#include "llvm/Target/TargetData.h"
#include "Support/STLExtras.h"
#include "Support/Statistic.h"
+#include "Support/Timer.h"
#include <algorithm>
-#include <set>
-using std::vector;
+namespace {
+ Statistic<> NumFolds ("dsnode", "Number of nodes completely folded");
+ Statistic<> NumCallNodesMerged("dsnode", "Number of call nodes merged");
+};
-// TODO: FIXME
-namespace DataStructureAnalysis {
- // isPointerType - Return true if this first class type is big enough to hold
- // a pointer.
- //
- bool isPointerType(const Type *Ty);
+namespace DS { // TODO: FIXME
extern TargetData TD;
}
-using namespace DataStructureAnalysis;
-
-//===----------------------------------------------------------------------===//
-// DSNode Implementation
-//===----------------------------------------------------------------------===//
+using namespace DS;
-DSNode::DSNode(enum NodeTy NT, const Type *T) : NodeType(NT) {
- // If this node is big enough to have pointer fields, add space for them now.
- if (T != Type::VoidTy && !isa<FunctionType>(T)) { // Avoid TargetData assert's
- MergeMap.resize(TD.getTypeSize(T));
+DSNode *DSNodeHandle::HandleForwarding() const {
+ assert(!N->ForwardNH.isNull() && "Can only be invoked if forwarding!");
- // Assign unique values to all of the elements of MergeMap
- if (MergeMap.size() < 128) {
- // Handle the common case of reasonable size structures...
- for (unsigned i = 0, e = MergeMap.size(); i != e; ++i)
- MergeMap[i] = -1-i; // Assign -1, -2, -3, ...
- } else {
- // It's possible that we have something really big here. In this case,
- // divide the object into chunks until it will fit into 128 elements.
- unsigned Multiple = MergeMap.size()/128;
-
- // It's probably an array, and probably some power of two in size.
- // Because of this, find the biggest power of two that is bigger than
- // multiple to use as our real Multiple.
- unsigned RealMultiple = 2;
- while (RealMultiple <= Multiple) RealMultiple <<= 1;
+ // Handle node forwarding here!
+ DSNode *Next = N->ForwardNH.getNode(); // Cause recursive shrinkage
+ Offset += N->ForwardNH.getOffset();
- unsigned RealBound = MergeMap.size()/RealMultiple;
- assert(RealBound <= 128 && "Math didn't work out right");
+ if (--N->NumReferrers == 0) {
+ // Removing the last referrer to the node, sever the forwarding link
+ N->stopForwarding();
+ }
- // Now go through and assign indexes that are between -1 and -128
- // inclusive
- //
- for (unsigned i = 0, e = MergeMap.size(); i != e; ++i)
- MergeMap[i] = -1-(i % RealBound); // Assign -1, -2, -3...
- }
+ 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
+//===----------------------------------------------------------------------===//
- TypeEntries.push_back(TypeRec(T, 0));
+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), MergeMap(N.MergeMap),
- TypeEntries(N.TypeEntries), Globals(N.Globals), 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).
- 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!");
+}
+
+/// 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
//
void DSNode::addGlobal(GlobalValue *GV) {
// Keep the list sorted.
- vector<GlobalValue*>::iterator I =
+ std::vector<GlobalValue*>::iterator I =
std::lower_bound(Globals.begin(), Globals.end(), GV);
if (I == Globals.end() || *I != GV) {
}
}
+/// foldNodeCompletely - If we determine that this node has some funny
+/// behavior happening to it that we cannot represent, we fold it down to a
+/// single, completely pessimistic, node. This node is represented as a
+/// single byte with a single TypeEntry of "void".
+///
+void DSNode::foldNodeCompletely() {
+ assert(!hasNoReferrers() &&
+ "Why would we collapse a node with no referrers?");
+ if (isNodeCompletelyFolded()) return; // If this node is already folded...
+
+ ++NumFolds;
+
+ // Create the node we are going to forward to...
+ DSNode *DestNode = new DSNode(NodeType|DSNode::Array, 0, ParentGraph);
+ DestNode->Ty = Type::VoidTy;
+ DestNode->Size = 1;
+ DestNode->Globals.swap(Globals);
+
+ // 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
+/// folded down to something that can never be expanded, effectively losing
+/// all of the field sensitivity that may be present in the node.
+///
+bool DSNode::isNodeCompletelyFolded() const {
+ return getSize() == 1 && Ty == Type::VoidTy && isArray();
+}
-/// setLink - Set the link at the specified offset to the specified
-/// NodeHandle, replacing what was there. It is uncommon to use this method,
-/// instead one of the higher level methods should be used, below.
+
+/// mergeTypeInfo - This method merges the specified type into the current node
+/// at the specified offset. This may update the current node's type record if
+/// this gives more information to the node, it may do nothing to the node if
+/// this information is already known, or it may merge the node completely (and
+/// return true) if the information is incompatible with what is already known.
+///
+/// This method returns true if the node is completely folded, otherwise false.
///
-void DSNode::setLink(unsigned i, const DSNodeHandle &NH) {
- // Create a new entry in the Links vector to hold a new element for offset.
- if (!hasLink(i)) {
- signed char NewIdx = Links.size();
- // Check to see if we allocate more than 128 distinct links for this node.
- // If so, just merge with the last one. This really shouldn't ever happen,
- // but it should work regardless of whether it does or not.
+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.
+ // Size = 0, Ty = FnTy: FunctionPtr doesn't have a size, so we use zero
+ // Size = 1, Ty = Void, Array = 1: The node is collapsed
+ // Otherwise, sizeof(Ty) = Size
+ //
+ assert(((Size == 0 && Ty == Type::VoidTy && !isArray()) ||
+ (Size == 0 && !Ty->isSized() && !isArray()) ||
+ (Size == 1 && Ty == Type::VoidTy && isArray()) ||
+ (Size == 0 && !Ty->isSized() && !isArray()) ||
+ (TD.getTypeSize(Ty) == Size)) &&
+ "Size member of DSNode doesn't match the type structure!");
+ assert(NewTy != Type::VoidTy && "Cannot merge void type into DSNode!");
+
+ if (Offset == 0 && NewTy == Ty)
+ return false; // This should be a common case, handle it efficiently
+
+ // Return true immediately if the node is completely folded.
+ if (isNodeCompletelyFolded()) return true;
+
+ // If this is an array type, eliminate the outside arrays because they won't
+ // be used anyway. This greatly reduces the size of large static arrays used
+ // as global variables, for example.
+ //
+ bool WillBeArray = false;
+ while (const ArrayType *AT = dyn_cast<ArrayType>(NewTy)) {
+ // FIXME: we might want to keep small arrays, but must be careful about
+ // things like: [2 x [10000 x int*]]
+ NewTy = AT->getElementType();
+ WillBeArray = true;
+ }
+
+ // Figure out how big the new type we're merging in is...
+ unsigned NewTySize = NewTy->isSized() ? TD.getTypeSize(NewTy) : 0;
+
+ // Otherwise check to see if we can fold this type into the current node. If
+ // we can't, we fold the node completely, if we can, we potentially update our
+ // internal state.
+ //
+ if (Ty == Type::VoidTy) {
+ // If this is the first type that this node has seen, just accept it without
+ // question....
+ assert(Offset == 0 && "Cannot have an offset into a void node!");
+ assert(!isArray() && "This shouldn't happen!");
+ Ty = NewTy;
+ NodeType &= ~Array;
+ if (WillBeArray) NodeType |= Array;
+ Size = NewTySize;
+
+ // Calculate the number of outgoing links from this node.
+ Links.resize((Size+DS::PointerSize-1) >> DS::PointerShift);
+ return false;
+ }
+
+ // Handle node expansion case here...
+ if (Offset+NewTySize > Size) {
+ // It is illegal to grow this node if we have treated it as an array of
+ // objects...
+ if (isArray()) {
+ 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");
+ if (FoldIfIncompatible) foldNodeCompletely();
+ return true;
+ }
+
+ // Okay, the situation is nice and simple, we are trying to merge a type in
+ // at offset 0 that is bigger than our current type. Implement this by
+ // switching to the new type and then merge in the smaller one, which should
+ // hit the other code path here. If the other code path decides it's not
+ // ok, it will collapse the node as appropriate.
