/// SimplifyDivRemOfSelect - Try to fold a divide or remainder of a select
/// instruction.
bool InstCombiner::SimplifyDivRemOfSelect(BinaryOperator &I) {
SelectInst *SI = cast<SelectInst>(I.getOperand(1));
// div/rem X, (Cond ? 0 : Y) -> div/rem X, Y
int NonNullOperand = -1;
if (Constant *ST = dyn_cast<Constant>(SI->getOperand(1)))
if (ST->isNullValue())
NonNullOperand = 2;
// div/rem X, (Cond ? Y : 0) -> div/rem X, Y
if (Constant *ST = dyn_cast<Constant>(SI->getOperand(2)))
if (ST->isNullValue())
NonNullOperand = 1;
if (NonNullOperand == -1)
return false;
Value *SelectCond = SI->getOperand(0);
// Change the div/rem to use 'Y' instead of the select.
I.setOperand(1, SI->getOperand(NonNullOperand));
// Okay, we know we replace the operand of the div/rem with 'Y' with no
// problem. However, the select, or the condition of the select may have
// multiple uses. Based on our knowledge that the operand must be non-zero,
// propagate the known value for the select into other uses of it, and
// propagate a known value of the condition into its other users.
// If the select and condition only have a single use, don't bother with this,
// early exit.
if (SI->use_empty() && SelectCond->hasOneUse())
return true;
// Scan the current block backward, looking for other uses of SI.
BasicBlock::iterator BBI = &I, BBFront = I.getParent()->begin();
while (BBI != BBFront) {
--BBI;
// If we found a call to a function, we can't assume it will return, so
// information from below it cannot be propagated above it.
if (isa<CallInst>(BBI) && !isa<IntrinsicInst>(BBI))
break;
// Replace uses of the select or its condition with the known values.
for (Instruction::op_iterator I = BBI->op_begin(), E = BBI->op_end();
I != E; ++I) {
if (*I == SI) {
*I = SI->getOperand(NonNullOperand);
Worklist.Add(BBI);
} else if (*I == SelectCond) {
*I = NonNullOperand == 1 ? ConstantInt::getTrue(BBI->getContext()) :
ConstantInt::getFalse(BBI->getContext());
Worklist.Add(BBI);
}
}
// If we past the instruction, quit looking for it.
if (&*BBI == SI)
SI = 0;
if (&*BBI == SelectCond)
SelectCond = 0;
// If we ran out of things to eliminate, break out of the loop.
if (SelectCond == 0 && SI == 0)
break;
}
return true;
}
/// SimplifyStoreAtEndOfBlock - Turn things like:
/// if () { *P = v1; } else { *P = v2 }
/// into a phi node with a store in the successor.
///
/// Simplify things like:
/// *P = v1; if () { *P = v2; }
/// into a phi node with a store in the successor.
///
bool InstCombiner::SimplifyStoreAtEndOfBlock(StoreInst &SI) {
BasicBlock *StoreBB = SI.getParent();
// Check to see if the successor block has exactly two incoming edges. If
// so, see if the other predecessor contains a store to the same location.
// if so, insert a PHI node (if needed) and move the stores down.
BasicBlock *DestBB = StoreBB->getTerminator()->getSuccessor(0);
// Determine whether Dest has exactly two predecessors and, if so, compute
// the other predecessor.
pred_iterator PI = pred_begin(DestBB);
BasicBlock *P = *PI;
BasicBlock *OtherBB = nullptr;
if (P != StoreBB)
OtherBB = P;
if (++PI == pred_end(DestBB))
return false;
P = *PI;
if (P != StoreBB) {
if (OtherBB)
return false;
OtherBB = P;
}
if (++PI != pred_end(DestBB))
return false;
// Bail out if all the relevant blocks aren't distinct (this can happen,
// for example, if SI is in an infinite loop)
if (StoreBB == DestBB || OtherBB == DestBB)
return false;
// Verify that the other block ends in a branch and is not otherwise empty.
BasicBlock::iterator BBI(OtherBB->getTerminator());
BranchInst *OtherBr = dyn_cast<BranchInst>(BBI);
if (!OtherBr || BBI == OtherBB->begin())
return false;
// If the other block ends in an unconditional branch, check for the 'if then
// else' case. there is an instruction before the branch.
StoreInst *OtherStore = nullptr;
if (OtherBr->isUnconditional()) {
--BBI;
// Skip over debugging info.
while (isa<DbgInfoIntrinsic>(BBI) ||
(isa<BitCastInst>(BBI) && BBI->getType()->isPointerTy())) {
if (BBI==OtherBB->begin())
return false;
--BBI;
}
// If this isn't a store, isn't a store to the same location, or is not the
// right kind of store, bail out.
OtherStore = dyn_cast<StoreInst>(BBI);
if (!OtherStore || OtherStore->getOperand(1) != SI.getOperand(1) ||
!SI.isSameOperationAs(OtherStore))
return false;
} else {
// Otherwise, the other block ended with a conditional branch. If one of the
// destinations is StoreBB, then we have the if/then case.
if (OtherBr->getSuccessor(0) != StoreBB &&
OtherBr->getSuccessor(1) != StoreBB)
return false;
// Okay, we know that OtherBr now goes to Dest and StoreBB, so this is an
// if/then triangle. See if there is a store to the same ptr as SI that
// lives in OtherBB.
for (;; --BBI) {
// Check to see if we find the matching store.
if ((OtherStore = dyn_cast<StoreInst>(BBI))) {
if (OtherStore->getOperand(1) != SI.getOperand(1) ||
!SI.isSameOperationAs(OtherStore))
return false;
break;
}
// If we find something that may be using or overwriting the stored
// value, or if we run out of instructions, we can't do the xform.
if (BBI->mayReadFromMemory() || BBI->mayWriteToMemory() ||
BBI == OtherBB->begin())
return false;
}
// In order to eliminate the store in OtherBr, we have to
// make sure nothing reads or overwrites the stored value in
// StoreBB.
for (BasicBlock::iterator I = StoreBB->begin(); &*I != &SI; ++I) {
// FIXME: This should really be AA driven.
if (I->mayReadFromMemory() || I->mayWriteToMemory())
return false;
}
}
// Insert a PHI node now if we need it.
Value *MergedVal = OtherStore->getOperand(0);
if (MergedVal != SI.getOperand(0)) {
PHINode *PN = PHINode::Create(MergedVal->getType(), 2, "storemerge");
PN->addIncoming(SI.getOperand(0), SI.getParent());
PN->addIncoming(OtherStore->getOperand(0), OtherBB);
MergedVal = InsertNewInstBefore(PN, DestBB->front());
}
// Advance to a place where it is safe to insert the new store and
// insert it.
BBI = DestBB->getFirstInsertionPt();
StoreInst *NewSI = new StoreInst(MergedVal, SI.getOperand(1),
SI.isVolatile(),
SI.getAlignment(),
SI.getOrdering(),
SI.getSynchScope());
InsertNewInstBefore(NewSI, *BBI);
NewSI->setDebugLoc(OtherStore->getDebugLoc());
// If the two stores had AA tags, merge them.
AAMDNodes AATags;
SI.getAAMetadata(AATags);
if (AATags) {
OtherStore->getAAMetadata(AATags, /* Merge = */ true);
NewSI->setAAMetadata(AATags);
}
// Nuke the old stores.
