+++ /dev/null
-//===- DataStructure.cpp - Implement the core data structure analysis -----===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the core data structure functionality.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/DataStructure/DSGraphTraits.h"
-#include "llvm/Constants.h"
-#include "llvm/Function.h"
-#include "llvm/GlobalVariable.h"
-#include "llvm/Instructions.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Assembly/Writer.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SCCIterator.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Support/Timer.h"
-#include <algorithm>
-using namespace llvm;
-
-#define COLLAPSE_ARRAYS_AGGRESSIVELY 0
-
-namespace {
- Statistic NumFolds ("dsa", "Number of nodes completely folded");
- Statistic NumCallNodesMerged("dsa", "Number of call nodes merged");
- Statistic NumNodeAllocated ("dsa", "Number of nodes allocated");
- Statistic NumDNE ("dsa", "Number of nodes removed by reachability");
- Statistic NumTrivialDNE ("dsa", "Number of nodes trivially removed");
- Statistic NumTrivialGlobalDNE("dsa", "Number of globals trivially removed");
- static cl::opt<unsigned>
- DSAFieldLimit("dsa-field-limit", cl::Hidden,
- cl::desc("Number of fields to track before collapsing a node"),
- cl::init(256));
-}
-
-#if 0
-#define TIME_REGION(VARNAME, DESC) \
- NamedRegionTimer VARNAME(DESC)
-#else
-#define TIME_REGION(VARNAME, DESC)
-#endif
-
-using namespace DS;
-
-/// isForwarding - Return true if this NodeHandle is forwarding to another
-/// one.
-bool DSNodeHandle::isForwarding() const {
- return N && N->isForwarding();
-}
-
-DSNode *DSNodeHandle::HandleForwarding() const {
- assert(N->isForwarding() && "Can only be invoked if forwarding!");
- DEBUG(
- { //assert not looping
- DSNode* NH = N;
- std::set<DSNode*> seen;
- while(NH && NH->isForwarding()) {
- assert(seen.find(NH) == seen.end() && "Loop detected");
- seen.insert(NH);
- NH = NH->ForwardNH.N;
- }
- }
- );
- // Handle node forwarding here!
- DSNode *Next = N->ForwardNH.getNode(); // Cause recursive shrinkage
- Offset += N->ForwardNH.getOffset();
-
- if (--N->NumReferrers == 0) {
- // Removing the last referrer to the node, sever the forwarding link
- N->stopForwarding();
- }
-
- N = Next;
- N->NumReferrers++;
- if (N->Size <= Offset) {
- assert(N->Size <= 1 && "Forwarded to shrunk but not collapsed node?");
- Offset = 0;
- }
- return N;
-}
-
-//===----------------------------------------------------------------------===//
-// DSScalarMap Implementation
-//===----------------------------------------------------------------------===//
-
-DSNodeHandle &DSScalarMap::AddGlobal(GlobalValue *GV) {
- assert(ValueMap.count(GV) == 0 && "GV already exists!");
-
- // If the node doesn't exist, check to see if it's a global that is
- // equated to another global in the program.
- EquivalenceClasses<GlobalValue*>::iterator ECI = GlobalECs.findValue(GV);
- if (ECI != GlobalECs.end()) {
- GlobalValue *Leader = *GlobalECs.findLeader(ECI);
- if (Leader != GV) {
- GV = Leader;
- iterator I = ValueMap.find(GV);
- if (I != ValueMap.end())
- return I->second;
- }
- }
-
- // Okay, this is either not an equivalenced global or it is the leader, it
- // will be inserted into the scalar map now.
- GlobalSet.insert(GV);
-
- return ValueMap.insert(std::make_pair(GV, DSNodeHandle())).first->second;
-}
-
-
-//===----------------------------------------------------------------------===//
-// DSNode Implementation
-//===----------------------------------------------------------------------===//
-
-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);
- if (G) G->addNode(this);
- ++NumNodeAllocated;
-}
-
-// DSNode copy constructor... do not copy over the referrers list!
-DSNode::DSNode(const DSNode &N, DSGraph *G, bool NullLinks)
- : NumReferrers(0), Size(N.Size), ParentGraph(G),
- Ty(N.Ty), Globals(N.Globals), NodeType(N.NodeType) {
- if (!NullLinks) {
- Links = N.Links;
- } else
- Links.resize(N.Links.size()); // Create the appropriate number of null links
- G->addNode(this);
- ++NumNodeAllocated;
-}
-
-/// getTargetData - Get the target data object used to construct this node.
-///
-const TargetData &DSNode::getTargetData() const {
- return ParentGraph->getTargetData();
-}
-
-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 DSScalarMap &SM = ParentGraph->getScalarMap();
- for (unsigned i = 0, e = Globals.size(); i != e; ++i) {
- assert(SM.global_count(Globals[i]));
- assert(SM.find(Globals[i])->second.getNode() == this);
- }
-}
-
-/// forwardNode - Mark this node as being obsolete, and all references to it
-/// should be forwarded to the specified node and offset.
-///
-void DSNode::forwardNode(DSNode *To, unsigned Offset) {
- assert(this != To && "Cannot forward a node to itself!");
- assert(ForwardNH.isNull() && "Already forwarding from this node!");
- if (To->Size <= 1) Offset = 0;
- assert((Offset < To->Size || (Offset == To->Size && Offset == 0)) &&
- "Forwarded offset is wrong!");
- ForwardNH.setTo(To, Offset);
- NodeType = DEAD;
- Size = 0;
- Ty = Type::VoidTy;
-
- // Remove this node from the parent graph's Nodes list.
- ParentGraph->unlinkNode(this);
- ParentGraph = 0;
-}
-
-// addGlobal - Add an entry for a global value to the Globals list. This also
-// marks the node with the 'G' flag if it does not already have it.
-//
-void DSNode::addGlobal(GlobalValue *GV) {
- // First, check to make sure this is the leader if the global is in an
- // equivalence class.
- GV = getParentGraph()->getScalarMap().getLeaderForGlobal(GV);
-
- // Keep the list sorted.
- std::vector<GlobalValue*>::iterator I =
- std::lower_bound(Globals.begin(), Globals.end(), GV);
-
- if (I == Globals.end() || *I != GV) {
- Globals.insert(I, GV);
- NodeType |= GlobalNode;
- }
-}
-
-// removeGlobal - Remove the specified global that is explicitly in the globals
-// list.
-void DSNode::removeGlobal(GlobalValue *GV) {
- std::vector<GlobalValue*>::iterator I =
- std::lower_bound(Globals.begin(), Globals.end(), GV);
- assert(I != Globals.end() && *I == GV && "Global not in node!");
- Globals.erase(I);
-}
-
-/// 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;
-
- // If this node has a size that is <= 1, we don't need to create a forwarding
- // node.
- if (getSize() <= 1) {
- NodeType |= DSNode::Array;
- Ty = Type::VoidTy;
- Size = 1;
- assert(Links.size() <= 1 && "Size is 1, but has more links?");
- Links.resize(1);
- } else {
- // Create the node we are going to forward to. This is required because
- // some referrers may have an offset that is > 0. By forcing them to
- // forward, the forwarder has the opportunity to correct the offset.
- 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.empty()) {
- DestNode->Links.reserve(1);
-
- DSNodeHandle NH(DestNode);
- DestNode->Links.push_back(Links[0]);
-
- // 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();
-}
-
-/// addFullGlobalsList - Compute the full set of global values that are
-/// represented by this node. Unlike getGlobalsList(), this requires fair
-/// amount of work to compute, so don't treat this method call as free.
-void DSNode::addFullGlobalsList(std::vector<GlobalValue*> &List) const {
- if (globals_begin() == globals_end()) return;
-
- EquivalenceClasses<GlobalValue*> &EC = getParentGraph()->getGlobalECs();
-
- for (globals_iterator I = globals_begin(), E = globals_end(); I != E; ++I) {
- EquivalenceClasses<GlobalValue*>::iterator ECI = EC.findValue(*I);
- if (ECI == EC.end())
- List.push_back(*I);
- else
- List.insert(List.end(), EC.member_begin(ECI), EC.member_end());
- }
-}
-
-/// addFullFunctionList - Identical to addFullGlobalsList, but only return the
-/// functions in the full list.
-void DSNode::addFullFunctionList(std::vector<Function*> &List) const {
- if (globals_begin() == globals_end()) return;
-
- EquivalenceClasses<GlobalValue*> &EC = getParentGraph()->getGlobalECs();
-
- for (globals_iterator I = globals_begin(), E = globals_end(); I != E; ++I) {
- EquivalenceClasses<GlobalValue*>::iterator ECI = EC.findValue(*I);
- if (ECI == EC.end()) {
- if (Function *F = dyn_cast<Function>(*I))
- List.push_back(F);
- } else {
- for (EquivalenceClasses<GlobalValue*>::member_iterator MI =
- EC.member_begin(ECI), E = EC.member_end(); MI != E; ++MI)
- if (Function *F = dyn_cast<Function>(*MI))
- List.push_back(F);
- }
- }
-}
-
-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;
- const TargetData &TD;
- public:
- TypeElementWalker(const Type *T, const TargetData &td) : TD(td) {
- 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->getNumElements()) {
- const StructLayout *SL = TD.getStructLayout(ST);
- SS.Offset +=
- unsigned(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 += unsigned(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->getNumElements() == 0) {
- assert(SS.Idx == 0);
- PopStackAndAdvance();
- } else {
- // Step into the structure...
- assert(SS.Idx < ST->getNumElements());
- const StructLayout *SL = TD.getStructLayout(ST);
- Stack.push_back(StackState(ST->getElementType(SS.Idx),
- SS.Offset+unsigned(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*
- unsigned(TD.getTypeSize(AT->getElementType()))));
- }
- }
- }
- }
- };
-} // end anonymous namespace
-
-/// 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. If AllowLargerT1
-/// is true, then we also allow a larger T1.