//
- if (NewIdx >= 0) {
- Links.push_back(NH); // Allocate space: common case
- } else { // Wrap around? Too many links?
- NewIdx--; // Merge with whatever happened last
- assert(NewIdx > 0 && "Should wrap back around");
- std::cerr << "\n*** DSNode found that requires more than 128 "
- << "active links at once!\n\n";
- }
-
- signed char OldIdx = MergeMap[i];
- assert (OldIdx < 0 && "Shouldn't contain link!");
-
- // Make sure that anything aliasing this field gets updated to point to the
- // new link field.
- rewriteMergeMap(OldIdx, NewIdx);
- assert(MergeMap[i] == NewIdx && "Field not replaced!");
- } else {
- Links[MergeMap[i]] = NH;
+ const Type *OldTy = Ty;
+ Ty = NewTy;
+ NodeType &= ~Array;
+ if (WillBeArray) NodeType |= Array;
+ Size = NewTySize;
+
+ // Must grow links to be the appropriate size...
+ Links.resize((Size+DS::PointerSize-1) >> DS::PointerShift);
+
+ // Merge in the old type now... which is guaranteed to be smaller than the
+ // "current" type.
+ return mergeTypeInfo(OldTy, 0);
+ }
+
+ assert(Offset <= Size &&
+ "Cannot merge something into a part of our type that doesn't exist!");
+
+ // Find the section of Ty that NewTy overlaps with... first we find the
+ // type that starts at offset Offset.
+ //
+ unsigned O = 0;
+ const Type *SubType = Ty;
+ while (O < Offset) {
+ assert(Offset-O < TD.getTypeSize(SubType) && "Offset out of range!");
+
+ switch (SubType->getPrimitiveID()) {
+ case Type::StructTyID: {
+ const StructType *STy = cast<StructType>(SubType);
+ const StructLayout &SL = *TD.getStructLayout(STy);
+
+ unsigned i = 0, e = SL.MemberOffsets.size();
+ for (; i+1 < e && SL.MemberOffsets[i+1] <= Offset-O; ++i)
+ /* empty */;
+
+ // The offset we are looking for must be in the i'th element...
+ SubType = STy->getElementTypes()[i];
+ O += SL.MemberOffsets[i];
+ break;
+ }
+ case Type::ArrayTyID: {
+ SubType = cast<ArrayType>(SubType)->getElementType();
+ unsigned ElSize = TD.getTypeSize(SubType);
+ unsigned Remainder = (Offset-O) % ElSize;
+ O = Offset-Remainder;
+ break;
+ }
+ default:
+ if (FoldIfIncompatible) foldNodeCompletely();
+ return true;
+ }
+ }
+
+ assert(O == Offset && "Could not achieve the correct offset!");
+
+ // If we found our type exactly, early exit
+ if (SubType == NewTy) return false;
+
+ // Okay, so we found the leader type at the offset requested. Search the list
+ // of types that starts at this offset. If SubType is currently an array or
+ // structure, the type desired may actually be the first element of the
+ // composite type...
+ //
+ unsigned SubTypeSize = SubType->isSized() ? TD.getTypeSize(SubType) : 0;
+ unsigned PadSize = SubTypeSize; // Size, including pad memory which is ignored
+ while (SubType != NewTy) {
+ const Type *NextSubType = 0;
+ unsigned NextSubTypeSize = 0;
+ unsigned NextPadSize = 0;
+ switch (SubType->getPrimitiveID()) {
+ case Type::StructTyID: {
+ const StructType *STy = cast<StructType>(SubType);
+ const StructLayout &SL = *TD.getStructLayout(STy);
+ if (SL.MemberOffsets.size() > 1)
+ NextPadSize = SL.MemberOffsets[1];
+ else
+ NextPadSize = SubTypeSize;
+ NextSubType = STy->getElementTypes()[0];
+ NextSubTypeSize = TD.getTypeSize(NextSubType);
+ break;
+ }
+ case Type::ArrayTyID:
+ NextSubType = cast<ArrayType>(SubType)->getElementType();
+ NextSubTypeSize = TD.getTypeSize(NextSubType);
+ NextPadSize = NextSubTypeSize;
+ break;
+ default: ;
+ // fall out
+ }
+
+ if (NextSubType == 0)
+ break; // In the default case, break out of the loop
+
+ if (NextPadSize < NewTySize)
+ break; // Don't allow shrinking to a smaller type than NewTySize
+ SubType = NextSubType;
+ SubTypeSize = NextSubTypeSize;
+ PadSize = NextPadSize;
+ }
+
+ // If we found the type exactly, return it...
+ if (SubType == NewTy)
+ return false;
+
+ // Check to see if we have a compatible, but different type...
+ if (NewTySize == SubTypeSize) {
+ // Check to see if this type is obviously convertable... int -> uint f.e.
+ if (NewTy->isLosslesslyConvertableTo(SubType))
+ return false;
+
+ // Check to see if we have a pointer & integer mismatch going on here,
+ // loading a pointer as a long, for example.
+ //
+ if (SubType->isInteger() && isa<PointerType>(NewTy) ||
+ NewTy->isInteger() && isa<PointerType>(SubType))
+ return false;
+ } else if (NewTySize > SubTypeSize && NewTySize <= PadSize) {
+ // We are accessing the field, plus some structure padding. Ignore the
+ // structure padding.
+ return false;
}
+
+
+ DEBUG(std::cerr << "MergeTypeInfo Folding OrigTy: " << Ty
+ << "\n due to:" << NewTy << " @ " << Offset << "!\n"
+ << "SubType: " << SubType << "\n\n");
+
+ if (FoldIfIncompatible) foldNodeCompletely();
+ return true;
}
+
+
// addEdgeTo - Add an edge from the current node to the specified node. This
// can cause merging of nodes in the graph.
//
void DSNode::addEdgeTo(unsigned Offset, const DSNodeHandle &NH) {
- assert(Offset < getSize() && "Offset out of range!");
if (NH.getNode() == 0) return; // Nothing to do
- if (DSNodeHandle *ExistingNH = getLink(Offset)) {
+ DSNodeHandle &ExistingEdge = getLink(Offset);
+ if (ExistingEdge.getNode()) {
// Merge the two nodes...
- ExistingNH->mergeWith(NH);
+ ExistingEdge.mergeWith(NH);
} else { // No merging to perform...
setLink(Offset, NH); // Just force a link in there...
}
}
-/// mergeMappedValues - This is the higher level form of rewriteMergeMap. It is
-/// fully capable of merging links together if neccesary as well as simply
-/// rewriting the map entries.
-///
-void DSNode::mergeMappedValues(signed char V1, signed char V2) {
- assert(V1 != V2 && "Cannot merge two identical mapped values!");
-
- if (V1 < 0) { // If there is no outgoing link from V1, merge it with V2
- if (V2 < 0 && V1 > V2)
- // If both are not linked, merge to the field closer to 0
- rewriteMergeMap(V2, V1);
- else
- rewriteMergeMap(V1, V2);
- } else if (V2 < 0) { // Is V2 < 0 && V1 >= 0?
- rewriteMergeMap(V2, V1); // Merge into the one with the link...
- } else { // Otherwise, links exist at both locations
- // Merge Links[V1] with Links[V2] so they point to the same place now...
- Links[V1].mergeWith(Links[V2]);
-
- // Merge the V2 link into V1 so that we reduce the overall value of the
- // links are reduced...
- //
- if (V2 < V1) std::swap(V1, V2); // Ensure V1 < V2
- rewriteMergeMap(V2, V1); // After this, V2 is "dead"
-
- // Change the user of the last link to use V2 instead
- if ((unsigned)V2 != Links.size()-1) {
- rewriteMergeMap(Links.size()-1, V2); // Point to V2 instead of last el...
- // Make sure V2 points the right DSNode
- Links[V2] = Links.back();
- }
-
- // Reduce the number of distinct outgoing links...
- Links.pop_back();
- }
-}
-
// MergeSortedVectors - Efficiently merge a vector into another vector where
// duplicates are not allowed and both are sorted. This assumes that 'T's are
// efficiently copyable and have sane comparison semantics.
