llvm-6502/lib/Transforms/IPO/PoolAllocate.cpp
2003-02-03 19:08:18 +00:00

444 lines
16 KiB
C++

//===-- PoolAllocate.cpp - Pool Allocation Pass ---------------------------===//
//
// This transform changes programs so that disjoint data structures are
// allocated out of different pools of memory, increasing locality.
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/PoolAllocate.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Analysis/DataStructure.h"
#include "llvm/Analysis/DSGraph.h"
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Constants.h"
#include "llvm/Instructions.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Support/InstVisitor.h"
#include "Support/Statistic.h"
#include "Support/VectorExtras.h"
using namespace PA;
namespace {
const Type *VoidPtrTy = PointerType::get(Type::SByteTy);
// The type to allocate for a pool descriptor: { sbyte*, uint }
const Type *PoolDescType =
StructType::get(make_vector<const Type*>(VoidPtrTy, Type::UIntTy, 0));
const PointerType *PoolDescPtr = PointerType::get(PoolDescType);
RegisterOpt<PoolAllocate>
X("poolalloc", "Pool allocate disjoint data structures");
}
void PoolAllocate::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<BUDataStructures>();
AU.addRequired<TargetData>();
}
bool PoolAllocate::run(Module &M) {
if (M.begin() == M.end()) return false;
CurModule = &M;
AddPoolPrototypes();
BU = &getAnalysis<BUDataStructures>();
std::map<Function*, Function*> FuncMap;
// Loop over only the function initially in the program, don't traverse newly
// added ones. If the function uses memory, make it's clone.
Module::iterator LastOrigFunction = --M.end();
for (Module::iterator I = M.begin(); ; ++I) {
if (!I->isExternal())
if (Function *R = MakeFunctionClone(*I))
FuncMap[I] = R;
if (I == LastOrigFunction) break;
}
++LastOrigFunction;
// Now that all call targets are available, rewrite the function bodies of the
// clones.
for (Module::iterator I = M.begin(); I != LastOrigFunction; ++I)
if (!I->isExternal()) {
std::map<Function*, Function*>::iterator FI = FuncMap.find(I);
ProcessFunctionBody(*I, FI != FuncMap.end() ? *FI->second : *I);
}
FunctionInfo.clear();
return true;
}
// AddPoolPrototypes - Add prototypes for the pool functions to the specified
// module and update the Pool* instance variables to point to them.
//
void PoolAllocate::AddPoolPrototypes() {
CurModule->addTypeName("PoolDescriptor", PoolDescType);
// Get poolinit function...
FunctionType *PoolInitTy =
FunctionType::get(Type::VoidTy,
make_vector<const Type*>(PoolDescPtr, Type::UIntTy, 0),
false);
PoolInit = CurModule->getOrInsertFunction("poolinit", PoolInitTy);
// Get pooldestroy function...
std::vector<const Type*> PDArgs(1, PoolDescPtr);
FunctionType *PoolDestroyTy =
FunctionType::get(Type::VoidTy, PDArgs, false);
PoolDestroy = CurModule->getOrInsertFunction("pooldestroy", PoolDestroyTy);
// Get the poolalloc function...
FunctionType *PoolAllocTy = FunctionType::get(VoidPtrTy, PDArgs, false);
PoolAlloc = CurModule->getOrInsertFunction("poolalloc", PoolAllocTy);
// Get the poolfree function...
PDArgs.push_back(VoidPtrTy); // Pointer to free
FunctionType *PoolFreeTy = FunctionType::get(Type::VoidTy, PDArgs, false);
PoolFree = CurModule->getOrInsertFunction("poolfree", PoolFreeTy);
#if 0
Args[0] = Type::UIntTy; // Number of slots to allocate
FunctionType *PoolAllocArrayTy = FunctionType::get(VoidPtrTy, Args, true);
PoolAllocArray = CurModule->getOrInsertFunction("poolallocarray",
PoolAllocArrayTy);
#endif
}
// MakeFunctionClone - If the specified function needs to be modified for pool
// allocation support, make a clone of it, adding additional arguments as
// neccesary, and return it. If not, just return null.
