bool MemCpyOpt::processStore(StoreInst *SI, BasicBlock::iterator &BBI) {
if (!SI->isSimple()) return false;
// Avoid merging nontemporal stores since the resulting
// memcpy/memset would not be able to preserve the nontemporal hint.
// In theory we could teach how to propagate the !nontemporal metadata to
// memset calls. However, that change would force the backend to
// conservatively expand !nontemporal memset calls back to sequences of
// store instructions (effectively undoing the merging).
if (SI->getMetadata(LLVMContext::MD_nontemporal))
return false;
const DataLayout &DL = SI->getModule()->getDataLayout();
// Detect cases where we're performing call slot forwarding, but
// happen to be using a load-store pair to implement it, rather than
// a memcpy.
if (LoadInst *LI = dyn_cast<LoadInst>(SI->getOperand(0))) {
if (LI->isSimple() && LI->hasOneUse() &&
LI->getParent() == SI->getParent()) {
MemDepResult ldep = MD->getDependency(LI);
CallInst *C = nullptr;
if (ldep.isClobber() && !isa<MemCpyInst>(ldep.getInst()))
C = dyn_cast<CallInst>(ldep.getInst());
if (C) {
// Check that nothing touches the dest of the "copy" between
// the call and the store.
AliasAnalysis &AA = getAnalysis<AAResultsWrapperPass>().getAAResults();
MemoryLocation StoreLoc = MemoryLocation::get(SI);
for (BasicBlock::iterator I = --SI->getIterator(), E = C->getIterator();
I != E; --I) {
if (AA.getModRefInfo(&*I, StoreLoc) != MRI_NoModRef) {
C = nullptr;
break;
}
}
}
if (C) {
unsigned storeAlign = SI->getAlignment();
if (!storeAlign)
storeAlign = DL.getABITypeAlignment(SI->getOperand(0)->getType());
unsigned loadAlign = LI->getAlignment();
if (!loadAlign)
loadAlign = DL.getABITypeAlignment(LI->getType());
bool changed = performCallSlotOptzn(
LI, SI->getPointerOperand()->stripPointerCasts(),
LI->getPointerOperand()->stripPointerCasts(),
DL.getTypeStoreSize(SI->getOperand(0)->getType()),
std::min(storeAlign, loadAlign), C);
if (changed) {
MD->removeInstruction(SI);
SI->eraseFromParent();
MD->removeInstruction(LI);
LI->eraseFromParent();
++NumMemCpyInstr;
return true;
}
}
}
}
// There are two cases that are interesting for this code to handle: memcpy
// and memset. Right now we only handle memset.
// Ensure that the value being stored is something that can be memset'able a
// byte at a time like "0" or "-1" or any width, as well as things like
// 0xA0A0A0A0 and 0.0.
if (Value *ByteVal = isBytewiseValue(SI->getOperand(0)))
if (Instruction *I = tryMergingIntoMemset(SI, SI->getPointerOperand(),
ByteVal)) {
BBI = I->getIterator(); // Don't invalidate iterator.
return true;
}
return false;
}
bool LowerEmSetjmp::runOnModule(Module &M) {
TheModule = &M;
Function *Setjmp = TheModule->getFunction("setjmp");
Function *Longjmp = TheModule->getFunction("longjmp");
if (!Setjmp && !Longjmp) return false;
Type *i32 = Type::getInt32Ty(M.getContext());
Type *Void = Type::getVoidTy(M.getContext());
// Add functions
Function *EmSetjmp = NULL;
if (Setjmp) {
SmallVector<Type*, 2> EmSetjmpTypes;
EmSetjmpTypes.push_back(Setjmp->getFunctionType()->getParamType(0));
EmSetjmpTypes.push_back(i32); // extra param that says which setjmp in the function it is
FunctionType *EmSetjmpFunc = FunctionType::get(i32, EmSetjmpTypes, false);
EmSetjmp = Function::Create(EmSetjmpFunc, GlobalValue::ExternalLinkage, "emscripten_setjmp", TheModule);
}
Function *EmLongjmp = Longjmp ? Function::Create(Longjmp->getFunctionType(), GlobalValue::ExternalLinkage, "emscripten_longjmp", TheModule) : NULL;
SmallVector<Type*, 1> IntArgTypes;
IntArgTypes.push_back(i32);
FunctionType *IntIntFunc = FunctionType::get(i32, IntArgTypes, false);
Function *CheckLongjmp = Function::Create(IntIntFunc, GlobalValue::ExternalLinkage, "emscripten_check_longjmp", TheModule); // gets control flow
Function *GetLongjmpResult = Function::Create(IntIntFunc, GlobalValue::ExternalLinkage, "emscripten_get_longjmp_result", TheModule); // gets int value longjmp'd
FunctionType *VoidFunc = FunctionType::get(Void, false);
Function *PrepSetjmp = Function::Create(VoidFunc, GlobalValue::ExternalLinkage, "emscripten_prep_setjmp", TheModule);
Function *CleanupSetjmp = Function::Create(VoidFunc, GlobalValue::ExternalLinkage, "emscripten_cleanup_setjmp", TheModule);
Function *PreInvoke = TheModule->getFunction("emscripten_preinvoke");
if (!PreInvoke) PreInvoke = Function::Create(VoidFunc, GlobalValue::ExternalLinkage, "emscripten_preinvoke", TheModule);
FunctionType *IntFunc = FunctionType::get(i32, false);
Function *PostInvoke = TheModule->getFunction("emscripten_postinvoke");
if (!PostInvoke) PostInvoke = Function::Create(IntFunc, GlobalValue::ExternalLinkage, "emscripten_postinvoke", TheModule);
// Process all callers of setjmp and longjmp. Start with setjmp.
typedef std::vector<PHINode*> Phis;
typedef std::map<Function*, Phis> FunctionPhisMap;
FunctionPhisMap SetjmpOutputPhis;
std::vector<Instruction*> ToErase;
if (Setjmp) {
for (Instruction::user_iterator UI = Setjmp->user_begin(), UE = Setjmp->user_end(); UI != UE; ++UI) {
User *U = *UI;
if (CallInst *CI = dyn_cast<CallInst>(U)) {
BasicBlock *SJBB = CI->getParent();
// The tail is everything right after the call, and will be reached once when setjmp is
// called, and later when longjmp returns to the setjmp
BasicBlock *Tail = SplitBlock(SJBB, CI->getNextNode());
// Add a phi to the tail, which will be the output of setjmp, which indicates if this is the
// first call or a longjmp back. The phi directly uses the right value based on where we
// arrive from
PHINode *SetjmpOutput = PHINode::Create(i32, 2, "", Tail->getFirstNonPHI());
SetjmpOutput->addIncoming(ConstantInt::get(i32, 0), SJBB); // setjmp initial call returns 0
CI->replaceAllUsesWith(SetjmpOutput); // The proper output is now this, not the setjmp call itself
// longjmp returns to the setjmp will add themselves to this phi
Phis& P = SetjmpOutputPhis[SJBB->getParent()];
P.push_back(SetjmpOutput);
// fix call target
SmallVector<Value *, 2> Args;
Args.push_back(CI->getArgOperand(0));
Args.push_back(ConstantInt::get(i32, P.size())); // our index in the function is our place in the array + 1
CallInst::Create(EmSetjmp, Args, "", CI);
ToErase.push_back(CI);
} else {
errs() << **UI << "\n";
report_fatal_error("bad use of setjmp, should only call it");
}
}
}
// Update longjmp FIXME: we could avoid throwing in longjmp as an optimization when longjmping back into the current function perhaps?
if (Longjmp) Longjmp->replaceAllUsesWith(EmLongjmp);
// Update all setjmping functions
for (FunctionPhisMap::iterator I = SetjmpOutputPhis.begin(); I != SetjmpOutputPhis.end(); I++) {
Function *F = I->first;
Phis& P = I->second;
CallInst::Create(PrepSetjmp, "", F->begin()->begin());
// Update each call that can longjmp so it can return to a setjmp where relevant
for (Function::iterator BBI = F->begin(), E = F->end(); BBI != E; ) {
BasicBlock *BB = BBI++;
for (BasicBlock::iterator Iter = BB->begin(), E = BB->end(); Iter != E; ) {
Instruction *I = Iter++;
CallInst *CI;
if ((CI = dyn_cast<CallInst>(I))) {
Value *V = CI->getCalledValue();
if (V == PrepSetjmp || V == EmSetjmp || V == CheckLongjmp || V == GetLongjmpResult || V == PreInvoke || V == PostInvoke) continue;
if (Function *CF = dyn_cast<Function>(V)) if (CF->isIntrinsic()) continue;
// TODO: proper analysis of what can actually longjmp. Currently we assume anything but setjmp can.
// This may longjmp, so we need to check if it did. Split at that point, and
// envelop the call in pre/post invoke, if we need to
CallInst *After;
Instruction *Check = NULL;
if (Iter != E && (After = dyn_cast<CallInst>(Iter)) && After->getCalledValue() == PostInvoke) {
// use the pre|postinvoke that exceptions lowering already made
Check = Iter++;
}
BasicBlock *Tail = SplitBlock(BB, Iter); // Iter already points to the next instruction, as we need
TerminatorInst *TI = BB->getTerminator();
if (!Check) {
// no existing pre|postinvoke, create our own
CallInst::Create(PreInvoke, "", CI);
Check = CallInst::Create(PostInvoke, "", TI); // CI is at the end of the block
// If we are calling a function that is noreturn, we must remove that attribute. The code we
// insert here does expect it to return, after we catch the exception.
if (CI->doesNotReturn()) {
if (Function *F = dyn_cast<Function>(CI->getCalledValue())) {
F->removeFnAttr(Attribute::NoReturn);
}
CI->setAttributes(CI->getAttributes().removeAttribute(TheModule->getContext(), AttributeSet::FunctionIndex, Attribute::NoReturn));
assert(!CI->doesNotReturn());
}
}
// We need to replace the terminator in Tail - SplitBlock makes BB go straight to Tail, we need to check if a longjmp occurred, and
// go to the right setjmp-tail if so
SmallVector<Value *, 1> Args;
Args.push_back(Check);
Instruction *LongjmpCheck = CallInst::Create(CheckLongjmp, Args, "", BB);
Instruction *LongjmpResult = CallInst::Create(GetLongjmpResult, Args, "", BB);
SwitchInst *SI = SwitchInst::Create(LongjmpCheck, Tail, 2, BB);
// -1 means no longjmp happened, continue normally (will hit the default switch case). 0 means a longjmp that is not ours to handle, needs a rethrow. Otherwise
// the index mean is the same as the index in P+1 (to avoid 0).
for (unsigned i = 0; i < P.size(); i++) {
SI->addCase(cast<ConstantInt>(ConstantInt::get(i32, i+1)), P[i]->getParent());
P[i]->addIncoming(LongjmpResult, BB);
}
ToErase.push_back(TI); // new terminator is now the switch
// we are splitting the block here, and must continue to find other calls in the block - which is now split. so continue
// to traverse in the Tail
BB = Tail;
Iter = BB->begin();
E = BB->end();
} else if (InvokeInst *CI = dyn_cast<InvokeInst>(I)) { // XXX check if target is setjmp
(void)CI;
report_fatal_error("TODO: invoke inside setjmping functions");
}
}
}
// add a cleanup before each return
for (Function::iterator BBI = F->begin(), E = F->end(); BBI != E; ) {
BasicBlock *BB = BBI++;
TerminatorInst *TI = BB->getTerminator();
if (isa<ReturnInst>(TI)) {
CallInst::Create(CleanupSetjmp, "", TI);
}
}
}
for (unsigned i = 0; i < ToErase.size(); i++) {
ToErase[i]->eraseFromParent();
}
// Finally, our modifications to the cfg can break dominance of SSA variables. For example,
// if (x()) { .. setjmp() .. }
// if (y()) { .. longjmp() .. }
// We must split the longjmp block, and it can jump into the setjmp one. But that means that when
// we split the setjmp block, it's first part no longer dominates its second part - there is
// a theoretically possible control flow path where x() is false, then y() is true and we
// reach the second part of the setjmp block, without ever reaching the first part. So,
// we recalculate regs vs. mem
for (FunctionPhisMap::iterator I = SetjmpOutputPhis.begin(); I != SetjmpOutputPhis.end(); I++) {
Function *F = I->first;
doRegToMem(*F);
doMemToReg(*F);
}
return true;
}
void AAAnalyzer::handle_inst(Instruction *inst, FunctionWrapper * parent_func) {
//outs()<<*inst<<"\n"; outs().flush();
switch (inst->getOpcode()) {
// common/bitwise binary operations
// Terminator instructions
case Instruction::Ret:
{
ReturnInst* retInst = ((ReturnInst*) inst);
if (retInst->getNumOperands() > 0 && !retInst->getOperandUse(0)->getType()->isVoidTy()) {
parent_func->addRet(retInst->getOperandUse(0));
}
}
break;
case Instruction::Resume:
{
Value* resume = ((ResumeInst*) inst)->getOperand(0);
parent_func->addResume(resume);
}
break;
case Instruction::Switch:
case Instruction::Br:
case Instruction::IndirectBr:
case Instruction::Unreachable:
break;
// vector operations
case Instruction::ExtractElement:
{
}
break;
case Instruction::InsertElement:
{
}
break;
case Instruction::ShuffleVector:
{
}
break;
// aggregate operations
case Instruction::ExtractValue:
{
Value * agg = ((ExtractValueInst*) inst)->getAggregateOperand();
DyckVertex* aggV = wrapValue(agg);
Type* aggTy = agg->getType();
ArrayRef<unsigned> indices = ((ExtractValueInst*) inst)->getIndices();
DyckVertex* currentStruct = aggV;
for (unsigned int i = 0; i < indices.size(); i++) {
if (isa<CompositeType>(aggTy) && aggTy->isSized()) {
if (!aggTy->isStructTy()) {
aggTy = ((CompositeType*) aggTy)->getTypeAtIndex(indices[i]);
#ifndef ARRAY_SIMPLIFIED
current = addPtrOffset(current, (int) indices[i] * dl.getTypeAllocSize(aggTy), dgraph);
#endif
if (i == indices.size() - 1) {
this->makeAlias(currentStruct, wrapValue(inst));
}
} else {
aggTy = ((CompositeType*) aggTy)->getTypeAtIndex(indices[i]);
if (i != indices.size() - 1) {
currentStruct = this->addField(currentStruct, -2 - (int) indices[i], NULL);
} else {
currentStruct = this->addField(currentStruct, -2 - (int) indices[i], wrapValue(inst));
}
}
} else {
break;
}
}
}
break;
case Instruction::InsertValue:
{
DyckVertex* resultV = wrapValue(inst);
Value * agg = ((InsertValueInst*) inst)->getAggregateOperand();
if (!isa<UndefValue>(agg)) {
makeAlias(resultV, wrapValue(agg));
}
Value * val = ((InsertValueInst*) inst)->getInsertedValueOperand();
DyckVertex* insertedVal = wrapValue(val);
Type *aggTy = inst->getType();
ArrayRef<unsigned> indices = ((InsertValueInst*) inst)->getIndices();
DyckVertex* currentStruct = resultV;
for (unsigned int i = 0; i < indices.size(); i++) {
if (isa<CompositeType>(aggTy) && aggTy->isSized()) {
if (!aggTy->isStructTy()) {
aggTy = ((CompositeType*) aggTy)->getTypeAtIndex(indices[i]);
#ifndef ARRAY_SIMPLIFIED
current = addPtrOffset(current, (int) indices[i] * dl.getTypeAllocSize(aggTy), dgraph);
#endif
if (i == indices.size() - 1) {
this->makeAlias(currentStruct, insertedVal);
}
} else {
aggTy = ((CompositeType*) aggTy)->getTypeAtIndex(indices[i]);
if (i != indices.size() - 1) {
currentStruct = this->addField(currentStruct, -2 - (int) indices[i], NULL);
} else {
currentStruct = this->addField(currentStruct, -2 - (int) indices[i], insertedVal);
}
}
} else {
break;
}
}
}
break;
// memory accessing and addressing operations
case Instruction::Alloca:
{
}
break;
case Instruction::Fence:
{
}
break;
case Instruction::AtomicCmpXchg:
{
Value * retXchg = inst;
Value * ptrXchg = inst->getOperand(0);
Value * newXchg = inst->getOperand(2);
addPtrTo(wrapValue(ptrXchg), wrapValue(retXchg));
addPtrTo(wrapValue(ptrXchg), wrapValue(newXchg));
}
break;
case Instruction::AtomicRMW:
{
Value * retRmw = inst;
Value * ptrRmw = ((AtomicRMWInst*) inst)->getPointerOperand();
addPtrTo(wrapValue(ptrRmw), wrapValue(retRmw));
switch (((AtomicRMWInst*) inst)->getOperation()) {
case AtomicRMWInst::Max:
case AtomicRMWInst::Min:
case AtomicRMWInst::UMax:
case AtomicRMWInst::UMin:
case AtomicRMWInst::Xchg:
{
Value * newRmw = ((AtomicRMWInst*) inst)->getValOperand();
addPtrTo(wrapValue(ptrRmw), wrapValue(newRmw));
}
break;
default:
//others are binary ops like add/sub/...
