // Now merge cloned global nodes with their copies in the current graph
+ // Just look through OldNodeMap to find such nodes!
+ for (NodeMapTy::iterator I=OldNodeMap.begin(), E=OldNodeMap.end(); I!= E; ++I)
+ if (I->first->isGlobalNode()) {
+ DSNodeHandle &GClone = I->second;
+ assert(GClone.getNode() != NULL && "NULL node in OldNodeMap?");
+ const std::vector<GlobalValue*> &Globals = I->first->getGlobals();
+ for (unsigned gi = 0, ge = Globals.size(); gi != ge; ++gi) {
+ DSNodeHandle &GH = ScalarMap[Globals[gi]];
+ GH.mergeWith(GClone);
+ }
+ }
+}
+
+
+/// updateFromGlobalGraph - This function rematerializes global nodes and
+/// nodes reachable from them from the globals graph into the current graph.
+/// It invokes cloneReachableSubgraph, using the globals in the current graph
+/// as the roots. It also uses the vector InlinedGlobals to avoid cloning and
+/// merging globals that are already up-to-date in the current graph. In
+/// practice, in the TD pass, this is likely to be a large fraction of the
+/// live global nodes in each function (since most live nodes are likely to
+/// have been brought up-to-date in at _some_ caller or callee).
+///
+void DSGraph::updateFromGlobalGraph() {
+
+ // Use a map to keep track of the mapping between nodes in the globals graph
+ // and this graph for up-to-date global nodes, which do not need to be cloned.
+ NodeMapTy CompletedMap;
+
+ // Put the live, non-up-to-date global nodes into a set and the up-to-date
+ // ones in the map above, mapping node in GlobalsGraph to the up-to-date node.
+ hash_set<const DSNode*> GlobalNodeSet;
+ for (ScalarMapTy::const_iterator I = getScalarMap().begin(),
+ E = getScalarMap().end(); I != E; ++I)
+ if (GlobalValue* GV = dyn_cast<GlobalValue>(I->first)) {
+ DSNode* GNode = I->second.getNode();
+ assert(GNode && "No node for live global in current Graph?");
+ if (const DSNode* GGNode = GlobalsGraph->ScalarMap[GV].getNode())
+ if (InlinedGlobals.count(GV) == 0) // GNode is not up-to-date
+ GlobalNodeSet.insert(GGNode);
+ else { // GNode is up-to-date
+ CompletedMap[GGNode] = I->second;
+ assert(GGNode->getNumLinks() == GNode->getNumLinks() &&
+ "Links dont match in a node that is supposed to be up-to-date?"
+ "\nremapLinks() will not work if the links don't match!");
+ }
+ }
+
+ // Clone the subgraph reachable from the vector of nodes in GlobalNodes
+ // and merge the cloned global nodes with the corresponding ones, if any.
+ NodeMapTy OldNodeMap;
+ cloneReachableSubgraph(*GlobalsGraph, GlobalNodeSet, OldNodeMap,CompletedMap);
+
+ // Merging global nodes leaves behind unused nodes: get rid of them now.
+ OldNodeMap.clear(); // remove references before dead node cleanup
+ CompletedMap.clear(); // remove references before dead node cleanup
+ removeTriviallyDeadNodes();
+}
+
+/// cloneInto - Clone the specified DSGraph into the current graph. The
+/// translated ScalarMap for the old function is filled into the OldValMap
+/// member, and the translated ReturnNodes map is returned into ReturnNodes.
+///
+/// The CloneFlags member controls various aspects of the cloning process.
+///
+void DSGraph::cloneInto(const DSGraph &G, ScalarMapTy &OldValMap,
+ ReturnNodesTy &OldReturnNodes, NodeMapTy &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 BitsToClear = ((CloneFlags & StripAllocaBit)? DSNode::AllocaNode : 0)
+ | ((CloneFlags & StripModRefBits)? (DSNode::Modified | DSNode::Read) : 0)
+ | ((CloneFlags & StripIncompleteBit)? DSNode::Incomplete : 0);
+ BitsToClear |= 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->maskNodeTypes(~BitsToClear);
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 (hash_map<Value*, DSNodeHandle>::const_iterator I = G.ScalarMap.begin(),
+ // Copy the scalar map... merging all of the global nodes...