-///
-static bool ElementTypesAreCompatible(const Type *T1, const Type *T2,
- bool AllowLargerT1, const TargetData &TD){
- TypeElementWalker T1W(T1, TD), T2W(T2, TD);
-
- 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->canLosslesslyBitCastTo(T2))
- return false;
-
- T1W.StepToNextType();
- T2W.StepToNextType();
- }
-
- return AllowLargerT1 || 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) {
- DOUT << "merging " << *NewTy << " at " << Offset << " with " << *Ty << "\n";
- const TargetData &TD = getTargetData();
- // 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() ? (unsigned)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 && !isArray() &&
- "Cannot have an offset into a void node!");
-
- // If this node would have to have an unreasonable number of fields, just
- // collapse it. This can occur for fortran common blocks, which have stupid
- // things like { [100000000 x double], [1000000 x double] }.
- unsigned NumFields = (NewTySize+DS::PointerSize-1) >> DS::PointerShift;
- if (NumFields > DSAFieldLimit) {
- foldNodeCompletely();
- return true;
- }
-
- Ty = NewTy;
- NodeType &= ~Array;
- if (WillBeArray) NodeType |= Array;
- Size = NewTySize;
-
- // Calculate the number of outgoing links from this node.
- Links.resize(NumFields);
- 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 this node would have to have an unreasonable number of fields, just
- // collapse it. This can occur for fortran common blocks, which have stupid
- // things like { [100000000 x double], [1000000 x double] }.
- unsigned NumFields = (NewTySize+Offset+DS::PointerSize-1) >> DS::PointerShift;
- if (NumFields > DSAFieldLimit) {
- foldNodeCompletely();
- return true;
- }
-
- if (Offset) {
- //handle some common cases:
- // Ty: struct { t1, t2, t3, t4, ..., tn}
- // NewTy: struct { offset, stuff...}
- // try merge with NewTy: struct {t1, t2, stuff...} if offset lands exactly
- // on a field in Ty
- if (isa<StructType>(NewTy) && isa<StructType>(Ty)) {
- DOUT << "Ty: " << *Ty << "\nNewTy: " << *NewTy << "@" << Offset << "\n";
- const StructType *STy = cast<StructType>(Ty);
- const StructLayout &SL = *TD.getStructLayout(STy);
- unsigned i = SL.getElementContainingOffset(Offset);
- //Either we hit it exactly or give up
- if (SL.MemberOffsets[i] != Offset) {
- if (FoldIfIncompatible) foldNodeCompletely();
- return true;
- }
- std::vector<const Type*> nt;
- for (unsigned x = 0; x < i; ++x)
- nt.push_back(STy->getElementType(x));
- STy = cast<StructType>(NewTy);
- nt.insert(nt.end(), STy->element_begin(), STy->element_end());
- //and merge
- STy = StructType::get(nt);
- DOUT << "Trying with: " << *STy << "\n";
- return mergeTypeInfo(STy, 0);
- }
-
- //Ty: struct { t1, t2, t3 ... tn}
- //NewTy T offset x
- //try merge with NewTy: struct : {t1, t2, T} if offset lands on a field
- //in Ty
- if (isa<StructType>(Ty)) {
- DOUT << "Ty: " << *Ty << "\nNewTy: " << *NewTy << "@" << Offset << "\n";
- const StructType *STy = cast<StructType>(Ty);
- const StructLayout &SL = *TD.getStructLayout(STy);
- unsigned i = SL.getElementContainingOffset(Offset);
- //Either we hit it exactly or give up
- if (SL.MemberOffsets[i] != Offset) {
- if (FoldIfIncompatible) foldNodeCompletely();
- return true;
- }
- std::vector<const Type*> nt;
- for (unsigned x = 0; x < i; ++x)
- nt.push_back(STy->getElementType(x));
- nt.push_back(NewTy);
- //and merge
- STy = StructType::get(nt);
- DOUT << "Trying with: " << *STy << "\n";
- return mergeTypeInfo(STy, 0);
- }
-
- assert(0 &&
- "UNIMP: Trying to merge a growth type into "
- "offset != 0: Collapsing!");
- abort();
- 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.
- //
-
- const Type *OldTy = Ty;
- Ty = NewTy;
- NodeType &= ~Array;
- if (WillBeArray) NodeType |= Array;
- Size = NewTySize;
-
- // Must grow links to be the appropriate size...
- Links.resize(NumFields);
-
- // 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->getTypeID()) {
- case Type::StructTyID: {
- const StructType *STy = cast<StructType>(SubType);
- const StructLayout &SL = *TD.getStructLayout(STy);
- unsigned i = SL.getElementContainingOffset(Offset-O);
-
- // The offset we are looking for must be in the i'th element...
- SubType = STy->getElementType(i);
- O += (unsigned)SL.MemberOffsets[i];
- break;
- }
- case Type::ArrayTyID: {
- SubType = cast<ArrayType>(SubType)->getElementType();
- unsigned ElSize = (unsigned)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;
-
- // Differing function types don't require us to merge. They are not values
- // anyway.
- if (isa<FunctionType>(SubType) &&
- isa<FunctionType>(NewTy)) return false;
-
- unsigned SubTypeSize = SubType->isSized() ?
- (unsigned)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, !isArray(), TD))
- 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->getTypeID()) {
- case Type::StructTyID: {
- const StructType *STy = cast<StructType>(SubType);
- const StructLayout &SL = *TD.getStructLayout(STy);
- if (SL.MemberOffsets.size() > 1)
- NextPadSize = (unsigned)SL.MemberOffsets[1];
- else
- NextPadSize = SubTypeSize;
- NextSubType = STy->getElementType(0);
- NextSubTypeSize = (unsigned)TD.getTypeSize(NextSubType);
- break;
- }
- case Type::ArrayTyID:
- NextSubType = cast<ArrayType>(SubType)->getElementType();
- NextSubTypeSize = (unsigned)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->canLosslesslyBitCastTo(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()->retnodes_begin() != getParentGraph()->retnodes_end())
- M = getParentGraph()->retnodes_begin()->first->getParent();
-
- DOUT << "MergeTypeInfo Folding OrigTy: ";
- DEBUG(WriteTypeSymbolic(*cerr.stream(), Ty, M) << "\n due to:";
- WriteTypeSymbolic(*cerr.stream(), NewTy, M) << " @ " << Offset << "!\n"
- << "SubType: ";
- WriteTypeSymbolic(*cerr.stream(), 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) {
- if (NH.isNull()) return; // Nothing to do
-
- if (isNodeCompletelyFolded())
- Offset = 0;
-
- DSNodeHandle &ExistingEdge = getLink(Offset);
- if (!ExistingEdge.isNull()) {
- // Merge the two nodes...
- ExistingEdge.mergeWith(NH);
- } else { // No merging to perform...
- setLink(Offset, NH); // Just force a link in there...
- }
-}
-
-
-/// MergeSortedVectors - Efficiently merge a vector into another vector where
-/// duplicates are not allowed and both are sorted. This assumes that 'T's are
-/// efficiently copyable and have sane comparison semantics.
-///
-static void MergeSortedVectors(std::vector<GlobalValue*> &Dest,
- const std::vector<GlobalValue*> &Src) {
- // By far, the most common cases will be the simple ones. In these cases,
- // avoid having to allocate a temporary vector...
- //
- if (Src.empty()) { // Nothing to merge in...
- return;
- } else if (Dest.empty()) { // Just copy the result in...
- Dest = Src;
- } else if (Src.size() == 1) { // Insert a single element...
- const GlobalValue *V = Src[0];
- std::vector<GlobalValue*>::iterator I =
- std::lower_bound(Dest.begin(), Dest.end(), V);
- if (I == Dest.end() || *I != Src[0]) // If not already contained...
- Dest.insert(I, Src[0]);
- } else if (Dest.size() == 1) {
- GlobalValue *Tmp = Dest[0]; // Save value in temporary...
- Dest = Src; // Copy over list...
- std::vector<GlobalValue*>::iterator I =
- std::lower_bound(Dest.begin(), Dest.end(), Tmp);
- if (I == Dest.end() || *I != Tmp) // If not already contained...
- Dest.insert(I, Tmp);
-
- } else {
- // Make a copy to the side of Dest...
- std::vector<GlobalValue*> Old(Dest);
-
- // Make space for all of the type entries now...
- Dest.resize(Dest.size()+Src.size());
-
- // Merge the two sorted ranges together... into Dest.
- std::merge(Old.begin(), Old.end(), Src.begin(), Src.end(), Dest.begin());
-
- // Now erase any duplicate entries that may have accumulated into the
- // vectors (because they were in both of the input sets)
- Dest.erase(std::unique(Dest.begin(), Dest.end()), Dest.end());
- }
-}
-
-void DSNode::mergeGlobals(const std::vector<GlobalValue*> &RHS) {
- MergeSortedVectors(Globals, RHS);
-}
-
-// MergeNodes - Helper function for DSNode::mergeWith().
-// This function does the hard work of merging two nodes, CurNodeH
-// and NH after filtering out trivial cases and making sure that
-// CurNodeH.offset >= NH.offset.
-//
-// ***WARNING***
-// Since merging may cause either node to go away, we must always
-// use the node-handles to refer to the nodes. These node handles are
-// automatically updated during merging, so will always provide access
-// to the correct node after a merge.