EraseInstFromFunction(SI);
EraseInstFromFunction(*OtherStore);
return true;
}
void ArrayObfs::ArrObfuscate ( Function *F )
{
// Iterate the whole Function
Function *f = F;
for ( Function::iterator bb = f->begin(); bb != f->end(); ++bb )
{
for ( BasicBlock::iterator inst = bb->begin(); inst != bb->end(); )
{
if ( inst->getOpcode() == 29 ) // getelementptr
{
//errs() << "INST : " << *inst << "\n";
GetElementPtrInst *Ary = dyn_cast<GetElementPtrInst>(&*inst);
Value *ptrVal = Ary->getOperand(0);
Type *type = ptrVal->getType();
unsigned numOfOprand = Ary->getNumOperands();
unsigned lastOprand = numOfOprand - 1;
// Check Type Array
if ( PointerType *ptrType = dyn_cast<PointerType>( type ) )
{
Type *elementType = ptrType->getElementType();
if ( elementType->isArrayTy() )
{
// Skip if Index is a Variable
if ( dyn_cast<ConstantInt>( Ary->getOperand( lastOprand ) ) )
{
//////////////////////////////////////////////////////////////////////////////
// Do Real Stuff
Value *oprand = Ary->getOperand( lastOprand );
Value *basePtr = Ary->getOperand( 0 );
APInt offset = dyn_cast<ConstantInt>(oprand)->getValue();
Value *prevPtr = basePtr;
// Enter a Loop to Perform Random Obfuscation
unsigned cnt = 100;
// Prelog : Clone the Original Inst
unsigned ObfsIdx = cryptoutils->get_uint64_t() & 0xffff;
Value *newOprand = ConstantInt::get( oprand->getType(), ObfsIdx );
Instruction *gep = inst->clone();
gep->setOperand( lastOprand, newOprand );
gep->setOperand( 0, prevPtr );
gep->insertBefore( inst );
prevPtr = gep;
offset = offset - ObfsIdx;
// Create a Global Variable to Avoid Optimization
Module *M = f->getParent();
Constant *initGV = ConstantInt::get( prevPtr->getType(), 0 );
GlobalVariable *gv = new GlobalVariable( *M, prevPtr->getType(), false, GlobalValue::CommonLinkage, initGV );
while ( cnt-- )
{
// Iteratively Generate Obfuscated Code
switch( cryptoutils->get_uint64_t() & 7 )
{
// Random Indexing Obfuscation
case 0 :
case 1 :
case 2 :
{
//errs() << "=> Random Index \n";
// Create New Instruction
// Create Obfuscated New Oprand in ConstantInt Type
unsigned ObfsIdx = cryptoutils->get_uint64_t() & 0xffff;
Value *newOprand = ConstantInt::get( oprand->getType(), ObfsIdx );
// Create GetElementPtrInst Instruction
GetElementPtrInst *gep = GetElementPtrInst::Create( prevPtr, newOprand, "", inst );
//Set prevPtr
prevPtr = gep;
//errs() << "Created : " << *prevPtr << "\n";
offset = offset - ObfsIdx;
break;
}
// Ptr Dereference
case 3 :
case 4 :
{
//errs() << "=> Ptr Dereference \n";
Module *M = f->getParent();
Value *ONE = ConstantInt::get( Type::getInt32Ty( M->getContext() ), 1 );
Value *tmp = new AllocaInst( prevPtr->getType(), ONE, "", inst );
new StoreInst( prevPtr, tmp, inst );
prevPtr = new LoadInst( tmp, "", inst );
break;
}
// Ptr Value Transform
case 5 :
case 6 :
case 7 :
{
//errs() << "=> Ptr Value Trans \n";
unsigned RandNum = cryptoutils->get_uint64_t();
Value *ObfsVal = ConstantInt::get( prevPtr->getType(), RandNum );
BinaryOperator *op = BinaryOperator::Create( Instruction::FAdd, prevPtr, ObfsVal, "", inst );
new StoreInst( prevPtr, gv, inst );
BinaryOperator::Create( Instruction::FSub, gv, ObfsVal, "", inst );
prevPtr = new LoadInst( gv, "", inst );
break;
}
}
}
// Postlog : Fix the Original Indexing
{
Value *fixOprand = ConstantInt::get( oprand->getType(), offset );
// Refine the Last Instruction
GetElementPtrInst *gep = GetElementPtrInst::Create( prevPtr, fixOprand, "", inst );
// Fix the Relationship
inst->replaceAllUsesWith( gep );
// Finally : Unlink This Instruction From Parent
Instruction *DI = inst++;
//errs() << "user_back : " << *(DI->user_back()) << "\n";
DI->removeFromParent();
}
//////////////////////////////////////////////////////////////////////////////
// End : Variable Index
} else { inst++; }
// End : Check Array Type
} else { inst++; }
// End : Check Pointer Type
} else { inst++; }
// End : Check Opcode GetElementPtr
} else { inst++; }
}
}
++ArrayMod;
}
bool GenericToNVVM::runOnModule(Module &M) {
// Create a clone of each global variable that has the default address space.
// The clone is created with the global address space specifier, and the pair
// of original global variable and its clone is placed in the GVMap for later
// use.
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E;) {
GlobalVariable *GV = &*I++;
if (GV->getType()->getAddressSpace() == llvm::ADDRESS_SPACE_GENERIC &&
!llvm::isTexture(*GV) && !llvm::isSurface(*GV) &&
!llvm::isSampler(*GV) && !GV->getName().startswith("llvm.")) {
GlobalVariable *NewGV = new GlobalVariable(
M, GV->getValueType(), GV->isConstant(),
GV->getLinkage(),
GV->hasInitializer() ? GV->getInitializer() : nullptr,
"", GV, GV->getThreadLocalMode(), llvm::ADDRESS_SPACE_GLOBAL);
NewGV->copyAttributesFrom(GV);
GVMap[GV] = NewGV;
}
}
// Return immediately, if every global variable has a specific address space
// specifier.
if (GVMap.empty()) {
return false;
}
// Walk through the instructions in function defitinions, and replace any use
// of original global variables in GVMap with a use of the corresponding
// copies in GVMap. If necessary, promote constants to instructions.
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
if (I->isDeclaration()) {
continue;
}
IRBuilder<> Builder(I->getEntryBlock().getFirstNonPHIOrDbg());
for (Function::iterator BBI = I->begin(), BBE = I->end(); BBI != BBE;
++BBI) {
for (BasicBlock::iterator II = BBI->begin(), IE = BBI->end(); II != IE;
++II) {
for (unsigned i = 0, e = II->getNumOperands(); i < e; ++i) {
Value *Operand = II->getOperand(i);
if (isa<Constant>(Operand)) {
II->setOperand(
i, remapConstant(&M, &*I, cast<Constant>(Operand), Builder));
}
}
}
}
ConstantToValueMap.clear();
}
// Copy GVMap over to a standard value map.
