forked from OSchip/llvm-project
323 lines
11 KiB
C++
323 lines
11 KiB
C++
//===- ComputeLocal.cpp - Compute a local data structure graph for a fn ---===//
|
|
//
|
|
// Compute the local version of the data structure graph for a function. The
|
|
// external interface to this file is the DSGraph constructor.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Analysis/DataStructure.h"
|
|
#include "llvm/Function.h"
|
|
#include "llvm/iMemory.h"
|
|
#include "llvm/iTerminators.h"
|
|
#include "llvm/iPHINode.h"
|
|
#include "llvm/iOther.h"
|
|
#include "llvm/Constants.h"
|
|
#include "llvm/GlobalVariable.h"
|
|
#include "llvm/DerivedTypes.h"
|
|
#include "llvm/Support/InstVisitor.h"
|
|
using std::map;
|
|
using std::vector;
|
|
|
|
static RegisterAnalysis<LocalDataStructures>
|
|
X("datastructure", "Local Data Structure Analysis");
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// GraphBuilder Class
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This class is the builder class that constructs the local data structure
|
|
// graph by performing a single pass over the function in question.
|
|
//
|
|
|
|
namespace {
|
|
class GraphBuilder : InstVisitor<GraphBuilder> {
|
|
DSGraph &G;
|
|
vector<DSNode*> &Nodes;
|
|
DSNodeHandle &RetNode; // Node that gets returned...
|
|
map<Value*, DSNodeHandle> &ValueMap;
|
|
vector<vector<DSNodeHandle> > &FunctionCalls;
|
|
|
|
public:
|
|
GraphBuilder(DSGraph &g, vector<DSNode*> &nodes, DSNodeHandle &retNode,
|
|
map<Value*, DSNodeHandle> &vm,
|
|
vector<vector<DSNodeHandle> > &fc)
|
|
: G(g), Nodes(nodes), RetNode(retNode), ValueMap(vm), FunctionCalls(fc) {
|
|
|
|
// Create scalar nodes for all pointer arguments...
|
|
for (Function::aiterator I = G.getFunction().abegin(),
|
|
E = G.getFunction().aend(); I != E; ++I)
|
|
if (isa<PointerType>(I->getType()))
|
|
getValueNode(*I);
|
|
|
|
visit(G.getFunction()); // Single pass over the function
|
|
|
|
// Not inlining, only eliminate trivially dead nodes.
|
|
G.removeTriviallyDeadNodes();
|
|
}
|
|
|
|
private:
|
|
// Visitor functions, used to handle each instruction type we encounter...
|
|
friend class InstVisitor<GraphBuilder>;
|
|
void visitMallocInst(MallocInst &MI) { handleAlloc(MI, DSNode::NewNode); }
|
|
void visitAllocaInst(AllocaInst &AI) { handleAlloc(AI, DSNode::AllocaNode);}
|
|
void handleAlloc(AllocationInst &AI, DSNode::NodeTy NT);
|
|
|
|
void visitPHINode(PHINode &PN);
|
|
|
|
void visitGetElementPtrInst(GetElementPtrInst &GEP);
|
|
void visitReturnInst(ReturnInst &RI);
|
|
void visitLoadInst(LoadInst &LI);
|
|
void visitStoreInst(StoreInst &SI);
|
|
void visitCallInst(CallInst &CI);
|
|
void visitSetCondInst(SetCondInst &SCI) {} // SetEQ & friends are ignored
|
|
void visitFreeInst(FreeInst &FI) {} // Ignore free instructions
|
|
void visitInstruction(Instruction &I); // Visit unsafe ptr instruction
|
|
|
|
private:
|
|
// Helper functions used to implement the visitation functions...
|
|
|
|
// createNode - Create a new DSNode, ensuring that it is properly added to
|
|
// the graph.
|
|
//
|
|
DSNode *createNode(DSNode::NodeTy NodeType, const Type *Ty);
|
|
|
|
// getValueNode - Return a DSNode that corresponds the the specified LLVM
|
|
// value. This either returns the already existing node, or creates a new
|
|
// one and adds it to the graph, if none exists.
|
|
//
|
|
DSNode *getValueNode(Value &V);
|
|
|
|
// getGlobalNode - Just like getValueNode, except the global node itself is
|
|
// returned, not a scalar node pointing to a global.
|
|
//
|
|
DSNode *getGlobalNode(GlobalValue &V);
|
|
|
|
// getLink - This method is used to either return the specified link in the
|
|
// specified node if one exists. If a link does not already exist (it's
|
|
// null), then we create a new node, link it, then return it.
|
|
//
|
|
DSNode *getLink(DSNode *Node, unsigned Link);
|
|
|
|
// getSubscriptedNode - Perform the basic getelementptr functionality that
|
|
// must be factored out of gep, load and store while they are all MAI's.
|
|
//
|
|
DSNode *getSubscriptedNode(GetElementPtrInst &GEP, DSNode *Ptr);
|
|
};
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// DSGraph constructor - Simply use the GraphBuilder to construct the local
|
|
// graph.
