#include "llvm/Analysis/DSGraph.h"
#include "llvm/Function.h"
+#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"
#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
-//===----------------------------------------------------------------------===//
-
-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));
+using namespace DS;
- // 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;
+DSNode *DSNodeHandle::HandleForwarding() const {
+ assert(!N->ForwardNH.isNull() && "Can only be invoked if forwarding!");
- // 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(std::make_pair(T, 0));
+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), 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::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);
+ }
}
-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);
+/// 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() {
+ if (isNodeCompletelyFolded()) return; // If this node is already folded...
+
+ ++NumFolds;
+
+ // 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
+/// 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();
+}
+
+
+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())));
+ }
+ }
+ }
+ }
+ };
+}
-/// 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.
+/// 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.
///
-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.
+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 information is already known, or it may merge the node completely (and
+/// return true) if the information is incompatible with what is already known.
+///
+/// This method returns true if the node is completely folded, otherwise false.
+///
+bool DSNode::mergeTypeInfo(const Type *NewTy, unsigned Offset,
+ 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...
+ 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;
+
+ 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 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 convertible... int -> uint f.e.
+ if (NewTy->isLosslesslyConvertibleTo(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;
}
+
+ 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");
+
+ 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
-
- assert(NH.getNode() != this &&
- "Cannot merge two portions of the same node yet!");
+void DSNode::MergeNodes(DSNodeHandle& CurNodeH, DSNodeHandle& NH) {
+ assert(CurNodeH.getOffset() >= NH.getOffset() &&
+ "This should have been enforced in the caller.");
- // 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 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();
+ }
}
-#if 0
- std::cerr << "\n\nMerging:\n";
- N->print(std::cerr, 0);
- std::cerr << " and:\n";
- print(std::cerr, 0);
-#endif
-
- // Now we know that Offset <= NH.Offset, so convert it so our "Offset" (with
- // respect to NH.Offset) is now zero.
- //
- unsigned NOffset = NH.getOffset()-Offset;
-
- unsigned NSize = N->getSize();
- assert(NSize+NOffset <= getSize() &&
- "Don't know how to merge extend a merged nodes size yet!");
+ // 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());
- // Remove all edges pointing at N, causing them to point to 'this' instead.
- // Make sure to adjust their offset, not just the node pointer.
+ // If we are merging a node with a completely folded node, then both nodes are
+ // now completely folded.
//
- while (!N->Referrers.empty()) {
- DSNodeHandle &Ref = *N->Referrers.back();
- Ref = DSNodeHandle(this, NOffset+Ref.getOffset());
- }
-
- // 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).
- //
- 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];
+ 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);
}
- // Make all of the outgoing links of N now be outgoing links of this. This
- // can cause recursive merging!
+ DSNode *N = NH.getNode();
+ if (CurNodeH.getNode() == N || N == 0) return;
+ assert(!CurNodeH.getNode()->isDeadNode());
+
+ // Merge the NodeType information...
+ CurNodeH.getNode()->NodeType |= N->NodeType;
+
+ // 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, e = NSize; i != e; ++i)
- if (DSNodeHandle *Link = N->getLink(i)) {
- addEdgeTo(i+NOffset, *Link);
- N->MergeMap[i] = -1; // Kill outgoing edge
+ for (unsigned i = 0; i < N->getNumLinks(); ++i) {
+ DSNodeHandle &Link = N->getLink(i << DS::PointerShift);
+ if (Link.getNode()) {
+ // Compute the offset into the current node at which to
+ // merge this link. In the common case, this is a linear
+ // relation to the offset in the original node (with
+ // wrapping), but if the current node gets collapsed due to
+ // recursive merging, we must make sure to merge in all remaining
+ // links at offset zero.
+ unsigned MergeOffset = 0;
+ DSNode *CN = CurNodeH.getNode();
+ if (CN->Size != 1)
+ MergeOffset = ((i << DS::PointerShift)+NOffset) % CN->getSize();
+ CN->addEdgeTo(MergeOffset, Link);
}
+ }
// Now that there are no outgoing edges, all of the Links are dead.
N->Links.clear();
- // Merge the node types
- NodeType |= N->NodeType;
- N->NodeType = 0; // N is now a dead node.
+ // Merge the globals list...
+ if (!N->Globals.empty()) {
+ MergeSortedVectors(CurNodeH.getNode()->Globals, N->Globals);
- // 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].first != Type::VoidTy) {
- // If the current node just has a Void entry in it, remove it.
- if (TypeEntries.size() == 1 && TypeEntries[0].first == Type::VoidTy)
- TypeEntries.clear();
+ // Delete the globals from the old node...
+ std::vector<GlobalValue*>().swap(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].second += NOffset;
- }
- MergeSortedVectors(TypeEntries, N->TypeEntries);
+// 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
- N->TypeEntries.clear();
- }
+ assert(!N->isDeadNode() && !isDeadNode());
+ assert(!hasNoReferrers() && "Should not try to fold a useless node!");
- // Merge the globals list...