///@TODO
break;
}
}
break;
case Instruction::Load:
{
Value *lval = inst;
Value *ladd = inst->getOperand(0);
addPtrTo(wrapValue(ladd), wrapValue(lval));
}
break;
case Instruction::Store:
{
Value * sval = inst->getOperand(0);
Value * sadd = inst->getOperand(1);
addPtrTo(wrapValue(sadd), wrapValue(sval));
}
break;
case Instruction::GetElementPtr:
{
makeAlias(wrapValue(inst), handle_gep((GEPOperator*) inst));
}
break;
// conversion operations
case Instruction::Trunc:
case Instruction::ZExt:
case Instruction::SExt:
case Instruction::FPTrunc:
case Instruction::FPExt:
case Instruction::FPToUI:
case Instruction::FPToSI:
case Instruction::UIToFP:
case Instruction::SIToFP:
case Instruction::BitCast:
case Instruction::PtrToInt:
case Instruction::IntToPtr:
{
Value * itpv = inst->getOperand(0);
makeAlias(wrapValue(inst), wrapValue(itpv));
}
break;
// other operations
case Instruction::Invoke: // invoke is a terminal operation
{
InvokeInst * invoke = (InvokeInst*) inst;
LandingPadInst* lpd = invoke->getLandingPadInst();
parent_func->addLandingPad(invoke, lpd);
Value * cv = invoke->getCalledValue();
vector<Value*> args;
for (unsigned i = 0; i < invoke->getNumArgOperands(); i++) {
args.push_back(invoke->getArgOperand(i));
}
this->handle_invoke_call_inst(invoke, cv, &args, parent_func);
}
break;
case Instruction::Call:
{
CallInst * callinst = (CallInst*) inst;
if (callinst->isInlineAsm()) {
break;
}
Value * cv = callinst->getCalledValue();
vector<Value*> args;
for (unsigned i = 0; i < callinst->getNumArgOperands(); i++) {
args.push_back(callinst->getArgOperand(i));
}
this->handle_invoke_call_inst(callinst, cv, &args, parent_func);
}
break;
case Instruction::PHI:
{
PHINode *phi = (PHINode *) inst;
int nums = phi->getNumIncomingValues();
for (int i = 0; i < nums; i++) {
Value * p = phi->getIncomingValue(i);
makeAlias(wrapValue(inst), wrapValue(p));
}
}
break;
case Instruction::Select:
{
Value *first = ((SelectInst*) inst)->getTrueValue();
Value *second = ((SelectInst*) inst)->getFalseValue();
makeAlias(wrapValue(inst), wrapValue(first));
makeAlias(wrapValue(inst), wrapValue(second));
}
break;
case Instruction::VAArg:
{
parent_func->addVAArg(inst);
DyckVertex* vaarg = wrapValue(inst);
Value * ptrVaarg = inst->getOperand(0);
addPtrTo(wrapValue(ptrVaarg), vaarg);
}
break;
case Instruction::LandingPad: // handled with invoke inst
case Instruction::ICmp:
case Instruction::FCmp:
default:
break;
}
}
/// HandleURoRInvokes - Handle invokes of "_Unwind_Resume_or_Rethrow" calls. The
/// "unwind" part of these invokes jump to a landing pad within the current
/// function. This is a candidate to merge the selector associated with the URoR
/// invoke with the one from the URoR's landing pad.
bool DwarfEHPrepare::HandleURoRInvokes() {
if (!EHCatchAllValue) {
EHCatchAllValue =
F->getParent()->getNamedGlobal("llvm.eh.catch.all.value");
if (!EHCatchAllValue) return false;
}
if (!SelectorIntrinsic) {
SelectorIntrinsic =
Intrinsic::getDeclaration(F->getParent(), Intrinsic::eh_selector);
if (!SelectorIntrinsic) return false;
}
SmallPtrSet<IntrinsicInst*, 32> Sels;
SmallPtrSet<IntrinsicInst*, 32> CatchAllSels;
FindAllCleanupSelectors(Sels, CatchAllSels);
if (!DT)
// We require DominatorTree information.
return CleanupSelectors(CatchAllSels);
if (!URoR) {
URoR = F->getParent()->getFunction("_Unwind_Resume_or_Rethrow");
if (!URoR) return CleanupSelectors(CatchAllSels);
}
SmallPtrSet<InvokeInst*, 32> URoRInvokes;
FindAllURoRInvokes(URoRInvokes);
SmallPtrSet<IntrinsicInst*, 32> SelsToConvert;
for (SmallPtrSet<IntrinsicInst*, 32>::iterator
SI = Sels.begin(), SE = Sels.end(); SI != SE; ++SI) {
const BasicBlock *SelBB = (*SI)->getParent();
for (SmallPtrSet<InvokeInst*, 32>::iterator
UI = URoRInvokes.begin(), UE = URoRInvokes.end(); UI != UE; ++UI) {
const BasicBlock *URoRBB = (*UI)->getParent();
if (DT->dominates(SelBB, URoRBB)) {
SelsToConvert.insert(*SI);
break;
}
}
}
bool Changed = false;
if (Sels.size() != SelsToConvert.size()) {
// If we haven't been able to convert all of the clean-up selectors, then
// loop through the slow way to see if they still need to be converted.
if (!ExceptionValueIntrinsic) {
ExceptionValueIntrinsic =
Intrinsic::getDeclaration(F->getParent(), Intrinsic::eh_exception);
if (!ExceptionValueIntrinsic)
return CleanupSelectors(CatchAllSels);
}
for (Value::use_iterator
I = ExceptionValueIntrinsic->use_begin(),
E = ExceptionValueIntrinsic->use_end(); I != E; ++I) {
IntrinsicInst *EHPtr = dyn_cast<IntrinsicInst>(*I);
if (!EHPtr || EHPtr->getParent()->getParent() != F) continue;
Changed |= PromoteEHPtrStore(EHPtr);
bool URoRInvoke = false;
SmallPtrSet<IntrinsicInst*, 8> SelCalls;
Changed |= FindSelectorAndURoR(EHPtr, URoRInvoke, SelCalls);
if (URoRInvoke) {
// This EH pointer is being used by an invoke of an URoR instruction and
// an eh.selector intrinsic call. If the eh.selector is a 'clean-up', we
// need to convert it to a 'catch-all'.
for (SmallPtrSet<IntrinsicInst*, 8>::iterator
SI = SelCalls.begin(), SE = SelCalls.end(); SI != SE; ++SI)
if (!HasCatchAllInSelector(*SI))
SelsToConvert.insert(*SI);
}
}
}
if (!SelsToConvert.empty()) {
// Convert all clean-up eh.selectors, which are associated with "invokes" of
// URoR calls, into catch-all eh.selectors.
Changed = true;
for (SmallPtrSet<IntrinsicInst*, 8>::iterator
SI = SelsToConvert.begin(), SE = SelsToConvert.end();
SI != SE; ++SI) {
IntrinsicInst *II = *SI;
// Use the exception object pointer and the personality function
// from the original selector.
CallSite CS(II);
IntrinsicInst::op_iterator I = CS.arg_begin();
IntrinsicInst::op_iterator E = CS.arg_end();
IntrinsicInst::op_iterator B = prior(E);
// Exclude last argument if it is an integer.
if (isa<ConstantInt>(B)) E = B;
// Add exception object pointer (front).
// Add personality function (next).
// Add in any filter IDs (rest).
SmallVector<Value*, 8> Args(I, E);
Args.push_back(EHCatchAllValue->getInitializer()); // Catch-all indicator.
CallInst *NewSelector =
CallInst::Create(SelectorIntrinsic, Args.begin(), Args.end(),
"eh.sel.catch.all", II);
NewSelector->setTailCall(II->isTailCall());
NewSelector->setAttributes(II->getAttributes());
NewSelector->setCallingConv(II->getCallingConv());
II->replaceAllUsesWith(NewSelector);
II->eraseFromParent();
}
}
Changed |= CleanupSelectors(CatchAllSels);
return Changed;
}
//
// Method: runOnModule()
//
// Description:
// Entry point for this LLVM pass.
// If a function returns a struct, make it return
// a pointer to the struct.
//
// Inputs:
// M - A reference to the LLVM module to transform
//
// Outputs:
// M - The transformed LLVM module.
//
// Return value:
// true - The module was modified.
// false - The module was not modified.
//
bool StructRet::runOnModule(Module& M) {
const llvm::DataLayout targetData(&M);
std::vector<Function*> worklist;
for (Module::iterator I = M.begin(); I != M.end(); ++I)
if (!I->mayBeOverridden()) {
if(I->hasAddressTaken())
continue;
if(I->getReturnType()->isStructTy()) {
worklist.push_back(I);
}
}
while(!worklist.empty()) {
Function *F = worklist.back();
worklist.pop_back();
Type *NewArgType = F->getReturnType()->getPointerTo();
// Construct the new Type
std::vector<Type*>TP;
TP.push_back(NewArgType);
for (Function::arg_iterator ii = F->arg_begin(), ee = F->arg_end();
ii != ee; ++ii) {
TP.push_back(ii->getType());
}
FunctionType *NFTy = FunctionType::get(F->getReturnType(), TP, F->isVarArg());
// Create the new function body and insert it into the module.
Function *NF = Function::Create(NFTy,
F->getLinkage(),
F->getName(), &M);
ValueToValueMapTy ValueMap;
Function::arg_iterator NI = NF->arg_begin();
NI->setName("ret");
++NI;
for (Function::arg_iterator II = F->arg_begin(); II != F->arg_end(); ++II, ++NI) {
ValueMap[II] = NI;
NI->setName(II->getName());
AttributeSet attrs = F->getAttributes().getParamAttributes(II->getArgNo() + 1);
if (!attrs.isEmpty())
NI->addAttr(attrs);
}
// Perform the cloning.
SmallVector<ReturnInst*,100> Returns;
if (!F->isDeclaration())
CloneFunctionInto(NF, F, ValueMap, false, Returns);
std::vector<Value*> fargs;
for(Function::arg_iterator ai = NF->arg_begin(),
ae= NF->arg_end(); ai != ae; ++ai) {
fargs.push_back(ai);
}
NF->setAttributes(NF->getAttributes().addAttributes(
M.getContext(), 0, F->getAttributes().getRetAttributes()));
NF->setAttributes(NF->getAttributes().addAttributes(
M.getContext(), ~0, F->getAttributes().getFnAttributes()));
for (Function::iterator B = NF->begin(), FE = NF->end(); B != FE; ++B) {
for (BasicBlock::iterator I = B->begin(), BE = B->end(); I != BE;) {
ReturnInst * RI = dyn_cast<ReturnInst>(I++);
if(!RI)
continue;
LoadInst *LI = dyn_cast<LoadInst>(RI->getOperand(0));
assert(LI && "Return should be preceded by a load instruction");
IRBuilder<> Builder(RI);
Builder.CreateMemCpy(fargs.at(0),
LI->getPointerOperand(),
targetData.getTypeStoreSize(LI->getType()),
targetData.getPrefTypeAlignment(LI->getType()));
}
}
for(Value::use_iterator ui = F->use_begin(), ue = F->use_end();
ui != ue; ) {
CallInst *CI = dyn_cast<CallInst>(*ui++);
if(!CI)
continue;
if(CI->getCalledFunction() != F)
continue;
if(CI->hasByValArgument())
continue;
AllocaInst *AllocaNew = new AllocaInst(F->getReturnType(), 0, "", CI);
SmallVector<Value*, 8> Args;
//this should probably be done in a different manner
AttributeSet NewCallPAL=AttributeSet();
// Get the initial attributes of the call
AttributeSet CallPAL = CI->getAttributes();
AttributeSet RAttrs = CallPAL.getRetAttributes();
AttributeSet FnAttrs = CallPAL.getFnAttributes();
if (!RAttrs.isEmpty())
NewCallPAL=NewCallPAL.addAttributes(F->getContext(),0, RAttrs);
Args.push_back(AllocaNew);
for(unsigned j = 0; j < CI->getNumOperands()-1; j++) {
Args.push_back(CI->getOperand(j));
// position in the NewCallPAL
AttributeSet Attrs = CallPAL.getParamAttributes(j);
if (!Attrs.isEmpty())
NewCallPAL=NewCallPAL.addAttributes(F->getContext(),Args.size(), Attrs);
}
// Create the new attributes vec.
if (!FnAttrs.isEmpty())
NewCallPAL=NewCallPAL.addAttributes(F->getContext(),~0, FnAttrs);
CallInst *CallI = CallInst::Create(NF, Args, "", CI);
CallI->setCallingConv(CI->getCallingConv());
CallI->setAttributes(NewCallPAL);
LoadInst *LI = new LoadInst(AllocaNew, "", CI);
CI->replaceAllUsesWith(LI);
CI->eraseFromParent();
}
if(F->use_empty())
F->eraseFromParent();
}
return true;
}
bool PathList::runOnModule(Module &M) {
module = &M;
llvm::dbgs() << "[runOnModule]: Moduel M has " << M.getFunctionList().size() << " Functions in all.\n";
// for test
Function *f1 = M.getFunction("fprintf");
if (!f1)
dbgs() << "[Test]: can not find function fprintf.\n";
else
dbgs() << "[Test]: find function fprintf.\n";
CallGraph &CG = getAnalysis<CallGraph>();
// CG.dump();
CallGraphNode *cgNode = CG.getRoot();
cgNode->dump();
// errs()<<node->getFunction()->getName()<<'\n';
Function *startFunc;
Function *endFunc;
startFunc = M.getFunction("__user_main");
//std::string fileName("/home/xqx/data/xqx/projects/benckmarks-klee/texinfo-4.8/build-shit/makeinfo/../../makeinfo/insertion.c");
//int lineNo = 407;
BB = getBB(fileName, lineNo);
*targetBbpp = getBB(fileName, lineNo);
if (BB) {
endFunc = BB->getParent();
if (!endFunc) {
errs()<<"Error: get endFunc failed.\n";
return false;
}
if (!startFunc) {
errs()<<"Error: get startFunc failed.\n";
return false;
}
errs()<<startFunc->getName()<<'\n';
}
else {
errs()<<"Error: get BB failed.\n";
return false;
}
//read start and end from xml files
// defectList enStart, enEnd;
// getEntryList("/tmp/entrys.xml", &enStart, "start");
// getEntryList("/tmp/entrys.xml", &enEnd, "end");
// getEntryList("/tmp/entrys.xml", &dl, "end");
// dumpEntryList(&enStart);
// dumpEntryList(&enEnd);
// dumpEntryList(&dl);
//read bug information from xml file
/* for (defectList::iterator dit = dl.begin(); dit != dl.end(); dit++) {
StringRef file(dit->first.c_str());
std::vector<int> lines = dit->second;
BasicBlock *BB = getBB(file, *(lines.begin()));
if (BB) {
endFunc = BB->getParent();
}
}
*/
//to store temporary path
std::vector<BasicBlock*> p;
// a counter
int map_count = 0;
for (Module::iterator i = M.begin(), e = M.end(); i != e; ++i) {
Function *F = i;
if (!F) {
llvm::errs() << "***NULL Function***\n";
continue;
}
cgNode = CG.getOrInsertFunction(F);
F = cgNode->getFunction();
//
for (CallGraphNode::iterator I = cgNode->begin(), E = cgNode->end();
I != E; ++I){
CallGraphNode::CallRecord *cr = &*I;
// llvm::errs() << "\tCS<" << cr->first << "> calls";
// check if the CallInst is existed
if(cr->first){
Instruction *TmpIns = dyn_cast<Instruction>(cr->first);
if(TmpIns) {
// errs() << "\t" << *TmpIns << "\n";
//unsigned int l, c;
//std::string cfi_path = getInstPath(TmpIns, l, c);
//if (!cfi_path.empty()) {
// if (cfi_path.find("uclibc") != std::string::npos) {
// dbgs() << "[Filter Uclib]: find an instruction from uclibc.\n";
// continue;
// } else if (cfi_path.find("POSIX") != std::string::npos) {
// dbgs() << "[Filter Uclib]: find an instruction from POSIX.\n";
// continue;
// }
//}
} else
continue;
}
// get the funciton pointer which is called by current CallRecord cr
Function *FI = cr->second->getFunction();
if (!FI)
continue;
// create a new CalledFunctions element and push it into calledFunctionMap.
