[llvm-commits] CVS: llvm-poolalloc/lib/Macroscopic/DeadFieldElimination.cpp Makefile README.txt StructureFieldVisitor.cpp StructureFieldVisitor.h
John Criswell
criswell at cs.uiuc.edu
Wed May 18 12:56:41 PDT 2005
Changes in directory llvm-poolalloc/lib/Macroscopic:
DeadFieldElimination.cpp updated: 1.2 -> 1.3
Makefile updated: 1.2 -> 1.3
README.txt updated: 1.2 -> 1.3
StructureFieldVisitor.cpp updated: 1.4 -> 1.5
StructureFieldVisitor.h updated: 1.5 -> 1.6
---
Log message:
Bring all of these files back from the "release_15" merge.
---
Diffs of the changes: (+1481 -0)
DeadFieldElimination.cpp | 248 ++++++++++++
Makefile | 12
README.txt | 5
StructureFieldVisitor.cpp | 939 ++++++++++++++++++++++++++++++++++++++++++++++
StructureFieldVisitor.h | 277 +++++++++++++
5 files changed, 1481 insertions(+)
Index: llvm-poolalloc/lib/Macroscopic/DeadFieldElimination.cpp
diff -u /dev/null llvm-poolalloc/lib/Macroscopic/DeadFieldElimination.cpp:1.3
--- /dev/null Wed May 18 14:56:37 2005
+++ llvm-poolalloc/lib/Macroscopic/DeadFieldElimination.cpp Wed May 18 14:56:26 2005
@@ -0,0 +1,248 @@
+//===-- DeadFieldElimination.cpp - Dead Field Elimination Pass ------------===//
+//
+// 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 -rds-deadfieldelim pass, which implements
+// Macroscopic Dead Field Elimination.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "rds-deadfieldelim"
+#include "StructureFieldVisitor.h"
+#include "llvm/Analysis/DataStructure/DataStructure.h"
+#include "llvm/Analysis/DataStructure/DSGraph.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/Timer.h"
+using namespace llvm;
+using namespace llvm::Macroscopic;
+
+namespace {
+ /// DeadFieldElim - This class implements the dead field elimination
+ /// optimization. This transformation is a very simple macroscopic
+ /// optimization whose high-level algorithm works like this:
+ ///
+ /// 1. Identify all type-homogenous data structures that only contain HGS
+ /// composition bits.
+ /// 2. For each data structure, visit every load of fields in the node.
+ /// Keep track of whether a field is ever loaded.
+ /// 3. If we found fields that are never loaded from, rewrite the affected
+ /// data structures, deleting the dead fields!
+ ///
+ class DeadFieldElim : public ModulePass {
+
+ bool runOnModule(Module &M);
+
+ void getAnalysisUsage(AnalysisUsage &AU) const {
+ // Need information from DSA.
+ AU.addRequired<EquivClassGraphs>();
+ AU.addPreserved<EquivClassGraphs>();
+ }
+ };
+ RegisterOpt<DeadFieldElim>
+ X("rds-deadfieldelim", "Macroscopic Dead Field Elimination");
+} // end anonymous namespace
+
+
+namespace {
+ /// DeadFieldElimLattice - This is the most trivial lattice possible: it
+ /// consists of two states, dead (the default) and alive (overdefined,
+ /// bottom). Because it has only two states, it does not need to maintain any
+ /// actual state.
+ struct DeadFieldElimLattice : public LatticeValue {
+ DeadFieldElimLattice(DSNode *Node, const std::vector<unsigned> &Idxs,
+ const Type *FieldTy)
+ : LatticeValue(Node, Idxs, FieldTy) {}
+
+ // getInterestingEvents - We only care about reads from memory?
+ static unsigned getInterestingEvents() { return Macroscopic::Visit::Loads; }
+
+ virtual void dump() const {
+ LatticeValue::dump();
+ std::cerr << " DEAD FIELD!\n";
+ }
+
+ // create - Return a dataflow fact for this field, initialized to top.
+ static DeadFieldElimLattice *create(DSNode *Node,
+ const std::vector<unsigned> &Idxs,
+ const Type *FieldTy) {
+ return new DeadFieldElimLattice(Node, Idxs, FieldTy);
+ }
+
+ virtual bool mergeInValue(const LatticeValue *RHS) {
+ return false; // Neither LHS nor RHS are overdefined.
+ }
+
+ // VisitLoad - Load events always move us to bottom.
+ virtual bool visitLoad(LoadInst &LI) {
+ return true; // Bottom!
+ }
+ };
+}
+
+
+#include "llvm/Constants.h"
+#include "llvm/Instructions.h"
+namespace {
+ /// ConstPropLattice - This is the standard 3-level constant propagation
+ /// lattice. When CstVal is null it is undefined, when it is non-null it is
+ /// defined to that constant, and it hits bottom of set to something
+ /// unanalyzable or multiple values.
+ struct ConstPropLattice : public LatticeValue {
+ Constant *CstVal;
+
+ ConstPropLattice(DSNode *Node, const std::vector<unsigned> &Idxs,
+ const Type *FieldTy)
+ : LatticeValue(Node, Idxs, FieldTy), CstVal(0) {}
+
+ // getInterestingEvents - We only care about reads from memory?
+ static unsigned getInterestingEvents() { return Macroscopic::Visit::Stores;}
+
+ // create - Return a dataflow fact for this field, initialized to top.
+ static ConstPropLattice *create(DSNode *Node,
+ const std::vector<unsigned> &Idxs,
+ const Type *FieldTy) {
+ return new ConstPropLattice(Node, Idxs, FieldTy);
+ }
+
+ bool mergeInValue(Constant *V) {
+ if (V == 0 || isa<UndefValue>(V)) return false;
+ if (CstVal == 0)
+ CstVal = V;
+ else if (CstVal != V)
+ return true;
+ return false;
+ }
+
+ virtual void dump() const {
+ LatticeValue::dump();
+ if (CstVal)
+ std::cerr << " CONSTANT VALUE = " << *CstVal << "\n";
+ else
+ std::cerr << " FIELD NEVER DEFINED!\n";
+ }
+
+ virtual bool mergeInValue(const LatticeValue *RHSLV) {
+ const ConstPropLattice *RHS = static_cast<const ConstPropLattice*>(RHSLV);
+ return mergeInValue(RHS->CstVal);
+ }
+
+ virtual bool visitStore(StoreInst &SI) {
+ if (Constant *CV = dyn_cast<Constant>(SI.getOperand(0)))
+ return mergeInValue(CV);
+ return true; // Bottom!
+ }
+
+ bool visitGlobalInit(Constant *InitVal) {
+ return mergeInValue(InitVal);
+ }
+
+ virtual bool visitMemSet(CallInst &I) {
+ if (Constant *C = dyn_cast<Constant>(I.getOperand(2)))
+ if (C->isNullValue()) {
+ std::cerr << "HANDLED MEMSET: " << I;
+ return mergeInValue(Constant::getNullValue(getFieldType()));
+ }
+ return true;
+ }
+ };
+}
+
+
+
+bool DeadFieldElim::runOnModule(Module &M) {
+ EquivClassGraphs &ECG = getAnalysis<EquivClassGraphs>();
+
+ // Step #1: Identify all type-homogenous HGS (non-U) data structure nodes.
+ std::set<DSNode*> Nodes;
+
+ { NamedRegionTimer XX("Dead Fields");
+
+ FindAllDataStructures(Nodes, 0 /*nothing required*/,
+ DSNode::UnknownNode, true /*typesafe*/, ECG);
+
+ DEBUG(std::cerr << "DeadFieldElim: Found " << Nodes.size()
+ << " eligible data structure nodes.\n");
+
+ // Step #2: For each data structure, visit every load of fields in the node.
+ // Keep track of whether a field is ever loaded. The visitor returns a set of
+ // lattice values that have not reached bottom (in this case, that means it
+ // returns a set of dead fields).