//
Function *PoolAllocate::MakeFunctionClone(Function &F) {
DSGraph &G = BU->getDSGraph(F);
std::vector<DSNode*> &Nodes = G.getNodes();
if (Nodes.empty()) return 0; // No memory activity, nothing is required
FuncInfo &FI = FunctionInfo[&F]; // Create a new entry for F
FI.Clone = 0;
// Find DataStructure nodes which are allocated in pools non-local to the
// current function. This set will contain all of the DSNodes which require
// pools to be passed in from outside of the function.
hash_set<DSNode*> &MarkedNodes = FI.MarkedNodes;
// Mark globals and incomplete nodes as live... (this handles arguments)
if (F.getName() != "main")
for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
if (Nodes[i]->NodeType & (DSNode::GlobalNode | DSNode::Incomplete) &&
Nodes[i]->NodeType & (DSNode::HeapNode))
Nodes[i]->markReachableNodes(MarkedNodes);
// Marked the returned node as alive...
G.getRetNode().getNode()->markReachableNodes(MarkedNodes);
if (MarkedNodes.empty()) // We don't need to clone the function if there
return 0; // are no incoming arguments to be added.
// Figure out what the arguments are to be for the new version of the function
const FunctionType *OldFuncTy = F.getFunctionType();
std::vector<const Type*> ArgTys;
ArgTys.reserve(OldFuncTy->getParamTypes().size() + MarkedNodes.size());
FI.ArgNodes.reserve(MarkedNodes.size());
for (hash_set<DSNode*>::iterator I = MarkedNodes.begin(),
E = MarkedNodes.end(); I != E; ++I)
if ((*I)->NodeType & DSNode::Incomplete) {
ArgTys.push_back(PoolDescPtr); // Add the appropriate # of pool descs
FI.ArgNodes.push_back(*I);
}
if (FI.ArgNodes.empty()) return 0; // No nodes to be pool allocated!
ArgTys.insert(ArgTys.end(), OldFuncTy->getParamTypes().begin(),
OldFuncTy->getParamTypes().end());
// Create the new function prototype
FunctionType *FuncTy = FunctionType::get(OldFuncTy->getReturnType(), ArgTys,
OldFuncTy->isVarArg());
// Create the new function...
Function *New = new Function(FuncTy, true, F.getName(), F.getParent());
// Set the rest of the new arguments names to be PDa<n> and add entries to the
// pool descriptors map
std::map<DSNode*, Value*> &PoolDescriptors = FI.PoolDescriptors;
Function::aiterator NI = New->abegin();
for (unsigned i = 0, e = FI.ArgNodes.size(); i != e; ++i, ++NI) {
NI->setName("PDa"); // Add pd entry
PoolDescriptors.insert(std::make_pair(FI.ArgNodes[i], NI));
}
// Map the existing arguments of the old function to the corresponding
// arguments of the new function.
std::map<const Value*, Value*> ValueMap;
for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I, ++NI) {
ValueMap[I] = NI;
NI->setName(I->getName());
}
// Populate the value map with all of the globals in the program.
// FIXME: This should be unneccesary!
Module &M = *F.getParent();
for (Module::iterator I = M.begin(), E=M.end(); I!=E; ++I) ValueMap[I] = I;
for (Module::giterator I = M.gbegin(), E=M.gend(); I!=E; ++I) ValueMap[I] = I;
// Perform the cloning.
std::vector<ReturnInst*> Returns;
CloneFunctionInto(New, &F, ValueMap, Returns);
// Invert the ValueMap into the NewToOldValueMap
std::map<Value*, const Value*> &NewToOldValueMap = FI.NewToOldValueMap;
for (std::map<const Value*, Value*>::iterator I = ValueMap.begin(),
E = ValueMap.end(); I != E; ++I)
NewToOldValueMap.insert(std::make_pair(I->second, I->first));
return FI.Clone = New;
}
// processFunction - Pool allocate any data structures which are contained in
// the specified function...
//
void PoolAllocate::ProcessFunctionBody(Function &F, Function &NewF) {
DSGraph &G = BU->getDSGraph(F);
std::vector<DSNode*> &Nodes = G.getNodes();
if (Nodes.empty()) return; // Quick exit if nothing to do...
FuncInfo &FI = FunctionInfo[&F]; // Get FuncInfo for F
hash_set<DSNode*> &MarkedNodes = FI.MarkedNodes;
DEBUG(std::cerr << "[" << F.getName() << "] Pool Allocate: ");
// Loop over all of the nodes which are non-escaping, adding pool-allocatable
// ones to the NodesToPA vector.
std::vector<DSNode*> NodesToPA;
for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
if (Nodes[i]->NodeType & DSNode::HeapNode && // Pick nodes with heap elems
!(Nodes[i]->NodeType & DSNode::Array) && // Doesn't handle arrays yet.