+ for (ScalarMapTy::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());
+ DSNodeHandle &H = OldValMap[I->first];
+ H.mergeWith(DSNodeHandle(MappedNode.getNode(),
+ I->second.getOffset()+MappedNode.getOffset()));
- 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 this is a global, add the global to this fn or merge if already exists
+ if (GlobalValue* GV = dyn_cast<GlobalValue>(I->first)) {
+ ScalarMap[GV].mergeWith(H);
+ InlinedGlobals.insert(GV);
}
}
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());
+ // Map the return node pointers over...
+ for (ReturnNodesTy::const_iterator I = G.getReturnNodes().begin(),
+ E = G.getReturnNodes().end(); I != E; ++I) {
+ const DSNodeHandle &Ret = I->second;
+ DSNodeHandle &MappedRet = OldNodeMap[Ret.getNode()];
+ OldReturnNodes.insert(std::make_pair(I->first,
+ DSNodeHandle(MappedRet.getNode(),
+ MappedRet.getOffset()+Ret.getOffset())));
+ }
}
/// mergeInGraph - The method is used for merging graphs together. If the
/// 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;
+void DSGraph::mergeInGraph(const DSCallSite &CS, Function &F,
+ const DSGraph &Graph, unsigned CloneFlags) {
+ ScalarMapTy OldValMap, *ScalarMap;
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;
+ NodeMapTy 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);
+ ReturnNodesTy OldRetNodes;
+ cloneInto(Graph, OldValMap, OldRetNodes, OldNodeMap, CloneFlags);
+
+ // We need to map the arguments for the function to the cloned nodes old
+ // argument values. Do this now.
+ RetVal = OldRetNodes[&F];
ScalarMap = &OldValMap;
} else {
- RetVal = getRetNode();
+ RetVal = getReturnNodeFor(F);
ScalarMap = &getScalarMap();
}
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 (!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;
+/// getCallSiteForArguments - Get the arguments and return value bindings for
+/// the specified function in the current graph.
+///
+DSCallSite DSGraph::getCallSiteForArguments(Function &F) const {
+ std::vector<DSNodeHandle> Args;
+
+ for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I)
+ if (isPointerType(I->getType()))
+ Args.push_back(getScalarMap().find(I)->second);
+
+ return DSCallSite(*(CallInst*)0, getReturnNodeFor(F), &F, Args);
}
-#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
-// of the nodes it can reach imcomplete if the node itself is incomplete, we
+// of the nodes it can reach incomplete 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;
+ if (N == 0 || N->isIncomplete()) return;
// Actually mark the node
- N->NodeType |= DSNode::Incomplete;
+ N->setIncompleteMarker();
// Recusively process children...
for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
//
void DSGraph::markIncompleteNodes(unsigned Flags) {
// Mark any incoming arguments as incomplete...
- if ((Flags & DSGraph::MarkFormalArgs) && Func)
- 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());
+ if (Flags & DSGraph::MarkFormalArgs)
+ for (ReturnNodesTy::iterator FI = ReturnNodes.begin(), E =ReturnNodes.end();
+ FI != E; ++FI) {
+ Function &F = *FI->first;
+ if (F.getName() != "main")
+ for (Function::aiterator I = F.abegin(), E = F.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())
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,
- hash_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]->isGlobalNode() && 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->NodeType & ~DSNode::Incomplete) == 0 && // No interesting info?
+ if (N->getNumReferrers() == 1) // Does it point to a lonely node?
+ // No interesting info?
+ if ((N->getNodeFlags() & ~DSNode::Incomplete) == 0 &&
N->getType() == Type::VoidTy && !N->isNodeCompletelyFolded())
Edge.setNode(0); // Kill the edge!
}
return false;
}
-static void removeIdenticalCalls(std::vector<DSCallSite> &Calls,
- const std::string &where) {
+static void removeIdenticalCalls(std::vector<DSCallSite> &Calls) {
+
// 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;
+ 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()->getNodeFlags() == 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 1
if (LastCalleeContainsExternalFunction ||
// This should be more than enough context sensitivity!