- if (!N->Globals.empty()) {
- MergeSortedVectors(Globals, N->Globals);
+ 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;
+ }
- // 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);
+}
+
+//===----------------------------------------------------------------------===//
+// DSCallSite Implementation
+//===----------------------------------------------------------------------===//
+
+// Define here to avoid including iOther.h and BasicBlock.h in DSGraph.h
+Function &DSCallSite::getCaller() const {
+ return *Inst->getParent()->getParent();
}
+
//===----------------------------------------------------------------------===//
// DSGraph Implementation
//===----------------------------------------------------------------------===//
-DSGraph::DSGraph(const DSGraph &G) : Func(G.Func) {
- std::map<const DSNode*, DSNode*> NodeMap;
- RetNode = cloneInto(G, ValueMap, NodeMap);
+/// 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;
+ NodeMapTy NodeMap;
+ cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
+ InlinedGlobals.clear(); // clear set of "up-to-date" globals
+}
+
+DSGraph::DSGraph(const DSGraph &G, NodeMapTy &NodeMap)
+ : GlobalsGraph(0) {
+ PrintAuxCalls = false;
+ cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
+ InlinedGlobals.clear(); // clear set of "up-to-date" globals
}
DSGraph::~DSGraph() {
FunctionCalls.clear();
- ValueMap.clear();
- RetNode = 0;
+ AuxFunctionCalls.clear();
+ InlinedGlobals.clear();
+ ScalarMap.clear();
+ ReturnNodes.clear();
-#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>);
// dump - Allow inspection of graph in a debugger.
void DSGraph::dump() const { print(std::cerr); }
-// Helper function used to clone a function list.
-//
-static void CopyFunctionCallsList(const vector<vector<DSNodeHandle> >&fromCalls,
- vector<vector<DSNodeHandle> > &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(vector<DSNodeHandle>());
-
- const vector<DSNodeHandle> &CurCall = fromCalls[i];
- toCalls.back().reserve(CurCall.size());
- for (unsigned j = 0, ej = fromCalls[i].size(); j != ej; ++j)
- toCalls[FC+i].push_back(DSNodeHandle(NodeMap[CurCall[j].getNode()],
- CurCall[j].getOffset()));
- }
-}
/// 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(DSGraph::NodeMapTy &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.
-//
-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) {
+
+/// 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!");
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 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);
- Nodes.push_back(New);
+ DSNode *New = new DSNode(*Old, this);
+ New->maskNodeTypes(~BitsToClear);
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...
- for (std::map<Value*, DSNodeHandle>::const_iterator I = G.ValueMap.begin(),
- E = G.ValueMap.end(); I != E; ++I)
- OldValMap[I->first] = DSNodeHandle(OldNodeMap[I->second.getNode()],
- I->second.getOffset());
- // Copy the function calls list...
- CopyFunctionCallsList(G.FunctionCalls, FunctionCalls, OldNodeMap);
-
-#if 0
- if (CopyOrigCalls)
- CopyFunctionCallsList(G.OrigFunctionCalls, OrigFunctionCalls, OldNodeMap);
-
- // Copy the list of unresolved callers
- if (CopyCallers)
- PendingCallers.insert(G.PendingCallers.begin(), G.PendingCallers.end());
-#endif
+ // 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 &MappedNode = OldNodeMap[I->second.getNode()];
+ DSNodeHandle &H = OldValMap[I->first];
+ H.mergeWith(DSNodeHandle(MappedNode.getNode(),
+ I->second.getOffset()+MappedNode.getOffset()));
+
+ // 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);
+ }
+ }
- // Return the returned node pointer...
- return DSNodeHandle(OldNodeMap[G.RetNode.getNode()], G.RetNode.getOffset());
+ 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));
+ }
+
+ // 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())));
+ }
}
-#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;
+/// 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(const DSCallSite &CS, Function &F,
+ const DSGraph &Graph, unsigned CloneFlags) {
+ ScalarMapTy OldValMap, *ScalarMap;
+ DSNodeHandle RetVal;
+
+ // 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.
+ 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
+ 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 = getReturnNodeFor(F);
+ ScalarMap = &getScalarMap();
+ }
- // If a clone has already been created for GNode, return it.
- DSNodeHandle& ValMapEntry = ValueMap[GNode->getGlobals()[0]];
- if (ValMapEntry != 0)
- return ValMapEntry;
+ // Merge the return value with the return value of the context...
+ RetVal.mergeWith(CS.getRetVal());
- // 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;
+ // Resolve all of the function arguments...
+ Function::aiterator AI = F.abegin();
- // 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)));
+ 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));
+ }
+}
- 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)
- 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)
- 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 (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...
- for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i) {
- vector<DSNodeHandle> &Args = FunctionCalls[i];
- // Then the return value is certainly incomplete!
- markIncompleteNode(Args[0].getNode());
-
- // The call does not make the function argument incomplete...
-
- // All arguments to the function call are incomplete though!
- for (unsigned i = 2, e = Args.size(); i != e; ++i)
- markIncompleteNode(Args[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]->isGlobalNode() && 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?
+ // No interesting info?