ValueToValueMapTy VM;
for (auto I = GVMap.begin(), E = GVMap.end(); I != E; ++I)
VM[I->first] = I->second;
// Walk through the metadata section and update the debug information
// associated with the global variables in the default address space.
for (NamedMDNode &I : M.named_metadata()) {
remapNamedMDNode(VM, &I);
}
// Walk through the global variable initializers, and replace any use of
// original global variables in GVMap with a use of the corresponding copies
// in GVMap. The copies need to be bitcast to the original global variable
// types, as we cannot use cvta in global variable initializers.
for (GVMapTy::iterator I = GVMap.begin(), E = GVMap.end(); I != E;) {
GlobalVariable *GV = I->first;
GlobalVariable *NewGV = I->second;
// Remove GV from the map so that it can be RAUWed. Note that
// DenseMap::erase() won't invalidate any iterators but this one.
auto Next = std::next(I);
GVMap.erase(I);
I = Next;
Constant *BitCastNewGV = ConstantExpr::getPointerCast(NewGV, GV->getType());
// At this point, the remaining uses of GV should be found only in global
// variable initializers, as other uses have been already been removed
// while walking through the instructions in function definitions.
GV->replaceAllUsesWith(BitCastNewGV);
std::string Name = GV->getName();
GV->eraseFromParent();
NewGV->setName(Name);
}
assert(GVMap.empty() && "Expected it to be empty by now");
return true;
}
/// tryAggregating - When scanning forward over instructions, we look for
/// other loads or stores that could be aggregated with this one.
/// Returns the last instruction added (if one was added) since we might have
/// removed some loads or stores and that might invalidate an iterator.
Instruction *AggregateGlobalOpsOpt::tryAggregating(Instruction *StartInst, Value *StartPtr,
bool DebugThis) {
if (TD == 0) return 0;
Module* M = StartInst->getParent()->getParent()->getParent();
LLVMContext& Context = StartInst->getContext();
Type* int8Ty = Type::getInt8Ty(Context);
Type* sizeTy = Type::getInt64Ty(Context);
Type* globalInt8PtrTy = int8Ty->getPointerTo(globalSpace);
bool isLoad = isa<LoadInst>(StartInst);
bool isStore = isa<StoreInst>(StartInst);
Instruction *lastAddedInsn = NULL;
Instruction *LastLoadOrStore = NULL;
SmallVector<Instruction*, 8> toRemove;
// Okay, so we now have a single global load/store. Scan to find
// all subsequent stores of the same value to offset from the same pointer.
// Join these together into ranges, so we can decide whether contiguous blocks
// are stored.
MemOpRanges Ranges(*TD);
// Put the first store in since we want to preserve the order.
Ranges.addInst(0, StartInst);
BasicBlock::iterator BI = StartInst;
for (++BI; !isa<TerminatorInst>(BI); ++BI) {
if( isGlobalLoadOrStore(BI, globalSpace, isLoad, isStore) ) {
// OK!
} else {
// If the instruction is readnone, ignore it, otherwise bail out. We
// don't even allow readonly here because we don't want something like:
// A[1] = 2; strlen(A); A[2] = 2; -> memcpy(A, ...); strlen(A).
if (BI->mayWriteToMemory())
break;
if (isStore && BI->mayReadFromMemory())
break;
continue;
}
if ( isStore && isa<StoreInst>(BI) ) {
StoreInst *NextStore = cast<StoreInst>(BI);
// If this is a store, see if we can merge it in.
if (!NextStore->isSimple()) break;
// Check to see if this store is to a constant offset from the start ptr.
int64_t Offset;
if (!IsPointerOffset(StartPtr, NextStore->getPointerOperand(), Offset, *TD))
break;
Ranges.addStore(Offset, NextStore);
LastLoadOrStore = NextStore;
} else {
LoadInst *NextLoad = cast<LoadInst>(BI);
if (!NextLoad->isSimple()) break;
// Check to see if this load is to a constant offset from the start ptr.
int64_t Offset;
if (!IsPointerOffset(StartPtr, NextLoad->getPointerOperand(), Offset, *TD))
break;
Ranges.addLoad(Offset, NextLoad);
LastLoadOrStore = NextLoad;
}
}
// If we have no ranges, then we just had a single store with nothing that
// could be merged in. This is a very common case of course.
if (!Ranges.moreThanOneOp())
return 0;
// Divide the instructions between StartInst and LastLoadOrStore into
// addressing, memops, and uses of memops (uses of loads)
reorderAddressingMemopsUses(StartInst, LastLoadOrStore, DebugThis);
Instruction* insertBefore = StartInst;
IRBuilder<> builder(insertBefore);
// Now that we have full information about ranges, loop over the ranges and
// emit memcpy's for anything big enough to be worthwhile.
for (MemOpRanges::const_iterator I = Ranges.begin(), E = Ranges.end();
I != E; ++I) {
const MemOpRange &Range = *I;
Value* oldBaseI = NULL;
Value* newBaseI = NULL;
if (Range.TheStores.size() == 1) continue; // Don't bother if there's only one thing...
builder.SetInsertPoint(insertBefore);
// Otherwise, we do want to transform this! Create a new memcpy.
// Get the starting pointer of the block.
StartPtr = Range.StartPtr;
if( DebugThis ) {
errs() << "base is:";
StartPtr->dump();
}
// Determine alignment
unsigned Alignment = Range.Alignment;
if (Alignment == 0) {
Type *EltType =
cast<PointerType>(StartPtr->getType())->getElementType();
Alignment = TD->getABITypeAlignment(EltType);
}
Instruction *alloc = NULL;
Value *globalPtr = NULL;
// create temporary alloca space to communicate to/from.
alloc = makeAlloca(int8Ty, "agg.tmp", insertBefore,
Range.End-Range.Start, Alignment);
// Generate the old and new base pointers before we output
// anything else.
{
Type* iPtrTy = TD->getIntPtrType(alloc->getType());
Type* iNewBaseTy = TD->getIntPtrType(alloc->getType());
oldBaseI = builder.CreatePtrToInt(StartPtr, iPtrTy, "agg.tmp.oldb.i");
newBaseI = builder.CreatePtrToInt(alloc, iNewBaseTy, "agg.tmp.newb.i");
}
// If storing, do the stores we had into our alloca'd region.
if( isStore ) {
for (SmallVector<Instruction*, 16>::const_iterator
SI = Range.TheStores.begin(),
SE = Range.TheStores.end(); SI != SE; ++SI) {
StoreInst* oldStore = cast<StoreInst>(*SI);
if( DebugThis ) {
errs() << "have store in range:";
oldStore->dump();
}
Value* ptrToAlloc = rebasePointer(oldStore->getPointerOperand(),
StartPtr, alloc, "agg.tmp",
&builder, *TD, oldBaseI, newBaseI);
// Old load must not be volatile or atomic... or we shouldn't have put
// it in ranges
assert(!(oldStore->isVolatile() || oldStore->isAtomic()));
StoreInst* newStore =
builder.CreateStore(oldStore->getValueOperand(), ptrToAlloc);
newStore->setAlignment(oldStore->getAlignment());
newStore->takeName(oldStore);
}
}
// cast the pointer that was load/stored to i8 if necessary.
if( StartPtr->getType()->getPointerElementType() == int8Ty ) {
globalPtr = StartPtr;
} else {
globalPtr = builder.CreatePointerCast(StartPtr, globalInt8PtrTy, "agg.cast");
}
// Get a Constant* for the length.