calledFunctionMap[FI].push_back(std::make_pair(F, dyn_cast<Instruction>(cr->first)));
// for debuging
map_count++;
}
}
dbgs() << "[Count Number of calledFunctionMap]: "<< calledFunctionMap.size() <<'\n';
// analyze the global function pointer table
if(function_pointer_analysis()) {
errs() << "[Analyze global function pointer table success]\n";
} else {
errs() << "[Analyze global function pointer table failed]\n";
}
dbgs() << "[Count Number of calledFunctionMap]: "<< calledFunctionMap.size() <<'\n';
// filter the instructions from uclibc
//filter_uclibc();
llvm::errs() << "=================================hh\n";
llvm::errs() << "get Function Path: " << endFunc->getName()
<< " to " << startFunc->getName() << " \n";
// printCalledFuncAndCFGPath(endFunc, startFunc, BB, p);
// modification by wh
evo_paths = new entire_path;
//filter_paths = new func_bbs_type;
//BB_paths_map = new std::map<std::pair<Function*, BasicBlock*>, std::vector<BasicBlock*> >;
std::vector<std::pair< Function*, Instruction*> > tmp_func_path;
// std::vector<BasicBlock*> tmp_bb_path;
// explore_function_paths(endFunc, startFunc, bug_Inst, &tmp_func_path);
collect_funcitons(endFunc, startFunc, bug_Inst, &tmp_func_path);
// dbgs() << "++++++Found " << evo_paths->size() << " function paths.\n";
// for (entire_path::iterator ep_it = evo_paths->begin(); ep_it != evo_paths->end(); ep_it++) {
// for (std::vector<std::pair< Function*, Instruction*> >::iterator pair_it = ep_it->begin(); pair_it != ep_it->end(); pair_it++) {
// if (filter_paths->size() != 0) {
// std::vector<Instruction*>::iterator inst_it = std::find((*filter_paths)[pair_it->first].begin(), (*filter_paths)[pair_it->first].end(), pair_it->second);
// if (inst_it != (*filter_paths)[pair_it->first].end()) {
// continue;
// }
// }
// (*filter_paths)[pair_it->first].push_back(pair_it->second);
// }
// }
dbgs() << "[filter_paths]: contain " << filter_paths->size() << " functions in all.\n";
for (func_bbs_type::iterator fbs_it = filter_paths->begin(); fbs_it != filter_paths->end(); fbs_it++) {
for (std::vector<Instruction*>::iterator bb_it2 = fbs_it->second.begin(); bb_it2 != fbs_it->second.end(); bb_it2++) {
dbgs() << "^^^^^^ " << fbs_it->first->getName() << ": " << (*bb_it2)->getParent()->getName() << '\n';
// to expand functions
call_insts.push_back((*bb_it2));
explore_basicblock_paths(fbs_it->first, (*bb_it2)->getParent(), &(*BB_paths_map)[std::make_pair(fbs_it->first, *bb_it2)]);
dbgs() << "^^^^^^ found " << (*BB_paths_map)[std::make_pair(fbs_it->first, *bb_it2)].size() << " basicblocks.\n";
}
}
llvm::dbgs() << "!!!!!!!! Found " << call_insts.size() << " call instructions.\n";
llvm::dbgs() << "!!!!!!!! Found " << path_basicblocks.size() << " path basicblocks.\n";
// expand functions
for (std::vector<Instruction*>::iterator ci_it = call_insts.begin(); ci_it != call_insts.end(); ci_it++) {
BasicBlock *call_bb = (*ci_it)->getParent();
if (!call_bb) {
continue;
}
for (BasicBlock::iterator inst = call_bb->begin(); inst != call_bb->end(); inst++) {
if (&*inst == *ci_it) {
break;
}
if (isa<CallInst>(&*inst)) {
std::vector<Instruction*>::iterator ci = std::find(path_call_insts.begin(), path_call_insts.end(), &*inst);
if (ci != path_call_insts.end())
continue;
path_call_insts.push_back(&*inst);
}
}
}
llvm::dbgs() << "@@@@@@@@ After search call_insts, found " << path_call_insts.size() << " call instructions.\n";
for (std::vector<BasicBlock*>::iterator p_bb_it = path_basicblocks.begin(); p_bb_it != path_basicblocks.end(); p_bb_it++) {
for (BasicBlock::iterator inst = (*p_bb_it)->begin(); inst != (*p_bb_it)->end(); inst++) {
if (isa<CallInst>(&*inst)) {
std::vector<Instruction*>::iterator ci = std::find(path_call_insts.begin(), path_call_insts.end(), &*inst);
if (ci != path_call_insts.end())
continue;
path_call_insts.push_back(&*inst);
}
}
}
llvm::dbgs() << "@@@@@@@@ After search path_basicblocks, found " << path_call_insts.size() << " call instructions.\n";
for (std::vector<Instruction*>::iterator iit = path_call_insts.begin(); iit != path_call_insts.end(); iit++) {
CallInst *ci = dyn_cast<CallInst>(*iit);
if (!ci)
continue;
Function *ff = ci->getCalledFunction();
if (!ff) {
//ci->dump();
//dbgs() << "\t[called value] " << ci->getOperand(0)->getName() << '\n';
continue;
}
std::vector<Function*>::iterator fit = std::find(otherCalledFuncs->begin(), otherCalledFuncs->end(), ff);
if (fit == otherCalledFuncs->end())
otherCalledFuncs->push_back(ff);
}
llvm::dbgs() << "((((((((( Found " << otherCalledFuncs->size() << " functions.\n";
for (int index = 0; index < otherCalledFuncs->size(); index++) {
Function *f = otherCalledFuncs->at(index);
/* if (!f) {
//f->dump();
llvm::dbgs() << "?????? index = " << index << " size = " << otherCalledFuncs->size()<< '\n';
continue;
}
*/ for (inst_iterator f_it = inst_begin(f); f_it != inst_end(f); f_it++) {
CallInst *ci = dyn_cast<CallInst>(&*f_it);
if (!ci)
continue;
if (!ci->getCalledFunction()) {
//ci->dump();
continue;
}
std::vector<Function*>::iterator fit = std::find(otherCalledFuncs->begin(), otherCalledFuncs->end(), ci->getCalledFunction());
if (fit == otherCalledFuncs->end())
otherCalledFuncs->push_back(ci->getCalledFunction());
}
}
llvm::dbgs() << "((((((((( Found " << otherCalledFuncs->size() << " functions.\n";
//This should be just for statistic.
int tmp_funcNum_in_filter_notIn_other = 0;
for (func_bbs_type::iterator fbs_it = filter_paths->begin(); fbs_it != filter_paths->end(); fbs_it++) {
if (!fbs_it->first) {
llvm::dbgs() << "[Warning]: Found a null Function pointer in filter_paths.\n";
continue;
}
std::vector<Function*>::iterator fit = std::find(otherCalledFuncs->begin(), otherCalledFuncs->end(), fbs_it->first);
if (fit == otherCalledFuncs->end())
//otherCalledFuncs->push_back(fbs_it->first);
tmp_funcNum_in_filter_notIn_other ++;
}
llvm::dbgs() << "<><><><> After searching filter_paths, found " << otherCalledFuncs->size() + tmp_funcNum_in_filter_notIn_other << " functions.\n";
/* for (entire_path::iterator ep_it = evo_paths->begin(); ep_it != evo_paths->end(); ep_it++) {
dbgs() << "Path length is: " << ep_it->size() << '\n';
for (std::vector<std::pair< Function*, BasicBlock*> >::iterator pair_it = ep_it->begin(); pair_it != ep_it->end(); pair_it++) {
dbgs() << "^^^^^^ " << pair_it->first->getName() << ": " << pair_it->second->getName() << '\n';
explore_basicblock_paths(pair_it->first, pair_it->second, &(*BB_paths_map)[*pair_it]);
dbgs() << "^^^^^^ found " << (*BB_paths_map)[*pair_it].size() << " basicblocks.\n";
}
}
*/
llvm::errs() << "on-end\n";
llvm::errs() << "=================================\n";
// output all of the paths
/* errs()<<"Find "<<paths_found->size()<<" paths in all.\n";
for(paths::iterator ips = paths_found->begin();ips != paths_found->end();ips++) {
// std::vector<BasicBlock*> *tmpP = dyn_cast<std::vector<BasicBlock*>*>(&*ips);
dbgs() << "=========A Path Start============\n";
for(std::vector<BasicBlock*>::iterator ps = ips->begin(), pe = ips->end(); ps != pe; ps++) {
BasicBlock *tmpStr = *ps;
errs()<<"\t"<<tmpStr->getParent()->getName()<<": "<<tmpStr->getName()<<" -> \n";
}
errs()<<"=================================\n";
}
*/
return false;
}
bool SjLjEHPass::insertSjLjEHSupport(Function &F) {
SmallVector<ReturnInst*,16> Returns;
SmallVector<UnwindInst*,16> Unwinds;
SmallVector<InvokeInst*,16> Invokes;
// Look through the terminators of the basic blocks to find invokes, returns
// and unwinds.
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
// Remember all return instructions in case we insert an invoke into this
// function.
Returns.push_back(RI);
} else if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
Invokes.push_back(II);
} else if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
Unwinds.push_back(UI);
}
}
// If we don't have any invokes or unwinds, there's nothing to do.
if (Unwinds.empty() && Invokes.empty()) return false;
// Find the eh.selector.*, eh.exception and alloca calls.
//
// Remember any allocas() that aren't in the entry block, as the
// jmpbuf saved SP will need to be updated for them.
//
// We'll use the first eh.selector to determine the right personality
// function to use. For SJLJ, we always use the same personality for the
// whole function, not on a per-selector basis.
// FIXME: That's a bit ugly. Better way?
SmallVector<CallInst*,16> EH_Selectors;
SmallVector<CallInst*,16> EH_Exceptions;
SmallVector<Instruction*,16> JmpbufUpdatePoints;
// Note: Skip the entry block since there's nothing there that interests
// us. eh.selector and eh.exception shouldn't ever be there, and we
// want to disregard any allocas that are there.
for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;) {
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
if (CallInst *CI = dyn_cast<CallInst>(I)) {
if (CI->getCalledFunction() == SelectorFn) {
if (!PersonalityFn) PersonalityFn = CI->getArgOperand(1);
EH_Selectors.push_back(CI);
} else if (CI->getCalledFunction() == ExceptionFn) {
EH_Exceptions.push_back(CI);
} else if (CI->getCalledFunction() == StackRestoreFn) {
JmpbufUpdatePoints.push_back(CI);
}
} else if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
JmpbufUpdatePoints.push_back(AI);
}
}
}
// If we don't have any eh.selector calls, we can't determine the personality
// function. Without a personality function, we can't process exceptions.
if (!PersonalityFn) return false;
NumInvokes += Invokes.size();
NumUnwinds += Unwinds.size();
if (!Invokes.empty()) {
// We have invokes, so we need to add register/unregister calls to get
// this function onto the global unwind stack.
//
// First thing we need to do is scan the whole function for values that are
// live across unwind edges. Each value that is live across an unwind edge
// we spill into a stack location, guaranteeing that there is nothing live
// across the unwind edge. This process also splits all critical edges
// coming out of invoke's.
splitLiveRangesAcrossInvokes(Invokes);
BasicBlock *EntryBB = F.begin();
// Create an alloca for the incoming jump buffer ptr and the new jump buffer
// that needs to be restored on all exits from the function. This is an
// alloca because the value needs to be added to the global context list.
unsigned Align = 4; // FIXME: Should be a TLI check?
AllocaInst *FunctionContext =
new AllocaInst(FunctionContextTy, 0, Align,
"fcn_context", F.begin()->begin());
Value *Idxs[2];
const Type *Int32Ty = Type::getInt32Ty(F.getContext());
Value *Zero = ConstantInt::get(Int32Ty, 0);
// We need to also keep around a reference to the call_site field
Idxs[0] = Zero;
Idxs[1] = ConstantInt::get(Int32Ty, 1);
CallSite = GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2,
"call_site",
EntryBB->getTerminator());
// The exception selector comes back in context->data[1]
Idxs[1] = ConstantInt::get(Int32Ty, 2);
Value *FCData = GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2,
"fc_data",
EntryBB->getTerminator());
Idxs[1] = ConstantInt::get(Int32Ty, 1);
Value *SelectorAddr = GetElementPtrInst::Create(FCData, Idxs, Idxs+2,
"exc_selector_gep",
EntryBB->getTerminator());
// The exception value comes back in context->data[0]
Idxs[1] = Zero;
Value *ExceptionAddr = GetElementPtrInst::Create(FCData, Idxs, Idxs+2,
"exception_gep",
EntryBB->getTerminator());
// The result of the eh.selector call will be replaced with a
// a reference to the selector value returned in the function
// context. We leave the selector itself so the EH analysis later
// can use it.
for (int i = 0, e = EH_Selectors.size(); i < e; ++i) {
CallInst *I = EH_Selectors[i];
Value *SelectorVal = new LoadInst(SelectorAddr, "select_val", true, I);
I->replaceAllUsesWith(SelectorVal);
}
// eh.exception calls are replaced with references to the proper
// location in the context. Unlike eh.selector, the eh.exception
// calls are removed entirely.
for (int i = 0, e = EH_Exceptions.size(); i < e; ++i) {
CallInst *I = EH_Exceptions[i];
// Possible for there to be duplicates, so check to make sure
// the instruction hasn't already been removed.
if (!I->getParent()) continue;
Value *Val = new LoadInst(ExceptionAddr, "exception", true, I);
const Type *Ty = Type::getInt8PtrTy(F.getContext());
Val = CastInst::Create(Instruction::IntToPtr, Val, Ty, "", I);
I->replaceAllUsesWith(Val);
I->eraseFromParent();
}
// The entry block changes to have the eh.sjlj.setjmp, with a conditional
// branch to a dispatch block for non-zero returns. If we return normally,
// we're not handling an exception and just register the function context
// and continue.
// Create the dispatch block. The dispatch block is basically a big switch
// statement that goes to all of the invoke landing pads.
BasicBlock *DispatchBlock =
BasicBlock::Create(F.getContext(), "eh.sjlj.setjmp.catch", &F);
// Insert a load in the Catch block, and a switch on its value. By default,
// we go to a block that just does an unwind (which is the correct action
// for a standard call).
BasicBlock *UnwindBlock =
BasicBlock::Create(F.getContext(), "unwindbb", &F);
Unwinds.push_back(new UnwindInst(F.getContext(), UnwindBlock));
Value *DispatchLoad = new LoadInst(CallSite, "invoke.num", true,
DispatchBlock);
SwitchInst *DispatchSwitch =
SwitchInst::Create(DispatchLoad, UnwindBlock, Invokes.size(),
DispatchBlock);
// Split the entry block to insert the conditional branch for the setjmp.
BasicBlock *ContBlock = EntryBB->splitBasicBlock(EntryBB->getTerminator(),
"eh.sjlj.setjmp.cont");
// Populate the Function Context
// 1. LSDA address
// 2. Personality function address
// 3. jmpbuf (save SP, FP and call eh.sjlj.setjmp)
// LSDA address
Idxs[0] = Zero;
Idxs[1] = ConstantInt::get(Int32Ty, 4);
Value *LSDAFieldPtr =
GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2,
"lsda_gep",
EntryBB->getTerminator());
Value *LSDA = CallInst::Create(LSDAAddrFn, "lsda_addr",
EntryBB->getTerminator());
new StoreInst(LSDA, LSDAFieldPtr, true, EntryBB->getTerminator());
Idxs[1] = ConstantInt::get(Int32Ty, 3);
Value *PersonalityFieldPtr =
GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2,
"lsda_gep",
EntryBB->getTerminator());
new StoreInst(PersonalityFn, PersonalityFieldPtr, true,
EntryBB->getTerminator());
// Save the frame pointer.
Idxs[1] = ConstantInt::get(Int32Ty, 5);
Value *JBufPtr
= GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2,
"jbuf_gep",
EntryBB->getTerminator());
Idxs[1] = ConstantInt::get(Int32Ty, 0);
Value *FramePtr =
GetElementPtrInst::Create(JBufPtr, Idxs, Idxs+2, "jbuf_fp_gep",
EntryBB->getTerminator());
Value *Val = CallInst::Create(FrameAddrFn,
ConstantInt::get(Int32Ty, 0),
"fp",
EntryBB->getTerminator());
new StoreInst(Val, FramePtr, true, EntryBB->getTerminator());
// Save the stack pointer.