-//
-void DSNode::MergeNodes(DSNodeHandle& CurNodeH, DSNodeHandle& NH) {
- assert(CurNodeH.getOffset() >= NH.getOffset() &&
- "This should have been enforced in the caller.");
- assert(CurNodeH.getNode()->getParentGraph()==NH.getNode()->getParentGraph() &&
- "Cannot merge two nodes that are not in the same graph!");
-
- // Now we know that Offset >= NH.Offset, so convert it so our "Offset" (with
- // respect to NH.Offset) is now zero. NOffset is the distance from the base
- // of our object that N starts from.
- //
- unsigned NOffset = CurNodeH.getOffset()-NH.getOffset();
- unsigned NSize = NH.getNode()->getSize();
-
- // If the two nodes are of different size, and the smaller node has the array
- // bit set, collapse!
- if (NSize != CurNodeH.getNode()->getSize()) {
-#if COLLAPSE_ARRAYS_AGGRESSIVELY
- if (NSize < CurNodeH.getNode()->getSize()) {
- if (NH.getNode()->isArray())
- NH.getNode()->foldNodeCompletely();
- } else if (CurNodeH.getNode()->isArray()) {
- NH.getNode()->foldNodeCompletely();
- }
-#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()->isDeadNode());
-
- // If we are merging a node with a completely folded node, then both nodes are
- // now completely folded.
- //
- if (CurNodeH.getNode()->isNodeCompletelyFolded()) {
- if (!NH.getNode()->isNodeCompletelyFolded()) {
- NH.getNode()->foldNodeCompletely();
- assert(NH.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?");
- NSize = NH.getNode()->getSize();
- NOffset = NH.getOffset();
- assert(NOffset == 0 && NSize == 1);
- }
-
- 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; i < N->getNumLinks(); ++i) {
- DSNodeHandle &Link = N->getLink(i << DS::PointerShift);
- if (Link.getNode()) {
- // Compute the offset into the current node at which to
- // merge this link. In the common case, this is a linear
- // relation to the offset in the original node (with
- // wrapping), but if the current node gets collapsed due to
- // recursive merging, we must make sure to merge in all remaining
- // links at offset zero.
- unsigned MergeOffset = 0;
- DSNode *CN = CurNodeH.getNode();
- if (CN->Size != 1)
- MergeOffset = ((i << DS::PointerShift)+NOffset) % CN->getSize();
- CN->addEdgeTo(MergeOffset, Link);
- }
- }
-
- // Now that there are no outgoing edges, all of the Links are dead.
- N->Links.clear();
-
- // Merge the globals list...
- if (!N->Globals.empty()) {
- CurNodeH.getNode()->mergeGlobals(N->Globals);
-
- // Delete the globals from the old node...
- std::vector<GlobalValue*>().swap(N->Globals);
- }
-}
-
-
-/// mergeWith - Merge this node and the specified node, moving all links to and
-/// from the argument node into the current node, deleting the node argument.
-/// Offset indicates what offset the specified node is to be merged into the
-/// current node.
-///
-/// The specified node may be a null pointer (in which case, we update it to
-/// point to this node).
-///
-void DSNode::mergeWith(const DSNodeHandle &NH, unsigned Offset) {
- DSNode *N = NH.getNode();
- if (N == this && NH.getOffset() == Offset)
- return; // Noop
-
- // If the RHS is a null node, make it point to this node!
- if (N == 0) {
- NH.mergeWith(DSNodeHandle(this, Offset));
- return;
- }
-
- assert(!N->isDeadNode() && !isDeadNode());
- 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.
- DOUT << "Attempting to merge two chunks of the same node together!\n";
- foldNodeCompletely();
- return;
- }
-
- // If both nodes are not at offset 0, make sure that we are merging the node
- // at an later offset into the node with the zero offset.
- //
- if (Offset < NH.getOffset()) {
- N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
- return;
- } else if (Offset == NH.getOffset() && getSize() < N->getSize()) {
- // If the offsets are the same, merge the smaller node into the bigger node
- N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
- return;
- }
-
- // Ok, now we can merge the two nodes. Use a static helper that works with
- // two node handles, since "this" may get merged away at intermediate steps.
- DSNodeHandle CurNodeH(this, Offset);
- DSNodeHandle NHCopy(NH);
- if (CurNodeH.getOffset() >= NHCopy.getOffset())
- DSNode::MergeNodes(CurNodeH, NHCopy);
- else
- DSNode::MergeNodes(NHCopy, CurNodeH);
-}
-
-
-//===----------------------------------------------------------------------===//
-// ReachabilityCloner Implementation
-//===----------------------------------------------------------------------===//
-
-DSNodeHandle ReachabilityCloner::getClonedNH(const DSNodeHandle &SrcNH) {
- if (SrcNH.isNull()) return DSNodeHandle();
- const DSNode *SN = SrcNH.getNode();
-
- DSNodeHandle &NH = NodeMap[SN];
- if (!NH.isNull()) { // Node already mapped?
- DSNode *NHN = NH.getNode();
- return DSNodeHandle(NHN, NH.getOffset()+SrcNH.getOffset());
- }
-
- // If SrcNH has globals and the destination graph has one of the same globals,
- // merge this node with the destination node, which is much more efficient.
- if (SN->globals_begin() != SN->globals_end()) {
- DSScalarMap &DestSM = Dest.getScalarMap();
- for (DSNode::globals_iterator I = SN->globals_begin(),E = SN->globals_end();
- I != E; ++I) {
- GlobalValue *GV = *I;
- DSScalarMap::iterator GI = DestSM.find(GV);
- if (GI != DestSM.end() && !GI->second.isNull()) {
- // We found one, use merge instead!
- merge(GI->second, Src.getNodeForValue(GV));
- assert(!NH.isNull() && "Didn't merge node!");
- DSNode *NHN = NH.getNode();
- return DSNodeHandle(NHN, NH.getOffset()+SrcNH.getOffset());
- }
- }
- }
-
- DSNode *DN = new DSNode(*SN, &Dest, true /* Null out all links */);
- DN->maskNodeTypes(BitsToKeep);
- NH = DN;
-
- // Next, recursively clone all outgoing links as necessary. Note that
- // adding these links can cause the node to collapse itself at any time, and
- // the current node may be merged with arbitrary other nodes. For this
- // reason, we must always go through NH.
- DN = 0;
- for (unsigned i = 0, e = SN->getNumLinks(); i != e; ++i) {
- const DSNodeHandle &SrcEdge = SN->getLink(i << DS::PointerShift);
- if (!SrcEdge.isNull()) {
- const DSNodeHandle &DestEdge = getClonedNH(SrcEdge);
- // 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 = NH.getNode();
- if (CN->getSize() != 1)
- MergeOffset = ((i << DS::PointerShift)+NH.getOffset()) % CN->getSize();
- CN->addEdgeTo(MergeOffset, DestEdge);
- }
- }
-
- // If this node contains any globals, make sure they end up in the scalar
- // map with the correct offset.
- for (DSNode::globals_iterator I = SN->globals_begin(), E = SN->globals_end();
- I != E; ++I) {
- GlobalValue *GV = *I;
- const DSNodeHandle &SrcGNH = Src.getNodeForValue(GV);
- DSNodeHandle &DestGNH = NodeMap[SrcGNH.getNode()];
- assert(DestGNH.getNode() == NH.getNode() &&"Global mapping inconsistent");
- Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
- DestGNH.getOffset()+SrcGNH.getOffset()));
- }
- NH.getNode()->mergeGlobals(SN->getGlobalsList());
-
- return DSNodeHandle(NH.getNode(), NH.getOffset()+SrcNH.getOffset());
-}
-
-void ReachabilityCloner::merge(const DSNodeHandle &NH,
- const DSNodeHandle &SrcNH) {
- if (SrcNH.isNull()) return; // Noop
- if (NH.isNull()) {
- // If there is no destination node, just clone the source and assign the
- // destination node to be it.
- NH.mergeWith(getClonedNH(SrcNH));
- return;
- }
-
- // Okay, at this point, we know that we have both a destination and a source
- // node that need to be merged. Check to see if the source node has already
- // been cloned.
- const DSNode *SN = SrcNH.getNode();
- DSNodeHandle &SCNH = NodeMap[SN]; // SourceClonedNodeHandle
- if (!SCNH.isNull()) { // Node already cloned?
- DSNode *SCNHN = SCNH.getNode();
- NH.mergeWith(DSNodeHandle(SCNHN,
- SCNH.getOffset()+SrcNH.getOffset()));
- return; // Nothing to do!
- }
-
- // Okay, so the source node has not already been cloned. Instead of creating
- // a new DSNode, only to merge it into the one we already have, try to perform
- // the merge in-place. The only case we cannot handle here is when the offset
- // into the existing node is less than the offset into the virtual node we are
- // merging in. In this case, we have to extend the existing node, which
- // requires an allocation anyway.
- DSNode *DN = NH.getNode(); // Make sure the Offset is up-to-date
- if (NH.getOffset() >= SrcNH.getOffset()) {
- if (!DN->isNodeCompletelyFolded()) {
- // Make sure the destination node is folded if the source node is folded.
- if (SN->isNodeCompletelyFolded()) {
- DN->foldNodeCompletely();
- DN = NH.getNode();
- } else if (SN->getSize() != DN->getSize()) {
- // If the two nodes are of different size, and the smaller node has the
- // array bit set, collapse!
-#if COLLAPSE_ARRAYS_AGGRESSIVELY
- if (SN->getSize() < DN->getSize()) {
- if (SN->isArray()) {
- DN->foldNodeCompletely();
- DN = NH.getNode();
- }
- } else if (DN->isArray()) {
- DN->foldNodeCompletely();
- DN = NH.getNode();
- }
-#endif
- }
-
- // Merge the type entries of the two nodes together...