+ std::set<DeadFieldElimLattice*> DeadFields =
+ StructureFieldVisitor<DeadFieldElimLattice>(ECG).visit(Nodes);
+
+ DEBUG(std::cerr << "DeadFieldElim: Found " << DeadFields.size()
+ << " dead fields!\n");
+ for (std::set<DeadFieldElimLattice*>::iterator I = DeadFields.begin(),
+ E = DeadFields.end(); I != E; ++I) {
+ DEBUG((*I)->dump());
+ delete *I;
+ }
+ DEBUG(std::cerr << "\n");
+ }
+ //return true;
+
+ { NamedRegionTimer XX("Constants");
+
+ Nodes.clear();
+ FindAllDataStructures(Nodes, 0 /*nothing required*/,
+ DSNode::UnknownNode, true /*typesafe*/, ECG);
+
+ // Step #2: For each data structure, visit every stores to fields in the node.
+ // Keep track of whether a field is always constant. The visitor returns a
+ // set of lattice values that have not reached bottom (in this case, that
+ // means they are either undefined or overdefined.
+ std::set<ConstPropLattice*> ConstantFields =
+ StructureFieldVisitor<ConstPropLattice>(ECG).visit(Nodes);
+
+ DEBUG(std::cerr << "ConstProp: Found " << ConstantFields.size()
+ << " constant or uninitialized fields!\n");
+ for (std::set<ConstPropLattice*>::iterator I = ConstantFields.begin(),
+ E = ConstantFields.end(); I != E; ++I) {
+ DEBUG((*I)->dump());
+ delete *I;
+ }
+ DEBUG(std::cerr << "\n");
+
+ }
+
+ return true;
+
+ // NOTE: We could do a simple thing that checks for fields whose loads are
+ // immediately casted to something smaller, and stores that are casted from
+ // something smaller to shrink them.
+
+
+ { NamedRegionTimer XX("Combined");
+
+ Nodes.clear();
+ FindAllDataStructures(Nodes, 0 /*nothing required*/,
+ DSNode::UnknownNode, true /*typesafe*/, ECG);
+
+ typedef CombinedLatticeValue<DeadFieldElimLattice,ConstPropLattice>
+ CombinedLattice;
+
+ // Step #2: For each data structure, visit every stores to fields in the node.
+ // Keep track of whether a field is always constant. The visitor returns a
+ // set of lattice values that have not reached bottom (in this case, that
+ // means they are either undefined or overdefined.
+ std::set<CombinedLattice*> CombinedFields =
+ StructureFieldVisitor<CombinedLattice>(ECG).visit(Nodes);
+
+ DEBUG(std::cerr << "Combined: Found " << CombinedFields.size()
+ << " interesting fields!\n");
+ for (std::set<CombinedLattice*>::iterator I = CombinedFields.begin(),
+ E = CombinedFields.end(); I != E; ++I) {
+ DEBUG((*I)->dump());
+ delete *I;
+ }
+ DEBUG(std::cerr << "\n");
+
+ }
+
+ return true;
+}
Index: llvm-poolalloc/lib/Macroscopic/Makefile
diff -u /dev/null llvm-poolalloc/lib/Macroscopic/Makefile:1.3
--- /dev/null Wed May 18 14:56:41 2005
+++ llvm-poolalloc/lib/Macroscopic/Makefile Wed May 18 14:56:26 2005
@@ -0,0 +1,12 @@
+# Indicate where we are relative to the top of the source tree.
+LEVEL=../..
+
+# Give the name of a library. This will build a dynamic version.
+SHARED_LIBRARY=1
+LOADABLE_MODULE = 1
+DONT_BUILD_RELINKED=1
+LIBRARYNAME=macroscopic
+
+# Include Makefile.common so we know what to do.
+include $(LEVEL)/Makefile.common
+
Index: llvm-poolalloc/lib/Macroscopic/README.txt
diff -u /dev/null llvm-poolalloc/lib/Macroscopic/README.txt:1.3
--- /dev/null Wed May 18 14:56:41 2005
+++ llvm-poolalloc/lib/Macroscopic/README.txt Wed May 18 14:56:26 2005
@@ -0,0 +1,5 @@
+//===- llvm-poolalloc/lib/Macroscopic -------------------------------------===//
+
+This directory contains an experimental implementation of several ideas for
+Macroscopic analyses and transformations, which may eventually include
+reimplementation of the pool allocator and other passes.
Index: llvm-poolalloc/lib/Macroscopic/StructureFieldVisitor.cpp
diff -u /dev/null llvm-poolalloc/lib/Macroscopic/StructureFieldVisitor.cpp:1.5
--- /dev/null Wed May 18 14:56:41 2005
+++ llvm-poolalloc/lib/Macroscopic/StructureFieldVisitor.cpp Wed May 18 14:56:26 2005
@@ -0,0 +1,939 @@
+//===-- StructureFieldVisitor.cpp - Implement StructureFieldVisitor -------===//
+//
+// 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 StructureFieldVisitor and related classes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "StructureFieldVisitor.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Analysis/DataStructure/DataStructure.h"
+#include "llvm/Analysis/DataStructure/DSGraph.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/Support/InstVisitor.h"
+#include <algorithm>
+#include <iostream>
+
+using namespace llvm::Macroscopic;
+using namespace llvm;
+
+/// FindAllDataStructures - Inspect the program specified by ECG, adding to
+/// 'Nodes' all of the data structures node in the program that contain the
+/// "IncludeFlags" and do not contain "ExcludeFlags" node flags. If
+/// OnlyHomogenous is true, only type-homogenous nodes are considered.
+void FindAllDataStructures(std::set<DSNode*> &Nodes, unsigned IncludeFlags,
+ unsigned ExcludeFlags, bool OnlyHomogenous,
+ EquivClassGraphs &ECG) {
+ // Loop over all of the graphs in ECG, finding nodes that are not incomplete
+ // and do not have any of the flags specified by Flags.
+ ExcludeFlags |= DSNode::Incomplete;
+
+ /// FIXME: nodes in the global graph should not be marked incomplete in main!!
+ for (hash_map<const Function*, DSGraph*>::iterator GI = ECG.DSInfo.begin(),
+ E = ECG.DSInfo.end(); GI != E; ++GI) {
+ assert(GI->second && "Null graph pointer?");
+ DSGraph &G = *GI->second;
+ for (DSGraph::node_iterator I = G.node_begin(), E = G.node_end();
+ I != E; ++I)
+ // If this node matches our constraints, include it.
+ if ((I->getNodeFlags() & IncludeFlags) == IncludeFlags &&
+ (I->getNodeFlags() & ExcludeFlags) == 0)
+ if (!OnlyHomogenous || !I->isNodeCompletelyFolded())
+ Nodes.insert(I);
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// LatticeValue class implementation
+//
+
+DSGraph &LatticeValue::getParentGraph() const {
+ DSGraph *PG = getNode()->getParentGraph();
+ assert(PG && "Node doesn't have a parent, is it a GlobalGraph node?");
+ return *PG;
+}
+
+/// getFieldOffset - Return the offset of this field from the start of the node.
+///
+unsigned LatticeValue::getFieldOffset() const {
+ const TargetData &TD = getNode()->getParentGraph()->getTargetData();
+
+ unsigned Offset = 0;
+ const Type *Ty = Node->getType();
+ for (unsigned i = 0, e = Idxs.size(); i != e; ++i)
+ if (const StructType *STy = dyn_cast<StructType>(Ty)) {
+ const StructLayout *SL = TD.getStructLayout(STy);
+ Offset += SL->MemberOffsets[Idxs[i]];
+ Ty = STy->getElementType(Idxs[i]);
+ } else {
+ const SequentialType *STy = cast<SequentialType>(Ty);
+ Ty = STy->getElementType();
+ --i; // This doesn't index a struct.