Constant* len = ConstantInt::get(sizeTy, Range.End-Range.Start, false);
// Now add the memcpy instruction
unsigned addrSpaceDst,addrSpaceSrc;
addrSpaceDst = addrSpaceSrc = 0;
if( isStore ) addrSpaceDst = globalSpace;
if( isLoad ) addrSpaceSrc = globalSpace;
Type *types[3];
types[0] = PointerType::get(int8Ty, addrSpaceDst);
types[1] = PointerType::get(int8Ty, addrSpaceSrc);
types[2] = sizeTy;
Function *func = Intrinsic::getDeclaration(M, Intrinsic::memcpy, types);
Value* args[5]; // dst src len alignment isvolatile
if( isStore ) {
// it's a store (ie put)
args[0] = globalPtr;
args[1] = alloc;
} else {
// it's a load (ie get)
args[0] = alloc;
args[1] = globalPtr;
}
args[2] = len;
// alignment
args[3] = ConstantInt::get(Type::getInt32Ty(Context), 0, false);
// isvolatile
args[4] = ConstantInt::get(Type::getInt1Ty(Context), 0, false);
Instruction* aMemCpy = builder.CreateCall(func, args);
/*
DEBUG(dbgs() << "Replace ops:\n";
for (unsigned i = 0, e = Range.TheStores.size(); i != e; ++i)
dbgs() << *Range.TheStores[i] << '\n';
dbgs() << "With: " << *AMemSet << '\n');
*/
if (!Range.TheStores.empty())
aMemCpy->setDebugLoc(Range.TheStores[0]->getDebugLoc());
lastAddedInsn = aMemCpy;
// If loading, load from the memcpy'd region
if( isLoad ) {
for (SmallVector<Instruction*, 16>::const_iterator
SI = Range.TheStores.begin(),
SE = Range.TheStores.end(); SI != SE; ++SI) {
LoadInst* oldLoad = cast<LoadInst>(*SI);
if( DebugThis ) {
errs() << "have load in range:";
oldLoad->dump();
}
Value* ptrToAlloc = rebasePointer(oldLoad->getPointerOperand(),
StartPtr, alloc, "agg.tmp",
&builder, *TD, oldBaseI, newBaseI);
// Old load must not be volatile or atomic... or we shouldn't have put
// it in ranges
assert(!(oldLoad->isVolatile() || oldLoad->isAtomic()));
LoadInst* newLoad = builder.CreateLoad(ptrToAlloc);
newLoad->setAlignment(oldLoad->getAlignment());
oldLoad->replaceAllUsesWith(newLoad);
newLoad->takeName(oldLoad);
lastAddedInsn = newLoad;
}
}
// Save old loads/stores for removal
for (SmallVector<Instruction*, 16>::const_iterator
SI = Range.TheStores.begin(),
SE = Range.TheStores.end(); SI != SE; ++SI) {
Instruction* insn = *SI;
toRemove.push_back(insn);
}
}
// Zap all the old loads/stores
for (SmallVector<Instruction*, 16>::const_iterator
SI = toRemove.begin(),
SE = toRemove.end(); SI != SE; ++SI) {
(*SI)->eraseFromParent();
}
return lastAddedInsn;
}
/// runOnFunction - Insert code to maintain the shadow stack.
bool ShadowStackGC::performCustomLowering(Function &F) {
LLVMContext &Context = F.getContext();
// Find calls to llvm.gcroot.
CollectRoots(F);
// If there are no roots in this function, then there is no need to add a
// stack map entry for it.
if (Roots.empty())
return false;
// Build the constant map and figure the type of the shadow stack entry.
Value *FrameMap = GetFrameMap(F);
Type *ConcreteStackEntryTy = GetConcreteStackEntryType(F);
// Build the shadow stack entry at the very start of the function.
BasicBlock::iterator IP = F.getEntryBlock().begin();
IRBuilder<> AtEntry(IP->getParent(), IP);
Instruction *StackEntry = AtEntry.CreateAlloca(ConcreteStackEntryTy, 0,
"gc_frame");
while (isa<AllocaInst>(IP)) ++IP;
AtEntry.SetInsertPoint(IP->getParent(), IP);
// Initialize the map pointer and load the current head of the shadow stack.
Instruction *CurrentHead = AtEntry.CreateLoad(Head, "gc_currhead");
Instruction *EntryMapPtr = CreateGEP(Context, AtEntry, StackEntry,
0,1,"gc_frame.map");
AtEntry.CreateStore(FrameMap, EntryMapPtr);
// After all the allocas...
for (unsigned I = 0, E = Roots.size(); I != E; ++I) {
// For each root, find the corresponding slot in the aggregate...
Value *SlotPtr = CreateGEP(Context, AtEntry, StackEntry, 1 + I, "gc_root");
// And use it in lieu of the alloca.
AllocaInst *OriginalAlloca = Roots[I].second;
SlotPtr->takeName(OriginalAlloca);
OriginalAlloca->replaceAllUsesWith(SlotPtr);
}
// Move past the original stores inserted by GCStrategy::InitRoots. This isn't
// really necessary (the collector would never see the intermediate state at
// runtime), but it's nicer not to push the half-initialized entry onto the
// shadow stack.
while (isa<StoreInst>(IP)) ++IP;
AtEntry.SetInsertPoint(IP->getParent(), IP);
// Push the entry onto the shadow stack.
Instruction *EntryNextPtr = CreateGEP(Context, AtEntry,
StackEntry,0,0,"gc_frame.next");
Instruction *NewHeadVal = CreateGEP(Context, AtEntry,
StackEntry, 0, "gc_newhead");
AtEntry.CreateStore(CurrentHead, EntryNextPtr);
AtEntry.CreateStore(NewHeadVal, Head);
// For each instruction that escapes...
EscapeEnumerator EE(F, "gc_cleanup");
while (IRBuilder<> *AtExit = EE.Next()) {
// Pop the entry from the shadow stack. Don't reuse CurrentHead from
// AtEntry, since that would make the value live for the entire function.
Instruction *EntryNextPtr2 = CreateGEP(Context, *AtExit, StackEntry, 0, 0,
"gc_frame.next");
Value *SavedHead = AtExit->CreateLoad(EntryNextPtr2, "gc_savedhead");
AtExit->CreateStore(SavedHead, Head);
}
// Delete the original allocas (which are no longer used) and the intrinsic
// calls (which are no longer valid). Doing this last avoids invalidating
// iterators.
for (unsigned I = 0, E = Roots.size(); I != E; ++I) {
Roots[I].first->eraseFromParent();
Roots[I].second->eraseFromParent();
}
Roots.clear();
return true;
}
Instruction *InstCombiner::visitStoreInst(StoreInst &SI) {
Value *Val = SI.getOperand(0);
Value *Ptr = SI.getOperand(1);
// If the RHS is an alloca with a single use, zapify the store, making the
// alloca dead.