!MarkedNodes.count(Nodes[i])) // Can't be marked
NodesToPA.push_back(Nodes[i]);
DEBUG(std::cerr << NodesToPA.size() << " nodes to pool allocate\n");
if (!NodesToPA.empty()) {
// Create pool construction/destruction code
std::map<DSNode*, Value*> &PoolDescriptors = FI.PoolDescriptors;
CreatePools(NewF, NodesToPA, PoolDescriptors);
}
// Transform the body of the function now...
TransformFunctionBody(NewF, G, FI);
}
// CreatePools - This creates the pool initialization and destruction code for
// the DSNodes specified by the NodesToPA list. This adds an entry to the
// PoolDescriptors map for each DSNode.
//
void PoolAllocate::CreatePools(Function &F,
const std::vector<DSNode*> &NodesToPA,
std::map<DSNode*, Value*> &PoolDescriptors) {
// Find all of the return nodes in the CFG...
std::vector<BasicBlock*> ReturnNodes;
for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
if (isa<ReturnInst>(I->getTerminator()))
ReturnNodes.push_back(I);
TargetData &TD = getAnalysis<TargetData>();
// Loop over all of the pools, inserting code into the entry block of the
// function for the initialization and code in the exit blocks for
// destruction.
//
Instruction *InsertPoint = F.front().begin();
for (unsigned i = 0, e = NodesToPA.size(); i != e; ++i) {
DSNode *Node = NodesToPA[i];
// Create a new alloca instruction for the pool...
Value *AI = new AllocaInst(PoolDescType, 0, "PD", InsertPoint);
Value *ElSize =
ConstantUInt::get(Type::UIntTy, TD.getTypeSize(Node->getType()));
// Insert the call to initialize the pool...
new CallInst(PoolInit, make_vector(AI, ElSize, 0), "", InsertPoint);
// Update the PoolDescriptors map
PoolDescriptors.insert(std::make_pair(Node, AI));
// Insert a call to pool destroy before each return inst in the function
for (unsigned r = 0, e = ReturnNodes.size(); r != e; ++r)
new CallInst(PoolDestroy, make_vector(AI, 0), "",
ReturnNodes[r]->getTerminator());
}
}
namespace {
/// FuncTransform - This class implements transformation required of pool
/// allocated functions.
struct FuncTransform : public InstVisitor<FuncTransform> {
PoolAllocate &PAInfo;
DSGraph &G;
FuncInfo &FI;
FuncTransform(PoolAllocate &P, DSGraph &g, FuncInfo &fi)
: PAInfo(P), G(g), FI(fi) {}
void visitMallocInst(MallocInst &MI);
void visitFreeInst(FreeInst &FI);
void visitCallInst(CallInst &CI);
private:
DSNode *getDSNodeFor(Value *V) {
if (!FI.NewToOldValueMap.empty()) {
// If the NewToOldValueMap is in effect, use it.
std::map<Value*,const Value*>::iterator I = FI.NewToOldValueMap.find(V);
if (I != FI.NewToOldValueMap.end())
V = (Value*)I->second;
}
return G.getScalarMap()[V].getNode();
}
Value *getPoolHandle(Value *V) {
DSNode *Node = getDSNodeFor(V);
// Get the pool handle for this DSNode...
std::map<DSNode*, Value*>::iterator I = FI.PoolDescriptors.find(Node);
return I != FI.PoolDescriptors.end() ? I->second : 0;
}
};
}
void PoolAllocate::TransformFunctionBody(Function &F, DSGraph &G, FuncInfo &FI){
FuncTransform(*this, G, FI).visit(F);
}
void FuncTransform::visitMallocInst(MallocInst &MI) {
// Get the pool handle for the node that this contributes to...
Value *PH = getPoolHandle(&MI);
if (PH == 0) return;
// Insert a call to poolalloc
Value *V = new CallInst(PAInfo.PoolAlloc, make_vector(PH, 0),
MI.getName(), &MI);
MI.setName(""); // Nuke MIs name
// Cast to the appropriate type...
Value *Casted = new CastInst(V, MI.getType(), V->getName(), &MI);
// Update def-use info
MI.replaceAllUsesWith(Casted);
// Remove old malloc instruction
MI.getParent()->getInstList().erase(&MI);
hash_map<Value*, DSNodeHandle> &SM = G.getScalarMap();
hash_map<Value*, DSNodeHandle>::iterator MII = SM.find(&MI);
// If we are modifying the original function, update the DSGraph...
if (MII != SM.end()) {
// V and Casted now point to whatever the original malloc did...