+ if ((N->getNodeFlags() & ~DSNode::Incomplete) == 0 &&
+ 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<vector<DSNodeHandle> > &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());
+ 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()->getNodeFlags() == 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 1
+ 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;
+ }
+#endif
+ } 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";);
+ std::cerr << "Merged " << (NumFns-Calls.size()) << " call nodes.\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);
+ removeIdenticalCalls(AuxFunctionCalls);
+
+ 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();
+ }
}
- removeIdenticalCalls(FunctionCalls, Func ? Func->getName() : "");
-}
+#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
-// 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;
+ // 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
+ }
- 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->getNodeFlags() == 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);
+/// 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);
+}
- // 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;
- }
+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);
+}
- // 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;
- }
+// 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,
+ bool IgnoreGlobals) {
+ if (N == 0) return false;
+ assert(N->getForwardNode() == 0 && "Cannot mark a forwarded node!");
- Visiting.erase(N);
- return false;
-}
+ // 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;
-// 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<vector<DSNodeHandle> > &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);
- }
- }
+ // 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...
- // 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 (int i = 0, ei = Calls.size(); i < ei; ++i) {
- bool CallIsDead = true, CallHasDeadArg = false;
- for (unsigned j = 0, ej = Calls[i].size(); j != ej; ++j) {
- bool argIsDead = Calls[i][j].getNode() == 0 ||
- Alive.count(Calls[i][j].getNode()) == 0;
- CallHasDeadArg |= (Calls[i][j].getNode() != 0 && argIsDead);
- CallIsDead &= argIsDead;
- }
- 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 = Calls[i].size(); j != ej; ++j)
- markAlive(Calls[i][j].getNode(), Alive);
- }
+ for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
+ if (CanReachAliveNodes(N->getLink(i).getNode(), Alive, Visited,
+ IgnoreGlobals)) {
+ 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<vector<DSNodeHandle> > &Calls = G.getFunctionCalls();
- if (FilterCalls) {
- for (unsigned i = 0, e = Calls.size(); i != e; ++i)
- for (unsigned j = 0, e = Calls[i].size(); j != e; ++j)
- if (Calls[i][j].getNode())
- GlobalNodes.insert(Calls[i][j].getNode());
- }
-
- // 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].size(); CallIsDead && j != ej; ++j)
- CallIsDead = Alive.count(Calls[i][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,
+ bool IgnoreGlobals) {
+ if (CanReachAliveNodes(CS.getRetVal().getNode(), Alive, Visited,
+ IgnoreGlobals))
+ return true;
+ 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;
}
// 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");
+void DSGraph::removeDeadNodes(unsigned Flags) {
+ DEBUG(AssertGraphOK(); GlobalsGraph->AssertGraphOK());
- // Reduce the amount of work we have to do...
- removeTriviallyDeadNodes(KeepAllGlobals);
+ // 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].size(); j != e; ++j)
- markAlive(FunctionCalls[i][j].getNode(), Alive);
-
-#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);
+ hash_set<DSNode*> Alive;
+ std::vector<std::pair<Value*, DSNode*> > GlobalNodes;
+
+ // Mark all nodes reachable by (non-global) scalar nodes as alive...
+ 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...
- markAlive(RetNode.getNode(), Alive);
-
- // 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);
-
- // Loop over all unreachable nodes, dropping their references...
- vector<DSNode*> DeadNodes;
- DeadNodes.reserve(Nodes.size()); // Only one allocation is allowed.
- 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
+ for (ReturnNodesTy::iterator I = ReturnNodes.begin(), E = ReturnNodes.end();
+ I != E; ++I)
+ I->second.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);
+
+ // 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;
+
+ 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
+
+ // 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]);
+
+ // 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());
}
-
- // 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;
+
+ // 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));
}
-}
-// Bits used in the next function
-static const char ExternalTypeBits = DSNode::GlobalNode | DSNode::NewNode;
+ // Remove all dead aux function calls...
+ if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
+ assert(GlobalsGraph && "No globals graph available??");
-#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.
+ // 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();
+
+ // 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.
//
- 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
+ std::vector<DSNode*> DeadNodes;
+ DeadNodes.reserve(Nodes.size());
+ for (unsigned i = 0; i != Nodes.size(); ++i)
+ if (!Alive.count(Nodes[i])) {
+ DSNode *N = Nodes[i];
+ Nodes[i--] = Nodes.back(); // move node to end of vector
+ Nodes.pop_back(); // Erase node from alive list.
+ 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)
- 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);
- }
+ // 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::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
-}
-
-
-// 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<vector<DSNodeHandle> >& FromCalls =Graph.FunctionCalls;
-
- FunctionCalls.reserve(FunctionCalls.size() + FromCalls.size());
-
- for (int i = 0, ei = FromCalls.size(); i < ei; ++i) {
- FunctionCalls.push_back(vector<DSNodeHandle>());
- FunctionCalls.back().reserve(FromCalls[i].size());
- for (unsigned j = 0, ej = FromCalls[i].size(); j != ej; ++j)
- FunctionCalls.back().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