// If the RHS is an alloca with a two uses, the other one being a
// llvm.dbg.declare, zapify the store and the declare, making the
// alloca dead. We must do this to prevent declares from affecting
// codegen.
if (!SI.isVolatile()) {
if (Ptr->hasOneUse()) {
if (isa<AllocaInst>(Ptr))
return EraseInstFromFunction(SI);
if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr)) {
if (isa<AllocaInst>(GEP->getOperand(0))) {
if (GEP->getOperand(0)->hasOneUse())
return EraseInstFromFunction(SI);
if (DbgDeclareInst *DI = hasOneUsePlusDeclare(GEP->getOperand(0))) {
EraseInstFromFunction(*DI);
return EraseInstFromFunction(SI);
}
}
}
}
if (DbgDeclareInst *DI = hasOneUsePlusDeclare(Ptr)) {
EraseInstFromFunction(*DI);
return EraseInstFromFunction(SI);
}
}
// Attempt to improve the alignment.
if (TD) {
unsigned KnownAlign =
GetOrEnforceKnownAlignment(Ptr, TD->getPrefTypeAlignment(Val->getType()));
unsigned StoreAlign = SI.getAlignment();
unsigned EffectiveStoreAlign = StoreAlign != 0 ? StoreAlign :
TD->getABITypeAlignment(Val->getType());
if (KnownAlign > EffectiveStoreAlign)
SI.setAlignment(KnownAlign);
else if (StoreAlign == 0)
SI.setAlignment(EffectiveStoreAlign);
}
// Do really simple DSE, to catch cases where there are several consecutive
// stores to the same location, separated by a few arithmetic operations. This
// situation often occurs with bitfield accesses.
BasicBlock::iterator BBI = &SI;
for (unsigned ScanInsts = 6; BBI != SI.getParent()->begin() && ScanInsts;
--ScanInsts) {
--BBI;
// Don't count debug info directives, lest they affect codegen,
// and we skip pointer-to-pointer bitcasts, which are NOPs.
if (isa<DbgInfoIntrinsic>(BBI) ||
(isa<BitCastInst>(BBI) && BBI->getType()->isPointerTy())) {
ScanInsts++;
continue;
}
if (StoreInst *PrevSI = dyn_cast<StoreInst>(BBI)) {
// Prev store isn't volatile, and stores to the same location?
if (!PrevSI->isVolatile() &&equivalentAddressValues(PrevSI->getOperand(1),
SI.getOperand(1))) {
++NumDeadStore;
++BBI;
EraseInstFromFunction(*PrevSI);
continue;
}
break;
}
// If this is a load, we have to stop. However, if the loaded value is from
// the pointer we're loading and is producing the pointer we're storing,
// then *this* store is dead (X = load P; store X -> P).
if (LoadInst *LI = dyn_cast<LoadInst>(BBI)) {
if (LI == Val && equivalentAddressValues(LI->getOperand(0), Ptr) &&
!SI.isVolatile())
return EraseInstFromFunction(SI);
// Otherwise, this is a load from some other location. Stores before it
// may not be dead.
break;
}
// Don't skip over loads or things that can modify memory.
if (BBI->mayWriteToMemory() || BBI->mayReadFromMemory())
break;
}
if (SI.isVolatile()) return 0; // Don't hack volatile stores.
// store X, null -> turns into 'unreachable' in SimplifyCFG
if (isa<ConstantPointerNull>(Ptr) && SI.getPointerAddressSpace() == 0) {
if (!isa<UndefValue>(Val)) {
SI.setOperand(0, UndefValue::get(Val->getType()));
if (Instruction *U = dyn_cast<Instruction>(Val))
Worklist.Add(U); // Dropped a use.
}
return 0; // Do not modify these!
}
// store undef, Ptr -> noop
if (isa<UndefValue>(Val))
return EraseInstFromFunction(SI);
// If the pointer destination is a cast, see if we can fold the cast into the
// source instead.
if (isa<CastInst>(Ptr))
if (Instruction *Res = InstCombineStoreToCast(*this, SI))
return Res;
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
if (CE->isCast())
if (Instruction *Res = InstCombineStoreToCast(*this, SI))
return Res;
// If this store is the last instruction in the basic block (possibly
// excepting debug info instructions), and if the block ends with an
// unconditional branch, try to move it to the successor block.
BBI = &SI;
do {
++BBI;
} while (isa<DbgInfoIntrinsic>(BBI) ||
(isa<BitCastInst>(BBI) && BBI->getType()->isPointerTy()));
if (BranchInst *BI = dyn_cast<BranchInst>(BBI))
if (BI->isUnconditional())
if (SimplifyStoreAtEndOfBlock(SI))
return 0; // xform done!
return 0;
}
void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
bool UseCalls) {
// Don't insert coverage for unreachable blocks: we will never call
// __sanitizer_cov() for them, so counting them in
// NumberOfInstrumentedBlocks() might complicate calculation of code coverage
// percentage. Also, unreachable instructions frequently have no debug
// locations.
if (isa<UnreachableInst>(BB.getTerminator()))
return;
BasicBlock::iterator IP = BB.getFirstInsertionPt();
bool IsEntryBB = &BB == &F.getEntryBlock();
DebugLoc EntryLoc;
if (IsEntryBB) {
if (auto SP = getDISubprogram(&F))
EntryLoc = DebugLoc::get(SP->getScopeLine(), 0, SP);
// Keep static allocas and llvm.localescape calls in the entry block. Even
// if we aren't splitting the block, it's nice for allocas to be before
// calls.
IP = PrepareToSplitEntryBlock(BB, IP);
} else {
EntryLoc = IP->getDebugLoc();
}
IRBuilder<> IRB(&*IP);
IRB.SetCurrentDebugLocation(EntryLoc);
Value *GuardP = IRB.CreateAdd(
IRB.CreatePointerCast(GuardArray, IntptrTy),
ConstantInt::get(IntptrTy, (1 + NumberOfInstrumentedBlocks()) * 4));
Type *Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty());
GuardP = IRB.CreateIntToPtr(GuardP, Int32PtrTy);
if (Options.TracePC) {
IRB.CreateCall(SanCovTracePC);
} else if (Options.TraceBB) {
IRB.CreateCall(IsEntryBB ? SanCovTraceEnter : SanCovTraceBB, GuardP);
} else if (UseCalls) {
IRB.CreateCall(SanCovWithCheckFunction, GuardP);
} else {
LoadInst *Load = IRB.CreateLoad(GuardP);
Load->setAtomic(Monotonic);
Load->setAlignment(4);
SetNoSanitizeMetadata(Load);
Value *Cmp = IRB.CreateICmpSGE(Constant::getNullValue(Load->getType()), Load);
Instruction *Ins = SplitBlockAndInsertIfThen(
Cmp, &*IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
IRB.SetInsertPoint(Ins);
IRB.SetCurrentDebugLocation(EntryLoc);
// __sanitizer_cov gets the PC of the instruction using GET_CALLER_PC.
IRB.CreateCall(SanCovFunction, GuardP);
IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge.
}
if (Options.Use8bitCounters) {
IRB.SetInsertPoint(&*IP);
Value *P = IRB.CreateAdd(
IRB.CreatePointerCast(EightBitCounterArray, IntptrTy),
ConstantInt::get(IntptrTy, NumberOfInstrumentedBlocks() - 1));
P = IRB.CreateIntToPtr(P, IRB.getInt8PtrTy());
LoadInst *LI = IRB.CreateLoad(P);
Value *Inc = IRB.CreateAdd(LI, ConstantInt::get(IRB.getInt8Ty(), 1));
StoreInst *SI = IRB.CreateStore(Inc, P);
SetNoSanitizeMetadata(LI);
SetNoSanitizeMetadata(SI);
}
}
/// SplitBlockPredecessors - This method transforms BB by introducing a new
/// basic block into the function, and moving some of the predecessors of BB to
/// be predecessors of the new block. The new predecessors are indicated by the
/// Preds array, which has NumPreds elements in it. The new block is given a
/// suffix of 'Suffix'.