|
|
DSGraph::DSGraph(Function &F, GlobalDSGraph* GlobalsG)
|
|
: Func(F), RetNode(0), GlobalsGraph(GlobalsG) {
|
|
if (GlobalsGraph != this) {
|
|
GlobalsGraph->addReference(this);
|
|
// Use the graph builder to construct the local version of the graph
|
|
GraphBuilder B(*this, Nodes, RetNode, ValueMap, FunctionCalls);
|
|
markIncompleteNodes();
|
|
}
|
|
}
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Helper method implementations...
|
|
//
|
|
|
|
|
|
// createNode - Create a new DSNode, ensuring that it is properly added to the
|
|
// graph.
|
|
//
|
|
DSNode *GraphBuilder::createNode(DSNode::NodeTy NodeType, const Type *Ty) {
|
|
DSNode *N = new DSNode(NodeType, Ty);
|
|
Nodes.push_back(N);
|
|
return N;
|
|
}
|
|
|
|
|
|
// getGlobalNode - Just like getValueNode, except the global node itself is
|
|
// returned, not a scalar node pointing to a global.
|
|
//
|
|
DSNode *GraphBuilder::getGlobalNode(GlobalValue &V) {
|
|
DSNodeHandle &NH = ValueMap[&V];
|
|
if (NH) return NH; // Already have a node? Just return it...
|
|
|
|
// Create a new global node for this global variable...
|
|
DSNode *G = createNode(DSNode::GlobalNode, V.getType()->getElementType());
|
|
G->addGlobal(&V);
|
|
|
|
// If this node has outgoing edges, make sure to recycle the same node for
|
|
// each use. For functions and other global variables, this is unneccesary,
|
|
// so avoid excessive merging by cloning these nodes on demand.
|
|
//
|
|
NH = G;
|
|
return G;
|
|
}
|
|
|
|
|
|
// getValueNode - Return a DSNode that corresponds the the specified LLVM value.
|
|
// This either returns the already existing node, or creates a new one and adds
|
|
// it to the graph, if none exists.
|
|
//
|
|
DSNode *GraphBuilder::getValueNode(Value &V) {
|
|
assert(isa<PointerType>(V.getType()) && "Should only use pointer scalars!");
|
|
if (!isa<GlobalValue>(V)) {
|
|
DSNodeHandle &NH = ValueMap[&V];
|
|
if (NH) return NH; // Already have a node? Just return it...
|
|
}
|
|
|
|
// Otherwise we need to create a new scalar node...
|
|
DSNode *N = createNode(DSNode::ScalarNode, V.getType());
|
|
|
|
// If this is a global value, create the global pointed to.
|
|
if (GlobalValue *GV = dyn_cast<GlobalValue>(&V)) {
|
|
DSNode *G = getGlobalNode(*GV);
|
|
N->addEdgeTo(G);
|
|
} else {
|
|
ValueMap[&V] = N;
|
|
}
|
|
|
|
return N;
|
|
}
|
|
|
|
|
|
// getLink - This method is used to either return the specified link in the
|
|
// specified node if one exists. If a link does not already exist (it's
|
|
// null), then we create a new node, link it, then return it.
|
|
//
|
|
DSNode *GraphBuilder::getLink(DSNode *Node, unsigned Link) {
|
|
assert(Link < Node->getNumLinks() && "Link accessed out of range!");
|
|
if (Node->getLink(Link) == 0) {
|
|
DSNode::NodeTy NT;
|
|
const Type *Ty;
|
|
|
|
switch (Node->getType()->getPrimitiveID()) {
|
|
case Type::PointerTyID:
|
|
Ty = cast<PointerType>(Node->getType())->getElementType();
|
|
NT = DSNode::ShadowNode;
|
|
break;
|
|
case Type::ArrayTyID:
|
|
Ty = cast<ArrayType>(Node->getType())->getElementType();
|
|
NT = DSNode::SubElement;
|
|
break;
|
|
case Type::StructTyID:
|
|
Ty = cast<StructType>(Node->getType())->getContainedType(Link);
|
|
NT = DSNode::SubElement;
|
|
break;
|
|
default:
|
|
assert(0 && "Unexpected type to dereference!");
|
|
abort();
|
|
}
|
|
|
|
DSNode *New = createNode(NT, Ty);
|
|
Node->addEdgeTo(Link, New);
|
|
}
|
|
|
|
return Node->getLink(Link);
|
|
}
|
|
|
|
// getSubscriptedNode - Perform the basic getelementptr functionality that must
|
|
// be factored out of gep, load and store while they are all MAI's.
|
|
//
|
|
DSNode *GraphBuilder::getSubscriptedNode(GetElementPtrInst &GEP, DSNode *Ptr) {
|
|
for (unsigned i = 1, e = GEP.getNumOperands(); i != e; ++i)
|
|
if (GEP.getOperand(i)->getType() == Type::UIntTy)
|
|
Ptr = getLink(Ptr, 0);
|
|
else if (GEP.getOperand(i)->getType() == Type::UByteTy)
|
|
Ptr = getLink(Ptr, cast<ConstantUInt>(GEP.getOperand(i))->getValue());
|
|
|
|
if (GEP.getNumOperands() == 1)
|
|
Ptr = getLink(Ptr, 0); // All GEP's have an implicit 0 if nothing else.