//
-template<typename T>
-void MergeSortedVectors(vector<T> &Dest, const vector<T> &Src) {
+static void MergeSortedVectors(std::vector<GlobalValue*> &Dest,
+ const std::vector<GlobalValue*> &Src) {
// By far, the most common cases will be the simple ones. In these cases,
// avoid having to allocate a temporary vector...
//
} else if (Dest.empty()) { // Just copy the result in...
Dest = Src;
} else if (Src.size() == 1) { // Insert a single element...
- const T &V = Src[0];
- typename vector<T>::iterator I =
+ const GlobalValue *V = Src[0];
+ std::vector<GlobalValue*>::iterator I =
std::lower_bound(Dest.begin(), Dest.end(), V);
if (I == Dest.end() || *I != Src[0]) // If not already contained...
Dest.insert(I, Src[0]);
} else if (Dest.size() == 1) {
- T Tmp = Dest[0]; // Save value in temporary...
+ GlobalValue *Tmp = Dest[0]; // Save value in temporary...
Dest = Src; // Copy over list...
- typename vector<T>::iterator I =
- std::lower_bound(Dest.begin(), Dest.end(),Tmp);
- if (I == Dest.end() || *I != Src[0]) // If not already contained...
- Dest.insert(I, Src[0]);
+ std::vector<GlobalValue*>::iterator I =
+ std::lower_bound(Dest.begin(), Dest.end(), Tmp);
+ if (I == Dest.end() || *I != Tmp) // If not already contained...
+ Dest.insert(I, Tmp);
} else {
// Make a copy to the side of Dest...
- vector<T> Old(Dest);
+ std::vector<GlobalValue*> Old(Dest);
// Make space for all of the type entries now...
Dest.resize(Dest.size()+Src.size());
}
-// mergeWith - Merge this node and the specified node, moving all links to and
-// from the argument node into the current node, deleting the node argument.
-// Offset indicates what offset the specified node is to be merged into the
-// current node.
-//
-// The specified node may be a null pointer (in which case, nothing happens).
+// MergeNodes() - Helper function for DSNode::mergeWith().
+// This function does the hard work of merging two nodes, CurNodeH
+// and NH after filtering out trivial cases and making sure that
+// CurNodeH.offset >= NH.offset.
+//
+// ***WARNING***
+// Since merging may cause either node to go away, we must always
+// use the node-handles to refer to the nodes. These node handles are
+// automatically updated during merging, so will always provide access
+// to the correct node after a merge.
//
-void DSNode::mergeWith(const DSNodeHandle &NH, unsigned Offset) {
- DSNode *N = NH.getNode();
- if (N == 0 || (N == this && NH.getOffset() == Offset))
- return; // Noop
+void DSNode::MergeNodes(DSNodeHandle& CurNodeH, DSNodeHandle& NH) {
+ assert(CurNodeH.getOffset() >= NH.getOffset() &&
+ "This should have been enforced in the caller.");
- assert(NH.getNode() != this &&
- "Cannot merge two portions of the same node yet!");
-
- // If both nodes are not at offset 0, make sure that we are merging the node
- // at an later offset into the node with the zero offset.
+ // Now we know that Offset >= NH.Offset, so convert it so our "Offset" (with
+ // respect to NH.Offset) is now zero. NOffset is the distance from the base
+ // of our object that N starts from.
//
- if (Offset > NH.getOffset()) {
- N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
- return;
- }
+ unsigned NOffset = CurNodeH.getOffset()-NH.getOffset();
+ unsigned NSize = NH.getNode()->getSize();
-#if 0
- std::cerr << "\n\nMerging:\n";
- N->print(std::cerr, 0);
- std::cerr << " and:\n";
- print(std::cerr, 0);
-#endif
+ // Merge the type entries of the two nodes together...
+ if (NH.getNode()->Ty != Type::VoidTy)
+ CurNodeH.getNode()->mergeTypeInfo(NH.getNode()->Ty, NOffset);
+ assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
- // Now we know that Offset <= NH.Offset, so convert it so our "Offset" (with
- // respect to NH.Offset) is now zero.
+ // If we are merging a node with a completely folded node, then both nodes are
+ // now completely folded.
//
- unsigned NOffset = NH.getOffset()-Offset;
+ if (CurNodeH.getNode()->isNodeCompletelyFolded()) {
+ if (!NH.getNode()->isNodeCompletelyFolded()) {
+ NH.getNode()->foldNodeCompletely();
+ assert(NH.getNode() && NH.getOffset() == 0 &&
+ "folding did not make offset 0?");
+ NOffset = NH.getOffset();
+ NSize = NH.getNode()->getSize();
+ assert(NOffset == 0 && NSize == 1);
+ }
+ } else if (NH.getNode()->isNodeCompletelyFolded()) {
+ CurNodeH.getNode()->foldNodeCompletely();
+ assert(CurNodeH.getNode() && CurNodeH.getOffset() == 0 &&
+ "folding did not make offset 0?");
+ NOffset = NH.getOffset();
+ NSize = NH.getNode()->getSize();
+ assert(NOffset == 0 && NSize == 1);
+ }
- unsigned NSize = N->getSize();
- assert(NSize+NOffset <= getSize() &&
- "Don't know how to merge extend a merged nodes size yet!");
+ 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.
- //
- while (!N->Referrers.empty()) {
- DSNodeHandle &Ref = *N->Referrers.back();
- Ref = DSNodeHandle(this, NOffset+Ref.getOffset());
- }
+ // Start forwarding to the new node!
+ CurNodeH.getNode()->NodeType |= N->NodeType;
+ N->forwardNode(CurNodeH.getNode(), NOffset);
+ assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
- // We must merge fields in this node due to nodes merged in the source node.
- // In order to handle this we build a map that converts from the source node's
- // MergeMap values to our MergeMap values. This map is indexed by the
- // expression: MergeMap[SMM+SourceNodeSize] so we need to allocate at least
- // 2*SourceNodeSize elements of space for the mapping. We can do this because
- // we know that there are at most SourceNodeSize outgoing links in the node
- // (thus that many positive values) and at most SourceNodeSize distinct fields
- // (thus that many negative values).
+ // Make all of the outgoing links of N now be outgoing links of CurNodeH.
//
- std::vector<signed char> MergeMapMap(NSize*2, 127);
-
- // Loop through the structures, merging them together...
- for (unsigned i = 0, e = NSize; i != e; ++i) {
- // Get what this byte of N maps to...
- signed char NElement = N->MergeMap[i];
-
- // Get what we map this byte to...
- signed char Element = MergeMap[i+NOffset];
- // We use 127 as a sentinal and don't check for it's existence yet...
- assert(Element != 127 && "MergeMapMap doesn't permit 127 values yet!");
-
- signed char CurMappedVal = MergeMapMap[NElement+NSize];
- if (CurMappedVal == 127) { // Haven't seen this NElement yet?
- MergeMapMap[NElement+NSize] = Element; // Map the two together...
- } else if (CurMappedVal != Element) {
- // If we are mapping two different fields together this means that we need
- // to merge fields in the current node due to merging in the source node.
- //
- mergeMappedValues(CurMappedVal, Element);
- MergeMapMap[NElement+NSize] = MergeMap[i+NOffset];
+ for (unsigned i = 0; i < N->getNumLinks(); ++i) {
+ DSNodeHandle &Link = N->getLink(i << DS::PointerShift);
+ if (Link.getNode()) {
+ // Compute the offset into the current node at which to
+ // merge this link. In the common case, this is a linear
+ // relation to the offset in the original node (with
+ // wrapping), but if the current node gets collapsed due to
+ // recursive merging, we must make sure to merge in all remaining
+ // links at offset zero.
+ unsigned MergeOffset = 0;
+ DSNode *CN = CurNodeH.getNode();
+ if (CN->Size != 1)
+ MergeOffset = ((i << DS::PointerShift)+NOffset) % CN->getSize();
+ CN->addEdgeTo(MergeOffset, Link);
}
}
- // Make all of the outgoing links of N now be outgoing links of this. This
- // can cause recursive merging!
- //
- for (unsigned i = 0, e = NSize; i != e; ++i)
- if (DSNodeHandle *Link = N->getLink(i)) {
- addEdgeTo(i+NOffset, *Link);
- N->MergeMap[i] = -1; // Kill outgoing edge
- }
-
// Now that there are no outgoing edges, all of the Links are dead.