///
/// This currently updates the LLVM IR, AliasAnalysis, DominatorTree,
/// DominanceFrontier, LoopInfo, and LCCSA but no other analyses.
/// In particular, it does not preserve LoopSimplify (because it's
/// complicated to handle the case where one of the edges being split
/// is an exit of a loop with other exits).
///
BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
BasicBlock *const *Preds,
unsigned NumPreds, const char *Suffix,
Pass *P) {
// Create new basic block, insert right before the original block.
BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), BB->getName()+Suffix,
BB->getParent(), BB);
// The new block unconditionally branches to the old block.
BranchInst *BI = BranchInst::Create(BB, NewBB);
LoopInfo *LI = P ? P->getAnalysisIfAvailable<LoopInfo>() : 0;
Loop *L = LI ? LI->getLoopFor(BB) : 0;
bool PreserveLCSSA = P->mustPreserveAnalysisID(LCSSAID);
// Move the edges from Preds to point to NewBB instead of BB.
// While here, if we need to preserve loop analyses, collect
// some information about how this split will affect loops.
bool HasLoopExit = false;
bool IsLoopEntry = !!L;
bool SplitMakesNewLoopHeader = false;
for (unsigned i = 0; i != NumPreds; ++i) {
// This is slightly more strict than necessary; the minimum requirement
// is that there be no more than one indirectbr branching to BB. And
// all BlockAddress uses would need to be updated.
assert(!isa<IndirectBrInst>(Preds[i]->getTerminator()) &&
"Cannot split an edge from an IndirectBrInst");
Preds[i]->getTerminator()->replaceUsesOfWith(BB, NewBB);
if (LI) {
// If we need to preserve LCSSA, determine if any of
// the preds is a loop exit.
if (PreserveLCSSA)
if (Loop *PL = LI->getLoopFor(Preds[i]))
if (!PL->contains(BB))
HasLoopExit = true;
// If we need to preserve LoopInfo, note whether any of the
// preds crosses an interesting loop boundary.
if (L) {
if (L->contains(Preds[i]))
IsLoopEntry = false;
else
SplitMakesNewLoopHeader = true;
}
}
}
// Update dominator tree and dominator frontier if available.
DominatorTree *DT = P ? P->getAnalysisIfAvailable<DominatorTree>() : 0;
if (DT)
DT->splitBlock(NewBB);
if (DominanceFrontier *DF = P ? P->getAnalysisIfAvailable<DominanceFrontier>():0)
DF->splitBlock(NewBB);
// Insert a new PHI node into NewBB for every PHI node in BB and that new PHI
// node becomes an incoming value for BB's phi node. However, if the Preds
// list is empty, we need to insert dummy entries into the PHI nodes in BB to
// account for the newly created predecessor.
if (NumPreds == 0) {
// Insert dummy values as the incoming value.
for (BasicBlock::iterator I = BB->begin(); isa<PHINode>(I); ++I)
cast<PHINode>(I)->addIncoming(UndefValue::get(I->getType()), NewBB);
return NewBB;
}
AliasAnalysis *AA = P ? P->getAnalysisIfAvailable<AliasAnalysis>() : 0;
if (L) {
if (IsLoopEntry) {
// Add the new block to the nearest enclosing loop (and not an
// adjacent loop). To find this, examine each of the predecessors and
// determine which loops enclose them, and select the most-nested loop
// which contains the loop containing the block being split.
Loop *InnermostPredLoop = 0;
for (unsigned i = 0; i != NumPreds; ++i)
if (Loop *PredLoop = LI->getLoopFor(Preds[i])) {
// Seek a loop which actually contains the block being split (to
// avoid adjacent loops).
while (PredLoop && !PredLoop->contains(BB))
PredLoop = PredLoop->getParentLoop();
// Select the most-nested of these loops which contains the block.
if (PredLoop &&
PredLoop->contains(BB) &&
(!InnermostPredLoop ||
InnermostPredLoop->getLoopDepth() < PredLoop->getLoopDepth()))
InnermostPredLoop = PredLoop;
}
if (InnermostPredLoop)
InnermostPredLoop->addBasicBlockToLoop(NewBB, LI->getBase());
} else {
L->addBasicBlockToLoop(NewBB, LI->getBase());
if (SplitMakesNewLoopHeader)
L->moveToHeader(NewBB);
}
}
// Otherwise, create a new PHI node in NewBB for each PHI node in BB.
for (BasicBlock::iterator I = BB->begin(); isa<PHINode>(I); ) {
PHINode *PN = cast<PHINode>(I++);
// Check to see if all of the values coming in are the same. If so, we
// don't need to create a new PHI node, unless it's needed for LCSSA.
Value *InVal = 0;
if (!HasLoopExit) {
InVal = PN->getIncomingValueForBlock(Preds[0]);
for (unsigned i = 1; i != NumPreds; ++i)
if (InVal != PN->getIncomingValueForBlock(Preds[i])) {
InVal = 0;
break;
}
}
if (InVal) {
// If all incoming values for the new PHI would be the same, just don't
// make a new PHI. Instead, just remove the incoming values from the old
// PHI.
for (unsigned i = 0; i != NumPreds; ++i)
PN->removeIncomingValue(Preds[i], false);
} else {
// If the values coming into the block are not the same, we need a PHI.
// Create the new PHI node, insert it into NewBB at the end of the block
PHINode *NewPHI =
PHINode::Create(PN->getType(), PN->getName()+".ph", BI);
if (AA) AA->copyValue(PN, NewPHI);
// Move all of the PHI values for 'Preds' to the new PHI.
for (unsigned i = 0; i != NumPreds; ++i) {
Value *V = PN->removeIncomingValue(Preds[i], false);
NewPHI->addIncoming(V, Preds[i]);
}
InVal = NewPHI;
}
// Add an incoming value to the PHI node in the loop for the preheader
// edge.
PN->addIncoming(InVal, NewBB);
}
return NewBB;
}
/// RemoveBlockIfDead - If the specified block is dead, remove it, update loop
/// information, and remove any dead successors it has.
///
void LoopUnswitch::RemoveBlockIfDead(BasicBlock *BB,
std::vector<Instruction*> &Worklist,
Loop *L) {
if (pred_begin(BB) != pred_end(BB)) {
// This block isn't dead, since an edge to BB was just removed, see if there
// are any easy simplifications we can do now.
if (BasicBlock *Pred = BB->getSinglePredecessor()) {
// If it has one pred, fold phi nodes in BB.
while (isa<PHINode>(BB->begin()))
ReplaceUsesOfWith(BB->begin(),
cast<PHINode>(BB->begin())->getIncomingValue(0),
Worklist, L, LPM);
// If this is the header of a loop and the only pred is the latch, we now
// have an unreachable loop.
if (Loop *L = LI->getLoopFor(BB))
if (loopHeader == BB && L->contains(Pred)) {
// Remove the branch from the latch to the header block, this makes
// the header dead, which will make the latch dead (because the header
// dominates the latch).
LPM->deleteSimpleAnalysisValue(Pred->getTerminator(), L);
Pred->getTerminator()->eraseFromParent();
new UnreachableInst(BB->getContext(), Pred);
// The loop is now broken, remove it from LI.