SM.insert(std::make_pair(V, MII->second));
SM.insert(std::make_pair(Casted, MII->second));
SM.erase(MII); // The malloc is now destroyed
} else { // Otherwise, update the NewToOldValueMap
std::map<Value*,const Value*>::iterator MII =
FI.NewToOldValueMap.find(&MI);
assert(MII != FI.NewToOldValueMap.end() && "MI not found in clone?");
FI.NewToOldValueMap.insert(std::make_pair(V, MII->second));
FI.NewToOldValueMap.insert(std::make_pair(Casted, MII->second));
FI.NewToOldValueMap.erase(MII);
}
}
void FuncTransform::visitFreeInst(FreeInst &FI) {
Value *Arg = FI.getOperand(0);
Value *PH = getPoolHandle(Arg); // Get the pool handle for this DSNode...
if (PH == 0) return;
// Insert a cast and a call to poolfree...
Value *Casted = new CastInst(Arg, PointerType::get(Type::SByteTy),
Arg->getName()+".casted", &FI);
new CallInst(PAInfo.PoolFree, make_vector(PH, Casted, 0), "", &FI);
// Delete the now obsolete free instruction...
FI.getParent()->getInstList().erase(&FI);
}
static void CalcNodeMapping(DSNode *Caller, DSNode *Callee,
std::map<DSNode*, DSNode*> &NodeMapping) {
if (Callee == 0) return;
assert(Caller && "Callee has node but caller doesn't??");
std::map<DSNode*, DSNode*>::iterator I = NodeMapping.find(Callee);
if (I != NodeMapping.end()) { // Node already in map...
assert(I->second == Caller && "Node maps to different nodes on paths?");
} else {
NodeMapping.insert(I, std::make_pair(Callee, Caller));
// Recursively add pointed to nodes...
for (unsigned i = 0, e = Callee->getNumLinks(); i != e; ++i)
CalcNodeMapping(Caller->getLink(i << DS::PointerShift).getNode(),
Callee->getLink(i << DS::PointerShift).getNode(),
NodeMapping);
}
}
void FuncTransform::visitCallInst(CallInst &CI) {
Function *CF = CI.getCalledFunction();
assert(CF && "FIXME: Pool allocation doesn't handle indirect calls!");
FuncInfo *CFI = PAInfo.getFuncInfo(*CF);
if (CFI == 0 || CFI->Clone == 0) return; // Nothing to transform...
DEBUG(std::cerr << " Handling call: " << CI);
DSGraph &CG = PAInfo.getBUDataStructures().getDSGraph(*CF); // Callee graph
// We need to figure out which local pool descriptors correspond to the pool
// descriptor arguments passed into the function call. Calculate a mapping
// from callee DSNodes to caller DSNodes. We construct a partial isomophism
// between the graphs to figure out which pool descriptors need to be passed
// in. The roots of this mapping is found from arguments and return values.
//
std::map<DSNode*, DSNode*> NodeMapping;
Function::aiterator AI = CF->abegin(), AE = CF->aend();
unsigned OpNum = 1;
for (; AI != AE; ++AI, ++OpNum)
CalcNodeMapping(getDSNodeFor(CI.getOperand(OpNum)),
CG.getScalarMap()[AI].getNode(), NodeMapping);
assert(OpNum == CI.getNumOperands() && "Varargs calls not handled yet!");
// Map the return value as well...
CalcNodeMapping(getDSNodeFor(&CI), CG.getRetNode().getNode(), NodeMapping);
// Okay, now that we have established our mapping, we can figure out which
// pool descriptors to pass in...
std::vector<Value*> Args;
// Add an argument for each pool which must be passed in...
for (unsigned i = 0, e = CFI->ArgNodes.size(); i != e; ++i) {
if (NodeMapping.count(CFI->ArgNodes[i])) {
assert(NodeMapping.count(CFI->ArgNodes[i]) && "Node not in mapping!");
DSNode *LocalNode = NodeMapping.find(CFI->ArgNodes[i])->second;
assert(FI.PoolDescriptors.count(LocalNode) && "Node not pool allocated?");
Args.push_back(FI.PoolDescriptors.find(LocalNode)->second);
} else {
Args.push_back(Constant::getNullValue(PoolDescPtr));
}
}
// Add the rest of the arguments...
Args.insert(Args.end(), CI.op_begin()+1, CI.op_end());
std::string Name = CI.getName(); CI.setName("");
Value *NewCall = new CallInst(CFI->Clone, Args, Name, &CI);
CI.replaceAllUsesWith(NewCall);
DEBUG(std::cerr << " Result Call: " << *NewCall);
CI.getParent()->getInstList().erase(&CI);
}