+ }
+ return Offset;
+}
+
+
+
+void LatticeValue::dump() const {
+ std::cerr << "\nFunction: " << Node->getParentGraph()->getFunctionNames()
+ << "\n";
+ Node->dump();
+ if (!Idxs.empty()) {
+ std::cerr << "Field: ";
+ for (unsigned i = 0, e = Idxs.size(); i != e; ++i)
+ std::cerr << Idxs[i] << ".";
+ }
+ std::cerr << "\n";
+}
+
+bool LatticeValue::visitLoad(LoadInst &) {
+ std::cerr << "ERROR: Client requested load visitation, but did not "
+ << "overload visitLoad!\n";
+ dump();
+ return true;
+}
+bool LatticeValue::visitStore(StoreInst &) {
+ std::cerr << "ERROR: Client requested store visitation, but did not "
+ << "overload visitStore!\n";
+ dump();
+ return true;
+}
+
+bool LatticeValue::visitGlobalInit(Constant *) {
+ std::cerr << "ERROR: Client requested store visitation, but did not "
+ << "overload visitGlobalInit!\n";
+ dump();
+ return true;
+}
+
+//===----------------------------------------------------------------------===//
+// SFVInstVisitor class implementation
+//
+
+namespace {
+ /// SFVInstVisitor - This visitor is used to do the actual visitation of
+ /// memory instructions in the program.
+ ///
+ struct SFVInstVisitor : public InstVisitor<SFVInstVisitor, bool> {
+ DSGraph &DSG;
+ const unsigned Callbacks;
+ std::multimap<DSNode*, LatticeValue*> &NodeLVs;
+
+ // DirectCallSites - When we see call sites, we don't process them, but we
+ // do remember them if they are direct calls.
+ std::set<Instruction*> DirectCallSites;
+
+ SFVInstVisitor(DSGraph &dsg, unsigned CBs,
+ std::multimap<DSNode*, LatticeValue*> &LVs)
+ : DSG(dsg), Callbacks(CBs), NodeLVs(LVs) {}
+
+ // Methods used by visitation methods.
+ LatticeValue *getLatticeValueForField(Value *Ptr);
+ bool RemoveLatticeValueAtBottom(LatticeValue *LV);
+
+ /// Visitation methods - These methods should return true when a lattice
+ /// value is driven to 'bottom' and removed from NodeLVs.
+ bool visitLoadInst(LoadInst &LI);
+ bool visitStoreInst(StoreInst &SI);
+
+ /// These are not implemented yet.
+ bool visitGetElementPtrInst(GetElementPtrInst &GEPI) { return false; }
+ bool visitMallocInst(MallocInst &MI) { return false; }
+ bool visitAllocaInst(AllocaInst &AI) { return false; }
+ bool visitFreeInst(FreeInst &FI) { return false; }
+ bool visitPHINode(PHINode &PN) { return false; }
+ bool visitSelectInst(SelectInst &SI) { return false; }
+ bool visitSetCondInst(SetCondInst &SCI) { return false; }
+ bool visitCastInst(CastInst &CI) { return false; }
+ bool visitReturnInst(ReturnInst &RI) { return false; }
+
+ // visitCallInst/visitInvokeInst - Call and invoke are handled specially, so
+ // they are just noops here.
+ bool visitCallInst(CallInst &CI) { return visitCallSite(CI); }
+ bool visitInvokeInst(InvokeInst &II) { return visitCallSite(II); }
+ bool visitCallSite(Instruction &I) {
+ // Remember direct function calls.
+ if (isa<Function>(I.getOperand(0))) DirectCallSites.insert(&I);
+ return false;
+ }
+
+ bool visitInstruction(Instruction &I) {
+#ifndef NDEBUG
+ // Check to make sure this instruction really isn't using anything we the
+ // client needs to know about.
+ assert(getLatticeValueForField(&I) == 0 && "Inst should be handled!");
+ for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
+ assert(getLatticeValueForField(I.getOperand(i)) == 0 &&
+ "Inst should be handled by visitor!");
+#endif
+ return false;
+ }
+ };
+}
+
+static void ComputeStructureFieldIndices(const Type *Ty, unsigned Offset,
+ std::vector<unsigned> &Idxs,
+ const TargetData &TD) {
+ if (Ty->isFirstClassType()) {
+ assert(Offset == 0 && "Illegal structure index!");
+ return;
+ }
+
+ if (const SequentialType *STy = dyn_cast<SequentialType>(Ty)) {
+ ComputeStructureFieldIndices(STy->getElementType(), Offset, Idxs, TD);
+ } else if (const StructType *STy = dyn_cast<StructType>(Ty)) {
+ const StructLayout *SL = TD.getStructLayout(STy);
+
+ std::vector<uint64_t>::const_iterator SI =
+ std::upper_bound(SL->MemberOffsets.begin(), SL->MemberOffsets.end(),
+ Offset);
+ assert(SI != SL->MemberOffsets.begin() && "Offset not in structure type!");
+ --SI;
+ assert(*SI <= Offset && "upper_bound didn't work");
+ assert((SI == SL->MemberOffsets.begin() || *(SI-1) < Offset) &&
+ (SI+1 == SL->MemberOffsets.end() || *(SI+1) > Offset) &&
+ "Upper bound didn't work!");
+ Offset -= *SI; // Skip over the offset to this structure field.
+ unsigned Idx = SI - SL->MemberOffsets.begin();
+ assert(Idx < STy->getNumElements() && "Illegal structure index");
+ Idxs.push_back(Idx);
+ ComputeStructureFieldIndices(STy->getElementType(Idx), Offset, Idxs, TD);
+ } else {
+ assert(0 && "Unknown type to index into!");
+ }
+}
+
+LatticeValue *SFVInstVisitor::getLatticeValueForField(Value *Ptr) {
+ if (!isa<PointerType>(Ptr->getType()) ||
+ isa<ConstantPointerNull>(Ptr)) return 0;
+
+ const DSNodeHandle *NH = &DSG.getNodeForValue(Ptr);
+ DSNode *Node = NH->getNode();
+ assert(Node && "Pointer doesn't have node??");
+
+ std::multimap<DSNode*, LatticeValue*>::iterator I = NodeLVs.find(Node);
+ if (I == NodeLVs.end()) return 0; // Not a node we are still tracking.
+
+ // Okay, next convert the node offset to a field index expression.
+ std::vector<unsigned> Idxs;
+ ComputeStructureFieldIndices(Node->getType(), NH->getOffset(), Idxs,
+ Node->getParentGraph()->getTargetData());
+
+ for (; I != NodeLVs.end() && I->first == Node; ++I)
+ if (I->second->getIndices() == Idxs)
+ return I->second;
+ return 0;
+}
+
+/// RemoveLatticeValueAtBottom - When analysis determines that LV hit bottom,
+/// this method is used to remove it from the NodeLVs map. This method always
+/// returns true to simplify caller code.
+///
+bool SFVInstVisitor::RemoveLatticeValueAtBottom(LatticeValue *LV) {
+ for (std::multimap<DSNode*, LatticeValue*>::iterator I
+ = NodeLVs.find(LV->getNode());; ++I) {
+ assert(I != NodeLVs.end() && "Lattice value not in map??");
+ if (I->second == LV) {
+ NodeLVs.erase(I);
+ return true;
+ }
+ }
+}
+
+
+bool SFVInstVisitor::visitLoadInst(LoadInst &LI) {
+ if ((Callbacks & Visit::Loads) == 0) return false;
+
+ if (LatticeValue *LV = getLatticeValueForField(LI.getOperand(0)))
+ if (LV->visitLoad(LI))
+ return RemoveLatticeValueAtBottom(LV);
+
+ return false;
+}
+
+bool SFVInstVisitor::visitStoreInst(StoreInst &SI) {
+ if ((Callbacks & Visit::Stores) == 0) return false;
+
+ if (LatticeValue *LV = getLatticeValueForField(SI.getOperand(1)))
+ if (LV->visitStore(SI))
+ return RemoveLatticeValueAtBottom(LV);
+
+ return false;
+}
+
+
+//===----------------------------------------------------------------------===//
+// StructureFieldVisitorBase class implementation
+//
+
+void StructureFieldVisitorBase::
+AddLatticeValuesForFields(DSNode *Node, const Type *Ty,
+ const std::vector<unsigned> &Idxs,
+ std::set<LatticeValue*> &Values) {
+ if (Ty->isFirstClassType()) {
+ if (LatticeValue *LV = createLatticeValue(Node, Idxs, Ty))
+ Values.insert(LV);
+ return;
+ }
+
+ const StructType *STy = dyn_cast<StructType>(Ty);
+ if (STy == 0) return; // Not handling arrays yet!