RemoveLoopFromHierarchy(L);
// Reprocess the header, which now IS dead.
RemoveBlockIfDead(BB, Worklist, L);
return;
}
// If pred ends in a uncond branch, add uncond branch to worklist so that
// the two blocks will get merged.
if (BranchInst *BI = dyn_cast<BranchInst>(Pred->getTerminator()))
if (BI->isUnconditional())
Worklist.push_back(BI);
}
return;
}
DEBUG(dbgs() << "Nuking dead block: " << *BB);
// Remove the instructions in the basic block from the worklist.
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
RemoveFromWorklist(I, Worklist);
// Anything that uses the instructions in this basic block should have their
// uses replaced with undefs.
// If I is not void type then replaceAllUsesWith undef.
// This allows ValueHandlers and custom metadata to adjust itself.
if (!I->getType()->isVoidTy())
I->replaceAllUsesWith(UndefValue::get(I->getType()));
}
// If this is the edge to the header block for a loop, remove the loop and
// promote all subloops.
if (Loop *BBLoop = LI->getLoopFor(BB)) {
if (BBLoop->getLoopLatch() == BB) {
RemoveLoopFromHierarchy(BBLoop);
if (currentLoop == BBLoop) {
currentLoop = 0;
redoLoop = false;
}
}
}
// Remove the block from the loop info, which removes it from any loops it
// was in.
LI->removeBlock(BB);
// Remove phi node entries in successors for this block.
TerminatorInst *TI = BB->getTerminator();
SmallVector<BasicBlock*, 4> Succs;
for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i) {
Succs.push_back(TI->getSuccessor(i));
TI->getSuccessor(i)->removePredecessor(BB);
}
// Unique the successors, remove anything with multiple uses.
array_pod_sort(Succs.begin(), Succs.end());
Succs.erase(std::unique(Succs.begin(), Succs.end()), Succs.end());
// Remove the basic block, including all of the instructions contained in it.
LPM->deleteSimpleAnalysisValue(BB, L);
BB->eraseFromParent();
// Remove successor blocks here that are not dead, so that we know we only
// have dead blocks in this list. Nondead blocks have a way of becoming dead,
// then getting removed before we revisit them, which is badness.
//
for (unsigned i = 0; i != Succs.size(); ++i)
if (pred_begin(Succs[i]) != pred_end(Succs[i])) {
// One exception is loop headers. If this block was the preheader for a
// loop, then we DO want to visit the loop so the loop gets deleted.
// We know that if the successor is a loop header, that this loop had to
// be the preheader: the case where this was the latch block was handled
// above and headers can only have two predecessors.
if (!LI->isLoopHeader(Succs[i])) {
Succs.erase(Succs.begin()+i);
--i;
}
}
for (unsigned i = 0, e = Succs.size(); i != e; ++i)
RemoveBlockIfDead(Succs[i], Worklist, L);
}
/// Determine whether the instructions in this range may be safely and cheaply
/// speculated. This is not an important enough situation to develop complex
/// heuristics. We handle a single arithmetic instruction along with any type
/// conversions.
static bool shouldSpeculateInstrs(BasicBlock::iterator Begin,
BasicBlock::iterator End, Loop *L) {
bool seenIncrement = false;
bool MultiExitLoop = false;
if (!L->getExitingBlock())
MultiExitLoop = true;
for (BasicBlock::iterator I = Begin; I != End; ++I) {
if (!isSafeToSpeculativelyExecute(I))
return false;
if (isa<DbgInfoIntrinsic>(I))
continue;
switch (I->getOpcode()) {
default:
return false;
case Instruction::GetElementPtr:
// GEPs are cheap if all indices are constant.
if (!cast<GEPOperator>(I)->hasAllConstantIndices())
return false;
// fall-thru to increment case
case Instruction::Add:
case Instruction::Sub:
case Instruction::And:
case Instruction::Or:
case Instruction::Xor:
case Instruction::Shl:
case Instruction::LShr:
case Instruction::AShr: {
Value *IVOpnd = !isa<Constant>(I->getOperand(0))
? I->getOperand(0)
: !isa<Constant>(I->getOperand(1))
? I->getOperand(1)
: nullptr;
if (!IVOpnd)
return false;
// If increment operand is used outside of the loop, this speculation
// could cause extra live range interference.
if (MultiExitLoop) {
for (User *UseI : IVOpnd->users()) {
auto *UserInst = cast<Instruction>(UseI);
if (!L->contains(UserInst))
return false;
}
}
if (seenIncrement)
return false;
seenIncrement = true;
break;
}
case Instruction::Trunc:
case Instruction::ZExt:
case Instruction::SExt:
// ignore type conversions
break;
}
}
return true;
}
/// IsTrivialUnswitchCondition - Check to see if this unswitch condition is
/// trivial: that is, that the condition controls whether or not the loop does
/// anything at all. If this is a trivial condition, unswitching produces no
/// code duplications (equivalently, it produces a simpler loop and a new empty
/// loop, which gets deleted).
///
/// If this is a trivial condition, return true, otherwise return false. When
/// returning true, this sets Cond and Val to the condition that controls the
/// trivial condition: when Cond dynamically equals Val, the loop is known to
/// exit. Finally, this sets LoopExit to the BB that the loop exits to when
/// Cond == Val.
///
bool LoopUnswitch::IsTrivialUnswitchCondition(Value *Cond, Constant **Val,
BasicBlock **LoopExit) {
BasicBlock *Header = currentLoop->getHeader();
TerminatorInst *HeaderTerm = Header->getTerminator();
LLVMContext &Context = Header->getContext();
BasicBlock *LoopExitBB = 0;
if (BranchInst *BI = dyn_cast<BranchInst>(HeaderTerm)) {
// If the header block doesn't end with a conditional branch on Cond, we
// can't handle it.
if (!BI->isConditional() || BI->getCondition() != Cond)
return false;
// Check to see if a successor of the branch is guaranteed to
// exit through a unique exit block without having any
// side-effects. If so, determine the value of Cond that causes it to do
// this.
if ((LoopExitBB = isTrivialLoopExitBlock(currentLoop,
BI->getSuccessor(0)))) {
if (Val) *Val = ConstantInt::getTrue(Context);
} else if ((LoopExitBB = isTrivialLoopExitBlock(currentLoop,
BI->getSuccessor(1)))) {
if (Val) *Val = ConstantInt::getFalse(Context);
}
} else if (SwitchInst *SI = dyn_cast<SwitchInst>(HeaderTerm)) {
// If this isn't a switch on Cond, we can't handle it.
if (SI->getCondition() != Cond) return false;
// Check to see if a successor of the switch is guaranteed to go to the
// latch block or exit through a one exit block without having any
// side-effects. If so, determine the value of Cond that causes it to do
// this.
// Note that we can't trivially unswitch on the default case or
// on already unswitched cases.
for (SwitchInst::CaseIt i = SI->case_begin(), e = SI->case_end();
i != e; ++i) {
BasicBlock* LoopExitCandidate;
if ((LoopExitCandidate = isTrivialLoopExitBlock(currentLoop,
i.getCaseSuccessor()))) {
// Okay, we found a trivial case, remember the value that is trivial.