- if (SN->getType() != Type::VoidTy && !DN->isNodeCompletelyFolded()) {
- DN->mergeTypeInfo(SN->getType(), NH.getOffset()-SrcNH.getOffset());
- DN = NH.getNode();
- }
- }
-
- assert(!DN->isDeadNode());
-
- // Merge the NodeType information.
- DN->mergeNodeFlags(SN->getNodeFlags() & BitsToKeep);
-
- // Before we start merging outgoing links and updating the scalar map, make
- // sure it is known that this is the representative node for the src node.
- SCNH = DSNodeHandle(DN, NH.getOffset()-SrcNH.getOffset());
-
- // If the source node contains any globals, make sure they end up in the
- // scalar map with the correct offset.
- if (SN->globals_begin() != SN->globals_end()) {
- // Update the globals in the destination node itself.
- DN->mergeGlobals(SN->getGlobalsList());
-
- // Update the scalar map for the graph we are merging the source node
- // into.
- for (DSNode::globals_iterator I = SN->globals_begin(),
- E = SN->globals_end(); I != E; ++I) {
- GlobalValue *GV = *I;
- const DSNodeHandle &SrcGNH = Src.getNodeForValue(GV);
- DSNodeHandle &DestGNH = NodeMap[SrcGNH.getNode()];
- assert(DestGNH.getNode()==NH.getNode() &&"Global mapping inconsistent");
- Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
- DestGNH.getOffset()+SrcGNH.getOffset()));
- }
- NH.getNode()->mergeGlobals(SN->getGlobalsList());
- }
- } else {
- // We cannot handle this case without allocating a temporary node. Fall
- // back on being simple.
- DSNode *NewDN = new DSNode(*SN, &Dest, true /* Null out all links */);
- NewDN->maskNodeTypes(BitsToKeep);
-
- unsigned NHOffset = NH.getOffset();
- NH.mergeWith(DSNodeHandle(NewDN, SrcNH.getOffset()));
-
- assert(NH.getNode() &&
- (NH.getOffset() > NHOffset ||
- (NH.getOffset() == 0 && NH.getNode()->isNodeCompletelyFolded())) &&
- "Merging did not adjust the offset!");
-
- // Before we start merging outgoing links and updating the scalar map, make
- // sure it is known that this is the representative node for the src node.
- SCNH = DSNodeHandle(NH.getNode(), NH.getOffset()-SrcNH.getOffset());
-
- // If the source node contained any globals, make sure to create entries
- // in the scalar map for them!
- for (DSNode::globals_iterator I = SN->globals_begin(),
- E = SN->globals_end(); I != E; ++I) {
- GlobalValue *GV = *I;
- const DSNodeHandle &SrcGNH = Src.getNodeForValue(GV);
- DSNodeHandle &DestGNH = NodeMap[SrcGNH.getNode()];
- assert(DestGNH.getNode()==NH.getNode() &&"Global mapping inconsistent");
- assert(SrcGNH.getNode() == SN && "Global mapping inconsistent");
- Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
- DestGNH.getOffset()+SrcGNH.getOffset()));
- }
- }
-
-
- // Next, recursively merge all outgoing links as necessary. Note that
- // adding these links can cause the destination node to collapse itself at
- // any time, and the current node may be merged with arbitrary other nodes.
- // For this reason, we must always go through NH.
- DN = 0;
- for (unsigned i = 0, e = SN->getNumLinks(); i != e; ++i) {
- const DSNodeHandle &SrcEdge = SN->getLink(i << DS::PointerShift);
- if (!SrcEdge.isNull()) {
- // 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.
- DSNode *CN = SCNH.getNode();
- unsigned MergeOffset =
- ((i << DS::PointerShift)+SCNH.getOffset()) % CN->getSize();
-
- DSNodeHandle Tmp = CN->getLink(MergeOffset);
- if (!Tmp.isNull()) {
- // Perform the recursive merging. Make sure to create a temporary NH,
- // because the Link can disappear in the process of recursive merging.
- merge(Tmp, SrcEdge);
- } else {
- Tmp.mergeWith(getClonedNH(SrcEdge));
- // Merging this could cause all kinds of recursive things to happen,
- // culminating in the current node being eliminated. Since this is
- // possible, make sure to reaquire the link from 'CN'.
-
- unsigned MergeOffset = 0;
- CN = SCNH.getNode();
- MergeOffset = ((i << DS::PointerShift)+SCNH.getOffset()) %CN->getSize();
- CN->getLink(MergeOffset).mergeWith(Tmp);
- }
- }
- }
-}
-
-/// mergeCallSite - Merge the nodes reachable from the specified src call
-/// site into the nodes reachable from DestCS.
-void ReachabilityCloner::mergeCallSite(DSCallSite &DestCS,
- const DSCallSite &SrcCS) {
- merge(DestCS.getRetVal(), SrcCS.getRetVal());
- unsigned MinArgs = DestCS.getNumPtrArgs();
- if (SrcCS.getNumPtrArgs() < MinArgs) MinArgs = SrcCS.getNumPtrArgs();
-
- for (unsigned a = 0; a != MinArgs; ++a)
- merge(DestCS.getPtrArg(a), SrcCS.getPtrArg(a));
-
- for (unsigned a = MinArgs, e = SrcCS.getNumPtrArgs(); a != e; ++a)
- DestCS.addPtrArg(getClonedNH(SrcCS.getPtrArg(a)));
-}
-
-
-//===----------------------------------------------------------------------===//
-// DSCallSite Implementation
-//===----------------------------------------------------------------------===//
-
-// Define here to avoid including iOther.h and BasicBlock.h in DSGraph.h
-Function &DSCallSite::getCaller() const {
- return *Site.getInstruction()->getParent()->getParent();
-}
-
-void DSCallSite::InitNH(DSNodeHandle &NH, const DSNodeHandle &Src,
- ReachabilityCloner &RC) {
- NH = RC.getClonedNH(Src);
-}
-
-//===----------------------------------------------------------------------===//
-// DSGraph Implementation
-//===----------------------------------------------------------------------===//
-
-/// 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 retnodes_begin()->first->getName();
- default:
- std::string Return;
- for (DSGraph::retnodes_iterator I = retnodes_begin();
- I != retnodes_end(); ++I)
- Return += I->first->getName() + " ";
- Return.erase(Return.end()-1, Return.end()); // Remove last space character
- return Return;
- }
-}
-
-
-DSGraph::DSGraph(const DSGraph &G, EquivalenceClasses<GlobalValue*> &ECs,
- unsigned CloneFlags)
- : GlobalsGraph(0), ScalarMap(ECs), TD(G.TD) {
- PrintAuxCalls = false;
- cloneInto(G, CloneFlags);
-}
-
-DSGraph::~DSGraph() {
- FunctionCalls.clear();
- AuxFunctionCalls.clear();
- ScalarMap.clear();
- ReturnNodes.clear();
-
- // Drop all intra-node references, so that assertions don't fail...
- for (node_iterator NI = node_begin(), E = node_end(); NI != E; ++NI)
- NI->dropAllReferences();
-
- // Free all of the nodes.
- Nodes.clear();
-}
-
-// dump - Allow inspection of graph in a debugger.
-void DSGraph::dump() const { print(cerr); }
-
-
-/// remapLinks - Change all of the Links in the current node according to the
-/// specified mapping.
-///
-void DSNode::remapLinks(DSGraph::NodeMapTy &OldNodeMap) {
- for (unsigned i = 0, e = Links.size(); i != e; ++i)
- if (DSNode *N = Links[i].getNode()) {
- DSGraph::NodeMapTy::const_iterator ONMI = OldNodeMap.find(N);
- if (ONMI != OldNodeMap.end()) {
- DSNode *ONMIN = ONMI->second.getNode();
- Links[i].setTo(ONMIN, Links[i].getOffset()+ONMI->second.getOffset());
- }
- }
-}
-
-/// addObjectToGraph - This method can be used to add global, stack, and heap
-/// objects to the graph. This can be used when updating DSGraphs due to the
-/// introduction of new temporary objects. The new object is not pointed to
-/// and does not point to any other objects in the graph.
-DSNode *DSGraph::addObjectToGraph(Value *Ptr, bool UseDeclaredType) {
- assert(isa<PointerType>(Ptr->getType()) && "Ptr is not a pointer!");
- const Type *Ty = cast<PointerType>(Ptr->getType())->getElementType();
- DSNode *N = new DSNode(UseDeclaredType ? Ty : 0, this);
- assert(ScalarMap[Ptr].isNull() && "Object already in this graph!");
- ScalarMap[Ptr] = N;
-
- if (GlobalValue *GV = dyn_cast<GlobalValue>(Ptr)) {
- N->addGlobal(GV);
- } else if (isa<MallocInst>(Ptr)) {
- N->setHeapNodeMarker();
- } else if (isa<AllocaInst>(Ptr)) {
- N->setAllocaNodeMarker();
- } else {
- assert(0 && "Illegal memory object input!");
- }
- return N;
-}
-
-
-/// cloneInto - Clone the specified DSGraph into the current graph. The
-/// translated ScalarMap for the old function is filled into the ScalarMap
-/// for the graph, 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, unsigned CloneFlags) {
- TIME_REGION(X, "cloneInto");
- assert(&G != this && "Cannot clone graph into itself!");
-
- NodeMapTy OldNodeMap;
-
- // 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 (node_const_iterator I = G.node_begin(), E = G.node_end(); I != E; ++I) {
- assert(!I->isForwarding() &&
- "Forward nodes shouldn't be in node list!");
- DSNode *New = new DSNode(*I, this);
- New->maskNodeTypes(~BitsToClear);
- OldNodeMap[I] = New;
- }
-
-#ifndef NDEBUG
- Timer::addPeakMemoryMeasurement();
-#endif
-
- // Rewrite the links in the new nodes to point into the current graph now.