+
+ std::vector<unsigned> NextIdxs(Idxs);
+ NextIdxs.push_back(0);
+ for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
+ NextIdxs.back() = i;
+ AddLatticeValuesForFields(Node, STy->getElementType(i), NextIdxs, Values);
+ }
+}
+
+void StructureFieldVisitorBase::
+AddLatticeValuesForNode(DSNode *N, std::set<LatticeValue*> &Values) {
+ if (N->isNodeCompletelyFolded() ||
+ N->getType() == Type::VoidTy) return; // Can't analyze node.
+ std::vector<unsigned> Idxs;
+ AddLatticeValuesForFields(N, N->getType(), Idxs, Values);
+}
+
+
+/// visitNodes - This is a simple wrapper around visitFields that creates a
+/// lattice value for every field in the specified collection of nodes.
+///
+std::set<LatticeValue*> StructureFieldVisitorBase::
+visitNodes(const std::set<DSNode*> &Nodes) {
+ std::set<LatticeValue*> Result;
+
+ // Create lattice values for all of the fields in these nodes.
+ for (std::set<DSNode*>::const_iterator I = Nodes.begin(), E = Nodes.end();
+ I != E; ++I)
+ AddLatticeValuesForNode(*I, Result);
+
+ // Now that we have the lattice values, just use visitFields to do the grunt
+ // work.
+ visitFields(Result);
+ return Result;
+}
+
+
+/// VisitGlobalInit - The specified lattice value corresponds to a field (or
+/// several) in the specified global. Merge all of the overlapping initializer
+/// values into LV (up-to and until it becomes overdefined).
+///
+static bool VisitGlobalInit(LatticeValue *LV, Constant *Init,
+ unsigned FieldOffset) {
+ const TargetData &TD = LV->getParentGraph().getTargetData();
+
+ if (Init->isNullValue())
+ return LV->visitGlobalInit(Constant::getNullValue(LV->getFieldType()));
+ if (isa<UndefValue>(Init))
+ return LV->visitGlobalInit(UndefValue::get(LV->getFieldType()));
+
+ if (LV->getNode()->isArray() &&
+ TD.getTypeSize(Init->getType()) > LV->getNode()->getSize()) {
+ ConstantArray *CA = cast<ConstantArray>(Init);
+ for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
+ if (VisitGlobalInit(LV, CA->getOperand(i), FieldOffset))
+ return true;
+ return false;
+ }
+
+NextStep: // Manual tail recursion
+
+ if (Init->isNullValue())
+ return LV->visitGlobalInit(Constant::getNullValue(LV->getFieldType()));
+ if (isa<UndefValue>(Init))
+ return LV->visitGlobalInit(UndefValue::get(LV->getFieldType()));
+ if (Init->getType()->isFirstClassType()) {
+ assert(FieldOffset == 0 && "GV Init mismatch!");
+ return LV->visitGlobalInit(Init);
+ }
+
+ if (const StructType *STy = dyn_cast<StructType>(Init->getType())) {
+ const StructLayout *SL = TD.getStructLayout(STy);
+ unsigned Field = SL->getElementContainingOffset(FieldOffset);
+ FieldOffset -= SL->MemberOffsets[Field];
+ Init = cast<ConstantStruct>(Init)->getOperand(Field);
+ goto NextStep;
+ } else if (const ArrayType *ATy = dyn_cast<ArrayType>(Init->getType())) {
+ unsigned ElSz = TD.getTypeSize(ATy->getElementType());
+ unsigned Idx = FieldOffset / ElSz;
+ FieldOffset -= Idx*ElSz;
+ Init = cast<ConstantArray>(Init)->getOperand(Idx);
+ goto NextStep;
+ } else {
+ assert(0 && "Unexpected initializer type!");
+ return true;
+ }
+}
+
+
+/// visitFields - Visit all uses of the specified fields, updating the lattice
+/// values as appropriate.
+///
+void StructureFieldVisitorBase::visitFields(std::set<LatticeValue*> &Fields) {
+ // Now that we added all of the initial nodes, find out what graphs these
+ // nodes are rooted in. For efficiency, handle batches of nodes in the same
+ // function together at the same time. To do this, pull everything out of
+ // Fields and put it into FieldsByGraph.
+ std::multimap<DSGraph*, LatticeValue*> FieldsByGraph;
+ while (!Fields.empty()) {
+ LatticeValue *LV = *Fields.begin();
+ Fields.erase(Fields.begin());
+ FieldsByGraph.insert(std::make_pair(&LV->getParentGraph(), LV));
+ }
+
+ // Now that everything is grouped by graph, process a graph worth of nodes at
+ // a time, moving the results back to Fields if they are not overdefined.
+ while (!FieldsByGraph.empty()) {
+ // NodeLVs - Inspect all of the lattice values that are active in this
+ // graph.
+ std::multimap<DSNode*, LatticeValue*> NodeLVs;
+ DSGraph &DSG = *FieldsByGraph.begin()->first;
+
+ // Pull out all nodes in this graph, putting them into NodeLVs.
+ while (FieldsByGraph.begin()->first == &DSG) {
+ LatticeValue *LV = FieldsByGraph.begin()->second;
+ FieldsByGraph.erase(FieldsByGraph.begin());
+ NodeLVs.insert(std::make_pair(LV->getNode(), LV));
+ }
+
+ // Visit all operations in this graph, looking at how these lattice values
+ // are used!
+ visitGraph(DSG, NodeLVs);
+
+ if (NodeLVs.empty()) continue;
+
+ // If any of the nodes have globals, and if we are inspecting stores, make
+ // sure to notice the global variable initializers.
+ if (Callbacks & Visit::Stores) {
+ for (std::multimap<DSNode*, LatticeValue*>::iterator I = NodeLVs.begin();
+ I != NodeLVs.end(); ) {
+ // If this node has globals, incorporate them.
+ bool LVisOverdefined = false;
+ std::vector<GlobalValue*> GVs;
+ I->first->addFullGlobalsList(GVs);
+ for (unsigned i = 0, e = GVs.size(); i != e; ++i)
+ if (GlobalVariable *GV = dyn_cast<GlobalVariable>(GVs[i])) {
+ assert(GV->hasInitializer() && "Should not be analyzing this GV!");
+ if (VisitGlobalInit(I->second, GV->getInitializer(),
+ I->second->getFieldOffset())) {
+ LVisOverdefined = true;
+ break;
+ }
+ }
+
+ if (LVisOverdefined)
+ NodeLVs.erase(I++);
+ else
+ ++I;
+ }
+ if (NodeLVs.empty()) continue;
+ }
+
+ // Okay, final check. If we have any dataflow facts about nodes that are
+ // reachable from global variable nodes, we must make sure to check every
+ // function in the program that uses the global for uses of the node.
+ // Because of the globals graph, we might not have all of the information we
+ // need with our (potentially) truncated call graph traversal.
+ ProcessNodesReachableFromGlobals(DSG, NodeLVs);
+
+ // Everything that survived goes into Fields now that we processed it.
+ while (!NodeLVs.empty()) {
+ Fields.insert(NodeLVs.begin()->second);
+ NodeLVs.erase(NodeLVs.begin());
+ }
+ }
+}
+
+/// ComputeInverseGraphFrom - Perform a simple depth-first search of the
+/// DSGraph, recording the inverse of all of the edges in the graph.
+///
+static void ComputeInverseGraphFrom(DSNode *N,
+ std::set<std::pair<DSNode*,DSNode*> > &InverseGraph) {
+ for (DSNode::edge_iterator I = N->edge_begin(), E = N->edge_end(); I != E;++I)
+ if (DSNode *Target = I->getNode())
+ if (InverseGraph.insert(std::make_pair(Target, N)).second)
+ ComputeInverseGraphFrom(Target, InverseGraph);
+}
+
+
+/// ComputeNodesReacahbleFrom - Compute the set of nodes in the specified
+/// inverse graph that are reachable from N. This is a simple depth first
+/// search.
+///
+static void ComputeNodesReachableFrom(DSNode *N,
+ std::set<std::pair<DSNode*,DSNode*> > &InverseGraph,
+ hash_set<const DSNode*> &Reachable) {
+ if (!Reachable.insert(N).second) return; // Already visited!