// FIXME: Evaluate how many times this is tripped!
else if (CS.getNumPtrArgs() > OCS.getNumPtrArgs())
OCS = CS;
}
+#endif
} else {
- LastCalleeNode = CS.getCallee().getNode();
+ if (CS.isDirectCall()) {
+ LastCalleeFunc = CS.getCalleeFunc();
+ LastCalleeNode = 0;
+ } else {
+ LastCalleeNode = CS.getCalleeNode();
+ LastCalleeFunc = 0;
+ }
NumDuplicateCalls = 0;
}
}
NumCallNodesMerged += NumFns-Calls.size();
DEBUG(if (NumFns != Calls.size())
- std::cerr << "Merged " << (NumFns-Calls.size())
- << " call nodes in " << where << "\n";);
+ std::cerr << "Merged " << (NumFns-Calls.size()) << " call nodes.\n";);
}
// we don't have to perform any non-trivial analysis here.
//
void DSGraph::removeTriviallyDeadNodes() {
- removeIdenticalCalls(FunctionCalls, Func ? Func->getName() : "");
- removeIdenticalCalls(AuxFunctionCalls, Func ? Func->getName() : "");
+ removeIdenticalCalls(FunctionCalls);
+ removeIdenticalCalls(AuxFunctionCalls);
- 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...
+ bool isGlobalsGraph = !GlobalsGraph;
+
+ for (unsigned i = 0; i != Nodes.size(); ++i) {
+ DSNode *Node = Nodes[i];
+
+ // Do not remove *any* global nodes in the globals graph.
+ // This is a special case because such nodes may not have I, M, R flags set.
+ if (Node->isGlobalNode() && isGlobalsGraph)
+ continue;
+
+ if (Node->isComplete() && !Node->isModified() && !Node->isRead()) {
+ // 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()) {
+ const 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 truly dead.
+ if (Node->getNumReferrers() == Globals.size()) {
+ for (unsigned j = 0, e = Globals.size(); j != e; ++j)
+ ScalarMap.erase(Globals[j]);
+ Node->makeNodeDead();
+ }
+ }
+
+#ifdef SANER_CODE_FOR_CHECKING_IF_ALL_REFERRERS_ARE_FROM_SCALARMAP
+ //
+ // *** It seems to me that we should be able to simply check if
+ // *** there are fewer or equal #referrers as #globals and make
+ // *** sure that all those referrers are in the scalar map?
+ //
+ if (Node->getNumReferrers() <= Node->getGlobals().size()) {
+ const std::vector<GlobalValue*> &Globals = Node->getGlobals();
+
+#ifndef NDEBUG
+ // 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!");
+ }
+#endif
+
+ // Make sure NumReferrers still agrees. The node is truly dead.
+ assert(Node->getNumReferrers() == Globals.size());
+ for (unsigned j = 0, e = Globals.size(); j != e; ++j)
+ ScalarMap.erase(Globals[j]);
+ Node->makeNodeDead();
+ }
+#endif
}
+
+ if (Node->getNodeFlags() == 0 && Node->hasNoReferrers()) {
+ // This node is dead!
+ delete Node; // Free memory...
+ Nodes[i--] = Nodes.back();
+ Nodes.pop_back(); // Remove from node list...
+ }
+ }
}
///
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
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, hash_set<DSNode*> &Alive,
- hash_set<DSNode*> &Visited) {
+static bool CanReachAliveNodes(DSNode *N, hash_set<DSNode*> &Alive,
+ hash_set<DSNode*> &Visited,
+ bool IgnoreGlobals) {
if (N == 0) return false;
+ assert(N->getForwardNode() == 0 && "Cannot mark a forwarded node!");
+
+ // If this is a global node, it will end up in the globals graph anyway, so we
+ // don't need to worry about it.
+ if (IgnoreGlobals && N->isGlobalNode()) return false;
// 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
- // No recursion, insert into Visited...