- // Note that we don't loop over the node's list to do this. The problem is
- // that remaping links can cause recursive merging to happen, which means
- // that node_iterator's can get easily invalidated! Because of this, we
- // loop over the OldNodeMap, which contains all of the new nodes as the
- // .second element of the map elements. Also note that if we remap a node
- // more than once, we won't break anything.
- for (NodeMapTy::iterator I = OldNodeMap.begin(), E = OldNodeMap.end();
- I != E; ++I)
- I->second.getNode()->remapLinks(OldNodeMap);
-
- // Copy the scalar map... merging all of the global nodes...
- for (DSScalarMap::const_iterator I = G.ScalarMap.begin(),
- E = G.ScalarMap.end(); I != E; ++I) {
- DSNodeHandle &MappedNode = OldNodeMap[I->second.getNode()];
- DSNodeHandle &H = ScalarMap.getRawEntryRef(I->first);
- DSNode *MappedNodeN = MappedNode.getNode();
- H.mergeWith(DSNodeHandle(MappedNodeN,
- I->second.getOffset()+MappedNode.getOffset()));
- }
-
- if (!(CloneFlags & DontCloneCallNodes)) {
- // Copy the function calls list.
- for (fc_iterator I = G.fc_begin(), E = G.fc_end(); I != E; ++I)
- FunctionCalls.push_back(DSCallSite(*I, OldNodeMap));
- }
-
- if (!(CloneFlags & DontCloneAuxCallNodes)) {
- // Copy the auxiliary function calls list.
- for (afc_iterator I = G.afc_begin(), E = G.afc_end(); I != E; ++I)
- AuxFunctionCalls.push_back(DSCallSite(*I, OldNodeMap));
- }
-
- // Map the return node pointers over...
- for (retnodes_iterator I = G.retnodes_begin(),
- E = G.retnodes_end(); I != E; ++I) {
- const DSNodeHandle &Ret = I->second;
- DSNodeHandle &MappedRet = OldNodeMap[Ret.getNode()];
- DSNode *MappedRetN = MappedRet.getNode();
- ReturnNodes.insert(std::make_pair(I->first,
- DSNodeHandle(MappedRetN,
- MappedRet.getOffset()+Ret.getOffset())));
- }
-}
-
-/// spliceFrom - Logically perform the operation of cloning the RHS graph into
-/// this graph, then clearing the RHS graph. Instead of performing this as
-/// two seperate operations, do it as a single, much faster, one.
-///
-void DSGraph::spliceFrom(DSGraph &RHS) {
- // Change all of the nodes in RHS to think we are their parent.
- for (NodeListTy::iterator I = RHS.Nodes.begin(), E = RHS.Nodes.end();
- I != E; ++I)
- I->setParentGraph(this);
- // Take all of the nodes.
- Nodes.splice(Nodes.end(), RHS.Nodes);
-
- // Take all of the calls.
- FunctionCalls.splice(FunctionCalls.end(), RHS.FunctionCalls);
- AuxFunctionCalls.splice(AuxFunctionCalls.end(), RHS.AuxFunctionCalls);
-
- // Take all of the return nodes.
- if (ReturnNodes.empty()) {
- ReturnNodes.swap(RHS.ReturnNodes);
- } else {
- ReturnNodes.insert(RHS.ReturnNodes.begin(), RHS.ReturnNodes.end());
- RHS.ReturnNodes.clear();
- }
-
- // Merge the scalar map in.
- ScalarMap.spliceFrom(RHS.ScalarMap);
-}
-
-/// spliceFrom - Copy all entries from RHS, then clear RHS.
-///
-void DSScalarMap::spliceFrom(DSScalarMap &RHS) {
- // Special case if this is empty.
- if (ValueMap.empty()) {
- ValueMap.swap(RHS.ValueMap);
- GlobalSet.swap(RHS.GlobalSet);
- } else {
- GlobalSet.insert(RHS.GlobalSet.begin(), RHS.GlobalSet.end());
- for (ValueMapTy::iterator I = RHS.ValueMap.begin(), E = RHS.ValueMap.end();
- I != E; ++I)
- ValueMap[I->first].mergeWith(I->second);
- RHS.ValueMap.clear();
- }
-}
-
-
-/// getFunctionArgumentsForCall - Given a function that is currently in this
-/// graph, return the DSNodeHandles that correspond to the pointer-compatible
-/// function arguments. The vector is filled in with the return value (or
-/// null if it is not pointer compatible), followed by all of the
-/// pointer-compatible arguments.
-void DSGraph::getFunctionArgumentsForCall(Function *F,
- std::vector<DSNodeHandle> &Args) const {
- Args.push_back(getReturnNodeFor(*F));
- for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
- AI != E; ++AI)
- if (isPointerType(AI->getType())) {
- Args.push_back(getNodeForValue(AI));
- assert(!Args.back().isNull() && "Pointer argument w/o scalarmap entry!?");
- }
-}
-
-namespace {
- // HackedGraphSCCFinder - This is used to find nodes that have a path from the
- // node to a node cloned by the ReachabilityCloner object contained. To be
- // extra obnoxious it ignores edges from nodes that are globals, and truncates
- // search at RC marked nodes. This is designed as an object so that
- // intermediate results can be memoized across invocations of
- // PathExistsToClonedNode.
- struct HackedGraphSCCFinder {
- ReachabilityCloner &RC;
- unsigned CurNodeId;
- std::vector<const DSNode*> SCCStack;
- std::map<const DSNode*, std::pair<unsigned, bool> > NodeInfo;
-
- HackedGraphSCCFinder(ReachabilityCloner &rc) : RC(rc), CurNodeId(1) {
- // Remove null pointer as a special case.
- NodeInfo[0] = std::make_pair(0, false);
- }
-
- std::pair<unsigned, bool> &VisitForSCCs(const DSNode *N);
-
- bool PathExistsToClonedNode(const DSNode *N) {
- return VisitForSCCs(N).second;
- }
-
- bool PathExistsToClonedNode(const DSCallSite &CS) {
- if (PathExistsToClonedNode(CS.getRetVal().getNode()))
- return true;
- for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i)
- if (PathExistsToClonedNode(CS.getPtrArg(i).getNode()))
- return true;
- return false;
- }
- };
-}
-
-std::pair<unsigned, bool> &HackedGraphSCCFinder::
-VisitForSCCs(const DSNode *N) {
- std::map<const DSNode*, std::pair<unsigned, bool> >::iterator
- NodeInfoIt = NodeInfo.lower_bound(N);
- if (NodeInfoIt != NodeInfo.end() && NodeInfoIt->first == N)
- return NodeInfoIt->second;
-
- unsigned Min = CurNodeId++;
- unsigned MyId = Min;
- std::pair<unsigned, bool> &ThisNodeInfo =
- NodeInfo.insert(NodeInfoIt,
- std::make_pair(N, std::make_pair(MyId, false)))->second;
-
- // Base case: if we find a global, this doesn't reach the cloned graph
- // portion.
- if (N->isGlobalNode()) {
- ThisNodeInfo.second = false;
- return ThisNodeInfo;
- }
-
- // Base case: if this does reach the cloned graph portion... it does. :)
- if (RC.hasClonedNode(N)) {
- ThisNodeInfo.second = true;
- return ThisNodeInfo;
- }
-
- SCCStack.push_back(N);
-
- // Otherwise, check all successors.
- bool AnyDirectSuccessorsReachClonedNodes = false;
- for (DSNode::const_edge_iterator EI = N->edge_begin(), EE = N->edge_end();
- EI != EE; ++EI)
- if (DSNode *Succ = EI->getNode()) {
- std::pair<unsigned, bool> &SuccInfo = VisitForSCCs(Succ);
- if (SuccInfo.first < Min) Min = SuccInfo.first;
- AnyDirectSuccessorsReachClonedNodes |= SuccInfo.second;
- }
-
- if (Min != MyId)
- return ThisNodeInfo; // Part of a large SCC. Leave self on stack.
-
- if (SCCStack.back() == N) { // Special case single node SCC.
- SCCStack.pop_back();
- ThisNodeInfo.second = AnyDirectSuccessorsReachClonedNodes;
- return ThisNodeInfo;
- }
-
- // Find out if any direct successors of any node reach cloned nodes.
- if (!AnyDirectSuccessorsReachClonedNodes)
- for (unsigned i = SCCStack.size()-1; SCCStack[i] != N; --i)
- for (DSNode::const_edge_iterator EI = N->edge_begin(), EE = N->edge_end();
- EI != EE; ++EI)
- if (DSNode *N = EI->getNode())
- if (NodeInfo[N].second) {
- AnyDirectSuccessorsReachClonedNodes = true;
- goto OutOfLoop;
- }
-OutOfLoop:
- // If any successor reaches a cloned node, mark all nodes in this SCC as
- // reaching the cloned node.
- if (AnyDirectSuccessorsReachClonedNodes)
- while (SCCStack.back() != N) {
- NodeInfo[SCCStack.back()].second = true;
- SCCStack.pop_back();
- }
- SCCStack.pop_back();
- ThisNodeInfo.second = true;
- return ThisNodeInfo;
-}
-
-/// mergeInCallFromOtherGraph - This graph merges in the minimal number of
-/// nodes from G2 into 'this' graph, merging the bindings specified by the
-/// call site (in this graph) with the bindings specified by the vector in G2.
-/// The two DSGraphs must be different.
-///
-void DSGraph::mergeInGraph(const DSCallSite &CS,
- std::vector<DSNodeHandle> &Args,
- const DSGraph &Graph, unsigned CloneFlags) {
- TIME_REGION(X, "mergeInGraph");
-
- assert((CloneFlags & DontCloneCallNodes) &&
- "Doesn't support copying of call nodes!");
-
- // If this is not a recursive call, clone the graph into this graph...