+
+ std::set<std::pair<DSNode*,DSNode*> >::iterator I =
+ InverseGraph.lower_bound(std::make_pair(N, (DSNode*)0));
+ for (; I != InverseGraph.end() && I->first == N; ++I)
+ ComputeNodesReachableFrom(I->second, InverseGraph, Reachable);
+}
+
+/// ProcessNodesReachableFromGlobals - If we inferred anything about nodes
+/// reachable from globals, we have to make sure that we incorporate data for
+/// all graphs that include those globals due to the nature of the globals
+/// graph.
+///
+void StructureFieldVisitorBase::
+ProcessNodesReachableFromGlobals(DSGraph &DSG,
+ std::multimap<DSNode*,LatticeValue*> &NodeLVs){
+ // Start by marking all nodes reachable from globals.
+ DSScalarMap &SM = DSG.getScalarMap();
+ if (SM.global_begin() == SM.global_end()) return;
+
+ hash_set<const DSNode*> Reachable;
+ for (DSScalarMap::global_iterator GI = SM.global_begin(),
+ E = SM.global_end(); GI != E; ++GI)
+ SM[*GI].getNode()->markReachableNodes(Reachable);
+ if (Reachable.empty()) return;
+
+ // If any of the nodes with dataflow facts are reachable from the globals
+ // graph, we have to do the GG processing step.
+ bool MustProcessThroughGlobalsGraph = false;
+ for (std::multimap<DSNode*, LatticeValue*>::iterator I = NodeLVs.begin(),
+ E = NodeLVs.end(); I != E; ++I)
+ if (Reachable.count(I->first)) {
+ MustProcessThroughGlobalsGraph = true;
+ break;
+ }
+
+ if (!MustProcessThroughGlobalsGraph) return;
+ Reachable.clear();
+
+ // Compute the mapping from DSG to the globals graph.
+ DSGraph::NodeMapTy DSGToGGMap;
+ DSG.computeGToGGMapping(DSGToGGMap);
+
+ // Most of the times when we find facts about things reachable from globals we
+ // we are in the main graph. This means that we have *all* of the globals
+ // graph in this DSG. To be efficient, we compute the minimum set of globals
+ // that can reach any of the NodeLVs facts.
+ //
+ // I'm not aware of any wonderful way of computing the set of globals that
+ // points to the set of nodes in NodeLVs that is not N^2 in either NodeLVs or
+ // the number of globals, except to compute the inverse of DSG. As such, we
+ // compute the inverse graph of DSG, which basically has the edges going from
+ // pointed to nodes to pointing nodes. Because we only care about one
+ // connectedness properties, we ignore field info. In addition, we only
+ // compute inverse of the portion of the graph reachable from the globals.
+ std::set<std::pair<DSNode*,DSNode*> > InverseGraph;
+
+ for (DSScalarMap::global_iterator GI = SM.global_begin(),
+ E = SM.global_end(); GI != E; ++GI)
+ ComputeInverseGraphFrom(SM[*GI].getNode(), InverseGraph);
+
+ // Okay, now that we have our bastardized inverse graph, compute the set of
+ // globals nodes reachable from our lattice nodes.
+ for (std::multimap<DSNode*, LatticeValue*>::iterator I = NodeLVs.begin(),
+ E = NodeLVs.end(); I != E; ++I)
+ ComputeNodesReachableFrom(I->first, InverseGraph, Reachable);
+
+ // Now that we know which nodes point to the data flow facts, figure out which
+ // globals point to the data flow facts.
+ std::set<GlobalValue*> Globals;
+ for (hash_set<const DSNode*>::iterator I = Reachable.begin(),
+ E = Reachable.end(); I != E; ++I)
+ Globals.insert((*I)->globals_begin(), (*I)->globals_end());
+
+ // Finally, loop over all of the DSGraphs for the program, computing
+ // information for the graph if not done already, mapping the result into our
+ // context.
+ for (hash_map<const Function*, DSGraph*>::iterator GI = ECG.DSInfo.begin(),
+ E = ECG.DSInfo.end(); GI != E; ++GI) {
+ DSGraph &FG = *GI->second;
+ // Graphs can contain multiple functions, only process the graph once.
+ if (GI->first != FG.retnodes_begin()->first ||
+ // Also, do not bother reprocessing DSG.
+ &FG == &DSG)
+ continue;
+
+ bool GraphUsesGlobal = false;
+ for (std::set<GlobalValue*>::iterator I = Globals.begin(),
+ E = Globals.end(); I != E; ++I)
+ if (FG.getScalarMap().count(*I)) {
+ GraphUsesGlobal = true;
+ break;
+ }
+
+ // If this graph does not contain the global at all, there is no reason to
+ // even think about it.
+ if (!GraphUsesGlobal) continue;
+
+ // Otherwise, compute the full set of dataflow effects of the function.
+ std::multimap<DSNode*, LatticeValue*> &FGF = getCalleeFacts(FG);
+ //std::cerr << "Computed: " << FG.getFunctionNames() << "\n";
+
+#if 0
+ for (std::multimap<DSNode*, LatticeValue*>::iterator I = FGF.begin(),
+ E = FGF.end(); I != E; ++I)
+ I->second->dump();
+#endif
+ // Compute the mapping of nodes in the globals graph to the function's
+ // graph. Note that this function graph may not have nodes (or may have
+ // fragments of full nodes) in the globals graph, and we don't want this to
+ // pessimize the analysis.
+ std::multimap<const DSNode*, std::pair<DSNode*,int> > GraphMap;
+ DSGraph::NodeMapTy GraphToGGMap;
+ FG.computeGToGGMapping(GraphToGGMap);
+
+ // "Invert" the mapping. We compute the mapping from the start of a global
+ // graph node to a place in the graph's node. Note that not all of the GG
+ // node may be present in the graphs node, so there may be a negative offset
+ // involved.
+ while (!GraphToGGMap.empty()) {
+ DSNode *GN = const_cast<DSNode*>(GraphToGGMap.begin()->first);
+ DSNodeHandle &GGNH = GraphToGGMap.begin()->second;
+ GraphMap.insert(std::make_pair(GGNH.getNode(),
+ std::make_pair(GN, -GGNH.getOffset())));
+ GraphToGGMap.erase(GraphToGGMap.begin());
+ }
+
+ // Loop over all of the dataflow facts that we have computed, mapping them
+ // to the globals graph.
+ for (std::multimap<DSNode*, LatticeValue*>::iterator I = NodeLVs.begin(),
+ E = NodeLVs.end(); I != E; ) {
+ bool FactHitBottom = false;
+
+ //I->second->dump();
+
+ assert(I->first->getParentGraph() == &DSG);
+ assert(I->second->getNode()->getParentGraph() == &DSG);
+
+ // Node is in the GG?
+ DSGraph::NodeMapTy::iterator DSGToGGMapI = DSGToGGMap.find(I->first);
+ if (DSGToGGMapI != DSGToGGMap.end()) {
+ DSNodeHandle &GGNH = DSGToGGMapI->second;
+ const DSNode *GGNode = GGNH.getNode();
+ unsigned DSGToGGOffset = GGNH.getOffset();
+
+ // See if there is a node in FG that corresponds to this one. If not,
+ // no information will be computed in this scope, as the memory is not
+ // accessed.
+ std::multimap<const DSNode*, std::pair<DSNode*,int> >::iterator GMI =
+ GraphMap.find(GGNode);
+
+ // LatticeValOffset - The offset from the start of the GG Node to the
+ // start of the field we are interested in.
+ unsigned LatticeValOffset = I->second->getFieldOffset()+DSGToGGOffset;
+
+ // Loop over all of the nodes in FG that correspond to this single node
+ // in the GG.
+ for (; GMI != GraphMap.end() && GMI->first == GGNode; ++GMI) {
+ // Compute the offset to the field in the user graph.
+ unsigned FieldOffset = LatticeValOffset - GMI->second.second;
+
+ // If the field is within the amount of memory accessed by this scope,
+ // then there must be a corresponding lattice value.