|
|
|
|
return Ptr;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Specific instruction type handler implementations...
|
|
//
|
|
|
|
// Alloca & Malloc instruction implementation - Simply create a new memory
|
|
// object, pointing the scalar to it.
|
|
//
|
|
void GraphBuilder::handleAlloc(AllocationInst &AI, DSNode::NodeTy NodeType) {
|
|
DSNode *Scalar = getValueNode(AI);
|
|
DSNode *New = createNode(NodeType, AI.getAllocatedType());
|
|
Scalar->addEdgeTo(New); // Make the scalar point to the new node...
|
|
}
|
|
|
|
// PHINode - Make the scalar for the PHI node point to all of the things the
|
|
// incoming values point to... which effectively causes them to be merged.
|
|
//
|
|
void GraphBuilder::visitPHINode(PHINode &PN) {
|
|
if (!isa<PointerType>(PN.getType())) return; // Only pointer PHIs
|
|
|
|
DSNode *Scalar = getValueNode(PN);
|
|
DSNode *ScalarDest = getLink(Scalar, 0);
|
|
for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i)
|
|
ScalarDest->mergeWith(getLink(getValueNode(*PN.getIncomingValue(i)), 0));
|
|
}
|
|
|
|
void GraphBuilder::visitGetElementPtrInst(GetElementPtrInst &GEP) {
|
|
DSNode *Ptr = getSubscriptedNode(GEP, getValueNode(*GEP.getOperand(0)));
|
|
getValueNode(GEP)->addEdgeTo(Ptr);
|
|
}
|
|
|
|
void GraphBuilder::visitLoadInst(LoadInst &LI) {
|
|
DSNode *Ptr = getValueNode(*LI.getOperand(0));
|
|
if (!isa<PointerType>(LI.getType())) return; // only loads OF pointers
|
|
getValueNode(LI)->addEdgeTo(getLink(Ptr, 0));
|
|
}
|
|
|
|
void GraphBuilder::visitStoreInst(StoreInst &SI) {
|
|
DSNode *DestPtr = getValueNode(*SI.getOperand(1));
|
|
if (!isa<PointerType>(SI.getOperand(0)->getType())) return;
|
|
DSNode *Value = getValueNode(*SI.getOperand(0));
|
|
DestPtr->addEdgeTo(getLink(Value, 0));
|
|
}
|
|
|
|
void GraphBuilder::visitReturnInst(ReturnInst &RI) {
|
|
if (RI.getNumOperands() && isa<PointerType>(RI.getOperand(0)->getType())) {
|
|
DSNode *Value = getLink(getValueNode(*RI.getOperand(0)), 0);
|
|
Value->mergeWith(RetNode);
|
|
RetNode = Value;
|
|
}
|
|
}
|
|
|
|
void GraphBuilder::visitCallInst(CallInst &CI) {
|
|
// Add a new function call entry...
|
|
FunctionCalls.push_back(vector<DSNodeHandle>());
|
|
vector<DSNodeHandle> &Args = FunctionCalls.back();
|
|
|
|
// Set up the return value...
|
|
if (isa<PointerType>(CI.getType()))
|
|
Args.push_back(getLink(getValueNode(CI), 0));
|
|
else
|
|
Args.push_back(0);
|
|
|
|
unsigned Start = 0;
|
|
// Special case for direct call, avoid creating spurious scalar node...
|
|
if (GlobalValue *GV = dyn_cast<GlobalValue>(CI.getOperand(0))) {
|
|
Args.push_back(getGlobalNode(*GV));
|
|
Start = 1;
|
|
}
|
|
|
|
// Pass the arguments in...
|
|
for (unsigned i = Start, e = CI.getNumOperands(); i != e; ++i)
|
|
if (isa<PointerType>(CI.getOperand(i)->getType()))
|
|
Args.push_back(getLink(getValueNode(*CI.getOperand(i)), 0));
|
|
}
|
|
|
|
// visitInstruction - All safe instructions have been processed above, this case
|
|
// is where unsafe ptr instructions land.
|
|
//
|
|
void GraphBuilder::visitInstruction(Instruction &I) {
|
|
// If the return type is a pointer, mark the pointed node as being a cast node
|
|
if (isa<PointerType>(I.getType()))
|
|
getLink(getValueNode(I), 0)->NodeType |= DSNode::CastNode;
|
|
|
|
// If any operands are pointers, mark the pointed nodes as being a cast node
|
|
for (Instruction::op_iterator i = I.op_begin(), E = I.op_end(); i!=E; ++i)
|
|
if (isa<PointerType>(i->get()->getType()))
|
|
getLink(getValueNode(*i->get()), 0)->NodeType |= DSNode::CastNode;
|
|
}
|
|
|