- if (&Graph == this) {
- // Merge the return value with the return value of the context.
- Args[0].mergeWith(CS.getRetVal());
-
- // Resolve all of the function arguments.
- for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i) {
- if (i == Args.size()-1)
- break;
-
- // Add the link from the argument scalar to the provided value.
- Args[i+1].mergeWith(CS.getPtrArg(i));
- }
- return;
- }
-
- // 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.
- ReachabilityCloner RC(*this, Graph, CloneFlags);
-
- // Map the return node pointer over.
- if (!CS.getRetVal().isNull())
- RC.merge(CS.getRetVal(), Args[0]);
-
- // Map over all of the arguments.
- for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i) {
- if (i == Args.size()-1)
- break;
-
- // Add the link from the argument scalar to the provided value.
- RC.merge(CS.getPtrArg(i), Args[i+1]);
- }
-
- // We generally don't want to copy global nodes or aux calls from the callee
- // graph to the caller graph. However, we have to copy them if there is a
- // path from the node to a node we have already copied which does not go
- // through another global. Compute the set of node that can reach globals and
- // aux call nodes to copy over, then do it.
- std::vector<const DSCallSite*> AuxCallToCopy;
- std::vector<GlobalValue*> GlobalsToCopy;
-
- // NodesReachCopiedNodes - Memoize results for efficiency. Contains a
- // true/false value for every visited node that reaches a copied node without
- // going through a global.
- HackedGraphSCCFinder SCCFinder(RC);
-
- if (!(CloneFlags & DontCloneAuxCallNodes))
- for (afc_iterator I = Graph.afc_begin(), E = Graph.afc_end(); I!=E; ++I)
- if (SCCFinder.PathExistsToClonedNode(*I))
- AuxCallToCopy.push_back(&*I);
-// else if (I->isIndirectCall()){
-// //If the call node doesn't have any callees, clone it
-// std::vector< Function *> List;
-// I->getCalleeNode()->addFullFunctionList(List);
-// if (!List.size())
-// AuxCallToCopy.push_back(&*I);
-// }
-
- const DSScalarMap &GSM = Graph.getScalarMap();
- for (DSScalarMap::global_iterator GI = GSM.global_begin(),
- E = GSM.global_end(); GI != E; ++GI) {
- DSNode *GlobalNode = Graph.getNodeForValue(*GI).getNode();
- for (DSNode::edge_iterator EI = GlobalNode->edge_begin(),
- EE = GlobalNode->edge_end(); EI != EE; ++EI)
- if (SCCFinder.PathExistsToClonedNode(EI->getNode())) {
- GlobalsToCopy.push_back(*GI);
- break;
- }
- }
-
- // Copy aux calls that are needed.
- for (unsigned i = 0, e = AuxCallToCopy.size(); i != e; ++i)
- AuxFunctionCalls.push_back(DSCallSite(*AuxCallToCopy[i], RC));
-
- // Copy globals that are needed.
- for (unsigned i = 0, e = GlobalsToCopy.size(); i != e; ++i)
- RC.getClonedNH(Graph.getNodeForValue(GlobalsToCopy[i]));
-}
-
-
-
-/// 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) {
- // Set up argument bindings.
- std::vector<DSNodeHandle> Args;
- Graph.getFunctionArgumentsForCall(&F, Args);
-
- mergeInGraph(CS, Args, Graph, CloneFlags);
-}
-
-/// 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::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I)
- if (isPointerType(I->getType()))
- Args.push_back(getNodeForValue(I));
-
- return DSCallSite(CallSite(), getReturnNodeFor(F), &F, Args);
-}
-
-/// getDSCallSiteForCallSite - Given an LLVM CallSite object that is live in
-/// the context of this graph, return the DSCallSite for it.
-DSCallSite DSGraph::getDSCallSiteForCallSite(CallSite CS) const {
- DSNodeHandle RetVal;
- Instruction *I = CS.getInstruction();
- if (isPointerType(I->getType()))
- RetVal = getNodeForValue(I);
-
- std::vector<DSNodeHandle> Args;
- Args.reserve(CS.arg_end()-CS.arg_begin());
-
- // Calculate the arguments vector...
- for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); I != E; ++I)
- if (isPointerType((*I)->getType()))
- if (isa<ConstantPointerNull>(*I))
- Args.push_back(DSNodeHandle());
- else
- Args.push_back(getNodeForValue(*I));
-
- // Add a new function call entry...
- if (Function *F = CS.getCalledFunction())
- return DSCallSite(CS, RetVal, F, Args);
- else
- return DSCallSite(CS, RetVal,
- getNodeForValue(CS.getCalledValue()).getNode(), Args);
-}
-
-
-
-// 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 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->isIncomplete()) return;
-
- // Actually mark the node
- N->setIncompleteMarker();
-
- // Recursively process children...
- for (DSNode::edge_iterator I = N->edge_begin(),E = N->edge_end(); I != E; ++I)
- if (DSNode *DSN = 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
-// nodes that are reachable through three sources of "unknownness":
-//
-// Global Variables, Function Calls, and Incoming Arguments
-//
-// For any node that may have unknown components (because something outside the
-// scope of current analysis may have modified it), the 'Incomplete' flag is
-// added to the NodeType.
-//
-void DSGraph::markIncompleteNodes(unsigned Flags) {
- // Mark any incoming arguments as incomplete.
- if (Flags & DSGraph::MarkFormalArgs)
- for (ReturnNodesTy::iterator FI = ReturnNodes.begin(), E =ReturnNodes.end();
- FI != E; ++FI) {
- Function &F = *FI->first;
- for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end();
- I != E; ++I)
- if (isPointerType(I->getType()))
- markIncompleteNode(getNodeForValue(I).getNode());
- markIncompleteNode(FI->second.getNode());
- }
-
- // Mark stuff passed into functions calls as being incomplete.
- if (!shouldPrintAuxCalls())
- for (std::list<DSCallSite>::iterator I = FunctionCalls.begin(),
- E = FunctionCalls.end(); I != E; ++I)
- markIncomplete(*I);
- else
- for (std::list<DSCallSite>::iterator I = AuxFunctionCalls.begin(),
- E = AuxFunctionCalls.end(); I != E; ++I)
- markIncomplete(*I);
-
- // Mark all global nodes as incomplete.
- for (DSScalarMap::global_iterator I = ScalarMap.global_begin(),
- E = ScalarMap.global_end(); I != E; ++I)
- if (GlobalVariable *GV = dyn_cast<GlobalVariable>(*I))
- if (!GV->hasInitializer() || // Always mark external globals incomp.
- (!GV->isConstant() && (Flags & DSGraph::IgnoreGlobals) == 0))
- markIncompleteNode(ScalarMap[GV].getNode());
-}
-
-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.setTo(0, 0); // Kill the edge!
-}
-
-static inline bool nodeContainsExternalFunction(const DSNode *N) {
- std::vector<Function*> Funcs;
- N->addFullFunctionList(Funcs);
- for (unsigned i = 0, e = Funcs.size(); i != e; ++i)
- if (Funcs[i]->isExternal()) return true;
- return false;
-}
-
-static void removeIdenticalCalls(std::list<DSCallSite> &Calls) {
- // Remove trivially identical function calls
- Calls.sort(); // Sort by callee as primary key!
-
- // Scan the call list cleaning it up as necessary...
- DSNodeHandle LastCalleeNode;
-#if 0
- Function *LastCalleeFunc = 0;
- unsigned NumDuplicateCalls = 0;
-#endif
- bool LastCalleeContainsExternalFunction = false;
-
- unsigned NumDeleted = 0;
- for (std::list<DSCallSite>::iterator I = Calls.begin(), E = Calls.end();
- I != E;) {
- DSCallSite &CS = *I;
- std::list<DSCallSite>::iterator OldIt = I++;
-
- if (!CS.isIndirectCall()) {
- LastCalleeNode = 0;
- } else {
- DSNode *Callee = CS.getCalleeNode();
-
- // If the Callee is a useless edge, this must be an unreachable call site,
- // eliminate it.
- if (Callee->getNumReferrers() == 1 && Callee->isComplete() &&
- Callee->getGlobalsList().empty()) { // No useful info?
- DOUT << "WARNING: Useless call site found.\n";
- Calls.erase(OldIt);
- ++NumDeleted;
- continue;
- }
-
- // If the last call site in the list has the same callee as this one, and
- // if the callee contains an external function, it will never be
- // resolvable, just merge the call sites.
- if (!LastCalleeNode.isNull() && LastCalleeNode.getNode() == Callee) {
- LastCalleeContainsExternalFunction =
- nodeContainsExternalFunction(Callee);
-
- std::list<DSCallSite>::iterator PrevIt = OldIt;
- --PrevIt;
- PrevIt->mergeWith(CS);
-
- // No need to keep this call anymore.
- Calls.erase(OldIt);
- ++NumDeleted;
- continue;
- } else {
- LastCalleeNode = Callee;
- }
- }
-
- // 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 0
- // 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();
- }
-
- // It is not clear why, but enabling this code makes DSA really
- // sensitive to node forwarding. Basically, with this enabled, DSA
- // performs different number of inlinings based on which nodes are
- // forwarding or not. This is clearly a problem, so this code is
- // disabled until this can be resolved.
-#if 1
- if (LastCalleeContainsExternalFunction
-#if 0
- ||
- // This should be more than enough context sensitivity!
- // FIXME: Evaluate how many times this is tripped!
- NumDuplicateCalls > 20
-#endif
- ) {
-
- std::list<DSCallSite>::iterator PrevIt = OldIt;
- --PrevIt;
- PrevIt->mergeWith(CS);
-
- // No need to keep this call anymore.