+ DSNode *FGNode = GMI->second.first;
+ if (FieldOffset < FGNode->getSize()) {
+ LatticeValue *CorrespondingLV = 0;
+
+ std::multimap<DSNode*, LatticeValue*>::iterator FGFI =
+ FGF.find(FGNode);
+ for (; FGFI != FGF.end() && FGFI->first == FGNode; ++FGFI)
+ if (FGFI->second->getFieldOffset() == FieldOffset) {
+ CorrespondingLV = FGFI->second;
+ break;
+ }
+
+ // Finally, if either there was no corresponding fact (because it
+ // hit bottom in this scope), or if merging the two pieces of
+ // information makes it hit bottom, remember this.
+ if (CorrespondingLV == 0 ||
+ I->second->mergeInValue(CorrespondingLV))
+ FactHitBottom = true;
+ }
+ }
+ }
+
+ if (FactHitBottom) {
+ delete I->second;
+ NodeLVs.erase(I++);
+ if (NodeLVs.empty()) return;
+ } else {
+ ++I;
+ }
+ }
+ }
+}
+
+
+/// getCalleeFacts - Compute the data flow effect that calling one of the
+/// functions in this graph has on the caller. This information is cached after
+/// it is computed for a function the first time.
+///
+std::multimap<DSNode*, LatticeValue*> &
+StructureFieldVisitorBase::getCalleeFacts(DSGraph &DSG) {
+ // Already computed?
+ std::map<DSGraph*, std::multimap<DSNode*,LatticeValue*> >::iterator
+ I = CalleeFnFacts.find(&DSG);
+ if (I != CalleeFnFacts.end())
+ return I->second; // We already computed stuff for this fn!
+
+ std::multimap<DSNode*, LatticeValue*> &Result = CalleeFnFacts[&DSG];
+
+ std::set<LatticeValue*> LVs;
+ for (DSGraph::node_iterator NI = DSG.node_begin(), E = DSG.node_end();
+ NI != E; ++NI)
+ AddLatticeValuesForNode(NI, LVs);
+
+ while (!LVs.empty()) {
+ Result.insert(std::make_pair((*LVs.begin())->getNode(), *LVs.begin()));
+ LVs.erase(LVs.begin());
+ }
+
+ if (!Result.empty())
+ visitGraph(DSG, Result);
+ return Result;
+}
+
+
+/// NodeCanPossiblyBeInteresting - Return true if the specified node can
+/// potentially be interesting to a client that is only interested in
+/// VisitFlags events. This is used to reduce the cost of interprocedural
+/// analysis by not traversing the call graph through portions that the DSGraph
+/// can answer immediately.
+///
+static bool NodeCanPossiblyBeInteresting(const DSNode *N, unsigned VisitFlags) {
+ // No fields are accessed in this context.
+ if (N->getType() == Type::VoidTy) return false;
+
+ // This node is possibly interesting if we are looking for reads and it is
+ // read, we're looking for writes and it is modified, etc.
+ if ((VisitFlags & Visit::Loads) && N->isRead()) return true;
+ if ((VisitFlags & Visit::Stores) && N->isModified()) return true;
+
+ assert((VisitFlags & ~(Visit::Loads|Visit::Stores)) == 0 &&
+ "Unknown visitation type!");
+
+ // Otherwise, this node is not interesting to the current client.
+ return false;
+}
+
+/// visitGraph - Visit the functions in the specified graph, updating the
+/// specified lattice values for all of their uses.
+///
+void StructureFieldVisitorBase::
+visitGraph(DSGraph &DSG, std::multimap<DSNode*, LatticeValue*> &NodeLVs) {
+ assert(!NodeLVs.empty() && "No lattice values to compute!");
+
+ // To visit a graph, first step, we visit the instruction making up each
+ // function in the graph, but ignore calls when processing them. We handle
+ // call nodes explicitly by looking at call nodes in the graph if needed. We
+ // handle instructions before calls to avoid interprocedural analysis if we
+ // can drive lattice values to bottom early.
+ //
+ SFVInstVisitor IV(DSG, Callbacks, NodeLVs);
+
+ for (DSGraph::retnodes_iterator FI = DSG.retnodes_begin(),
+ E = DSG.retnodes_end(); FI != E; ++FI)
+ for (Function::iterator BB = FI->first->begin(), E = FI->first->end();
+ BB != E; ++BB)
+ for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
+ if (IV.visit(*I) && NodeLVs.empty())
+ return; // Nothing left to analyze.
+
+ // Keep track of which actual direct callees are handled.
+ std::set<Function*> CalleesHandled;
+
+ // Once we have visited all of the instructions in the function bodies, if
+ // there are lattice values that have not been driven to bottom, see if any of
+ // the nodes involved are passed into function calls. If so, we potentially
+ // have to recursively traverse the call graph.
+ for (DSGraph::fc_iterator CS = DSG.fc_begin(), E = DSG.fc_end();
+ CS != E; ++CS) {
+ // Figure out the mapping from a node in the caller (potentially several)
+ // nodes in the callee.
+ DSGraph::NodeMapTy CallNodeMap;
+
+ Instruction *TheCall = CS->getCallSite().getInstruction();
+
+ // If this is an indirect function call, assume nothing gets passed through
+ // it. FIXME: THIS IS BROKEN! Just get the ECG for the fn ptr if it's not
+ // direct.
+ if (CS->isIndirectCall())
+ continue;
+
+ // If this is an external function call, it cannot be involved with this
+ // node, because otherwise the node would be marked incomplete!
+ if (CS->getCalleeFunc()->isExternal())
+ continue;
+
+ // If we can handle this function call, remove it from the set of direct
+ // calls found by the visitor.
+ CalleesHandled.insert(CS->getCalleeFunc());
+
+ std::vector<DSNodeHandle> Args;
+
+ DSGraph *CG = &ECG.getDSGraph(*CS->getCalleeFunc());
+ CG->getFunctionArgumentsForCall(CS->getCalleeFunc(), Args);
+
+ if (!CS->getRetVal().isNull())
+ DSGraph::computeNodeMapping(Args[0], CS->getRetVal(), CallNodeMap);
+ for (unsigned i = 0, e = CS->getNumPtrArgs(); i != e; ++i) {
+ if (i == Args.size()-1) break;
+ DSGraph::computeNodeMapping(Args[i+1], CS->getPtrArg(i), CallNodeMap);
+ }
+ Args.clear();
+
+ // The mapping we just computed maps from nodes in the callee to nodes in
+ // the caller, so we can't query it efficiently. Instead of going through
+ // the trouble of inverting the map to do this (linear time with the size of
+ // the mapping), we just do a linear search to see if any affected nodes are
+ // passed into this call.
+ bool CallCanModifyDataFlow = false;
+ for (DSGraph::NodeMapTy::iterator MI = CallNodeMap.begin(),
+ E = CallNodeMap.end(); MI != E; ++MI)
+ if (NodeLVs.count(MI->second.getNode()))
+ // Okay, the node is passed in, check to see if the call might do
+ // something interesting to it (i.e. if analyzing the call can produce
+ // anything other than "top").
+ if ((CallCanModifyDataFlow = NodeCanPossiblyBeInteresting(MI->first,
+ Callbacks)))
+ break;
+
+ // If this function call cannot impact the analysis (either because the
+ // nodes we are tracking are not passed into the call, or the DSGraph for
+ // the callee tells us that analysis of the callee can't provide interesting
+ // information), ignore it.
+ if (!CallCanModifyDataFlow)
+ continue;
+
+ // Okay, either compute analysis results for the callee function, or reuse
+ // results previously computed.
+ std::multimap<DSNode*, LatticeValue*> &CalleeFacts = getCalleeFacts(*CG);
+
+ // Merge all of the facts for the callee into the facts for the caller. If
+ // this reduces anything in the caller to 'bottom', remove them.
+ for (DSGraph::NodeMapTy::iterator MI = CallNodeMap.begin(),
+ E = CallNodeMap.end(); MI != E; ++MI) {
+ // If we have Lattice facts in the caller for this node in the callee,
+ // merge any information from the callee into the caller.