Idxs[1] = ConstantInt::get(Int32Ty, 2);
Value *StackPtr =
GetElementPtrInst::Create(JBufPtr, Idxs, Idxs+2, "jbuf_sp_gep",
EntryBB->getTerminator());
Val = CallInst::Create(StackAddrFn, "sp", EntryBB->getTerminator());
new StoreInst(Val, StackPtr, true, EntryBB->getTerminator());
// Call the setjmp instrinsic. It fills in the rest of the jmpbuf.
Value *SetjmpArg =
CastInst::Create(Instruction::BitCast, JBufPtr,
Type::getInt8PtrTy(F.getContext()), "",
EntryBB->getTerminator());
Value *DispatchVal = CallInst::Create(BuiltinSetjmpFn, SetjmpArg,
"dispatch",
EntryBB->getTerminator());
// check the return value of the setjmp. non-zero goes to dispatcher.
Value *IsNormal = new ICmpInst(EntryBB->getTerminator(),
ICmpInst::ICMP_EQ, DispatchVal, Zero,
"notunwind");
// Nuke the uncond branch.
EntryBB->getTerminator()->eraseFromParent();
// Put in a new condbranch in its place.
BranchInst::Create(ContBlock, DispatchBlock, IsNormal, EntryBB);
// Register the function context and make sure it's known to not throw
CallInst *Register =
CallInst::Create(RegisterFn, FunctionContext, "",
ContBlock->getTerminator());
Register->setDoesNotThrow();
// At this point, we are all set up, update the invoke instructions
// to mark their call_site values, and fill in the dispatch switch
// accordingly.
for (unsigned i = 0, e = Invokes.size(); i != e; ++i)
markInvokeCallSite(Invokes[i], i+1, CallSite, DispatchSwitch);
// Mark call instructions that aren't nounwind as no-action
// (call_site == -1). Skip the entry block, as prior to then, no function
// context has been created for this function and any unexpected exceptions
// thrown will go directly to the caller's context, which is what we want
// anyway, so no need to do anything here.
for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;) {
for (BasicBlock::iterator I = BB->begin(), end = BB->end(); I != end; ++I)
if (CallInst *CI = dyn_cast<CallInst>(I)) {
// Ignore calls to the EH builtins (eh.selector, eh.exception)
Constant *Callee = CI->getCalledFunction();
if (Callee != SelectorFn && Callee != ExceptionFn
&& !CI->doesNotThrow())
insertCallSiteStore(CI, -1, CallSite);
}
}
// Replace all unwinds with a branch to the unwind handler.
// ??? Should this ever happen with sjlj exceptions?
for (unsigned i = 0, e = Unwinds.size(); i != e; ++i) {
BranchInst::Create(UnwindBlock, Unwinds[i]);
Unwinds[i]->eraseFromParent();
}
// Following any allocas not in the entry block, update the saved SP
// in the jmpbuf to the new value.
for (unsigned i = 0, e = JmpbufUpdatePoints.size(); i != e; ++i) {
Instruction *AI = JmpbufUpdatePoints[i];
Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp");
StackAddr->insertAfter(AI);
Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true);
StoreStackAddr->insertAfter(StackAddr);
}
// Finally, for any returns from this function, if this function contains an
// invoke, add a call to unregister the function context.
for (unsigned i = 0, e = Returns.size(); i != e; ++i)
CallInst::Create(UnregisterFn, FunctionContext, "", Returns[i]);
}
return true;
}
GraphNode* Graph::addInst(Value *v) {
GraphNode *Op, *Var, *Operand;
CallInst* CI = dyn_cast<CallInst> (v);
bool hasVarNode = true;
if (isValidInst(v)) { //If is a data manipulator instruction
Var = this->findNode(v);
/*
* If Var is NULL, the value hasn't been processed yet, so we must process it
*
* However, if Var is a Pointer, maybe the memory node already exists but the
* operation node aren't in the graph, yet. Thus we must process it.
*/
if (Var == NULL || (Var != NULL && findOpNode(v) == NULL)) { //If it has not processed yet
//If Var isn't NULL, we won't create another node for it
if (Var == NULL) {
if (CI) {
hasVarNode = !CI->getType()->isVoidTy();
}
if (hasVarNode) {
if (StoreInst* SI = dyn_cast<StoreInst>(v))
Var = addInst(SI->getOperand(1)); // We do this here because we want to represent the store instructions as a flow of information of a data to a memory node
else if ((!isa<Constant> (v)) && isMemoryPointer(v)) {
Var = new MemNode(
USE_ALIAS_SETS ? AS->getValueSetKey(v) : 0, AS);
memNodes[USE_ALIAS_SETS ? AS->getValueSetKey(v) : 0]
= Var;
} else {
Var = new VarNode(v);
varNodes[v] = Var;
}
nodes.insert(Var);
}
}
if (isa<Instruction> (v)) {
if (CI) {
Op = new CallNode(CI);
callNodes[CI] = Op;
} else {
Op = new OpNode(dyn_cast<Instruction> (v)->getOpcode(), v);
}
opNodes[v] = Op;
nodes.insert(Op);
if (hasVarNode)
Op->connect(Var);
//Connect the operands to the OpNode
for (unsigned int i = 0; i < cast<User> (v)->getNumOperands(); i++) {
if (isa<StoreInst> (v) && i == 1)
continue; // We do this here because we want to represent the store instructions as a flow of information of a data to a memory node
Value *v1 = cast<User> (v)->getOperand(i);
Operand = this->addInst(v1);
if (Operand != NULL)
Operand->connect(Op);
}
}
}
return Var;
}
return NULL;
}
/// Attempt to merge an objc_release with a store, load, and objc_retain to form
/// an objc_storeStrong. This can be a little tricky because the instructions
/// don't always appear in order, and there may be unrelated intervening
/// instructions.
void ObjCARCContract::ContractRelease(Instruction *Release,
inst_iterator &Iter) {
LoadInst *Load = dyn_cast<LoadInst>(GetObjCArg(Release));
if (!Load || !Load->isSimple()) return;
// For now, require everything to be in one basic block.
BasicBlock *BB = Release->getParent();
if (Load->getParent() != BB) return;
// Walk down to find the store and the release, which may be in either order.
BasicBlock::iterator I = Load, End = BB->end();
++I;
AliasAnalysis::Location Loc = AA->getLocation(Load);
StoreInst *Store = 0;
bool SawRelease = false;
for (; !Store || !SawRelease; ++I) {
if (I == End)
return;
Instruction *Inst = I;
if (Inst == Release) {
SawRelease = true;
continue;
}
InstructionClass Class = GetBasicInstructionClass(Inst);
// Unrelated retains are harmless.
if (IsRetain(Class))
continue;
if (Store) {
// The store is the point where we're going to put the objc_storeStrong,
// so make sure there are no uses after it.
if (CanUse(Inst, Load, PA, Class))
return;
} else if (AA->getModRefInfo(Inst, Loc) & AliasAnalysis::Mod) {
// We are moving the load down to the store, so check for anything
// else which writes to the memory between the load and the store.
Store = dyn_cast<StoreInst>(Inst);
if (!Store || !Store->isSimple()) return;
if (Store->getPointerOperand() != Loc.Ptr) return;
}
}
Value *New = StripPointerCastsAndObjCCalls(Store->getValueOperand());
// Walk up to find the retain.
I = Store;
BasicBlock::iterator Begin = BB->begin();
while (I != Begin && GetBasicInstructionClass(I) != IC_Retain)
--I;
Instruction *Retain = I;
if (GetBasicInstructionClass(Retain) != IC_Retain) return;
if (GetObjCArg(Retain) != New) return;
Changed = true;
++NumStoreStrongs;
LLVMContext &C = Release->getContext();
Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C));
Type *I8XX = PointerType::getUnqual(I8X);
Value *Args[] = { Load->getPointerOperand(), New };
if (Args[0]->getType() != I8XX)
Args[0] = new BitCastInst(Args[0], I8XX, "", Store);
if (Args[1]->getType() != I8X)
Args[1] = new BitCastInst(Args[1], I8X, "", Store);
CallInst *StoreStrong =
CallInst::Create(getStoreStrongCallee(BB->getParent()->getParent()),
Args, "", Store);
StoreStrong->setDoesNotThrow();
StoreStrong->setDebugLoc(Store->getDebugLoc());
// We can't set the tail flag yet, because we haven't yet determined
// whether there are any escaping allocas. Remember this call, so that
// we can set the tail flag once we know it's safe.
StoreStrongCalls.insert(StoreStrong);
if (&*Iter == Store) ++Iter;
Store->eraseFromParent();
Release->eraseFromParent();
EraseInstruction(Retain);
if (Load->use_empty())
Load->eraseFromParent();
}
void DSWP::insertConsume(Instruction *u, Instruction *v, DType dtype,
int channel, int uthread, int vthread) {
Instruction *oldu = dyn_cast<Instruction>(newToOld[u]);
Instruction *insPos = placeEquivalents[vthread][oldu];
if (insPos == NULL) {
insPos = dyn_cast<Instruction>(instMap[vthread][oldu]);
if (insPos == NULL) {
error("can't insert nowhere");
}
}
// call sync_consume(channel)
Function *fun = module->getFunction("sync_consume");
vector<Value *> args;
args.push_back(ConstantInt::get(Type::getInt32Ty(*context), channel));
CallInst *call = CallInst::Create(fun, args, "c" + itoa(channel), insPos);
if (dtype == REG) {
CastInst *cast;
string name = call->getName().str() + "_val";
if (u->getType()->isIntegerTy()) {
cast = new TruncInst(call, u->getType(), name);
}
else if (u->getType()->isFloatingPointTy()) {
if (u->getType()->isFloatTy())
error("cannot deal with double");
cast = new BitCastInst(call, u->getType(), name);
}
else if (u->getType()->isPointerTy()){
cast = new IntToPtrInst(call, u->getType(), name);
} else {
error("what's the hell type");
}
cast->insertBefore(insPos);
// replace the uses
for (Instruction::use_iterator ui = oldu->use_begin(),
ue = oldu->use_end();
ui != ue; ++ui) {
Instruction *user = dyn_cast<Instruction>(*ui);
if (user == NULL) {
error("used by a non-instruction?");
}
// make sure it's in the same function...
if (user->getParent()->getParent() != v->getParent()->getParent()) {
continue;
}
// call replaceUses so that it handles phi nodes
map<Value *, Value *> reps;
reps[oldu] = cast;
replaceUses(user, reps);
}
} /* TODO: need to handle true memory dependences more than just syncing?
else if (dtype == DTRUE) { //READ after WRITE
error("check mem dep!!");
if (!isa<LoadInst>(v)) {
error("not true dependency");
}
BitCastInst *cast = new BitCastInst(
call, v->getType(), call->getName().str() + "_ptr");
cast->insertBefore(v);
// replace the v with 'cast' in v's thread:
// (other thread with be dealed using dependence)
for (Instruction::use_iterator ui = v->use_begin(), ue = v->use_end();
ui != ue; ui++) {
Instruction *user = dyn_cast<Instruction>(*ui);
if (user == NULL) {
error("how could it be NULL");
}
// int userthread = this->getNewInstAssigned(user);
if (user->getParent()->getParent() != v->getParent()->getParent()) {
continue;
}
for (unsigned i = 0; i < user->getNumOperands(); i++) {
Value * op = user->getOperand(i);
if (op == v) {
user->setOperand(i, cast);
}
}
}
} */ else {
// nothing to do
}
}
// The fractional part of a float is enough to accurately represent up to
// a 24-bit signed integer.
Value* AMDGPUCodeGenPrepare::expandDivRem24(IRBuilder<> &Builder,
BinaryOperator &I,
Value *Num, Value *Den,
bool IsDiv, bool IsSigned) const {
assert(Num->getType()->isIntegerTy(32));
const DataLayout &DL = Mod->getDataLayout();
unsigned LHSSignBits = ComputeNumSignBits(Num, DL, 0, AC, &I);
if (LHSSignBits < 9)
return nullptr;
unsigned RHSSignBits = ComputeNumSignBits(Den, DL, 0, AC, &I);
if (RHSSignBits < 9)
return nullptr;
unsigned SignBits = std::min(LHSSignBits, RHSSignBits);
unsigned DivBits = 32 - SignBits;
if (IsSigned)
++DivBits;
Type *Ty = Num->getType();
Type *I32Ty = Builder.getInt32Ty();
Type *F32Ty = Builder.getFloatTy();
ConstantInt *One = Builder.getInt32(1);
Value *JQ = One;
if (IsSigned) {
// char|short jq = ia ^ ib;
JQ = Builder.CreateXor(Num, Den);
// jq = jq >> (bitsize - 2)
JQ = Builder.CreateAShr(JQ, Builder.getInt32(30));
// jq = jq | 0x1
JQ = Builder.CreateOr(JQ, One);
}
// int ia = (int)LHS;
Value *IA = Num;
// int ib, (int)RHS;
Value *IB = Den;
// float fa = (float)ia;
Value *FA = IsSigned ? Builder.CreateSIToFP(IA, F32Ty)
: Builder.CreateUIToFP(IA, F32Ty);
// float fb = (float)ib;
Value *FB = IsSigned ? Builder.CreateSIToFP(IB,F32Ty)
: Builder.CreateUIToFP(IB,F32Ty);
Value *RCP = Builder.CreateFDiv(ConstantFP::get(F32Ty, 1.0), FB);
Value *FQM = Builder.CreateFMul(FA, RCP);
// fq = trunc(fqm);
CallInst* FQ = Builder.CreateIntrinsic(Intrinsic::trunc, { FQM });
FQ->copyFastMathFlags(Builder.getFastMathFlags());
// float fqneg = -fq;
Value *FQNeg = Builder.CreateFNeg(FQ);
// float fr = mad(fqneg, fb, fa);
Value *FR = Builder.CreateIntrinsic(Intrinsic::amdgcn_fmad_ftz,
{ FQNeg, FB, FA }, FQ);
// int iq = (int)fq;
Value *IQ = IsSigned ? Builder.CreateFPToSI(FQ, I32Ty)
: Builder.CreateFPToUI(FQ, I32Ty);
// fr = fabs(fr);
FR = Builder.CreateIntrinsic(Intrinsic::fabs, { FR }, FQ);
// fb = fabs(fb);
FB = Builder.CreateIntrinsic(Intrinsic::fabs, { FB }, FQ);
// int cv = fr >= fb;
Value *CV = Builder.CreateFCmpOGE(FR, FB);
// jq = (cv ? jq : 0);
JQ = Builder.CreateSelect(CV, JQ, Builder.getInt32(0));
// dst = iq + jq;
Value *Div = Builder.CreateAdd(IQ, JQ);
Value *Res = Div;
if (!IsDiv) {
// Rem needs compensation, it's easier to recompute it
Value *Rem = Builder.CreateMul(Div, Den);
Res = Builder.CreateSub(Num, Rem);
}
// Truncate to number of bits this divide really is.
if (IsSigned) {
Res = Builder.CreateTrunc(Res, Builder.getIntNTy(DivBits));
Res = Builder.CreateSExt(Res, Ty);
} else {
ConstantInt *TruncMask = Builder.getInt32((UINT64_C(1) << DivBits) - 1);
Res = Builder.CreateAnd(Res, TruncMask);
}
return Res;
}
LLVMValueRef LLVMGetCalledFunction(LLVMValueRef I)
{
CallInst *CI = (CallInst*)unwrap(I);
return wrap(CI->getCalledValue());
}
bool ObjCARCContract::tryToPeepholeInstruction(
Function &F, Instruction *Inst, inst_iterator &Iter,
SmallPtrSetImpl<Instruction *> &DependingInsts,
SmallPtrSetImpl<const BasicBlock *> &Visited,
bool &TailOkForStoreStrongs,
const DenseMap<BasicBlock *, ColorVector> &BlockColors) {
// Only these library routines return their argument. In particular,
// objc_retainBlock does not necessarily return its argument.
ARCInstKind Class = GetBasicARCInstKind(Inst);
switch (Class) {
case ARCInstKind::FusedRetainAutorelease:
case ARCInstKind::FusedRetainAutoreleaseRV:
return false;
case ARCInstKind::Autorelease:
case ARCInstKind::AutoreleaseRV:
return contractAutorelease(F, Inst, Class, DependingInsts, Visited);
case ARCInstKind::Retain:
// Attempt to convert retains to retainrvs if they are next to function
// calls.
if (!optimizeRetainCall(F, Inst))
return false;
// If we succeed in our optimization, fall through.