N->Links.clear();
- // Merge the node types
- NodeType |= N->NodeType;
- N->NodeType = 0; // N is now a dead node.
-
- // If this merging into node has more than just void nodes in it, merge!
- assert(!N->TypeEntries.empty() && "TypeEntries is empty for a node?");
- if (N->TypeEntries.size() != 1 || N->TypeEntries[0].Ty != Type::VoidTy) {
- // If the current node just has a Void entry in it, remove it.
- if (TypeEntries.size() == 1 && TypeEntries[0].Ty == Type::VoidTy)
- TypeEntries.clear();
+ // Merge the globals list...
+ if (!N->Globals.empty()) {
+ MergeSortedVectors(CurNodeH.getNode()->Globals, N->Globals);
- // Adjust all of the type entries we are merging in by the offset... and add
- // them to the TypeEntries list.
- //
- if (NOffset != 0) { // This case is common enough to optimize for
- // Offset all of the TypeEntries in N with their new offset
- for (unsigned i = 0, e = N->TypeEntries.size(); i != e; ++i)
- N->TypeEntries[i].Offset += NOffset;
- }
+ // Delete the globals from the old node...
+ std::vector<GlobalValue*>().swap(N->Globals);
+ }
+}
- MergeSortedVectors(TypeEntries, N->TypeEntries);
- N->TypeEntries.clear();
+// mergeWith - Merge this node and the specified node, moving all links to and
+// from the argument node into the current node, deleting the node argument.
+// Offset indicates what offset the specified node is to be merged into the
+// current node.
+//
+// The specified node may be a null pointer (in which case, nothing happens).
+//
+void DSNode::mergeWith(const DSNodeHandle &NH, unsigned Offset) {
+ DSNode *N = NH.getNode();
+ if (N == 0 || (N == this && NH.getOffset() == Offset))
+ return; // Noop
+
+ assert((N->NodeType & DSNode::DEAD) == 0);
+ assert((NodeType & DSNode::DEAD) == 0);
+ assert(!hasNoReferrers() && "Should not try to fold a useless node!");
+
+ if (N == this) {
+ // We cannot merge two pieces of the same node together, collapse the node
+ // completely.
+ DEBUG(std::cerr << "Attempting to merge two chunks of"
+ << " the same node together!\n");
+ foldNodeCompletely();
+ return;
}
- // Merge the globals list...
- if (!N->Globals.empty()) {
- MergeSortedVectors(Globals, N->Globals);
-
- // Delete the globals from the old node...
- N->Globals.clear();
+ // If both nodes are not at offset 0, make sure that we are merging the node
+ // at an later offset into the node with the zero offset.
+ //
+ if (Offset < NH.getOffset()) {
+ N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
+ return;
+ } else if (Offset == NH.getOffset() && getSize() < N->getSize()) {
+ // If the offsets are the same, merge the smaller node into the bigger node
+ N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
+ return;
}
+
+ // Ok, now we can merge the two nodes. Use a static helper that works with
+ // two node handles, since "this" may get merged away at intermediate steps.
+ DSNodeHandle CurNodeH(this, Offset);
+ DSNodeHandle NHCopy(NH);
+ DSNode::MergeNodes(CurNodeH, NHCopy);
}
//===----------------------------------------------------------------------===//
// DSGraph Implementation
//===----------------------------------------------------------------------===//
-DSGraph::DSGraph(const DSGraph &G) : Func(G.Func) {
- std::map<const DSNode*, DSNode*> NodeMap;
- RetNode = cloneInto(G, ValueMap, NodeMap);
+DSGraph::DSGraph(const DSGraph &G) : Func(G.Func), GlobalsGraph(0) {
+ PrintAuxCalls = false;
+ hash_map<const DSNode*, DSNodeHandle> NodeMap;
+ RetNode = cloneInto(G, ScalarMap, NodeMap);
}
-DSGraph::DSGraph(const DSGraph &G, std::map<const DSNode*, DSNode*> &NodeMap)
- : Func(G.Func) {
- RetNode = cloneInto(G, ValueMap, NodeMap);
+DSGraph::DSGraph(const DSGraph &G,
+ hash_map<const DSNode*, DSNodeHandle> &NodeMap)
+ : Func(G.Func), GlobalsGraph(0) {
+ PrintAuxCalls = false;
+ RetNode = cloneInto(G, ScalarMap, NodeMap);
}
DSGraph::~DSGraph() {
FunctionCalls.clear();
- ValueMap.clear();
+ AuxFunctionCalls.clear();
+ ScalarMap.clear();
RetNode.setNode(0);
-#ifndef NDEBUG
// Drop all intra-node references, so that assertions don't fail...
std::for_each(Nodes.begin(), Nodes.end(),
std::mem_fun(&DSNode::dropAllReferences));
-#endif
// Delete all of the nodes themselves...
std::for_each(Nodes.begin(), Nodes.end(), deleter<DSNode>);
void DSGraph::dump() const { print(std::cerr); }
-// Helper function used to clone a function list.
-//
-static void CopyFunctionCallsList(const vector<DSCallSite>& fromCalls,
- vector<DSCallSite> &toCalls,
- std::map<const DSNode*, DSNode*> &NodeMap) {
- unsigned FC = toCalls.size(); // FirstCall
- toCalls.reserve(FC+fromCalls.size());
- for (unsigned i = 0, ei = fromCalls.size(); i != ei; ++i)
- toCalls.push_back(DSCallSite(fromCalls[i], NodeMap));
-}
-
/// remapLinks - Change all of the Links in the current node according to the
/// specified mapping.
-void DSNode::remapLinks(std::map<const DSNode*, DSNode*> &OldNodeMap) {
- for (unsigned i = 0, e = Links.size(); i != e; ++i)
- Links[i].setNode(OldNodeMap[Links[i].getNode()]);
+///
+void DSNode::remapLinks(hash_map<const DSNode*, DSNodeHandle> &OldNodeMap) {
+ for (unsigned i = 0, e = Links.size(); i != e; ++i) {
+ DSNodeHandle &H = OldNodeMap[Links[i].getNode()];
+ Links[i].setNode(H.getNode());
+ Links[i].setOffset(Links[i].getOffset()+H.getOffset());
+ }
}
// cloneInto - Clone the specified DSGraph into the current graph, returning the
-// Return node of the graph. The translated ValueMap for the old function is
-// filled into the OldValMap member. If StripLocals is set to true, Scalar and
-// Alloca markers are removed from the graph, as the graph is being cloned into
-// a calling function's graph.
+// 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,
- std::map<Value*, DSNodeHandle> &OldValMap,
- std::map<const DSNode*, DSNode*> &OldNodeMap,
- bool StripScalars, bool StripAllocas,
- bool CopyCallers, bool CopyOrigCalls) {
+ hash_map<Value*, DSNodeHandle> &OldValMap,
+ hash_map<const DSNode*, DSNodeHandle> &OldNodeMap,
+ unsigned CloneFlags) {
assert(OldNodeMap.empty() && "Returned OldNodeMap should be empty!");
+ assert(&G != this && "Cannot clone graph into itself!");
unsigned FN = Nodes.size(); // First new node...
// 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);
- Nodes.push_back(New);
+ DSNode *New = new DSNode(*Old, this);
+ New->NodeType &= ~clearBits;
OldNodeMap[Old] = New;
}
+#ifndef NDEBUG
+ Timer::addPeakMemoryMeasurement();
+#endif
+
// Rewrite the links in the new nodes to point into the current graph now.
for (unsigned i = FN, e = Nodes.size(); i != e; ++i)
Nodes[i]->remapLinks(OldNodeMap);
- // Remove local markers as specified
- unsigned char StripBits = (StripScalars ? DSNode::ScalarNode : 0) |
- (StripAllocas ? DSNode::AllocaNode : 0);
- if (StripBits)
- for (unsigned i = FN, e = Nodes.size(); i != e; ++i)
- Nodes[i]->NodeType &= ~StripBits;
-
- // Copy the value map... and merge all of the global nodes...