+
+ // If the node is not accessed in the callee at all, don't update.
+ if (MI->first->getType() == Type::VoidTy)
+ continue;
+
+ // If there are no data-flow facts live in the caller for this node, don't
+ // both processing it.
+ std::multimap<DSNode*, LatticeValue*>::iterator NLVI =
+ NodeLVs.find(MI->second.getNode());
+ if (NLVI == NodeLVs.end()) continue;
+
+
+ // Iterate over all of the lattice values that have corresponding fields
+ // in the callee, merging in information as we go. Be careful about the
+ // fact that the callee may get passed the address of a substructure and
+ // other funny games.
+ //if (CalleeFacts.count(const_cast<DSNode*>(MI->first)) == 0) {
+
+ DSNode *CalleeNode = const_cast<DSNode*>(MI->first);
+
+ unsigned CalleeNodeOffset = MI->second.getOffset();
+ while (NLVI->first == MI->second.getNode()) {
+ // Figure out what offset in the callee this field would land.
+ unsigned FieldOff = NLVI->second->getFieldOffset()+CalleeNodeOffset;
+
+ // If the field is not within the callee node, ignore it.
+ if (FieldOff >= CalleeNode->getSize()) {
+ ++NLVI;
+ continue;
+ }
+
+ // Okay, check to see if we have a lattice value for the field at offset
+ // FieldOff in the callee node.
+ const LatticeValue *CalleeLV = 0;
+
+ std::multimap<DSNode*, LatticeValue*>::iterator CFI =
+ CalleeFacts.lower_bound(CalleeNode);
+ for (; CFI != CalleeFacts.end() && CFI->first == CalleeNode; ++CFI)
+ if (CFI->second->getFieldOffset() == FieldOff) {
+ CalleeLV = CFI->second; // Found it!
+ break;
+ }
+
+ // If we don't, the lattice value hit bottom and we should remove the
+ // lattice value in the caller.
+ if (!CalleeLV) {
+ delete NLVI->second; // The lattice value hit bottom.
+ NodeLVs.erase(NLVI++);
+ continue;
+ }
+
+ // Finally, if we did find a corresponding entry, merge the information
+ // into the caller's lattice value and keep going.
+ if (NLVI->second->mergeInValue(CalleeLV)) {
+ // Okay, merging these two caused the caller value to hit bottom.
+ // Remove it.
+ delete NLVI->second; // The lattice value hit bottom.
+ NodeLVs.erase(NLVI++);
+ }
+
+ ++NLVI; // We successfully merged in some information!
+ }
+
+ // If we ran out of facts to prove, just exit.
+ if (NodeLVs.empty()) return;
+ }
+ }
+
+ // The local analysis pass inconveniently discards many local function calls
+ // from the graph if they are to known functions. Loop over direct function
+ // calls not handled above and visit them as appropriate.
+ while (!IV.DirectCallSites.empty()) {
+ Instruction *Call = *IV.DirectCallSites.begin();
+ IV.DirectCallSites.erase(IV.DirectCallSites.begin());
+
+ // Is this one actually handled by DSA?
+ if (CalleesHandled.count(cast<Function>(Call->getOperand(0))))
+ continue;
+
+ // Collect the pointers involved in this call.
+ std::vector<Value*> Pointers;
+ if (isa<PointerType>(Call->getType()))
+ Pointers.push_back(Call);
+ for (unsigned i = 1, e = Call->getNumOperands(); i != e; ++i)
+ if (isa<PointerType>(Call->getOperand(i)->getType()))
+ Pointers.push_back(Call->getOperand(i));
+
+ // If this is an intrinsic function call, figure out which one.
+ unsigned IID = cast<Function>(Call->getOperand(0))->getIntrinsicID();
+
+ for (unsigned i = 0, e = Pointers.size(); i != e; ++i) {
+ // If any of our lattice values are passed into this call, which is
+ // specially handled by the local analyzer, inform the lattice function.
+ DSNode *N = DSG.getNodeForValue(Pointers[i]).getNode();
+ for (std::multimap<DSNode*, LatticeValue*>::iterator LVI =
+ NodeLVs.lower_bound(N); LVI != NodeLVs.end() && LVI->first == N;) {
+ bool AtBottom = false;
+ switch (IID) {
+ default:
+ AtBottom = LVI->second->visitRecognizedCall(*Call);
+ break;
+ case Intrinsic::memset:
+ if (Callbacks & Visit::Stores)
+ AtBottom = LVI->second->visitMemSet(*cast<CallInst>(Call));
+ break;
+ }
+
+ if (AtBottom) {
+ delete LVI->second;
+ NodeLVs.erase(LVI++);
+ } else {
+ ++LVI;
+ }
+ }
+ }
+ }
+}
Index: llvm-poolalloc/lib/Macroscopic/StructureFieldVisitor.h
diff -u /dev/null llvm-poolalloc/lib/Macroscopic/StructureFieldVisitor.h:1.6
--- /dev/null Wed May 18 14:56:41 2005
+++ llvm-poolalloc/lib/Macroscopic/StructureFieldVisitor.h Wed May 18 14:56:27 2005
@@ -0,0 +1,277 @@
+//===-- StructureFieldVisitor.h - Macroscopic DS inspector ------*- C++ -*-===//
+//
+// 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 defines the public interface to the LatticeValue and
+// StructureFieldVisitor classes.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MACROSCOPIC_STRUCTUREFIELDVISITOR_H
+#define MACROSCOPIC_STRUCTUREFIELDVISITOR_H
+
+#include <set>
+#include <map>
+#include <vector>
+
+namespace llvm {
+ class Type;
+ class Constant;
+ class Instruction;
+ class LoadInst;
+ class CallInst;
+ class StoreInst;
+ class EquivClassGraphs;
+ class DSNode;
+ class DSGraph;
+
+namespace Macroscopic {
+
+/// FindAllDataStructures - Inspect the program specified by ECG, adding to
+/// 'Nodes' all of the data structures node in the program that contain the
+/// "IncludeFlags" and do not contain "ExcludeFlags" node flags. If
+/// OnlyHomogenous is true, only type-homogenous nodes are considered.
+void FindAllDataStructures(std::set<DSNode*> &Nodes, unsigned IncludeFlags,
+ unsigned ExcludeFlags, bool OnlyHomogenous,
+ EquivClassGraphs &ECG);
+
+//===----------------------------------------------------------------------===//
+/// Visit types - This describes an enum specifying which methods are
+/// overloaded in the concrete implementation of the LatticeValue class.
+namespace Visit {
+ enum {
+ Loads = 1,
+ Stores = 2,
+ Allocs = 4,
+ Deallocs = 8,
+ // ...
+ };
+}
+
+//===----------------------------------------------------------------------===//
+/// LatticeValue - Describe.
+///
+class LatticeValue {
+ DSNode *Node;
+ std::vector<unsigned> Idxs; // The index path to get to this field.
+ const Type *FieldTy; // The type of this field.
+public:
+ LatticeValue(DSNode *N, const std::vector<unsigned> &I,
+ const Type *Ty) : Node(N), Idxs(I), FieldTy(Ty) {}
+ virtual ~LatticeValue() {}
+
+ DSNode *getNode() const { return Node; }
+ DSGraph &getParentGraph() const;
+
+ const std::vector<unsigned> &getIndices() const { return Idxs; }
+ const Type *getFieldType() const { return FieldTy; }
+
+ /// getFieldOffset - Get the byte offset of this field from the start of the
+ /// node.
+ ///
+ unsigned getFieldOffset() const;
+
+ /// dump - Print debugging information about this class.
+ ///
+ virtual void dump() const;
+
+ /// mergeInValue - Merge the information from the RHS lattice value (which is
+ /// guaranteed to be the same dynamic type as 'this') into this lattice value.
+ /// If the resultant value hits bottom, return true. This is used for
+ /// interprocedural analysis.
+ ///
+ virtual bool mergeInValue(const LatticeValue *RHS) {
+ return true;
+ }
+
+ //===--------------------------------------------------------------------===//
+ // Visitation methods - These methods update the current lattice state
+ // based on the information in the operation. If the lattice value reaches
+ // bottom, the method implementation should return true so that analysis
+ // can be stopped as early as possible. Visitation methods are grouped by
+ // their Visitation class.