LLVM_FALLTHROUGH;
case ARCInstKind::RetainRV:
case ARCInstKind::ClaimRV: {
// If we're compiling for a target which needs a special inline-asm
// marker to do the return value optimization, insert it now.
if (!RVInstMarker)
return false;
BasicBlock::iterator BBI = Inst->getIterator();
BasicBlock *InstParent = Inst->getParent();
// Step up to see if the call immediately precedes the RV call.
// If it's an invoke, we have to cross a block boundary. And we have
// to carefully dodge no-op instructions.
do {
if (BBI == InstParent->begin()) {
BasicBlock *Pred = InstParent->getSinglePredecessor();
if (!Pred)
goto decline_rv_optimization;
BBI = Pred->getTerminator()->getIterator();
break;
}
--BBI;
} while (IsNoopInstruction(&*BBI));
if (&*BBI == GetArgRCIdentityRoot(Inst)) {
LLVM_DEBUG(dbgs() << "Adding inline asm marker for the return value "
"optimization.\n");
Changed = true;
InlineAsm *IA = InlineAsm::get(
FunctionType::get(Type::getVoidTy(Inst->getContext()),
/*isVarArg=*/false),
RVInstMarker->getString(),
/*Constraints=*/"", /*hasSideEffects=*/true);
createCallInst(IA, None, "", Inst, BlockColors);
}
decline_rv_optimization:
return false;
}
case ARCInstKind::InitWeak: {
// objc_initWeak(p, null) => *p = null
CallInst *CI = cast<CallInst>(Inst);
if (IsNullOrUndef(CI->getArgOperand(1))) {
Value *Null =
ConstantPointerNull::get(cast<PointerType>(CI->getType()));
Changed = true;
new StoreInst(Null, CI->getArgOperand(0), CI);
LLVM_DEBUG(dbgs() << "OBJCARCContract: Old = " << *CI << "\n"
<< " New = " << *Null << "\n");
CI->replaceAllUsesWith(Null);
CI->eraseFromParent();
}
return true;
}
case ARCInstKind::Release:
// Try to form an objc store strong from our release. If we fail, there is
// nothing further to do below, so continue.
tryToContractReleaseIntoStoreStrong(Inst, Iter, BlockColors);
return true;
case ARCInstKind::User:
// Be conservative if the function has any alloca instructions.
// Technically we only care about escaping alloca instructions,
// but this is sufficient to handle some interesting cases.
if (isa<AllocaInst>(Inst))
TailOkForStoreStrongs = false;
return true;
case ARCInstKind::IntrinsicUser:
// Remove calls to @llvm.objc.clang.arc.use(...).
Inst->eraseFromParent();
return true;
default:
return true;
}
}
/// Attempt to merge an objc_release with a store, load, and objc_retain to form
/// an objc_storeStrong. An objc_storeStrong:
///
/// objc_storeStrong(i8** %old_ptr, i8* new_value)
///
/// is equivalent to the following IR sequence:
///
/// ; Load old value.
/// %old_value = load i8** %old_ptr (1)
///
/// ; Increment the new value and then release the old value. This must occur
/// ; in order in case old_value releases new_value in its destructor causing
/// ; us to potentially have a dangling ptr.
/// tail call i8* @objc_retain(i8* %new_value) (2)
/// tail call void @objc_release(i8* %old_value) (3)
///
/// ; Store the new_value into old_ptr
/// store i8* %new_value, i8** %old_ptr (4)
///
/// The safety of this optimization is based around the following
/// considerations:
///
/// 1. We are forming the store strong at the store. Thus to perform this
/// optimization it must be safe to move the retain, load, and release to
/// (4).
/// 2. We need to make sure that any re-orderings of (1), (2), (3), (4) are
/// safe.
void ObjCARCContract::tryToContractReleaseIntoStoreStrong(
Instruction *Release, inst_iterator &Iter,
const DenseMap<BasicBlock *, ColorVector> &BlockColors) {
// See if we are releasing something that we just loaded.
auto *Load = dyn_cast<LoadInst>(GetArgRCIdentityRoot(Release));
if (!Load || !Load->isSimple())
return;
// For now, require everything to be in one basic block.
BasicBlock *BB = Release->getParent();
if (Load->getParent() != BB)
return;
// First scan down the BB from Load, looking for a store of the RCIdentityRoot
// of Load's
StoreInst *Store =
findSafeStoreForStoreStrongContraction(Load, Release, PA, AA);
// If we fail, bail.
if (!Store)
return;
// Then find what new_value's RCIdentity Root is.
Value *New = GetRCIdentityRoot(Store->getValueOperand());
// Then walk up the BB and look for a retain on New without any intervening
// instructions which conservatively might decrement ref counts.
Instruction *Retain =
findRetainForStoreStrongContraction(New, Store, Release, PA);
// If we fail, bail.
if (!Retain)
return;
Changed = true;
++NumStoreStrongs;
LLVM_DEBUG(
llvm::dbgs() << " Contracting retain, release into objc_storeStrong.\n"
<< " Old:\n"
<< " Store: " << *Store << "\n"
<< " Release: " << *Release << "\n"
<< " Retain: " << *Retain << "\n"
<< " Load: " << *Load << "\n");
LLVMContext &C = Release->getContext();
Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C));
Type *I8XX = PointerType::getUnqual(I8X);
Value *Args[] = { Load->getPointerOperand(), New };
if (Args[0]->getType() != I8XX)
Args[0] = new BitCastInst(Args[0], I8XX, "", Store);
if (Args[1]->getType() != I8X)
Args[1] = new BitCastInst(Args[1], I8X, "", Store);
Function *Decl = EP.get(ARCRuntimeEntryPointKind::StoreStrong);
CallInst *StoreStrong = createCallInst(Decl, Args, "", Store, BlockColors);
StoreStrong->setDoesNotThrow();
StoreStrong->setDebugLoc(Store->getDebugLoc());
// We can't set the tail flag yet, because we haven't yet determined
// whether there are any escaping allocas. Remember this call, so that
// we can set the tail flag once we know it's safe.
StoreStrongCalls.insert(StoreStrong);
LLVM_DEBUG(llvm::dbgs() << " New Store Strong: " << *StoreStrong
<< "\n");
if (&*Iter == Retain) ++Iter;
if (&*Iter == Store) ++Iter;
Store->eraseFromParent();
Release->eraseFromParent();
EraseInstruction(Retain);
if (Load->use_empty())
Load->eraseFromParent();
}
/// performLocalRetainMotion - Scan forward from the specified retain, moving it
/// later in the function if possible, over instructions that provably can't
/// release the object. If we get to a release of the object, zap both.
///
/// NOTE: this handles both objc_retain and swift_retain.
///
static bool performLocalRetainMotion(CallInst &Retain, BasicBlock &BB,
SwiftRCIdentity *RC) {
// FIXME: Call classifier should identify the object for us. Too bad C++
// doesn't have nice Swift-style enums.
Value *RetainedObject = RC->getSwiftRCIdentityRoot(Retain.getArgOperand(0));
BasicBlock::iterator BBI = Retain.getIterator(),
BBE = BB.getTerminator()->getIterator();
bool isObjCRetain = Retain.getCalledFunction()->getName() == "objc_retain";
bool MadeProgress = false;
// Scan until we get to the end of the block.
for (++BBI; BBI != BBE; ++BBI) {
Instruction &CurInst = *BBI;
// Classify the instruction. This switch does a "break" when the instruction
// can be skipped and is interesting, and a "continue" when it is a retain
// of the same pointer.
switch (classifyInstruction(CurInst)) {
// These instructions should not reach here based on the pass ordering.
// i.e. LLVMARCOpt -> LLVMContractOpt.
case RT_RetainN:
case RT_UnknownRetainN:
case RT_BridgeRetainN:
case RT_ReleaseN:
case RT_UnknownReleaseN:
case RT_BridgeReleaseN:
llvm_unreachable("These are only created by LLVMARCContract !");
case RT_NoMemoryAccessed:
case RT_AllocObject:
case RT_CheckUnowned:
// Skip over random instructions that don't touch memory. They don't need
// protection by retain/release.
break;
case RT_FixLifetime: // This only stops release motion. Retains can move over it.
break;
case RT_Retain:
case RT_UnknownRetain:
case RT_BridgeRetain:
case RT_RetainUnowned:
case RT_ObjCRetain: { // swift_retain(obj)
//CallInst &ThisRetain = cast<CallInst>(CurInst);
//Value *ThisRetainedObject = ThisRetain.getArgOperand(0);
// If we see a retain of the same object, we can skip over it, but we
// can't count it as progress. Just pushing a retain(x) past a retain(y)
// doesn't change the program.
continue;
}
case RT_UnknownRelease:
case RT_BridgeRelease:
case RT_ObjCRelease:
case RT_Release: {
// If we get to a release that is provably to this object, then we can zap
// it and the retain.
CallInst &ThisRelease = cast<CallInst>(CurInst);
Value *ThisReleasedObject = ThisRelease.getArgOperand(0);
ThisReleasedObject = RC->getSwiftRCIdentityRoot(ThisReleasedObject);
if (ThisReleasedObject == RetainedObject) {
Retain.eraseFromParent();
ThisRelease.eraseFromParent();
if (isObjCRetain) {
++NumObjCRetainReleasePairs;
} else {
++NumRetainReleasePairs;
}
return true;
}
// Otherwise, if this is some other pointer, we can only ignore it if we
// can prove that the two objects don't alias.
// Retain.dump(); ThisRelease.dump(); BB.getParent()->dump();
goto OutOfLoop;
}
case RT_Unknown:
// Loads cannot affect the retain.
if (isa<LoadInst>(CurInst))
continue;
// Load, store, memcpy etc can't do a release.
if (isa<LoadInst>(CurInst) || isa<StoreInst>(CurInst) ||
isa<MemIntrinsic>(CurInst))
break;
// CurInst->dump(); BBI->dump();
// Otherwise, we get to something unknown/unhandled. Bail out for now.
goto OutOfLoop;
}
// If the switch did a break, we made some progress moving this retain.
MadeProgress = true;
}
OutOfLoop:
// If we were able to move the retain down, move it now.
// TODO: This is where we'd plug in some global algorithms someday.
if (MadeProgress) {
Retain.moveBefore(&*BBI);
return true;
}
return false;
}
bool ObjCARCContract::runOnFunction(Function &F) {
if (!EnableARCOpts)
return false;
// If nothing in the Module uses ARC, don't do anything.
if (!Run)
return false;
Changed = false;
AA = &getAnalysis<AliasAnalysis>();
DT = &getAnalysis<DominatorTree>();
PA.setAA(&getAnalysis<AliasAnalysis>());
// Track whether it's ok to mark objc_storeStrong calls with the "tail"
// keyword. Be conservative if the function has variadic arguments.
// It seems that functions which "return twice" are also unsafe for the
// "tail" argument, because they are setjmp, which could need to
// return to an earlier stack state.
bool TailOkForStoreStrongs = !F.isVarArg() &&
!F.callsFunctionThatReturnsTwice();
// For ObjC library calls which return their argument, replace uses of the
// argument with uses of the call return value, if it dominates the use. This
// reduces register pressure.
SmallPtrSet<Instruction *, 4> DependingInstructions;
SmallPtrSet<const BasicBlock *, 4> Visited;
for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ) {
Instruction *Inst = &*I++;
DEBUG(dbgs() << "ObjCARCContract: Visiting: " << *Inst << "\n");
// Only these library routines return their argument. In particular,
// objc_retainBlock does not necessarily return its argument.
InstructionClass Class = GetBasicInstructionClass(Inst);
switch (Class) {
case IC_Retain:
case IC_FusedRetainAutorelease:
case IC_FusedRetainAutoreleaseRV:
break;
case IC_Autorelease:
case IC_AutoreleaseRV:
if (ContractAutorelease(F, Inst, Class, DependingInstructions, Visited))
continue;
break;
case IC_RetainRV: {
// If we're compiling for a target which needs a special inline-asm
// marker to do the retainAutoreleasedReturnValue optimization,
// insert it now.
if (!RetainRVMarker)
break;
BasicBlock::iterator BBI = Inst;
BasicBlock *InstParent = Inst->getParent();
// Step up to see if the call immediately precedes the RetainRV call.
// If it's an invoke, we have to cross a block boundary. And we have
// to carefully dodge no-op instructions.
do {
if (&*BBI == InstParent->begin()) {
BasicBlock *Pred = InstParent->getSinglePredecessor();
if (!Pred)
goto decline_rv_optimization;
BBI = Pred->getTerminator();
break;
}
--BBI;
} while (isNoopInstruction(BBI));
if (&*BBI == GetObjCArg(Inst)) {
DEBUG(dbgs() << "ObjCARCContract: Adding inline asm marker for "
"retainAutoreleasedReturnValue optimization.\n");
Changed = true;
InlineAsm *IA =
InlineAsm::get(FunctionType::get(Type::getVoidTy(Inst->getContext()),
/*isVarArg=*/false),
RetainRVMarker->getString(),
/*Constraints=*/"", /*hasSideEffects=*/true);
CallInst::Create(IA, "", Inst);
}
decline_rv_optimization:
break;
}
case IC_InitWeak: {
// objc_initWeak(p, null) => *p = null
CallInst *CI = cast<CallInst>(Inst);
if (isNullOrUndef(CI->getArgOperand(1))) {
Value *Null =
ConstantPointerNull::get(cast<PointerType>(CI->getType()));
Changed = true;
new StoreInst(Null, CI->getArgOperand(0), CI);
DEBUG(dbgs() << "OBJCARCContract: Old = " << *CI << "\n"
<< " New = " << *Null << "\n");
CI->replaceAllUsesWith(Null);
CI->eraseFromParent();
}
continue;
}
case IC_Release:
ContractRelease(Inst, I);
continue;
case IC_User:
// Be conservative if the function has any alloca instructions.
// Technically we only care about escaping alloca instructions,
// but this is sufficient to handle some interesting cases.
if (isa<AllocaInst>(Inst))
TailOkForStoreStrongs = false;
continue;
default:
continue;
}
DEBUG(dbgs() << "ObjCARCContract: Finished List.\n\n");
// Don't use GetObjCArg because we don't want to look through bitcasts
// and such; to do the replacement, the argument must have type i8*.
const Value *Arg = cast<CallInst>(Inst)->getArgOperand(0);
for (;;) {
// If we're compiling bugpointed code, don't get in trouble.
if (!isa<Instruction>(Arg) && !isa<Argument>(Arg))
break;
// Look through the uses of the pointer.
for (Value::const_use_iterator UI = Arg->use_begin(), UE = Arg->use_end();
UI != UE; ) {
Use &U = UI.getUse();
unsigned OperandNo = UI.getOperandNo();
++UI; // Increment UI now, because we may unlink its element.
// If the call's return value dominates a use of the call's argument
// value, rewrite the use to use the return value. We check for
// reachability here because an unreachable call is considered to
// trivially dominate itself, which would lead us to rewriting its
// argument in terms of its return value, which would lead to
// infinite loops in GetObjCArg.
if (DT->isReachableFromEntry(U) && DT->dominates(Inst, U)) {
Changed = true;
Instruction *Replacement = Inst;
Type *UseTy = U.get()->getType();
if (PHINode *PHI = dyn_cast<PHINode>(U.getUser())) {
// For PHI nodes, insert the bitcast in the predecessor block.
unsigned ValNo = PHINode::getIncomingValueNumForOperand(OperandNo);
BasicBlock *BB = PHI->getIncomingBlock(ValNo);
if (Replacement->getType() != UseTy)
Replacement = new BitCastInst(Replacement, UseTy, "",
&BB->back());
// While we're here, rewrite all edges for this PHI, rather
// than just one use at a time, to minimize the number of
// bitcasts we emit.
for (unsigned i = 0, e = PHI->getNumIncomingValues(); i != e; ++i)
if (PHI->getIncomingBlock(i) == BB) {
// Keep the UI iterator valid.
if (&PHI->getOperandUse(
PHINode::getOperandNumForIncomingValue(i)) ==
&UI.getUse())
++UI;
PHI->setIncomingValue(i, Replacement);
}
} else {
if (Replacement->getType() != UseTy)
Replacement = new BitCastInst(Replacement, UseTy, "",
cast<Instruction>(U.getUser()));
U.set(Replacement);
}
}
}
// If Arg is a no-op casted pointer, strip one level of casts and iterate.
if (const BitCastInst *BI = dyn_cast<BitCastInst>(Arg))
Arg = BI->getOperand(0);
else if (isa<GEPOperator>(Arg) &&
cast<GEPOperator>(Arg)->hasAllZeroIndices())
Arg = cast<GEPOperator>(Arg)->getPointerOperand();
else if (isa<GlobalAlias>(Arg) &&
!cast<GlobalAlias>(Arg)->mayBeOverridden())
Arg = cast<GlobalAlias>(Arg)->getAliasee();
else
break;
}
}
// If this function has no escaping allocas or suspicious vararg usage,
// objc_storeStrong calls can be marked with the "tail" keyword.
if (TailOkForStoreStrongs)
for (SmallPtrSet<CallInst *, 8>::iterator I = StoreStrongCalls.begin(),
E = StoreStrongCalls.end(); I != E; ++I)
(*I)->setTailCall();
StoreStrongCalls.clear();
return Changed;
}
/// performStoreOnlyObjectElimination - Scan the graph of uses of the specified
/// object allocation. If the object does not escape and is only stored to
/// (this happens because GVN and other optimizations hoists forward substitutes
/// all stores to the object to eliminate all loads from it), then zap the
/// object and all accesses related to it.
static bool performStoreOnlyObjectElimination(CallInst &Allocation,
BasicBlock::iterator &BBI) {
DtorKind DtorInfo = analyzeDestructor(Allocation.getArgOperand(0));
// We can't delete the object if its destructor has side effects.
if (DtorInfo != DtorKind::NoSideEffects)
return false;
// Do a depth first search exploring all of the uses of the object pointer,
// following through casts, pointer adjustments etc. If we find any loads or
// any escape sites of the object, we give up. If we succeed in walking the
// entire graph of uses, we can remove the resultant set.