- for (std::map<Value*, DSNodeHandle>::const_iterator I = G.ValueMap.begin(),
- E = G.ValueMap.end(); I != E; ++I) {
+ // 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];
- H = DSNodeHandle(OldNodeMap[I->second.getNode()], I->second.getOffset());
+ DSNodeHandle &MappedNode = OldNodeMap[I->second.getNode()];
+ H.setOffset(I->second.getOffset()+MappedNode.getOffset());
+ H.setNode(MappedNode.getNode());
if (isa<GlobalValue>(I->first)) { // Is this a global?
- std::map<Value*, DSNodeHandle>::iterator GVI = ValueMap.find(I->first);
- if (GVI != ValueMap.end()) { // Is the global value in this fun 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 {
- ValueMap[I->first] = H; // Add global pointer to this graph
- }
+ else
+ ScalarMap[I->first] = H; // Add global pointer to this graph
}
}
- // Copy the function calls list...
- CopyFunctionCallsList(G.FunctionCalls, FunctionCalls, OldNodeMap);
+ if (!(CloneFlags & DontCloneCallNodes)) {
+ // Copy the function calls list...
+ unsigned FC = FunctionCalls.size(); // FirstCall
+ FunctionCalls.reserve(FC+G.FunctionCalls.size());
+ for (unsigned i = 0, ei = G.FunctionCalls.size(); i != ei; ++i)
+ FunctionCalls.push_back(DSCallSite(G.FunctionCalls[i], OldNodeMap));
+ }
+
+ if (!(CloneFlags & DontCloneAuxCallNodes)) {
+ // Copy the auxillary function calls list...
+ unsigned FC = AuxFunctionCalls.size(); // FirstCall
+ AuxFunctionCalls.reserve(FC+G.AuxFunctionCalls.size());
+ for (unsigned i = 0, ei = G.AuxFunctionCalls.size(); i != ei; ++i)
+ AuxFunctionCalls.push_back(DSCallSite(G.AuxFunctionCalls[i], OldNodeMap));
+ }
// Return the returned node pointer...
- return DSNodeHandle(OldNodeMap[G.RetNode.getNode()], G.RetNode.getOffset());
+ DSNodeHandle &MappedRet = OldNodeMap[G.RetNode.getNode()];
+ return DSNodeHandle(MappedRet.getNode(),
+ MappedRet.getOffset()+G.RetNode.getOffset());
}
-#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 = ValueMap[GNode->getGlobals()[0]];
- if (ValMapEntry != 0)
- return ValMapEntry;
+/// mergeInGraph - The method is used for merging graphs together. If the
+/// argument graph is not *this, it makes a clone of the specified graph, then
+/// merges the nodes specified in the call site with the formal arguments in the
+/// graph.
+///
+void DSGraph::mergeInGraph(DSCallSite &CS, const DSGraph &Graph,
+ unsigned CloneFlags) {
+ hash_map<Value*, DSNodeHandle> OldValMap;
+ DSNodeHandle RetVal;
+ hash_map<Value*, DSNodeHandle> *ScalarMap = &OldValMap;
+
+ // If this is not a recursive call, clone the graph into this graph...
+ if (&Graph != this) {
+ // Clone the callee's graph into the current graph, keeping
+ // track of where scalars in the old graph _used_ to point,
+ // and of the new nodes matching nodes of the old graph.
+ hash_map<const DSNode*, DSNodeHandle> OldNodeMap;
+
+ // The clone call may invalidate any of the vectors in the data
+ // structure graph. Strip locals and don't copy the list of callers
+ RetVal = cloneInto(Graph, OldValMap, OldNodeMap, CloneFlags);
+ ScalarMap = &OldValMap;
+ } else {
+ RetVal = getRetNode();
+ ScalarMap = &getScalarMap();
+ }
- // 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)
- ValueMap[NewNode->getGlobals()[j]] = NewNode;
+ // Merge the return value with the return value of the context...
+ RetVal.mergeWith(CS.getRetVal());
- // 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)));
+ // Resolve all of the function arguments...
+ Function &F = Graph.getFunction();
+ Function::aiterator AI = F.abegin();
- return NewNode;
-}
+ for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i, ++AI) {
+ // Advance the argument iterator to the first pointer argument...
+ while (AI != F.aend() && !isPointerType(AI->getType())) {
+ ++AI;
+#ifndef NDEBUG
+ if (AI == F.aend())
+ std::cerr << "Bad call to Function: " << F.getName() << "\n";
#endif
+ }
+ if (AI == F.aend()) break;
+
+ // Add the link from the argument scalar to the provided value
+ assert(ScalarMap->count(AI) && "Argument not in scalar map?");
+ DSNodeHandle &NH = (*ScalarMap)[AI];
+ assert(NH.getNode() && "Pointer argument without scalarmap entry?");
+ NH.mergeWith(CS.getPtrArg(i));
+ }
+}
// markIncompleteNodes - Mark the specified node as having contents that are not
N->NodeType |= DSNode::Incomplete;
// Recusively process children...
- for (unsigned i = 0, e = N->getSize(); i != e; ++i)
- if (DSNodeHandle *DSNH = N->getLink(i))
- markIncompleteNode(DSNH->getNode());
+ for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
+ if (DSNode *DSN = N->getLink(i).getNode())
+ markIncompleteNode(DSN);
}
+static void markIncomplete(DSCallSite &Call) {
+ // Then the return value is certainly incomplete!
+ markIncompleteNode(Call.getRetVal().getNode());
+
+ // All objects pointed to by function arguments are incomplete!
+ for (unsigned i = 0, e = Call.getNumPtrArgs(); i != e; ++i)
+ markIncompleteNode(Call.getPtrArg(i).getNode());
+}
// markIncompleteNodes - Traverse the graph, identifying nodes that may be
// modified by other functions that have not been resolved yet. This marks
// scope of current analysis may have modified it), the 'Incomplete' flag is
// added to the NodeType.
//
-void DSGraph::markIncompleteNodes(bool markFormalArgs) {
+void DSGraph::markIncompleteNodes(unsigned Flags) {
// Mark any incoming arguments as incomplete...
- if (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()) && ValueMap.find(I) != ValueMap.end()) {
- DSNodeHandle &INH = ValueMap[I];
- if (INH.getNode() && INH.hasLink(0))
- markIncompleteNode(ValueMap[I].getLink(0)->getNode());
- }
+ if (isPointerType(I->getType()) && ScalarMap.find(I) != ScalarMap.end())
+ markIncompleteNode(ScalarMap[I].getNode());
// Mark stuff passed into functions calls as being incomplete...
- for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i) {
- DSCallSite &Call = FunctionCalls[i];
- // Then the return value is certainly incomplete!
- markIncompleteNode(Call.getRetVal().getNode());
-
- // The call does not make the function argument incomplete...
-
- // All arguments to the function call are incomplete though!
- for (unsigned i = 0, e = Call.getNumPtrArgs(); i != e; ++i)
- markIncompleteNode(Call.getPtrArg(i).getNode());
- }
+ if (!shouldPrintAuxCalls())
+ for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
+ markIncomplete(FunctionCalls[i]);
+ else
+ for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
+ markIncomplete(AuxFunctionCalls[i]);
+
- // Mark all of the nodes pointed to by global or cast 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)
- if (DSNodeHandle *DSNH = N->getLink(i))
- markIncompleteNode(DSNH->getNode());
- }
+ // 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]);
}
-// removeRefsToGlobal - Helper function that removes globals from the
-// ValueMap so that the referrer count will go down to zero.
-static void removeRefsToGlobal(DSNode* N,
- std::map<Value*, DSNodeHandle> &ValueMap) {
- while (!N->getGlobals().empty()) {
- GlobalValue *GV = N->getGlobals().back();
- N->getGlobals().pop_back();
- ValueMap.erase(GV);
- }
+static inline void killIfUselessEdge(DSNodeHandle &Edge) {
+ if (DSNode *N = Edge.getNode()) // Is there an edge?
+ if (N->getNumReferrers() == 1) // Does it point to a lonely node?
+ if ((N->NodeType & ~DSNode::Incomplete) == 0 && // No interesting info?
+ N->getType() == Type::VoidTy && !N->isNodeCompletelyFolded())
+ Edge.setNode(0); // Kill the edge!