- Calls.erase(OldIt);
- ++NumDeleted;
- continue;
- }
-#endif
- } else {
- if (CS.isDirectCall()) {
- LastCalleeFunc = CS.getCalleeFunc();
- LastCalleeNode = 0;
- } else {
- LastCalleeNode = CS.getCalleeNode();
- LastCalleeFunc = 0;
- }
- NumDuplicateCalls = 0;
- }
-#endif
-
- if (I != Calls.end() && CS == *I) {
- LastCalleeNode = 0;
- Calls.erase(OldIt);
- ++NumDeleted;
- continue;
- }
- }
-
- // Resort now that we simplified things.
- Calls.sort();
-
- // Now that we are in sorted order, eliminate duplicates.
- std::list<DSCallSite>::iterator CI = Calls.begin(), CE = Calls.end();
- if (CI != CE)
- while (1) {
- std::list<DSCallSite>::iterator OldIt = CI++;
- if (CI == CE) break;
-
- // If this call site is now the same as the previous one, we can delete it
- // as a duplicate.
- if (*OldIt == *CI) {
- Calls.erase(CI);
- CI = OldIt;
- ++NumDeleted;
- }
- }
-
- //Calls.erase(std::unique(Calls.begin(), Calls.end()), Calls.end());
-
- // Track the number of call nodes merged away...
- NumCallNodesMerged += NumDeleted;
-
- if (NumDeleted)
- DOUT << "Merged " << NumDeleted << " 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() {
- TIME_REGION(X, "removeTriviallyDeadNodes");
-
-#if 0
- /// NOTE: This code is disabled. This slows down DSA on 177.mesa
- /// substantially!
-
- // Loop over all of the nodes in the graph, calling getNode on each field.
- // This will cause all nodes to update their forwarding edges, causing
- // forwarded nodes to be delete-able.
- { TIME_REGION(X, "removeTriviallyDeadNodes:node_iterate");
- for (node_iterator NI = node_begin(), E = node_end(); NI != E; ++NI) {
- DSNode &N = *NI;
- for (unsigned l = 0, e = N.getNumLinks(); l != e; ++l)
- N.getLink(l*N.getPointerSize()).getNode();
- }
- }
-
- // NOTE: This code is disabled. Though it should, in theory, allow us to
- // remove more nodes down below, the scan of the scalar map is incredibly
- // expensive for certain programs (with large SCCs). In the future, if we can
- // make the scalar map scan more efficient, then we can reenable this.
- { TIME_REGION(X, "removeTriviallyDeadNodes:scalarmap");
-
- // Likewise, forward any edges from the scalar nodes. While we are at it,
- // clean house a bit.
- for (DSScalarMap::iterator I = ScalarMap.begin(),E = ScalarMap.end();I != E;){
- I->second.getNode();
- ++I;
- }
- }
-#endif
- bool isGlobalsGraph = !GlobalsGraph;
-
- for (NodeListTy::iterator NI = Nodes.begin(), E = Nodes.end(); NI != E; ) {
- DSNode &Node = *NI;
-
- // 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) {
- ++NI;
- 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.getGlobalsList().size()) {
- const std::vector<GlobalValue*> &Globals = Node.getGlobalsList();
-
- // 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 = getNodeForValue(Globals[j]).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();
- ++NumTrivialGlobalDNE;
- }
- }
- }
-
- if (Node.getNodeFlags() == 0 && Node.hasNoReferrers()) {
- // This node is dead!
- NI = Nodes.erase(NI); // Erase & remove from node list.
- ++NumTrivialDNE;
- } else {
- ++NI;
- }
- }
-
- removeIdenticalCalls(FunctionCalls);
- removeIdenticalCalls(AuxFunctionCalls);
-}
-
-
-/// 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<const DSNode*> &ReachableNodes) const {
- if (this == 0) return;
- assert(getForwardNode() == 0 && "Cannot mark a forwarded node!");
- if (ReachableNodes.insert(this).second) // Is newly reachable?
- for (DSNode::const_edge_iterator I = edge_begin(), E = edge_end();
- I != E; ++I)
- I->getNode()->markReachableNodes(ReachableNodes);
-}
-
-void DSCallSite::markReachableNodes(hash_set<const DSNode*> &Nodes) const {
- getRetVal().getNode()->markReachableNodes(Nodes);
- if (isIndirectCall()) getCalleeNode()->markReachableNodes(Nodes);
-
- for (unsigned i = 0, e = getNumPtrArgs(); i != e; ++i)
- getPtrArg(i).getNode()->markReachableNodes(Nodes);
-}
-
-// CanReachAliveNodes - Simple graph walker that recursively traverses the graph
-// looking for a node that is marked alive. If an alive node is found, return
-// true, otherwise return false. If an alive node is reachable, this node is
-// marked as alive...
-//
-static bool CanReachAliveNodes(DSNode *N, hash_set<const DSNode*> &Alive,
- hash_set<const DSNode*> &Visited,
- bool IgnoreGlobals) {
- if (N == 0) return false;
- assert(N->getForwardNode() == 0 && "Cannot mark a forwarded node!");
-
- // If this is a global node, it will end up in the globals graph anyway, so we
- // don't need to worry about it.
- if (IgnoreGlobals && N->isGlobalNode()) return false;
-
- // If we know that this node is alive, return so!
- if (Alive.count(N)) return true;
-
- // Otherwise, we don't think the node is alive yet, check for infinite
- // recursion.
- if (Visited.count(N)) return false; // Found a cycle
- Visited.insert(N); // No recursion, insert into Visited...
-
- for (DSNode::edge_iterator I = N->edge_begin(),E = N->edge_end(); I != E; ++I)
- if (CanReachAliveNodes(I->getNode(), Alive, Visited, IgnoreGlobals)) {
- N->markReachableNodes(Alive);
- return true;
- }
- return false;
-}
-
-// CallSiteUsesAliveArgs - Return true if the specified call site can reach any
-// alive nodes.
-//
-static bool CallSiteUsesAliveArgs(const DSCallSite &CS,
- hash_set<const DSNode*> &Alive,
- hash_set<const 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
-// subgraphs that are unreachable. This often occurs because the data
-// structure doesn't "escape" into it's caller, and thus should be eliminated
-// from the caller's graph entirely. This is only appropriate to use when
-// inlining graphs.
-//
-void DSGraph::removeDeadNodes(unsigned Flags) {
- DEBUG(AssertGraphOK(); if (GlobalsGraph) GlobalsGraph->AssertGraphOK());
-
- // Reduce the amount of work we have to do... remove dummy nodes left over by
- // merging...
- removeTriviallyDeadNodes();
-
- TIME_REGION(X, "removeDeadNodes");
-
- // FIXME: Merge non-trivially identical call nodes...
-
- // Alive - a set that holds all nodes found to be reachable/alive.
- hash_set<const DSNode*> Alive;
- std::vector<std::pair<Value*, DSNode*> > GlobalNodes;
-
- // Copy and merge all information about globals to the GlobalsGraph if this is
- // not a final pass (where unreachable globals are removed).
- //
- // 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.
- //
- ReachabilityCloner GGCloner(*GlobalsGraph, *this, DSGraph::StripAllocaBit |
- DSGraph::StripIncompleteBit);
-
- // Mark all nodes reachable by (non-global) scalar nodes as alive...
-{ TIME_REGION(Y, "removeDeadNodes:scalarscan");
- for (DSScalarMap::iterator I = ScalarMap.begin(), E = ScalarMap.end();
- I != E; ++I)
- if (isa<GlobalValue>(I->first)) { // Keep track of global nodes
- assert(!I->second.isNull() && "Null global node?");
- assert(I->second.getNode()->isGlobalNode() && "Should be a global node!");
- GlobalNodes.push_back(std::make_pair(I->first, I->second.getNode()));
-
- // Make sure that all globals are cloned over as roots.
- if (!(Flags & DSGraph::RemoveUnreachableGlobals) && GlobalsGraph) {
- DSGraph::ScalarMapTy::iterator SMI =
- GlobalsGraph->getScalarMap().find(I->first);
- if (SMI != GlobalsGraph->getScalarMap().end())
- GGCloner.merge(SMI->second, I->second);
- else
- GGCloner.getClonedNH(I->second);
- }
- } else {
- I->second.getNode()->markReachableNodes(Alive);
- }
-}
-
- // The return values are alive as well.
- 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 (fc_iterator I = fc_begin(), E = fc_end(); I != E; ++I)
- I->markReachableNodes(Alive);
-
-
- // 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<const DSNode*> Visited;
- hash_set<const DSCallSite*> AuxFCallsAlive;
- 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 (afc_iterator CI = afc_begin(), E = afc_end(); CI != E; ++CI)
- if (!AuxFCallsAlive.count(&*CI) &&
- (CI->isIndirectCall()
- || CallSiteUsesAliveArgs(*CI, Alive, Visited,
- Flags & DSGraph::RemoveUnreachableGlobals))) {
- CI->markReachableNodes(Alive);
- AuxFCallsAlive.insert(&*CI);
- Iterate = true;
- }
- } while (Iterate);
-
- // Move dead aux function calls to the end of the list
- for (std::list<DSCallSite>::iterator CI = AuxFunctionCalls.begin(),
- E = AuxFunctionCalls.end(); CI != E; )
- if (AuxFCallsAlive.count(&*CI))
- ++CI;
- else {
- // Copy and merge global nodes and dead aux call nodes into the
- // GlobalsGraph, and all nodes reachable from those nodes. Update their
- // target pointers using the GGCloner.
- //
- if (!(Flags & DSGraph::RemoveUnreachableGlobals))
- GlobalsGraph->AuxFunctionCalls.push_back(DSCallSite(*CI, GGCloner));
-
- AuxFunctionCalls.erase(CI++);
- }
-
- // We are finally done with the GGCloner so we can destroy it.