SmallSetVector<Instruction*, 16> InvolvedInstructions;
SmallVector<Instruction*, 16> Worklist;
Worklist.push_back(&Allocation);
// Stores - Keep track of all of the store instructions we see.
SmallVector<StoreInst*, 16> Stores;
while (!Worklist.empty()) {
Instruction *I = Worklist.pop_back_val();
// Insert the instruction into our InvolvedInstructions set. If we have
// already seen it, then don't reprocess all of the uses.
if (!InvolvedInstructions.insert(I)) continue;
// Okay, this is the first time we've seen this instruction, proceed.
switch (classifyInstruction(*I)) {
// These instructions should not reach here based on the pass ordering.
// i.e. LLVMARCOpt -> LLVMContractOpt.
case RT_RetainN:
case RT_UnknownRetainN:
case RT_BridgeRetainN:
case RT_ReleaseN:
case RT_UnknownReleaseN:
case RT_BridgeReleaseN:
llvm_unreachable("These are only created by LLVMARCContract !");
case RT_AllocObject:
// If this is a different swift_allocObject than we started with, then
// there is some computation feeding into a size or alignment computation
// that we have to keep... unless we can delete *that* entire object as
// well.
break;
case RT_NoMemoryAccessed:
// If no memory is accessed, then something is being done with the
// pointer: maybe it is bitcast or GEP'd. Since there are no side effects,
// it is perfectly fine to delete this instruction if all uses of the
// instruction are also eliminable.
if (I->mayHaveSideEffects() || isa<TerminatorInst>(I))
return false;
break;
case RT_Release:
case RT_Retain:
case RT_FixLifetime:
case RT_CheckUnowned:
// It is perfectly fine to eliminate various retains and releases of this
// object: we are zapping all accesses or none.
break;
// If this is an unknown instruction, we have more interesting things to
// consider.
case RT_Unknown:
case RT_ObjCRelease:
case RT_ObjCRetain:
case RT_UnknownRetain:
case RT_UnknownRelease:
case RT_BridgeRetain:
case RT_BridgeRelease:
case RT_RetainUnowned:
// Otherwise, this really is some unhandled instruction. Bail out.
return false;
}
// Okay, if we got here, the instruction can be eaten so-long as all of its
// uses can be. Scan through the uses and add them to the worklist for
// recursive processing.
for (auto UI = I->user_begin(), E = I->user_end(); UI != E; ++UI) {
Instruction *User = cast<Instruction>(*UI);
// Handle stores as a special case here: we want to make sure that the
// object is being stored *to*, not itself being stored (which would be an
// escape point). Since stores themselves don't have any uses, we can
// short-cut the classification scheme above.
if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
// If this is a store *to* the object, we can zap it.
if (UI.getUse().getOperandNo() == StoreInst::getPointerOperandIndex()) {
InvolvedInstructions.insert(SI);
continue;
}
// Otherwise, using the object as a source (or size) is an escape.
return false;
}
if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(User)) {
// If this is a memset/memcpy/memmove *to* the object, we can zap it.
if (UI.getUse().getOperandNo() == 0) {
InvolvedInstructions.insert(MI);
continue;
}
// Otherwise, using the object as a source (or size) is an escape.
return false;
}
// Otherwise, normal instructions just go on the worklist for processing.
Worklist.push_back(User);
}
}
// Ok, we succeeded! This means we can zap all of the instructions that use
// the object. One thing we have to be careful of is to make sure that we
// don't invalidate "BBI" (the iterator the outer walk of the optimization
// pass is using, and indicates the next instruction to process). This would
// happen if we delete the instruction it is pointing to. Advance the
// iterator if that would happen.
while (InvolvedInstructions.count(&*BBI))
++BBI;
// Zap all of the instructions.
for (auto I : InvolvedInstructions) {
if (!I->use_empty())
I->replaceAllUsesWith(UndefValue::get(I->getType()));
I->eraseFromParent();
}
++NumStoreOnlyObjectsEliminated;
return true;
}
/// LowerUnwinds - Turn unwind instructions into calls to _Unwind_Resume,
/// rethrowing any previously caught exception. This will crash horribly
/// at runtime if there is no such exception: using unwind to throw a new
/// exception is currently not supported.
bool DwarfEHPrepare::LowerUnwindsAndResumes() {
SmallVector<Instruction*, 16> ResumeInsts;
for (Function::iterator fi = F->begin(), fe = F->end(); fi != fe; ++fi) {
for (BasicBlock::iterator bi = fi->begin(), be = fi->end(); bi != be; ++bi){
if (isa<UnwindInst>(bi))
ResumeInsts.push_back(bi);
else if (CallInst *call = dyn_cast<CallInst>(bi))
if (Function *fn = dyn_cast<Function>(call->getCalledValue()))
if (fn->getName() == "llvm.eh.resume")
ResumeInsts.push_back(bi);
}
}
if (ResumeInsts.empty()) return false;
// Find the rewind function if we didn't already.
if (!RewindFunction) {
LLVMContext &Ctx = ResumeInsts[0]->getContext();
std::vector<const Type*>
Params(1, Type::getInt8PtrTy(Ctx));
FunctionType *FTy = FunctionType::get(Type::getVoidTy(Ctx),
Params, false);
const char *RewindName = TLI->getLibcallName(RTLIB::UNWIND_RESUME);
RewindFunction = F->getParent()->getOrInsertFunction(RewindName, FTy);
}
bool Changed = false;
for (SmallVectorImpl<Instruction*>::iterator
I = ResumeInsts.begin(), E = ResumeInsts.end(); I != E; ++I) {
Instruction *RI = *I;
// Replace the resuming instruction with a call to _Unwind_Resume (or the
// appropriate target equivalent).
llvm::Value *ExnValue;
if (isa<UnwindInst>(RI))
ExnValue = CreateExceptionValueCall(RI->getParent());
else
ExnValue = cast<CallInst>(RI)->getArgOperand(0);
// Create the call...
CallInst *CI = CallInst::Create(RewindFunction, ExnValue, "", RI);
CI->setCallingConv(TLI->getLibcallCallingConv(RTLIB::UNWIND_RESUME));
// ...followed by an UnreachableInst, if it was an unwind.
// Calls to llvm.eh.resume are typically already followed by this.
if (isa<UnwindInst>(RI))
new UnreachableInst(RI->getContext(), RI);
if (isa<UnwindInst>(RI))
++NumUnwindsLowered;
else
++NumResumesLowered;
// Nuke the resume instruction.
RI->eraseFromParent();
Changed = true;
}
return Changed;
}
bool ReplaceNopCastsAndByteSwaps::processBasicBlock(BasicBlock& BB)
{
bool Changed = false;
/**
* First pass: replace nopCasts with bitcasts and bswap intrinsics with logic operations
*/
for ( BasicBlock::iterator it = BB.begin(); it != BB.end(); )
{
Instruction * Inst = it++;
if (isNopCast(Inst) )
{
assert( isa<CallInst>(Inst) );
CallInst * call = cast<CallInst>(Inst);
if ( TypeSupport::isClientType( call->getType()) )
{
llvm::errs() << "Cast of client type: " << *call << "\n";
continue;
}
if ( TypeSupport::isClientType( call->getArgOperand(0)->getType()) )
{
llvm::errs() << "Cast of client type: " << *call->getArgOperand(0) << "\n";
continue;
}
ReplaceInstWithInst( call, BitCastInst::Create( Instruction::CastOps::BitCast, call->getArgOperand(0), call->getType() ) );
Changed = true;
}
else if( IntrinsicInst* II = dyn_cast<IntrinsicInst>(Inst) )
{
if(II->getIntrinsicID() == Intrinsic::bswap)
{
IL->LowerIntrinsicCall(II);
Changed = true;
}
else if(II->getIntrinsicID() == Intrinsic::cheerp_deallocate)
{
II->eraseFromParent();
Changed = true;
}
}
}
/**
* Second pass: collapse bitcasts of bitcasts.
*
* Note: this might leave some dead instruction around, but we don't care since bitcasts are inlined anyway
*/
for ( BasicBlock::iterator it = BB.begin(); it != BB.end(); ++it )
{
if ( isa<BitCastInst>(it) )
{
while ( BitCastInst * src = dyn_cast<BitCastInst>(it->getOperand(0) ) )
{
it->setOperand(0, src->getOperand(0) );
Changed = true;
}
}
}
return Changed;
}
/// processMemCpy - perform simplification of memcpy's. If we have memcpy A
/// which copies X to Y, and memcpy B which copies Y to Z, then we can rewrite
/// B to be a memcpy from X to Z (or potentially a memmove, depending on
/// circumstances). This allows later passes to remove the first memcpy
/// altogether.
bool MemCpyOpt::processMemCpy(MemCpyInst *M) {
MemoryDependenceAnalysis &MD = getAnalysis<MemoryDependenceAnalysis>();
// The are two possible optimizations we can do for memcpy:
// a) memcpy-memcpy xform which exposes redundance for DSE.
// b) call-memcpy xform for return slot optimization.
MemDepResult dep = MD.getDependency(M);
if (!dep.isClobber())
return false;
if (!isa<MemCpyInst>(dep.getInst())) {
if (CallInst *C = dyn_cast<CallInst>(dep.getInst()))
return performCallSlotOptzn(M, C);
return false;
}
MemCpyInst *MDep = cast<MemCpyInst>(dep.getInst());
// We can only transforms memcpy's where the dest of one is the source of the
// other
if (M->getSource() != MDep->getDest())
return false;
// Second, the length of the memcpy's must be the same, or the preceeding one
// must be larger than the following one.
ConstantInt *C1 = dyn_cast<ConstantInt>(MDep->getLength());
ConstantInt *C2 = dyn_cast<ConstantInt>(M->getLength());
if (!C1 || !C2)
return false;
uint64_t DepSize = C1->getValue().getZExtValue();
uint64_t CpySize = C2->getValue().getZExtValue();
if (DepSize < CpySize)
return false;
// Finally, we have to make sure that the dest of the second does not
// alias the source of the first
AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
if (AA.alias(M->getRawDest(), CpySize, MDep->getRawSource(), DepSize) !=
AliasAnalysis::NoAlias)
return false;
else if (AA.alias(M->getRawDest(), CpySize, M->getRawSource(), CpySize) !=
AliasAnalysis::NoAlias)
return false;
else if (AA.alias(MDep->getRawDest(), DepSize, MDep->getRawSource(), DepSize)
!= AliasAnalysis::NoAlias)
return false;
// If all checks passed, then we can transform these memcpy's
const Type *ArgTys[3] = { M->getRawDest()->getType(),
MDep->getRawSource()->getType(),
M->getLength()->getType() };
Function *MemCpyFun = Intrinsic::getDeclaration(
M->getParent()->getParent()->getParent(),
M->getIntrinsicID(), ArgTys, 3);
Value *Args[5] = {
M->getRawDest(), MDep->getRawSource(), M->getLength(),
M->getAlignmentCst(), M->getVolatileCst()
};
CallInst *C = CallInst::Create(MemCpyFun, Args, Args+5, "", M);
// If C and M don't interfere, then this is a valid transformation. If they
// did, this would mean that the two sources overlap, which would be bad.
if (MD.getDependency(C) == dep) {
MD.removeInstruction(M);
M->eraseFromParent();
++NumMemCpyInstr;
return true;
}
// Otherwise, there was no point in doing this, so we remove the call we
// inserted and act like nothing happened.
MD.removeInstruction(C);
C->eraseFromParent();
return false;
}
/// run - Start execution with the specified function and arguments.
///
GenericValue JIT::runFunction(Function *F,
const std::vector<GenericValue> &ArgValues) {
assert(F && "Function *F was null at entry to run()");
void *FPtr = getPointerToFunction(F);
assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
FunctionType *FTy = F->getFunctionType();
Type *RetTy = FTy->getReturnType();
assert((FTy->getNumParams() == ArgValues.size() ||
(FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) &&
"Wrong number of arguments passed into function!");
assert(FTy->getNumParams() == ArgValues.size() &&
"This doesn't support passing arguments through varargs (yet)!");
// Handle some common cases first. These cases correspond to common `main'
// prototypes.
if (RetTy->isIntegerTy(32) || RetTy->isVoidTy()) {
switch (ArgValues.size()) {
case 3:
if (FTy->getParamType(0)->isIntegerTy(32) &&
FTy->getParamType(1)->isPointerTy() &&
FTy->getParamType(2)->isPointerTy()) {
int (*PF)(int, char **, const char **) =
(int(*)(int, char **, const char **))(intptr_t)FPtr;
// Call the function.
GenericValue rv;
rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
(char **)GVTOP(ArgValues[1]),
(const char **)GVTOP(ArgValues[2])));
return rv;
}
break;
case 2:
if (FTy->getParamType(0)->isIntegerTy(32) &&
FTy->getParamType(1)->isPointerTy()) {
int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
// Call the function.
GenericValue rv;
rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
(char **)GVTOP(ArgValues[1])));
return rv;
}
break;
case 1:
if (FTy->getParamType(0)->isIntegerTy(32)) {
GenericValue rv;
int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
return rv;
}
if (FTy->getParamType(0)->isPointerTy()) {
GenericValue rv;
int (*PF)(char *) = (int(*)(char *))(intptr_t)FPtr;
rv.IntVal = APInt(32, PF((char*)GVTOP(ArgValues[0])));
return rv;
}
break;
}
}
// Handle cases where no arguments are passed first.
if (ArgValues.empty()) {
GenericValue rv;
switch (RetTy->getTypeID()) {
default: llvm_unreachable("Unknown return type for function call!");
case Type::IntegerTyID: {
unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
if (BitWidth == 1)
rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
else if (BitWidth <= 8)
rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
else if (BitWidth <= 16)
rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
else if (BitWidth <= 32)
rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
else if (BitWidth <= 64)
rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
else
llvm_unreachable("Integer types > 64 bits not supported");
return rv;
}
case Type::VoidTyID:
rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
return rv;
case Type::FloatTyID:
rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
return rv;
case Type::DoubleTyID:
rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
return rv;
case Type::X86_FP80TyID:
case Type::FP128TyID:
case Type::PPC_FP128TyID:
llvm_unreachable("long double not supported yet");
case Type::PointerTyID:
return PTOGV(((void*(*)())(intptr_t)FPtr)());
}
}
// Okay, this is not one of our quick and easy cases. Because we don't have a
// full FFI, we have to codegen a nullary stub function that just calls the
// function we are interested in, passing in constants for all of the
// arguments. Make this function and return.
// First, create the function.
FunctionType *STy=FunctionType::get(RetTy, false);
Function *Stub = Function::Create(STy, Function::InternalLinkage, "",
F->getParent());
// Insert a basic block.
BasicBlock *StubBB = BasicBlock::Create(F->getContext(), "", Stub);
// Convert all of the GenericValue arguments over to constants. Note that we
// currently don't support varargs.