}
-
-// 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...
- if (N->getReferrers().empty() && N->NodeType == 0)
- return true;
-
- // Is it a function node or some other trivially unused global?
- if (N->NodeType != 0 &&
- (N->NodeType & ~DSNode::GlobalNode) == 0 &&
- N->getSize() == 0 &&
- N->getReferrers().size() == N->getGlobals().size()) {
-
- // Remove the globals from the ValueMap, so that the referrer count will go
- // down to zero.
- removeRefsToGlobal(N, ValueMap);
- assert(N->getReferrers().empty() && "Referrers should all be gone now!");
- return true;
- }
-
+static inline bool nodeContainsExternalFunction(const DSNode *N) {
+ const std::vector<GlobalValue*> &Globals = N->getGlobals();
+ for (unsigned i = 0, e = Globals.size(); i != e; ++i)
+ if (Globals[i]->isExternal())
+ return true;
return false;
}
-static void removeIdenticalCalls(vector<DSCallSite> &Calls,
+static void removeIdenticalCalls(std::vector<DSCallSite> &Calls,
const std::string &where) {
// Remove trivially identical function calls
unsigned NumFns = Calls.size();
- std::sort(Calls.begin(), Calls.end());
+ std::sort(Calls.begin(), Calls.end()); // Sort by callee as primary key!
+
+ // Scan the call list cleaning it up as necessary...
+ DSNode *LastCalleeNode = 0;
+ Function *LastCalleeFunc = 0;
+ unsigned NumDuplicateCalls = 0;
+ bool LastCalleeContainsExternalFunction = false;
+ for (unsigned i = 0; i != Calls.size(); ++i) {
+ DSCallSite &CS = Calls[i];
+
+ // If the Callee is a useless edge, this must be an unreachable call site,
+ // eliminate it.
+ if (CS.isIndirectCall() && CS.getCalleeNode()->getNumReferrers() == 1 &&
+ CS.getCalleeNode()->NodeType == 0) { // No useful info?
+ std::cerr << "WARNING: Useless call site found??\n";
+ CS.swap(Calls.back());
+ Calls.pop_back();
+ --i;
+ } else {
+ // If the return value or any arguments point to a void node with no
+ // information at all in it, and the call node is the only node to point
+ // to it, remove the edge to the node (killing the node).
+ //
+ killIfUselessEdge(CS.getRetVal());
+ for (unsigned a = 0, e = CS.getNumPtrArgs(); a != e; ++a)
+ killIfUselessEdge(CS.getPtrArg(a));
+
+ // If this call site calls the same function as the last call site, and if
+ // the function pointer contains an external function, this node will
+ // never be resolved. Merge the arguments of the call node because no
+ // information will be lost.
+ //
+ if ((CS.isDirectCall() && CS.getCalleeFunc() == LastCalleeFunc) ||
+ (CS.isIndirectCall() && CS.getCalleeNode() == LastCalleeNode)) {
+ ++NumDuplicateCalls;
+ if (NumDuplicateCalls == 1) {
+ if (LastCalleeNode)
+ LastCalleeContainsExternalFunction =
+ nodeContainsExternalFunction(LastCalleeNode);
+ else
+ LastCalleeContainsExternalFunction = LastCalleeFunc->isExternal();
+ }
+
+ if (LastCalleeContainsExternalFunction ||
+ // This should be more than enough context sensitivity!
+ // FIXME: Evaluate how many times this is tripped!
+ NumDuplicateCalls > 20) {
+ DSCallSite &OCS = Calls[i-1];
+ OCS.mergeWith(CS);
+
+ // The node will now be eliminated as a duplicate!
+ if (CS.getNumPtrArgs() < OCS.getNumPtrArgs())
+ CS = OCS;
+ else if (CS.getNumPtrArgs() > OCS.getNumPtrArgs())
+ OCS = CS;
+ }
+ } else {
+ if (CS.isDirectCall()) {
+ LastCalleeFunc = CS.getCalleeFunc();
+ LastCalleeNode = 0;
+ } else {
+ LastCalleeNode = CS.getCalleeNode();
+ LastCalleeFunc = 0;
+ }
+ NumDuplicateCalls = 0;
+ }
+ }
+ }
+
Calls.erase(std::unique(Calls.begin(), Calls.end()),
Calls.end());
+ // Track the number of call nodes merged away...
+ NumCallNodesMerged += NumFns-Calls.size();
+
DEBUG(if (NumFns != Calls.size())
std::cerr << "Merged " << (NumFns-Calls.size())
<< " call nodes in " << where << "\n";);
}
+
// removeTriviallyDeadNodes - After the graph has been constructed, this method
// removes all unreachable nodes that are created because they got merged with
// other nodes in the graph. These nodes will all be trivially unreachable, so
// we don't have to perform any non-trivial analysis here.
//
-void DSGraph::removeTriviallyDeadNodes(bool KeepAllGlobals) {
- for (unsigned i = 0; i != Nodes.size(); ++i)
- if (!KeepAllGlobals || !(Nodes[i]->NodeType & DSNode::GlobalNode))
- if (isNodeDead(Nodes[i])) { // This node is dead!
- delete Nodes[i]; // Free memory...
- Nodes.erase(Nodes.begin()+i--); // Remove from node list...
- }
-
+void DSGraph::removeTriviallyDeadNodes() {
removeIdenticalCalls(FunctionCalls, Func ? Func->getName() : "");
-}
+ removeIdenticalCalls(AuxFunctionCalls, Func ? Func->getName() : "");
+
+ for (unsigned i = 0; i != Nodes.size(); ++i) {
+ DSNode *Node = Nodes[i];
+ if (!(Node->NodeType & ~(DSNode::Composition | DSNode::Array |
+ DSNode::DEAD))) {
+ // This is a useless node if it has no mod/ref info (checked above),
+ // outgoing edges (which it cannot, as it is not modified in this
+ // context), and it has no incoming edges. If it is a global node it may
+ // have all of these properties and still have incoming edges, due to the
+ // scalar map, so we check those now.
+ //
+ if (Node->getNumReferrers() == Node->getGlobals().size()) {
+ std::vector<GlobalValue*> &Globals = Node->getGlobals();
+
+ // Loop through and make sure all of the globals are referring directly
+ // to the node...
+ for (unsigned j = 0, e = Globals.size(); j != e; ++j) {
+ DSNode *N = ScalarMap.find(Globals[j])->second.getNode();
+ assert(N == Node && "ScalarMap doesn't match globals list!");
+ }
+ // Make sure numreferrers still agrees, if so, the node is truely dead.
+ if (Node->getNumReferrers() == Globals.size()) {
+ for (unsigned j = 0, e = Globals.size(); j != e; ++j)
+ ScalarMap.erase(Globals[j]);
-// markAlive - Simple graph walker that recursively traverses the graph, marking
-// stuff to be alive.
-//
-static void markAlive(DSNode *N, std::set<DSNode*> &Alive) {
- if (N == 0) return;
+ Globals.clear();
+ assert(Node->hasNoReferrers() && "Shouldn't have refs now!");
+
+ Node->NodeType = DSNode::DEAD;
+ }
+ }
+ }
- Alive.insert(N);
- for (unsigned i = 0, e = N->getSize(); i != e; ++i)
- if (DSNodeHandle *DSNH = N->getLink(i))
- if (!Alive.count(DSNH->getNode()))
- markAlive(DSNH->getNode(), Alive);
+ 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...
+ }
+ }
}
-static bool checkGlobalAlive(DSNode *N, std::set<DSNode*> &Alive,
- std::set<DSNode*> &Visiting) {
- if (N == 0) return false;
-
- if (Visiting.count(N)) return false; // terminate recursion on a cycle
- Visiting.insert(N);
-
- // If any immediate successor is alive, N is alive
- for (unsigned i = 0, e = N->getSize(); i != e; ++i)
- if (DSNodeHandle *DSNH = N->getLink(i))
- if (Alive.count(DSNH->getNode())) {
- Visiting.erase(N);
- return true;
- }
-
- // Else if any successor reaches a live node, N is alive
- for (unsigned i = 0, e = N->getSize(); i != e; ++i)
- if (DSNodeHandle *DSNH = N->getLink(i))
- if (checkGlobalAlive(DSNH->getNode(), Alive, Visiting)) {
- Visiting.erase(N); return true;
- }
- Visiting.erase(N);
- return false;
+/// markReachableNodes - This method recursively traverses the specified
+/// DSNodes, marking any nodes which are reachable. All reachable nodes it adds
+/// to the set, which allows it to only traverse visited nodes once.