- Visited.insert(N);
-
- if (N->NodeType & DSNode::GlobalNode)
- return false; // Global nodes will be marked on their own
-
- bool ChildrenAreAlive = false;
+ 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;
+ if (CanReachAliveNodes(N->getLink(i).getNode(), Alive, Visited,
+ IgnoreGlobals)) {
+ 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 (markAliveIfCanReachAlive(CS.getRetVal().getNode(), Alive, Visited) ||
- markAliveIfCanReachAlive(CS.getCallee().getNode(), Alive, Visited))
+ hash_set<DSNode*> &Visited,
+ bool IgnoreGlobals) {
+ if (CanReachAliveNodes(CS.getRetVal().getNode(), Alive, Visited,
+ IgnoreGlobals))
return true;
- for (unsigned j = 0, e = CS.getNumPtrArgs(); j != e; ++j)
- if (markAliveIfCanReachAlive(CS.getPtrArg(j).getNode(), Alive, Visited))
+ if (CS.isIndirectCall() &&
+ CanReachAliveNodes(CS.getCalleeNode(), Alive, Visited, IgnoreGlobals))
+ return true;
+ for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i)
+ if (CanReachAliveNodes(CS.getPtrArg(i).getNode(), Alive, Visited,
+ IgnoreGlobals))
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...
-//
-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;
-}
-
// 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
// inlining graphs.
//
void DSGraph::removeDeadNodes(unsigned Flags) {
- // Reduce the amount of work we have to do...
+ DEBUG(AssertGraphOK(); GlobalsGraph->AssertGraphOK());
+
+ // Reduce the amount of work we have to do... remove dummy nodes left over by
+ // merging...
removeTriviallyDeadNodes();
// FIXME: Merge nontrivially identical call nodes...
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; ++I)
- if (!isa<GlobalValue>(I->first) ||
- GlobalIsAlivenessRoot(I->second.getNode(), Flags))
- I->second.getNode()->markReachableNodes(Alive);
- else // Keep track of global nodes
+ for (ScalarMapTy::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?");
+ assert(I->second.getNode()->isGlobalNode() && "Should be a 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->getNodeFlags() == 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);
+ for (ReturnNodesTy::iterator I = ReturnNodes.begin(), E = ReturnNodes.end();
+ I != E; ++I)
+ I->second.getNode()->markReachableNodes(Alive);
- // If any global nodes points to a non-global that is "alive", the global is
- // "alive" as well...
- //
- hash_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;
- }
+ FunctionCalls[i].markReachableNodes(Alive);
- 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;
- }
+ // Copy and merge all information about globals to the GlobalsGraph
+ // if this is not a final pass (where unreachable globals are removed)
+ NodeMapTy GlobalNodeMap;
+ hash_set<const DSNode*> GlobalNodeSet;
- // 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 (std::vector<std::pair<Value*, DSNode*> >::const_iterator
+ I = GlobalNodes.begin(), E = GlobalNodes.end(); I != E; ++I)
+ GlobalNodeSet.insert(I->second); // put global nodes into a set
- // Remove all dead aux function calls...
- CurIdx = 0;
+ // Now find globals and aux call nodes that are already live or reach a live
+ // value (which makes them live in turn), and continue till no more are found.
+ //
+ bool Iterate;
+ hash_set<DSNode*> Visited;
+ std::vector<unsigned char> AuxFCallsAlive(AuxFunctionCalls.size());
+ do {
+ Visited.clear();
+ // If any global node 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;
+ if (!(Flags & DSGraph::RemoveUnreachableGlobals))
+ for (unsigned i = 0; i != GlobalNodes.size(); ++i)
+ if (CanReachAliveNodes(GlobalNodes[i].second, Alive, Visited,
+ Flags & DSGraph::RemoveUnreachableGlobals)) {
+ std::swap(GlobalNodes[i--], GlobalNodes.back()); // Move to end to...
+ GlobalNodes.pop_back(); // erase efficiently
+ Iterate = true;
+ }
+
+ // Mark only unresolvable call nodes for moving to the GlobalsGraph since
+ // call nodes that get resolved will be difficult to remove from that graph.
+ // The final unresolved call nodes must be handled specially at the end of
+ // the BU pass (i.e., in main or other roots of the call graph).