SmallVector<Value*, 8> Args;
for (unsigned i = 0, e = ArgValues.size(); i != e; ++i) {
Constant *C = 0;
Type *ArgTy = FTy->getParamType(i);
const GenericValue &AV = ArgValues[i];
switch (ArgTy->getTypeID()) {
default: llvm_unreachable("Unknown argument type for function call!");
case Type::IntegerTyID:
C = ConstantInt::get(F->getContext(), AV.IntVal);
break;
case Type::FloatTyID:
C = ConstantFP::get(F->getContext(), APFloat(AV.FloatVal));
break;
case Type::DoubleTyID:
C = ConstantFP::get(F->getContext(), APFloat(AV.DoubleVal));
break;
case Type::PPC_FP128TyID:
case Type::X86_FP80TyID:
case Type::FP128TyID:
C = ConstantFP::get(F->getContext(), APFloat(AV.IntVal));
break;
case Type::PointerTyID:
void *ArgPtr = GVTOP(AV);
if (sizeof(void*) == 4)
C = ConstantInt::get(Type::getInt32Ty(F->getContext()),
(int)(intptr_t)ArgPtr);
else
C = ConstantInt::get(Type::getInt64Ty(F->getContext()),
(intptr_t)ArgPtr);
// Cast the integer to pointer
C = ConstantExpr::getIntToPtr(C, ArgTy);
break;
}
Args.push_back(C);
}
CallInst *TheCall = CallInst::Create(F, Args, "", StubBB);
TheCall->setCallingConv(F->getCallingConv());
TheCall->setTailCall();
if (!TheCall->getType()->isVoidTy())
// Return result of the call.
ReturnInst::Create(F->getContext(), TheCall, StubBB);
else
ReturnInst::Create(F->getContext(), StubBB); // Just return void.
// Finally, call our nullary stub function.
GenericValue Result = runFunction(Stub, std::vector<GenericValue>());
// Erase it, since no other function can have a reference to it.
Stub->eraseFromParent();
// And return the result.
return Result;
}
void OptimizeFastMemoryChecks::visitCallInst(CallInst &CI) {
CheckInfoType *Info = MSCI->getCheckInfo(CI.getCalledFunction());
if (Info && Info->isFastMemoryCheck())
FastCheckCalls.push_back(&CI);
}
/// run - Start execution with the specified function and arguments.
///
GenericValue JIT::runFunction(Function *F,
const std::vector<GenericValue> &ArgValues) {
assert(F && "Function *F was null at entry to run()");
void *FPtr = getPointerToFunction(F);
assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
const FunctionType *FTy = F->getFunctionType();
const Type *RetTy = FTy->getReturnType();
assert((FTy->getNumParams() <= ArgValues.size() || FTy->isVarArg()) &&
"Too many arguments passed into function!");
assert(FTy->getNumParams() == ArgValues.size() &&
"This doesn't support passing arguments through varargs (yet)!");
//// Brooks
//// X86 Opcode 0x0f39 called here
cout<<"****** SWITCHING TO SIMULATION MODE FROM NATIVE MODE ***** \n";
ptlcall_switch_to_sim();
cout<<"____ SIWTCH DONE ____ \n";
int * a=(int*)0x85df65d;
cout<<"Value: "<<std::hex<<*(a)<<" "<<*(a+1)<<"\n";
asm(".byte 0x0f; .byte 0x39;");
// Handle some common cases first. These cases correspond to common `main'
// prototypes.
if (RetTy == Type::Int32Ty || RetTy == Type::VoidTy) {
switch (ArgValues.size()) {
case 3:
if (FTy->getParamType(0) == Type::Int32Ty &&
isa<PointerType>(FTy->getParamType(1)) &&
isa<PointerType>(FTy->getParamType(2))) {
int (*PF)(int, char **, const char **) =
(int(*)(int, char **, const char **))(intptr_t)FPtr;
// Call the function.
GenericValue rv;
rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
(char **)GVTOP(ArgValues[1]),
(const char **)GVTOP(ArgValues[2])));
return rv;
}
break;
case 2:
if (FTy->getParamType(0) == Type::Int32Ty &&
isa<PointerType>(FTy->getParamType(1))) {
int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
// Call the function.
GenericValue rv;
rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
(char **)GVTOP(ArgValues[1])));
return rv;
}
break;
case 1:
if (FTy->getNumParams() == 1 &&
FTy->getParamType(0) == Type::Int32Ty) {
GenericValue rv;
int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
return rv;
}
break;
}
}
// Handle cases where no arguments are passed first.
if (ArgValues.empty()) {
GenericValue rv;
switch (RetTy->getTypeID()) {
default: assert(0 && "Unknown return type for function call!");
case Type::IntegerTyID: {
unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
if (BitWidth == 1)
rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
else if (BitWidth <= 8)
rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
else if (BitWidth <= 16)
rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
else if (BitWidth <= 32)
rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
else if (BitWidth <= 64)
rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
else
assert(0 && "Integer types > 64 bits not supported");
return rv;
}
case Type::VoidTyID:
rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
return rv;
case Type::FloatTyID:
rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
return rv;
case Type::DoubleTyID:
rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
return rv;
case Type::X86_FP80TyID:
case Type::FP128TyID:
case Type::PPC_FP128TyID:
assert(0 && "long double not supported yet");
return rv;
case Type::PointerTyID:
return PTOGV(((void*(*)())(intptr_t)FPtr)());
}
}
// Okay, this is not one of our quick and easy cases. Because we don't have a
// full FFI, we have to codegen a nullary stub function that just calls the
// function we are interested in, passing in constants for all of the
// arguments. Make this function and return.
// First, create the function.
FunctionType *STy=FunctionType::get(RetTy, std::vector<const Type*>(), false);
Function *Stub = Function::Create(STy, Function::InternalLinkage, "",
F->getParent());
// Insert a basic block.
BasicBlock *StubBB = BasicBlock::Create("", Stub);
// Convert all of the GenericValue arguments over to constants. Note that we
// currently don't support varargs.
SmallVector<Value*, 8> Args;
for (unsigned i = 0, e = ArgValues.size(); i != e; ++i) {
Constant *C = 0;
const Type *ArgTy = FTy->getParamType(i);
const GenericValue &AV = ArgValues[i];
switch (ArgTy->getTypeID()) {
default: assert(0 && "Unknown argument type for function call!");
case Type::IntegerTyID:
C = ConstantInt::get(AV.IntVal);
break;
case Type::FloatTyID:
C = ConstantFP::get(APFloat(AV.FloatVal));
break;
case Type::DoubleTyID:
C = ConstantFP::get(APFloat(AV.DoubleVal));
break;
case Type::PPC_FP128TyID:
case Type::X86_FP80TyID:
case Type::FP128TyID:
C = ConstantFP::get(APFloat(AV.IntVal));
break;
case Type::PointerTyID:
void *ArgPtr = GVTOP(AV);
if (sizeof(void*) == 4)
C = ConstantInt::get(Type::Int32Ty, (int)(intptr_t)ArgPtr);
else
C = ConstantInt::get(Type::Int64Ty, (intptr_t)ArgPtr);
C = ConstantExpr::getIntToPtr(C, ArgTy); // Cast the integer to pointer
break;
}
Args.push_back(C);
}
CallInst *TheCall = CallInst::Create(F, Args.begin(), Args.end(), "", StubBB);
TheCall->setTailCall();
if (TheCall->getType() != Type::VoidTy)
ReturnInst::Create(TheCall, StubBB); // Return result of the call.
else
ReturnInst::Create(StubBB); // Just return void.
// Finally, return the value returned by our nullary stub function.
return runFunction(Stub, std::vector<GenericValue>());
}
bool IRTranslator::translateKnownIntrinsic(const CallInst &CI,
Intrinsic::ID ID) {
unsigned Op = 0;
switch (ID) {
default: return false;
case Intrinsic::uadd_with_overflow: Op = TargetOpcode::G_UADDE; break;
case Intrinsic::sadd_with_overflow: Op = TargetOpcode::G_SADDO; break;
case Intrinsic::usub_with_overflow: Op = TargetOpcode::G_USUBE; break;
case Intrinsic::ssub_with_overflow: Op = TargetOpcode::G_SSUBO; break;
case Intrinsic::umul_with_overflow: Op = TargetOpcode::G_UMULO; break;
case Intrinsic::smul_with_overflow: Op = TargetOpcode::G_SMULO; break;
case Intrinsic::memcpy:
return translateMemcpy(CI);
case Intrinsic::eh_typeid_for: {
GlobalValue *GV = ExtractTypeInfo(CI.getArgOperand(0));
unsigned Reg = getOrCreateVReg(CI);
unsigned TypeID = MIRBuilder.getMF().getMMI().getTypeIDFor(GV);
MIRBuilder.buildConstant(Reg, TypeID);
return true;
}
case Intrinsic::objectsize: {
// If we don't know by now, we're never going to know.
const ConstantInt *Min = cast<ConstantInt>(CI.getArgOperand(1));
MIRBuilder.buildConstant(getOrCreateVReg(CI), Min->isZero() ? -1ULL : 0);
return true;
}
case Intrinsic::stackguard:
getStackGuard(getOrCreateVReg(CI));
return true;
case Intrinsic::stackprotector: {
MachineFunction &MF = MIRBuilder.getMF();
LLT PtrTy{*CI.getArgOperand(0)->getType(), *DL};
unsigned GuardVal = MRI->createGenericVirtualRegister(PtrTy);
getStackGuard(GuardVal);
AllocaInst *Slot = cast<AllocaInst>(CI.getArgOperand(1));
MIRBuilder.buildStore(
GuardVal, getOrCreateVReg(*Slot),
*MF.getMachineMemOperand(
MachinePointerInfo::getFixedStack(MF, getOrCreateFrameIndex(*Slot)),
MachineMemOperand::MOStore | MachineMemOperand::MOVolatile,
PtrTy.getSizeInBits() / 8, 8));
return true;
}
}
LLT Ty{*CI.getOperand(0)->getType(), *DL};
LLT s1 = LLT::scalar(1);
unsigned Width = Ty.getSizeInBits();
unsigned Res = MRI->createGenericVirtualRegister(Ty);
unsigned Overflow = MRI->createGenericVirtualRegister(s1);
auto MIB = MIRBuilder.buildInstr(Op)
.addDef(Res)
.addDef(Overflow)
.addUse(getOrCreateVReg(*CI.getOperand(0)))
.addUse(getOrCreateVReg(*CI.getOperand(1)));
if (Op == TargetOpcode::G_UADDE || Op == TargetOpcode::G_USUBE) {
unsigned Zero = MRI->createGenericVirtualRegister(s1);
EntryBuilder.buildConstant(Zero, 0);
MIB.addUse(Zero);
}
MIRBuilder.buildSequence(getOrCreateVReg(CI), Res, 0, Overflow, Width);
return true;
}
/// setupEntryBlockAndCallSites - Setup the entry block by creating and filling
/// the function context and marking the call sites with the appropriate
/// values. These values are used by the DWARF EH emitter.
bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) {
SmallVector<ReturnInst *, 16> Returns;
SmallVector<InvokeInst *, 16> Invokes;
SmallSetVector<LandingPadInst *, 16> LPads;
// Look through the terminators of the basic blocks to find invokes.
for (BasicBlock &BB : F)
if (auto *II = dyn_cast<InvokeInst>(BB.getTerminator())) {
if (Function *Callee = II->getCalledFunction())
if (Callee->getIntrinsicID() == Intrinsic::donothing) {
// Remove the NOP invoke.
BranchInst::Create(II->getNormalDest(), II);
II->eraseFromParent();
continue;
}
Invokes.push_back(II);
LPads.insert(II->getUnwindDest()->getLandingPadInst());
} else if (auto *RI = dyn_cast<ReturnInst>(BB.getTerminator())) {
Returns.push_back(RI);
}
if (Invokes.empty())
return false;
NumInvokes += Invokes.size();
lowerIncomingArguments(F);
lowerAcrossUnwindEdges(F, Invokes);
Value *FuncCtx =
setupFunctionContext(F, makeArrayRef(LPads.begin(), LPads.end()));
BasicBlock *EntryBB = &F.front();
IRBuilder<> Builder(EntryBB->getTerminator());
// Get a reference to the jump buffer.
Value *JBufPtr =
Builder.CreateConstGEP2_32(FunctionContextTy, FuncCtx, 0, 5, "jbuf_gep");
// Save the frame pointer.
Value *FramePtr = Builder.CreateConstGEP2_32(doubleUnderJBufTy, JBufPtr, 0, 0,
"jbuf_fp_gep");
Value *Val = Builder.CreateCall(FrameAddrFn, Builder.getInt32(0), "fp");
Builder.CreateStore(Val, FramePtr, /*isVolatile=*/true);
// Save the stack pointer.
Value *StackPtr = Builder.CreateConstGEP2_32(doubleUnderJBufTy, JBufPtr, 0, 2,
"jbuf_sp_gep");
Val = Builder.CreateCall(StackAddrFn, {}, "sp");
Builder.CreateStore(Val, StackPtr, /*isVolatile=*/true);
// Call the setup_dispatch instrinsic. It fills in the rest of the jmpbuf.
Builder.CreateCall(BuiltinSetupDispatchFn, {});
// Store a pointer to the function context so that the back-end will know
// where to look for it.
Value *FuncCtxArg = Builder.CreateBitCast(FuncCtx, Builder.getInt8PtrTy());
Builder.CreateCall(FuncCtxFn, FuncCtxArg);
// At this point, we are all set up, update the invoke instructions to mark
// their call_site values.
for (unsigned I = 0, E = Invokes.size(); I != E; ++I) {
insertCallSiteStore(Invokes[I], I + 1);
ConstantInt *CallSiteNum =
ConstantInt::get(Type::getInt32Ty(F.getContext()), I + 1);
// Record the call site value for the back end so it stays associated with
// the invoke.
CallInst::Create(CallSiteFn, CallSiteNum, "", Invokes[I]);
}
// Mark call instructions that aren't nounwind as no-action (call_site ==
// -1). Skip the entry block, as prior to then, no function context has been
// created for this function and any unexpected exceptions thrown will go
// directly to the caller's context, which is what we want anyway, so no need
// to do anything here.
for (BasicBlock &BB : F) {
if (&BB == &F.front())
continue;
for (Instruction &I : BB)
if (I.mayThrow())
insertCallSiteStore(&I, -1);
}
// Register the function context and make sure it's known to not throw
CallInst *Register =
CallInst::Create(RegisterFn, FuncCtx, "", EntryBB->getTerminator());
Register->setDoesNotThrow();
// Following any allocas not in the entry block, update the saved SP in the
// jmpbuf to the new value.
for (BasicBlock &BB : F) {
if (&BB == &F.front())
continue;
for (Instruction &I : BB) {
if (auto *CI = dyn_cast<CallInst>(&I)) {
if (CI->getCalledFunction() != StackRestoreFn)
continue;
} else if (!isa<AllocaInst>(&I)) {
continue;
}
Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp");
StackAddr->insertAfter(&I);
Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true);
StoreStackAddr->insertAfter(StackAddr);
}
}
// Finally, for any returns from this function, if this function contains an
// invoke, add a call to unregister the function context.
for (ReturnInst *Return : Returns)
CallInst::Create(UnregisterFn, FuncCtx, "", Return);
return true;
}
//
// Function: insertPoolFrees()
//
// Description:
// This function takes a list of alloca instructions and inserts code to
// unregister them at every unwind and return instruction.
//
// Inputs:
// PoolRegisters - The list of calls to poolregister() inserted for stack
// objects.
// ExitPoints - The list of instructions that can cause the function to
// return.
// Context - The LLVM Context in which to insert instructions.
//
void
RegisterStackObjPass::insertPoolFrees
(const std::vector<CallInst *> & PoolRegisters,
const std::vector<Instruction *> & ExitPoints,
LLVMContext * Context) {
// List of alloca instructions we create to store the pointers to be
// deregistered.
std::vector<AllocaInst *> PtrList;
// List of pool handles; this is a parallel array to PtrList
std::vector<Value *> PHList;
// The infamous void pointer type
PointerType * VoidPtrTy = getVoidPtrType(*Context);
//
// Create alloca instructions for every registered alloca. These will hold
// a pointer to the registered stack objects and will be referenced by
// poolunregister().
//
for (unsigned index = 0; index < PoolRegisters.size(); ++index) {
//
// Take the first element off of the worklist.
//
CallInst * CI = PoolRegisters[index];
CallSite CS(CI);
//
// Get the pool handle and allocated pointer from the poolregister() call.
//
Value * PH = CS.getArgument(0);
Value * Ptr = CS.getArgument(1);
//
// Create a place to store the pointer returned from alloca. Initialize it
// with a null pointer.
//
BasicBlock & EntryBB = CI->getParent()->getParent()->getEntryBlock();
Instruction * InsertPt = &(EntryBB.front());
AllocaInst * PtrLoc = new AllocaInst (VoidPtrTy,
Ptr->getName() + ".st",
InsertPt);
Value * NullPointer = ConstantPointerNull::get(VoidPtrTy);
new StoreInst (NullPointer, PtrLoc, InsertPt);
//
// Store the registered pointer into the memory we allocated in the entry
// block.