+///
+void DSNode::markReachableNodes(hash_set<DSNode*> &ReachableNodes) {
+ if (this == 0) return;
+ assert(getForwardNode() == 0 && "Cannot mark a forwarded node!");
+ if (ReachableNodes.count(this)) return; // Already marked reachable
+ ReachableNodes.insert(this); // Is reachable now
+
+ for (unsigned i = 0, e = getSize(); i < e; i += DS::PointerSize)
+ getLink(i).getNode()->markReachableNodes(ReachableNodes);
}
+void DSCallSite::markReachableNodes(hash_set<DSNode*> &Nodes) {
+ getRetVal().getNode()->markReachableNodes(Nodes);
+ if (isIndirectCall()) getCalleeNode()->markReachableNodes(Nodes);
+
+ for (unsigned i = 0, e = getNumPtrArgs(); i != e; ++i)
+ getPtrArg(i).getNode()->markReachableNodes(Nodes);
+}
-// markGlobalsIteration - Recursive helper function for markGlobalsAlive().
-// This would be unnecessary if function calls were real nodes! In that case,
-// the simple iterative loop in the first few lines below suffice.
-//
-static void markGlobalsIteration(std::set<DSNode*>& GlobalNodes,
- vector<DSCallSite> &Calls,
- std::set<DSNode*> &Alive,
- bool FilterCalls) {
-
- // Iterate, marking globals or cast nodes alive until no new live nodes
- // are added to Alive
- std::set<DSNode*> Visiting; // Used to identify cycles
- std::set<DSNode*>::iterator I = GlobalNodes.begin(), E = GlobalNodes.end();
- for (size_t liveCount = 0; liveCount < Alive.size(); ) {
- liveCount = Alive.size();
- for ( ; I != E; ++I)
- if (Alive.count(*I) == 0) {
- Visiting.clear();
- if (checkGlobalAlive(*I, Alive, Visiting))
- markAlive(*I, 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 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!");
- // Find function calls with some dead and some live nodes.
- // Since all call nodes must be live if any one is live, we have to mark
- // all nodes of the call as live and continue the iteration (via recursion).
- if (FilterCalls) {
- bool Recurse = false;
- for (unsigned i = 0, ei = Calls.size(); i < ei; ++i) {
- bool CallIsDead = true, CallHasDeadArg = false;
- DSCallSite &CS = Calls[i];
- for (unsigned j = 0, ej = CS.getNumPtrArgs(); j != ej; ++j)
- if (DSNode *N = CS.getPtrArg(j).getNode()) {
- bool ArgIsDead = !Alive.count(N);
- CallHasDeadArg |= ArgIsDead;
- CallIsDead &= ArgIsDead;
- }
+ // If we know that this node is alive, return so!
+ if (Alive.count(N)) return true;
- if (DSNode *N = CS.getRetVal().getNode()) {
- bool RetIsDead = !Alive.count(N);
- CallHasDeadArg |= RetIsDead;
- CallIsDead &= RetIsDead;
- }
+ // Otherwise, we don't think the node is alive yet, check for infinite
+ // recursion.
+ if (Visited.count(N)) return false; // Found a cycle
+ Visited.insert(N); // No recursion, insert into Visited...
- DSNode *N = CS.getCallee().getNode();
- bool FnIsDead = !Alive.count(N);
- CallHasDeadArg |= FnIsDead;
- CallIsDead &= FnIsDead;
-
- if (!CallIsDead && CallHasDeadArg) {
- // Some node in this call is live and another is dead.
- // Mark all nodes of call as live and iterate once more.
- Recurse = true;
- for (unsigned j = 0, ej = CS.getNumPtrArgs(); j != ej; ++j)
- markAlive(CS.getPtrArg(j).getNode(), Alive);
- markAlive(CS.getRetVal().getNode(), Alive);
- markAlive(CS.getCallee().getNode(), Alive);
- }
+ for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
+ if (CanReachAliveNodes(N->getLink(i).getNode(), Alive, Visited)) {
+ N->markReachableNodes(Alive);
+ return true;
}
- if (Recurse)
- markGlobalsIteration(GlobalNodes, Calls, Alive, FilterCalls);
- }
+ return false;
}
-
-// markGlobalsAlive - Mark global nodes and cast nodes alive if they
-// can reach any other live node. Since this can produce new live nodes,
-// we use a simple iterative algorithm.
-//
-static void markGlobalsAlive(DSGraph &G, std::set<DSNode*> &Alive,
- bool FilterCalls) {
- // Add global and cast nodes to a set so we don't walk all nodes every time
- std::set<DSNode*> GlobalNodes;
- for (unsigned i = 0, e = G.getNodes().size(); i != e; ++i)
- if (G.getNodes()[i]->NodeType & DSNode::GlobalNode)
- GlobalNodes.insert(G.getNodes()[i]);
-
- // Add all call nodes to the same set
- vector<DSCallSite> &Calls = G.getFunctionCalls();
- if (FilterCalls) {
- for (unsigned i = 0, e = Calls.size(); i != e; ++i) {
- for (unsigned j = 0, e = Calls[i].getNumPtrArgs(); j != e; ++j)
- if (DSNode *N = Calls[i].getPtrArg(j).getNode())
- GlobalNodes.insert(N);
- if (DSNode *N = Calls[i].getRetVal().getNode())
- GlobalNodes.insert(N);
- if (DSNode *N = Calls[i].getCallee().getNode())
- GlobalNodes.insert(N);
- }
- }
-
- // Iterate and recurse until no new live node are discovered.
- // This would be a simple iterative loop if function calls were real nodes!
- markGlobalsIteration(GlobalNodes, Calls, Alive, FilterCalls);
-
- // Free up references to dead globals from the ValueMap
- std::set<DSNode*>::iterator I=GlobalNodes.begin(), E=GlobalNodes.end();
- for( ; I != E; ++I)
- if (Alive.count(*I) == 0)
- removeRefsToGlobal(*I, G.getValueMap());
-
- // Delete dead function calls
- if (FilterCalls)
- for (int ei = Calls.size(), i = ei-1; i >= 0; --i) {
- bool CallIsDead = true;
- for (unsigned j = 0, ej = Calls[i].getNumPtrArgs();
- CallIsDead && j != ej; ++j)
- CallIsDead = Alive.count(Calls[i].getPtrArg(j).getNode()) == 0;
- if (CallIsDead)
- Calls.erase(Calls.begin() + i); // remove the call entirely
- }
+// CallSiteUsesAliveArgs - Return true if the specified call site can reach any
+// alive nodes.
+//
+static bool CallSiteUsesAliveArgs(DSCallSite &CS, hash_set<DSNode*> &Alive,
+ hash_set<DSNode*> &Visited) {
+ if (CanReachAliveNodes(CS.getRetVal().getNode(), Alive, Visited))
+ return true;
+ if (CS.isIndirectCall() &&
+ CanReachAliveNodes(CS.getCalleeNode(), Alive, Visited))
+ return true;
+ for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i)
+ if (CanReachAliveNodes(CS.getPtrArg(i).getNode(), Alive, Visited))
+ return true;
+ return false;
}
// removeDeadNodes - Use a more powerful reachability analysis to eliminate
// from the caller's graph entirely. This is only appropriate to use when
// inlining graphs.
//
-void DSGraph::removeDeadNodes(bool KeepAllGlobals, bool KeepCalls) {
- assert((!KeepAllGlobals || KeepCalls) &&
- "KeepAllGlobals without KeepCalls is meaningless");
-
- // Reduce the amount of work we have to do...
- removeTriviallyDeadNodes(KeepAllGlobals);
+void DSGraph::removeDeadNodes(unsigned Flags) {
+ // Reduce the amount of work we have to do... remove dummy nodes left over by
+ // merging...
+ removeTriviallyDeadNodes();
// FIXME: Merge nontrivially identical call nodes...