+ for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
+ if (!AuxFCallsAlive[i] &&
+ (AuxFunctionCalls[i].isIndirectCall()
+ || CallSiteUsesAliveArgs(AuxFunctionCalls[i], Alive, Visited,
+ Flags & DSGraph::RemoveUnreachableGlobals))) {
+ AuxFunctionCalls[i].markReachableNodes(Alive);
+ AuxFCallsAlive[i] = true;
+ Iterate = true;
+ }
+ } while (Iterate);
+
+ // Move dead aux function calls to the end of the list
+ 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...
+
+ // Copy and merge all global nodes and dead aux call nodes into the
+ // GlobalsGraph, and all nodes reachable from those nodes
+ //
+ if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
+
+ // First, add the dead aux call nodes to the set of root nodes for cloning
+ // -- return value at this call site, if any
+ // -- actual arguments passed at this call site
+ // -- callee node at this call site, if this is an indirect call
+ for (unsigned i = CurIdx, e = AuxFunctionCalls.size(); i != e; ++i) {
+ if (const DSNode* RetNode = AuxFunctionCalls[i].getRetVal().getNode())
+ GlobalNodeSet.insert(RetNode);
+ for (unsigned j=0, N=AuxFunctionCalls[i].getNumPtrArgs(); j < N; ++j)
+ if (const DSNode* ArgTarget=AuxFunctionCalls[i].getPtrArg(j).getNode())
+ GlobalNodeSet.insert(ArgTarget);
+ if (AuxFunctionCalls[i].isIndirectCall())
+ GlobalNodeSet.insert(AuxFunctionCalls[i].getCalleeNode());
+ }
+
+ // There are no "pre-completed" nodes so use any empty map for those.
+ // Strip all alloca bits since the current function is only for the BU pass.
+ // Strip all incomplete bits since they are short-lived properties and they
+ // will be correctly computed when rematerializing nodes into the functions.
+ //
+ NodeMapTy CompletedMap;
+ GlobalsGraph->cloneReachableSubgraph(*this, GlobalNodeSet,
+ GlobalNodeMap, CompletedMap,
+ (DSGraph::StripAllocaBit |
+ DSGraph::StripIncompleteBit));
+ }
+
+ // Remove all dead aux function calls...
+ if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
+ assert(GlobalsGraph && "No globals graph available??");
+
+ // Copy the unreachable call nodes to the globals graph, updating
+ // their target pointers using the GlobalNodeMap
+ for (unsigned i = CurIdx, e = AuxFunctionCalls.size(); i != e; ++i)
+ GlobalsGraph->AuxFunctionCalls.push_back(DSCallSite(AuxFunctionCalls[i],
+ GlobalNodeMap));
+ }
+ // Crop all the useless ones out...
AuxFunctionCalls.erase(AuxFunctionCalls.begin()+CurIdx,
AuxFunctionCalls.end());
+ // We are finally done with the GlobalNodeMap so we can clear it and
+ // then get rid of unused nodes in the GlobalsGraph produced by merging.
+ GlobalNodeMap.clear();
+ GlobalsGraph->removeTriviallyDeadNodes();
- // 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 can be removed. Loop over all nodes, eliminating completely
+ // unreachable nodes.
+ //
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
- }
-
- // 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,
- hash_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.
- //
- 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
+ Nodes[i--] = Nodes.back(); // move node to end of vector
+ Nodes.pop_back(); // Erase node from alive list.
+ DeadNodes.push_back(N);
+ N->dropAllReferences();
+ } else {
+ assert(Nodes[i]->getForwardNode() == 0 && "Alive forwarded node?");
}
- // 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);
- }
+ // Remove all unreachable globals from the ScalarMap.
+ // If flag RemoveUnreachableGlobals is set, GlobalNodes has only dead nodes.
+ // In either case, the dead nodes will not be in the set Alive.
+ for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i) {
+ assert(((Flags & DSGraph::RemoveUnreachableGlobals) ||
+ !Alive.count(GlobalNodes[i].second)) && "huh? non-dead global");
+ if (!Alive.count(GlobalNodes[i].second))
+ ScalarMap.erase(GlobalNodes[i].first);
}
- // Remove all local markers
- NewNode->NodeType &= ~(DSNode::AllocaNode | DSNode::ScalarNode);
+ // Delete all dead nodes now since their referrer counts are 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) {
- hash_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();
+
+ for (ScalarMapTy::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()->isGlobalNode() &&
+ "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