//
new StoreInst (Ptr, PtrLoc, CI);
//
// Record the alloca that stores the pointer to deregister.
// Record the pool handle with it.
//
PtrList.push_back (PtrLoc);
PHList.push_back (PH);
}
//
// For each point where the function can exit, insert code to deregister all
// stack objects.
//
for (unsigned index = 0; index < ExitPoints.size(); ++index) {
//
// Take the first element off of the worklist.
//
Instruction * Return = ExitPoints[index];
//
// Deregister each registered stack object.
//
for (unsigned i = 0; i < PtrList.size(); ++i) {
//
// Get the location holding the pointer and the pool handle associated
// with it.
//
AllocaInst * PtrLoc = PtrList[i];
Value * PH = PHList[i];
//
// Generate a load instruction to get the registered pointer.
//
LoadInst * Ptr = new LoadInst (PtrLoc, "", Return);
//
// Create the call to poolunregister().
//
std::vector<Value *> args;
args.push_back (PH);
args.push_back (Ptr);
CallInst::Create (StackFree, args, "", Return);
}
}
//
// Lastly, promote the allocas we created into LLVM virtual registers.
//
PromoteMemToReg(PtrList, *DT);
}
/// DupRetToEnableTailCallOpts - Look for opportunities to duplicate return
/// instructions to the predecessor to enable tail call optimizations. The
/// case it is currently looking for is:
/// bb0:
/// %tmp0 = tail call i32 @f0()
/// br label %return
/// bb1:
/// %tmp1 = tail call i32 @f1()
/// br label %return
/// bb2:
/// %tmp2 = tail call i32 @f2()
/// br label %return
/// return:
/// %retval = phi i32 [ %tmp0, %bb0 ], [ %tmp1, %bb1 ], [ %tmp2, %bb2 ]
/// ret i32 %retval
///
/// =>
///
/// bb0:
/// %tmp0 = tail call i32 @f0()
/// ret i32 %tmp0
/// bb1:
/// %tmp1 = tail call i32 @f1()
/// ret i32 %tmp1
/// bb2:
/// %tmp2 = tail call i32 @f2()
/// ret i32 %tmp2
///
bool CodeGenPrepare::DupRetToEnableTailCallOpts(ReturnInst *RI) {
if (!TLI)
return false;
Value *V = RI->getReturnValue();
PHINode *PN = V ? dyn_cast<PHINode>(V) : NULL;
if (V && !PN)
return false;
BasicBlock *BB = RI->getParent();
if (PN && PN->getParent() != BB)
return false;
// It's not safe to eliminate the sign / zero extension of the return value.
// See llvm::isInTailCallPosition().
const Function *F = BB->getParent();
Attributes CallerRetAttr = F->getAttributes().getRetAttributes();
if ((CallerRetAttr & Attribute::ZExt) || (CallerRetAttr & Attribute::SExt))
return false;
// Make sure there are no instructions between the PHI and return, or that the
// return is the first instruction in the block.
if (PN) {
BasicBlock::iterator BI = BB->begin();
do { ++BI; } while (isa<DbgInfoIntrinsic>(BI));
if (&*BI != RI)
return false;
} else {
BasicBlock::iterator BI = BB->begin();
while (isa<DbgInfoIntrinsic>(BI)) ++BI;
if (&*BI != RI)
return false;
}
/// Only dup the ReturnInst if the CallInst is likely to be emitted as a tail
/// call.
SmallVector<CallInst*, 4> TailCalls;
if (PN) {
for (unsigned I = 0, E = PN->getNumIncomingValues(); I != E; ++I) {
CallInst *CI = dyn_cast<CallInst>(PN->getIncomingValue(I));
// Make sure the phi value is indeed produced by the tail call.
if (CI && CI->hasOneUse() && CI->getParent() == PN->getIncomingBlock(I) &&
TLI->mayBeEmittedAsTailCall(CI))
TailCalls.push_back(CI);
}
} else {
SmallPtrSet<BasicBlock*, 4> VisitedBBs;
for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); PI != PE; ++PI) {
if (!VisitedBBs.insert(*PI))
continue;
BasicBlock::InstListType &InstList = (*PI)->getInstList();
BasicBlock::InstListType::reverse_iterator RI = InstList.rbegin();
BasicBlock::InstListType::reverse_iterator RE = InstList.rend();
do { ++RI; } while (RI != RE && isa<DbgInfoIntrinsic>(&*RI));
if (RI == RE)
continue;
CallInst *CI = dyn_cast<CallInst>(&*RI);
if (CI && CI->use_empty() && TLI->mayBeEmittedAsTailCall(CI))
TailCalls.push_back(CI);
}
}
bool Changed = false;
for (unsigned i = 0, e = TailCalls.size(); i != e; ++i) {
CallInst *CI = TailCalls[i];
CallSite CS(CI);
// Conservatively require the attributes of the call to match those of the
// return. Ignore noalias because it doesn't affect the call sequence.
Attributes CalleeRetAttr = CS.getAttributes().getRetAttributes();
if ((CalleeRetAttr ^ CallerRetAttr) & ~Attribute::NoAlias)
continue;
// Make sure the call instruction is followed by an unconditional branch to
// the return block.
BasicBlock *CallBB = CI->getParent();
BranchInst *BI = dyn_cast<BranchInst>(CallBB->getTerminator());
if (!BI || !BI->isUnconditional() || BI->getSuccessor(0) != BB)
continue;
// Duplicate the return into CallBB.
(void)FoldReturnIntoUncondBranch(RI, BB, CallBB);
ModifiedDT = Changed = true;
++NumRetsDup;
}
// If we eliminated all predecessors of the block, delete the block now.
if (Changed && pred_begin(BB) == pred_end(BB))
BB->eraseFromParent();
return Changed;
}
/// performLocalReleaseMotion - Scan backwards from the specified release,
/// moving it earlier in the function if possible, over instructions that do not
/// access the released object. If we get to a retain or allocation of the
/// object, zap both.
static bool performLocalReleaseMotion(CallInst &Release, BasicBlock &BB,
SwiftRCIdentity *RC) {
// FIXME: Call classifier should identify the object for us. Too bad C++
// doesn't have nice Swift-style enums.
Value *ReleasedObject = RC->getSwiftRCIdentityRoot(Release.getArgOperand(0));
BasicBlock::iterator BBI = Release.getIterator();
// Scan until we get to the top of the block.
while (BBI != BB.begin()) {
--BBI;
// Don't analyze PHI nodes. We can't move retains before them and they
// aren't "interesting".
if (isa<PHINode>(BBI) ||
// If we found the instruction that defines the value we're releasing,
// don't push the release past it.
&*BBI == Release.getArgOperand(0)) {
++BBI;
goto OutOfLoop;
}
switch (classifyInstruction(*BBI)) {
// These instructions should not reach here based on the pass ordering.
// i.e. LLVMARCOpt -> LLVMContractOpt.
case RT_UnknownRetainN:
case RT_BridgeRetainN:
case RT_RetainN:
case RT_UnknownReleaseN:
case RT_BridgeReleaseN:
case RT_ReleaseN:
llvm_unreachable("These are only created by LLVMARCContract !");
case RT_NoMemoryAccessed:
// Skip over random instructions that don't touch memory. They don't need
// protection by retain/release.
continue;
case RT_UnknownRelease:
case RT_BridgeRelease:
case RT_ObjCRelease:
case RT_Release: {
// If we get to a release, we can generally ignore it and scan past it.
// However, if we get to a release of obviously the same object, we stop
// scanning here because it should have already be moved as early as
// possible, so there is no reason to move its friend to the same place.
//
// NOTE: If this occurs frequently, maybe we can have a release(Obj, N)
// API to drop multiple retain counts at once.
CallInst &ThisRelease = cast<CallInst>(*BBI);
Value *ThisReleasedObject = ThisRelease.getArgOperand(0);
ThisReleasedObject = RC->getSwiftRCIdentityRoot(ThisReleasedObject);
if (ThisReleasedObject == ReleasedObject) {
//Release.dump(); ThisRelease.dump(); BB.getParent()->dump();
++BBI;
goto OutOfLoop;
}
continue;
}
case RT_UnknownRetain:
case RT_BridgeRetain:
case RT_ObjCRetain:
case RT_Retain: { // swift_retain(obj)
CallInst &Retain = cast<CallInst>(*BBI);
Value *RetainedObject = Retain.getArgOperand(0);
RetainedObject = RC->getSwiftRCIdentityRoot(RetainedObject);
// Since we canonicalized earlier, we know that if our retain has any
// uses, they were replaced already. This assertion documents this
// assumption.
assert(Retain.use_empty() && "Retain should have been canonicalized to "
"have no uses.");
// If the retain and release are to obviously pointer-equal objects, then
// we can delete both of them. We have proven that they do not protect
// anything of value.
if (RetainedObject == ReleasedObject) {
Retain.eraseFromParent();
Release.eraseFromParent();
++NumRetainReleasePairs;
return true;
}
// Otherwise, this is a retain of an object that is not statically known
// to be the same object. It may still be dynamically the same object
// though. In this case, we can't move the release past it.
// TODO: Strengthen analysis.
//Release.dump(); ThisRelease.dump(); BB.getParent()->dump();
++BBI;
goto OutOfLoop;
}
case RT_AllocObject: { // %obj = swift_alloc(...)
CallInst &Allocation = cast<CallInst>(*BBI);
// If this is an allocation of an unrelated object, just ignore it.
// TODO: This is not safe without proving the object being released is not
// related to the allocated object. Consider something silly like this:
// A = allocate()
// B = bitcast A to object
// release(B)
if (ReleasedObject != &Allocation) {
// Release.dump(); BB.getParent()->dump();
++BBI;
goto OutOfLoop;
}
// If this is a release right after an allocation of the object, then we
// can zap both.
Allocation.replaceAllUsesWith(UndefValue::get(Allocation.getType()));
Allocation.eraseFromParent();
Release.eraseFromParent();
++NumAllocateReleasePairs;
return true;
}
case RT_FixLifetime:
case RT_RetainUnowned:
case RT_CheckUnowned:
case RT_Unknown:
// Otherwise, we have reached something that we do not understand. Do not
// attempt to shorten the lifetime of this object beyond this point so we
// are conservative.
++BBI;
goto OutOfLoop;
}
}
OutOfLoop:
// If we got to the top of the block, (and if the instruction didn't start
// there) move the release to the top of the block.
// TODO: This is where we'd plug in some global algorithms someday.
if (&*BBI != &Release) {
Release.moveBefore(&*BBI);
return true;
}
return false;
}
/// \brief Recursively handle the condition leading to a loop
Value *SIAnnotateControlFlow::handleLoopCondition(Value *Cond, PHINode *Broken,
llvm::Loop *L, BranchInst *Term) {
// Only search through PHI nodes which are inside the loop. If we try this
// with PHI nodes that are outside of the loop, we end up inserting new PHI
// nodes outside of the loop which depend on values defined inside the loop.
// This will break the module with
// 'Instruction does not dominate all users!' errors.
PHINode *Phi = nullptr;
if ((Phi = dyn_cast<PHINode>(Cond)) && L->contains(Phi)) {
BasicBlock *Parent = Phi->getParent();
PHINode *NewPhi = PHINode::Create(Int64, 0, "", &Parent->front());
Value *Ret = NewPhi;
// Handle all non-constant incoming values first
for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) {
Value *Incoming = Phi->getIncomingValue(i);
BasicBlock *From = Phi->getIncomingBlock(i);
if (isa<ConstantInt>(Incoming)) {
NewPhi->addIncoming(Broken, From);
continue;
}
Phi->setIncomingValue(i, BoolFalse);
Value *PhiArg = handleLoopCondition(Incoming, Broken, L, Term);
NewPhi->addIncoming(PhiArg, From);
}
BasicBlock *IDom = DT->getNode(Parent)->getIDom()->getBlock();
for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) {
Value *Incoming = Phi->getIncomingValue(i);
if (Incoming != BoolTrue)
continue;
BasicBlock *From = Phi->getIncomingBlock(i);
if (From == IDom) {
// We're in the following situation:
// IDom/From
// | \
// | If-block
// | /
// Parent
// where we want to break out of the loop if the If-block is not taken.
// Due to the depth-first traversal, there should be an end.cf
// intrinsic in Parent, and we insert an else.break before it.
//
// Note that the end.cf need not be the first non-phi instruction
// of parent, particularly when we're dealing with a multi-level
// break, but it should occur within a group of intrinsic calls
// at the beginning of the block.
CallInst *OldEnd = dyn_cast<CallInst>(Parent->getFirstInsertionPt());
while (OldEnd && OldEnd->getCalledFunction() != EndCf)
OldEnd = dyn_cast<CallInst>(OldEnd->getNextNode());
if (OldEnd && OldEnd->getCalledFunction() == EndCf) {
Value *Args[] = { OldEnd->getArgOperand(0), NewPhi };
Ret = CallInst::Create(ElseBreak, Args, "", OldEnd);
continue;
}
}
TerminatorInst *Insert = From->getTerminator();
Value *PhiArg = CallInst::Create(Break, Broken, "", Insert);
NewPhi->setIncomingValue(i, PhiArg);
}
eraseIfUnused(Phi);
return Ret;
} else if (Instruction *Inst = dyn_cast<Instruction>(Cond)) {
BasicBlock *Parent = Inst->getParent();
Instruction *Insert;
if (L->contains(Inst)) {
Insert = Parent->getTerminator();
} else {
Insert = L->getHeader()->getFirstNonPHIOrDbgOrLifetime();
}
Value *Args[] = { Cond, Broken };
return CallInst::Create(IfBreak, Args, "", Insert);
// Insert IfBreak before TERM for constant COND.
} else if (isa<ConstantInt>(Cond)) {
Value *Args[] = { Cond, Broken };
return CallInst::Create(IfBreak, Args, "", Term);
} else {
llvm_unreachable("Unhandled loop condition!");
}
return nullptr;
}
/// InlineHalfPowrs - Inline a sequence of adjacent half_powr calls, rearranging
/// their control flow to better facilitate subsequent optimization.
Instruction *
SimplifyHalfPowrLibCalls::
InlineHalfPowrs(const std::vector<Instruction *> &HalfPowrs,
Instruction *InsertPt) {
std::vector<BasicBlock *> Bodies;
BasicBlock *NewBlock = 0;
for (unsigned i = 0, e = HalfPowrs.size(); i != e; ++i) {
CallInst *Call = cast<CallInst>(HalfPowrs[i]);
Function *Callee = Call->getCalledFunction();
// Minimally sanity-check the CFG of half_powr to ensure that it contains
// the kind of code we expect. If we're running this pass, we have
// reason to believe it will be what we expect.
Function::iterator I = Callee->begin();
BasicBlock *Prologue = I++;
if (I == Callee->end()) break;
BasicBlock *SubnormalHandling = I++;
if (I == Callee->end()) break;
BasicBlock *Body = I++;
if (I != Callee->end()) break;
if (SubnormalHandling->getSinglePredecessor() != Prologue)
break;
BranchInst *PBI = dyn_cast<BranchInst>(Prologue->getTerminator());
if (!PBI || !PBI->isConditional())
break;
BranchInst *SNBI = dyn_cast<BranchInst>(SubnormalHandling->getTerminator());
if (!SNBI || SNBI->isConditional())
break;
if (!isa<ReturnInst>(Body->getTerminator()))
break;
Instruction *NextInst = llvm::next(BasicBlock::iterator(Call));
// Inline the call, taking care of what code ends up where.
NewBlock = SplitBlock(NextInst->getParent(), NextInst, this);
InlineFunctionInfo IFI(0, TD);
bool B = InlineFunction(Call, IFI);
assert(B && "half_powr didn't inline?"); B=B;
BasicBlock *NewBody = NewBlock->getSinglePredecessor();
assert(NewBody);
Bodies.push_back(NewBody);
}
if (!NewBlock)
return InsertPt;
// Put the code for all the bodies into one block, to facilitate
// subsequent optimization.
(void)SplitEdge(NewBlock->getSinglePredecessor(), NewBlock, this);
for (unsigned i = 0, e = Bodies.size(); i != e; ++i) {
BasicBlock *Body = Bodies[i];
Instruction *FNP = Body->getFirstNonPHI();
// Splice the insts from body into NewBlock.
NewBlock->getInstList().splice(NewBlock->begin(), Body->getInstList(),
FNP, Body->getTerminator());
}
return NewBlock->begin();
}