// Alive - a set that holds all nodes found to be reachable/alive.
- std::set<DSNode*> Alive;
-
- // If KeepCalls, mark all nodes reachable by call nodes as alive...
- if (KeepCalls)
- for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i) {
- for (unsigned j = 0, e = FunctionCalls[i].getNumPtrArgs(); j != e; ++j)
- markAlive(FunctionCalls[i].getPtrArg(j).getNode(), Alive);
- markAlive(FunctionCalls[i].getRetVal().getNode(), Alive);
- markAlive(FunctionCalls[i].getCallee().getNode(), Alive);
+ hash_set<DSNode*> Alive;
+ std::vector<std::pair<Value*, DSNode*> > GlobalNodes;
+
+ // Mark all nodes reachable by (non-global) scalar nodes as alive...
+ for (hash_map<Value*, DSNodeHandle>::iterator I = ScalarMap.begin(),
+ E = ScalarMap.end(); I != E; )
+ if (isa<GlobalValue>(I->first)) { // Keep track of global nodes
+ assert(I->second.getNode() && "Null global node?");
+ GlobalNodes.push_back(std::make_pair(I->first, I->second.getNode()));
+ ++I;
+ } else {
+ // Check to see if this is a worthless node generated for non-pointer
+ // values, such as integers. Consider an addition of long types: A+B.
+ // Assuming we can track all uses of the value in this context, and it is
+ // NOT used as a pointer, we can delete the node. We will be able to
+ // detect this situation if the node pointed to ONLY has Unknown bit set
+ // in the node. In this case, the node is not incomplete, does not point
+ // to any other nodes (no mod/ref bits set), and is therefore
+ // uninteresting for data structure analysis. If we run across one of
+ // these, prune the scalar pointing to it.
+ //
+ DSNode *N = I->second.getNode();
+ if (N->NodeType == DSNode::UnknownNode && !isa<Argument>(I->first)) {
+ ScalarMap.erase(I++);
+ } else {
+ I->second.getNode()->markReachableNodes(Alive);
+ ++I;
+ }
}
-#if 0
- for (unsigned i = 0, e = OrigFunctionCalls.size(); i != e; ++i)
- for (unsigned j = 0, e = OrigFunctionCalls[i].size(); j != e; ++j)
- markAlive(OrigFunctionCalls[i][j].getNode(), Alive);
-#endif
-
- // Mark all nodes reachable by scalar nodes (and global nodes, if
- // keeping them was specified) as alive...
- unsigned char keepBits = DSNode::ScalarNode |
- (KeepAllGlobals ? DSNode::GlobalNode : 0);
- for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
- if (Nodes[i]->NodeType & keepBits)
- markAlive(Nodes[i], Alive);
-
// The return value is alive as well...
- markAlive(RetNode.getNode(), Alive);
+ RetNode.getNode()->markReachableNodes(Alive);
+
+ // Mark any nodes reachable by primary calls as alive...
+ for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
+ FunctionCalls[i].markReachableNodes(Alive);
+
+ bool Iterate;
+ hash_set<DSNode*> Visited;
+ std::vector<unsigned char> AuxFCallsAlive(AuxFunctionCalls.size());
+ do {
+ Visited.clear();
+ // If any global nodes points to a non-global that is "alive", the global is
+ // "alive" as well... Remove it from the GlobalNodes list so we only have
+ // unreachable globals in the list.
+ //
+ Iterate = false;
+ for (unsigned i = 0; i != GlobalNodes.size(); ++i)
+ if (CanReachAliveNodes(GlobalNodes[i].second, Alive, Visited)) {
+ std::swap(GlobalNodes[i--], GlobalNodes.back()); // Move to end to erase
+ GlobalNodes.pop_back(); // Erase efficiently
+ Iterate = true;
+ }
- // Mark all globals or cast nodes that can reach a live node as alive.
- // This also marks all nodes reachable from such nodes as alive.
- // Of course, if KeepAllGlobals is specified, they would be live already.
- if (!KeepAllGlobals)
- markGlobalsAlive(*this, Alive, ! KeepCalls);
+ for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
+ if (!AuxFCallsAlive[i] &&
+ CallSiteUsesAliveArgs(AuxFunctionCalls[i], Alive, Visited)) {
+ AuxFunctionCalls[i].markReachableNodes(Alive);
+ AuxFCallsAlive[i] = true;
+ Iterate = true;
+ }
+ } while (Iterate);
+
+ // Remove all dead aux function calls...
+ unsigned CurIdx = 0;
+ for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
+ if (AuxFCallsAlive[i])
+ AuxFunctionCalls[CurIdx++].swap(AuxFunctionCalls[i]);
+ if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
+ assert(GlobalsGraph && "No globals graph available??");
+ // Move the unreachable call nodes to the globals graph...
+ GlobalsGraph->AuxFunctionCalls.insert(GlobalsGraph->AuxFunctionCalls.end(),
+ AuxFunctionCalls.begin()+CurIdx,
+ AuxFunctionCalls.end());
+ }
+ // Crop all the useless ones out...
+ AuxFunctionCalls.erase(AuxFunctionCalls.begin()+CurIdx,
+ AuxFunctionCalls.end());
- // Loop over all unreachable nodes, dropping their references...
- vector<DSNode*> DeadNodes;
- DeadNodes.reserve(Nodes.size()); // Only one allocation is allowed.
+ // At this point, any nodes which are visited, but not alive, are nodes which
+ // should be moved to the globals graph. Loop over all nodes, eliminating
+ // completely unreachable nodes, and moving visited nodes to the globals graph
+ //
+ std::vector<DSNode*> DeadNodes;
+ DeadNodes.reserve(Nodes.size());
for (unsigned i = 0; i != Nodes.size(); ++i)
if (!Alive.count(Nodes[i])) {
DSNode *N = Nodes[i];
- Nodes.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>);
-}
-
-
-// maskNodeTypes - Apply a mask to all of the node types in the graph. This
-// is useful for clearing out markers like Scalar or Incomplete.
-//
-void DSGraph::maskNodeTypes(unsigned char Mask) {
- for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
- Nodes[i]->NodeType &= Mask;
-}
-
-
-#if 0
-//===----------------------------------------------------------------------===//
-// GlobalDSGraph Implementation
-//===----------------------------------------------------------------------===//
-
-GlobalDSGraph::GlobalDSGraph() : DSGraph(*(Function*)0, this) {
-}
-
-GlobalDSGraph::~GlobalDSGraph() {
- assert(Referrers.size() == 0 &&
- "Deleting global graph while references from other graphs exist");
-}
-
-void GlobalDSGraph::addReference(const DSGraph* referrer) {
- if (referrer != this)
- Referrers.insert(referrer);
-}
-
-void GlobalDSGraph::removeReference(const DSGraph* referrer) {
- if (referrer != this) {
- assert(Referrers.find(referrer) != Referrers.end() && "This is very bad!");
- Referrers.erase(referrer);
- if (Referrers.size() == 0)
- delete this;
- }
-}
-
-// Bits used in the next function
-static const char ExternalTypeBits = DSNode::GlobalNode | DSNode::NewNode;
-
-#if 0
-// 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 = ValueMap[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)
- ValueMap[PrevNode->getGlobals()[k]] = NewNode;
- NewNode->mergeWith(PrevNode);
- }
- } else if (NewNode != 0) {
- ValueMap[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)
- ValueMap[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;
-}
-
-
-// GlobalDSGraph::cloneGlobals - Clone global nodes and all their externally
-// visible target links (and recursively their such links) into this graph.
-//
-void GlobalDSGraph::cloneGlobals(DSGraph& Graph, bool CloneCalls) {
- std::map<const DSNode*, DSNode*> NodeCache;
-#if 0
- for (unsigned i = 0, N = Graph.Nodes.size(); i < N; ++i)
- if (Graph.Nodes[i]->NodeType & DSNode::GlobalNode)
- GlobalsGraph->cloneNodeInto(Graph.Nodes[i], NodeCache, false);
- if (CloneCalls)
- GlobalsGraph->cloneCalls(Graph);
-
- GlobalsGraph->removeDeadNodes(/*KeepAllGlobals*/ true, /*KeepCalls*/ true);
-#endif
+ 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;
- 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