+
+ // All lattice values must implement these.
+
+ /// visitRecognizedCall - The node for this lattice value is passed into some
+ /// external function that is "known" by the Local analysis pass (e.g. atoi).
+ /// By default, this stops any analysis of the node.
+ ///
+ virtual bool visitRecognizedCall(Instruction &I) {
+ return true;
+ }
+
+ // Load Vistation methods.
+ virtual bool visitLoad(LoadInst &);
+
+ // Store Visitation methods.
+ virtual bool visitStore(StoreInst &);
+ virtual bool visitGlobalInit(Constant *InitVal);
+ virtual bool visitMemSet(CallInst &I) {
+ return visitRecognizedCall((Instruction&)I);
+ }
+};
+
+//===----------------------------------------------------------------------===//
+/// CombinedLatticeValue - Describe.
+///
+template<typename L1, typename L2>
+class CombinedLatticeValue : public LatticeValue {
+ L1 LV1; L2 LV2;
+ bool LV1Bottom, LV2Bottom;
+public:
+ CombinedLatticeValue(DSNode *Node, const std::vector<unsigned> &Idxs,
+ const Type *FieldTy)
+ : LatticeValue(Node, Idxs, FieldTy), LV1(Node, Idxs, FieldTy),
+ LV2(Node, Idxs, FieldTy), LV1Bottom(false), LV2Bottom(false) {}
+
+ static unsigned getInterestingEvents() {
+ return L1::getInterestingEvents() | L2::getInterestingEvents();
+ }
+
+ static CombinedLatticeValue *create(DSNode *Node,
+ const std::vector<unsigned> &Idxs,
+ const Type *FieldTy) {
+ return new CombinedLatticeValue(Node, Idxs, FieldTy);
+ }
+
+ void dump() const {
+ if (!LV1Bottom) LV1.dump();
+ if (!LV2Bottom) LV2.dump();
+ }
+
+ virtual bool mergeInValue(const LatticeValue *RHSLV) {
+ const CombinedLatticeValue *RHS =
+ static_cast<const CombinedLatticeValue *>(RHSLV);
+ LV1Bottom |= RHS->LV1Bottom;
+ LV2Bottom |= RHS->LV2Bottom;
+ if (!LV1Bottom) LV1Bottom = LV1.mergeInValue(&RHS->LV1);
+ if (!LV2Bottom) LV2Bottom = LV2.mergeInValue(&RHS->LV2);
+ return LV1Bottom & LV2Bottom;
+ }
+
+ virtual bool visitRecognizedCall(Instruction &I) {
+ if (!LV1Bottom) LV1Bottom = LV1.visitRecognizedCall(I);
+ if (!LV2Bottom) LV2Bottom = LV2.visitRecognizedCall(I);
+ return LV1Bottom & LV2Bottom;
+ }
+
+ // Load Vistation methods.
+ virtual bool visitLoad(LoadInst &LI) {
+ if (!LV1Bottom && (L1::getInterestingEvents() & Visit::Loads))
+ LV1Bottom = LV1.visitLoad(LI);
+ if (!LV2Bottom && (L2::getInterestingEvents() & Visit::Loads))
+ LV2Bottom = LV2.visitLoad(LI);
+ return LV1Bottom & LV2Bottom;
+ }
+
+ // Store Visitation methods.
+ virtual bool visitStore(StoreInst &SI) {
+ if (!LV1Bottom && (L1::getInterestingEvents() & Visit::Stores))
+ LV1Bottom = LV1.visitStore(SI);
+ if (!LV2Bottom && (L2::getInterestingEvents() & Visit::Stores))
+ LV2Bottom = LV2.visitStore(SI);
+ return LV1Bottom & LV2Bottom;
+ }
+
+ virtual bool visitGlobalInit(Constant *InitVal) {
+ if (!LV1Bottom && (L1::getInterestingEvents() & Visit::Stores))
+ LV1Bottom = LV1.visitGlobalInit(InitVal);
+ if (!LV2Bottom && (L2::getInterestingEvents() & Visit::Stores))
+ LV2Bottom = LV2.visitGlobalInit(InitVal);
+ return LV1Bottom & LV2Bottom;
+ }
+
+ virtual bool visitMemSet(CallInst &I) {
+ if (!LV1Bottom && (L1::getInterestingEvents() & Visit::Stores))
+ LV1Bottom = LV1.visitMemSet(I);
+ if (!LV2Bottom && (L2::getInterestingEvents() & Visit::Stores))
+ LV2Bottom = LV2.visitMemSet(I);
+ return LV1Bottom & LV2Bottom;
+ }
+};
+
+
+//===----------------------------------------------------------------------===//
+/// StructureFieldVisitorBase - This implements all of the heavy lifting
+/// for the StructureFieldVisitor class. This class should not be used
+/// directly, see it (below) for usage.
+///
+class StructureFieldVisitorBase {
+ unsigned Callbacks; // Bitfield containing bits from Macroscopic::Visit
+ EquivClassGraphs &ECG;
+
+ std::map<DSGraph*, std::multimap<DSNode*,LatticeValue*> > CalleeFnFacts;
+
+ // createLatticeValue - Provide a virtual ctor for the concrete lattice value.
+ virtual LatticeValue* createLatticeValue(DSNode *Node,
+ const std::vector<unsigned> &Idxs,
+ const Type *FieldTy) = 0;
+protected:
+ // Only allow this to be subclassed.
+ StructureFieldVisitorBase(unsigned CB, EquivClassGraphs &ecg)
+ : Callbacks(CB), ECG(ecg) {}
+ virtual ~StructureFieldVisitorBase() {}
+
+
+ std::set<LatticeValue*> visitNodes(const std::set<DSNode*> &Nodes);
+ void visitFields(std::set<LatticeValue*> &Fields);
+
+private:
+ void visitGraph(DSGraph &DSG, std::multimap<DSNode*, LatticeValue*> &NodeLVs);
+ std::multimap<DSNode*, LatticeValue*> &getCalleeFacts(DSGraph &DSG);
+
+ void AddLatticeValuesForFields(DSNode *N, const Type *Ty,
+ const std::vector<unsigned> &Idxs,
+ std::set<LatticeValue*> &Values);
+ void AddLatticeValuesForNode(DSNode *N, std::set<LatticeValue*> &Values);
+ void ProcessNodesReachableFromGlobals(DSGraph &DSG,
+ std::multimap<DSNode*,LatticeValue*> &NodeLVs);
+
+};
+
+
+
+//===----------------------------------------------------------------------===//
+/// FIXME: Describe
+template<typename ConcLatticeVal>
+class StructureFieldVisitor : public StructureFieldVisitorBase {
+public:
+ // FIXME: We really want to be able to infer which methods LatticeVal
+ // overloads from the base class using template metaprogramming techniques.
+ StructureFieldVisitor(EquivClassGraphs &ECG)
+ : StructureFieldVisitorBase(ConcLatticeVal::getInterestingEvents(), ECG) {}
+
+ /// visit - Visit the specified set of data structure nodes, recursively
+ /// visiting all accesses to structure fields defined in those nodes. This
+ /// method returns a set of lattice values that have not reached bottom.
+ std::set<ConcLatticeVal*> visit(const std::set<DSNode*> &Nodes) {
+ std::set<LatticeValue*> ResultVals = visitNodes(Nodes);
+
+ // Convert the result set to the appropriate lattice type.
+ std::set<ConcLatticeVal*> Result;
+ while (!ResultVals.empty()) {
+ Result.insert(static_cast<ConcLatticeVal*>(*ResultVals.begin()));
+ ResultVals.erase(ResultVals.begin());
+ }
+ return Result;
+ }
+
+
+private: // Virtual method implementations for the base class.
+ virtual LatticeValue* createLatticeValue(DSNode *N,
+ const std::vector<unsigned> &Idxs,
+ const Type *FieldTy) {
+ return ConcLatticeVal::create(N, Idxs, FieldTy);
+ }
+};
+
+} // End Macroscopic namespace
+} // End llvm namespace
+
+#endif
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