- GGCloner.destroy();
-
- // At this point, any nodes which are visited, but not alive, are nodes
- // which can be removed. Loop over all nodes, eliminating completely
- // unreachable nodes.
- //
- std::vector<DSNode*> DeadNodes;
- DeadNodes.reserve(Nodes.size());
- for (NodeListTy::iterator NI = Nodes.begin(), E = Nodes.end(); NI != E;) {
- DSNode *N = NI++;
- assert(!N->isForwarding() && "Forwarded node in nodes list?");
-
- if (!Alive.count(N)) {
- Nodes.remove(N);
- assert(!N->isForwarding() && "Cannot remove a forwarding node!");
- DeadNodes.push_back(N);
- N->dropAllReferences();
- ++NumDNE;
- }
- }
-
- // 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)
- if (!Alive.count(GlobalNodes[i].second))
- ScalarMap.erase(GlobalNodes[i].first);
- else
- assert((Flags & DSGraph::RemoveUnreachableGlobals) && "non-dead global");
-
- // Delete all dead nodes now since their referrer counts are zero.
- for (unsigned i = 0, e = DeadNodes.size(); i != e; ++i)
- delete DeadNodes[i];
-
- DEBUG(AssertGraphOK(); GlobalsGraph->AssertGraphOK());
-}
-
-void DSGraph::AssertNodeContainsGlobal(const DSNode *N, GlobalValue *GV) const {
- assert(std::find(N->globals_begin(),N->globals_end(), GV) !=
- N->globals_end() && "Global value not in node!");
-}
-
-void DSGraph::AssertCallSiteInGraph(const DSCallSite &CS) const {
- if (CS.isIndirectCall()) {
- AssertNodeInGraph(CS.getCalleeNode());
-#if 0
- if (CS.getNumPtrArgs() && CS.getCalleeNode() == CS.getPtrArg(0).getNode() &&
- CS.getCalleeNode() && CS.getCalleeNode()->getGlobals().empty())
- DOUT << "WARNING: WEIRD CALL SITE FOUND!\n";
-#endif
- }
- AssertNodeInGraph(CS.getRetVal().getNode());
- for (unsigned j = 0, e = CS.getNumPtrArgs(); j != e; ++j)
- AssertNodeInGraph(CS.getPtrArg(j).getNode());
-}
-
-void DSGraph::AssertCallNodesInGraph() const {
- for (fc_iterator I = fc_begin(), E = fc_end(); I != E; ++I)
- AssertCallSiteInGraph(*I);
-}
-void DSGraph::AssertAuxCallNodesInGraph() const {
- for (afc_iterator I = afc_begin(), E = afc_end(); I != E; ++I)
- AssertCallSiteInGraph(*I);
-}
-
-void DSGraph::AssertGraphOK() const {
- for (node_const_iterator NI = node_begin(), E = node_end(); NI != E; ++NI)
- NI->assertOK();
-
- for (ScalarMapTy::const_iterator I = ScalarMap.begin(),
- E = ScalarMap.end(); I != E; ++I) {
- assert(!I->second.isNull() && "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);
- }
- }
- AssertCallNodesInGraph();
- AssertAuxCallNodesInGraph();
-
- // Check that all pointer arguments to any functions in this graph have
- // destinations.
- for (ReturnNodesTy::const_iterator RI = ReturnNodes.begin(),
- E = ReturnNodes.end();
- RI != E; ++RI) {
- Function &F = *RI->first;
- for (Function::arg_iterator AI = F.arg_begin(); AI != F.arg_end(); ++AI)
- if (isPointerType(AI->getType()))
- assert(!getNodeForValue(AI).isNull() &&
- "Pointer argument must be in the scalar map!");
- }
-}
-
-/// computeNodeMapping - Given roots in two different DSGraphs, traverse the
-/// nodes reachable from the two graphs, computing the mapping of nodes from the
-/// first to the second graph. This mapping may be many-to-one (i.e. the first
-/// graph may have multiple nodes representing one node in the second graph),
-/// but it will not work if there is a one-to-many or many-to-many mapping.
-///
-void DSGraph::computeNodeMapping(const DSNodeHandle &NH1,
- const DSNodeHandle &NH2, NodeMapTy &NodeMap,
- bool StrictChecking) {
- DSNode *N1 = NH1.getNode(), *N2 = NH2.getNode();
- if (N1 == 0 || N2 == 0) return;
-
- DSNodeHandle &Entry = NodeMap[N1];
- if (!Entry.isNull()) {
- // Termination of recursion!
- if (StrictChecking) {
- assert(Entry.getNode() == N2 && "Inconsistent mapping detected!");
- assert((Entry.getOffset() == (NH2.getOffset()-NH1.getOffset()) ||
- Entry.getNode()->isNodeCompletelyFolded()) &&
- "Inconsistent mapping detected!");
- }
- return;
- }
-
- Entry.setTo(N2, NH2.getOffset()-NH1.getOffset());
-
- // Loop over all of the fields that N1 and N2 have in common, recursively
- // mapping the edges together now.
- int N2Idx = NH2.getOffset()-NH1.getOffset();
- unsigned N2Size = N2->getSize();
- if (N2Size == 0) return; // No edges to map to.
-
- for (unsigned i = 0, e = N1->getSize(); i < e; i += DS::PointerSize) {
- const DSNodeHandle &N1NH = N1->getLink(i);
- // Don't call N2->getLink if not needed (avoiding crash if N2Idx is not
- // aligned right).
- if (!N1NH.isNull()) {
- if (unsigned(N2Idx)+i < N2Size)
- computeNodeMapping(N1NH, N2->getLink(N2Idx+i), NodeMap);
- else
- computeNodeMapping(N1NH,
- N2->getLink(unsigned(N2Idx+i) % N2Size), NodeMap);
- }
- }
-}
-
-
-/// computeGToGGMapping - Compute the mapping of nodes in the global graph to
-/// nodes in this graph.
-void DSGraph::computeGToGGMapping(NodeMapTy &NodeMap) {
- DSGraph &GG = *getGlobalsGraph();
-
- DSScalarMap &SM = getScalarMap();
- for (DSScalarMap::global_iterator I = SM.global_begin(),
- E = SM.global_end(); I != E; ++I)
- DSGraph::computeNodeMapping(SM[*I], GG.getNodeForValue(*I), NodeMap);
-}
-
-/// computeGGToGMapping - Compute the mapping of nodes in the global graph to
-/// nodes in this graph. Note that any uses of this method are probably bugs,
-/// unless it is known that the globals graph has been merged into this graph!
-void DSGraph::computeGGToGMapping(InvNodeMapTy &InvNodeMap) {
- NodeMapTy NodeMap;
- computeGToGGMapping(NodeMap);
-
- while (!NodeMap.empty()) {
- InvNodeMap.insert(std::make_pair(NodeMap.begin()->second,
- NodeMap.begin()->first));
- NodeMap.erase(NodeMap.begin());
- }
-}
-
-
-/// computeCalleeCallerMapping - Given a call from a function in the current
-/// graph to the 'Callee' function (which lives in 'CalleeGraph'), compute the
-/// mapping of nodes from the callee to nodes in the caller.
-void DSGraph::computeCalleeCallerMapping(DSCallSite CS, const Function &Callee,
- DSGraph &CalleeGraph,
- NodeMapTy &NodeMap) {
-
- DSCallSite CalleeArgs =
- CalleeGraph.getCallSiteForArguments(const_cast<Function&>(Callee));
-
- computeNodeMapping(CalleeArgs.getRetVal(), CS.getRetVal(), NodeMap);
-
- unsigned NumArgs = CS.getNumPtrArgs();
- if (NumArgs > CalleeArgs.getNumPtrArgs())
- NumArgs = CalleeArgs.getNumPtrArgs();
-
- for (unsigned i = 0; i != NumArgs; ++i)
- computeNodeMapping(CalleeArgs.getPtrArg(i), CS.getPtrArg(i), NodeMap);
-
- // Map the nodes that are pointed to by globals.
- DSScalarMap &CalleeSM = CalleeGraph.getScalarMap();
- DSScalarMap &CallerSM = getScalarMap();
-
- if (CalleeSM.global_size() >= CallerSM.global_size()) {
- for (DSScalarMap::global_iterator GI = CallerSM.global_begin(),
- E = CallerSM.global_end(); GI != E; ++GI)
- if (CalleeSM.global_count(*GI))
- computeNodeMapping(CalleeSM[*GI], CallerSM[*GI], NodeMap);
- } else {
- for (DSScalarMap::global_iterator GI = CalleeSM.global_begin(),
- E = CalleeSM.global_end(); GI != E; ++GI)
- if (CallerSM.global_count(*GI))
- computeNodeMapping(CalleeSM[*GI], CallerSM[*GI], NodeMap);
- }
-}
-
-/// updateFromGlobalGraph - This function rematerializes global nodes and
-/// nodes reachable from them from the globals graph into the current graph.
-///
-void DSGraph::updateFromGlobalGraph() {
- TIME_REGION(X, "updateFromGlobalGraph");
- ReachabilityCloner RC(*this, *GlobalsGraph, 0);
-
- // Clone the non-up-to-date global nodes into this graph.
- for (DSScalarMap::global_iterator I = getScalarMap().global_begin(),
- E = getScalarMap().global_end(); I != E; ++I) {
- DSScalarMap::iterator It = GlobalsGraph->ScalarMap.find(*I);
- if (It != GlobalsGraph->ScalarMap.end())
- RC.merge(getNodeForValue(*I), It->second);
- }
-}
projects / oota-llvm.git / blobdiff