ConstantInt* CaseVal = i.getCaseValue();
// Check that it was not unswitched before, since already unswitched
// trivial vals are looks trivial too.
if (BranchesInfo.isUnswitched(SI, CaseVal))
continue;
LoopExitBB = LoopExitCandidate;
if (Val) *Val = CaseVal;
break;
}
}
}
// If we didn't find a single unique LoopExit block, or if the loop exit block
// contains phi nodes, this isn't trivial.
if (!LoopExitBB || isa<PHINode>(LoopExitBB->begin()))
return false; // Can't handle this.
if (LoopExit) *LoopExit = LoopExitBB;
// We already know that nothing uses any scalar values defined inside of this
// loop. As such, we just have to check to see if this loop will execute any
// side-effecting instructions (e.g. stores, calls, volatile loads) in the
// part of the loop that the code *would* execute. We already checked the
// tail, check the header now.
for (BasicBlock::iterator I = Header->begin(), E = Header->end(); I != E; ++I)
if (I->mayHaveSideEffects())
return false;
return true;
}
Instruction *InstCombiner::visitStoreInst(StoreInst &SI) {
Value *Val = SI.getOperand(0);
Value *Ptr = SI.getOperand(1);
// Try to canonicalize the stored type.
if (combineStoreToValueType(*this, SI))
return EraseInstFromFunction(SI);
// Attempt to improve the alignment.
unsigned KnownAlign = getOrEnforceKnownAlignment(
Ptr, DL.getPrefTypeAlignment(Val->getType()), DL, &SI, AC, DT);
unsigned StoreAlign = SI.getAlignment();
unsigned EffectiveStoreAlign =
StoreAlign != 0 ? StoreAlign : DL.getABITypeAlignment(Val->getType());
if (KnownAlign > EffectiveStoreAlign)
SI.setAlignment(KnownAlign);
else if (StoreAlign == 0)
SI.setAlignment(EffectiveStoreAlign);
// Try to canonicalize the stored type.
if (unpackStoreToAggregate(*this, SI))
return EraseInstFromFunction(SI);
// Replace GEP indices if possible.
if (Instruction *NewGEPI = replaceGEPIdxWithZero(*this, Ptr, SI)) {
Worklist.Add(NewGEPI);
return &SI;
}
// Don't hack volatile/atomic stores.
// FIXME: Some bits are legal for atomic stores; needs refactoring.
if (!SI.isSimple()) return nullptr;
// If the RHS is an alloca with a single use, zapify the store, making the
// alloca dead.
if (Ptr->hasOneUse()) {
if (isa<AllocaInst>(Ptr))
return EraseInstFromFunction(SI);
if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr)) {
if (isa<AllocaInst>(GEP->getOperand(0))) {
if (GEP->getOperand(0)->hasOneUse())
return EraseInstFromFunction(SI);
}
}
}
// Do really simple DSE, to catch cases where there are several consecutive
// stores to the same location, separated by a few arithmetic operations. This
// situation often occurs with bitfield accesses.
BasicBlock::iterator BBI = &SI;
for (unsigned ScanInsts = 6; BBI != SI.getParent()->begin() && ScanInsts;
--ScanInsts) {
--BBI;
// Don't count debug info directives, lest they affect codegen,
// and we skip pointer-to-pointer bitcasts, which are NOPs.
if (isa<DbgInfoIntrinsic>(BBI) ||
(isa<BitCastInst>(BBI) && BBI->getType()->isPointerTy())) {
ScanInsts++;
continue;
}
if (StoreInst *PrevSI = dyn_cast<StoreInst>(BBI)) {
// Prev store isn't volatile, and stores to the same location?
if (PrevSI->isSimple() && equivalentAddressValues(PrevSI->getOperand(1),
SI.getOperand(1))) {
++NumDeadStore;
++BBI;
EraseInstFromFunction(*PrevSI);
continue;
}
break;
}
// If this is a load, we have to stop. However, if the loaded value is from
// the pointer we're loading and is producing the pointer we're storing,
// then *this* store is dead (X = load P; store X -> P).
if (LoadInst *LI = dyn_cast<LoadInst>(BBI)) {
if (LI == Val && equivalentAddressValues(LI->getOperand(0), Ptr) &&
LI->isSimple())
return EraseInstFromFunction(SI);
// Otherwise, this is a load from some other location. Stores before it
// may not be dead.
break;
}
// Don't skip over loads or things that can modify memory.
if (BBI->mayWriteToMemory() || BBI->mayReadFromMemory())
break;
}
// store X, null -> turns into 'unreachable' in SimplifyCFG
if (isa<ConstantPointerNull>(Ptr) && SI.getPointerAddressSpace() == 0) {
if (!isa<UndefValue>(Val)) {
SI.setOperand(0, UndefValue::get(Val->getType()));
if (Instruction *U = dyn_cast<Instruction>(Val))
Worklist.Add(U); // Dropped a use.
}
return nullptr; // Do not modify these!
}
// store undef, Ptr -> noop
if (isa<UndefValue>(Val))
return EraseInstFromFunction(SI);
// If this store is the last instruction in the basic block (possibly
// excepting debug info instructions), and if the block ends with an
// unconditional branch, try to move it to the successor block.
BBI = &SI;
do {
++BBI;
} while (isa<DbgInfoIntrinsic>(BBI) ||
(isa<BitCastInst>(BBI) && BBI->getType()->isPointerTy()));
if (BranchInst *BI = dyn_cast<BranchInst>(BBI))
if (BI->isUnconditional())
if (SimplifyStoreAtEndOfBlock(SI))
return nullptr; // xform done!
return nullptr;
}
bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) {
for (BasicBlock::iterator J = BB->begin(), JE = BB->end();
J != JE; ++J) {
if (CallInst *CI = dyn_cast<CallInst>(J)) {
if (InlineAsm *IA = dyn_cast<InlineAsm>(CI->getCalledValue())) {
// Inline ASM is okay, unless it clobbers the ctr register.
InlineAsm::ConstraintInfoVector CIV = IA->ParseConstraints();
for (unsigned i = 0, ie = CIV.size(); i < ie; ++i) {
InlineAsm::ConstraintInfo &C = CIV[i];
if (C.Type != InlineAsm::isInput)
for (unsigned j = 0, je = C.Codes.size(); j < je; ++j)
if (StringRef(C.Codes[j]).equals_lower("{ctr}"))
return true;
}
continue;
}
if (!TM)
return true;
const TargetLowering *TLI = TM->getTargetLowering();
if (Function *F = CI->getCalledFunction()) {
// Most intrinsics don't become function calls, but some might.
// sin, cos, exp and log are always calls.
unsigned Opcode;
if (F->getIntrinsicID() != Intrinsic::not_intrinsic) {
switch (F->getIntrinsicID()) {
default: continue;
// VisualStudio defines setjmp as _setjmp
#if defined(_MSC_VER) && defined(setjmp) && \
!defined(setjmp_undefined_for_msvc)
# pragma push_macro("setjmp")
# undef setjmp
# define setjmp_undefined_for_msvc
#endif
case Intrinsic::setjmp:
#if defined(_MSC_VER) && defined(setjmp_undefined_for_msvc)
// let's return it to _setjmp state
# pragma pop_macro("setjmp")
# undef setjmp_undefined_for_msvc
#endif
case Intrinsic::longjmp:
// Exclude eh_sjlj_setjmp; we don't need to exclude eh_sjlj_longjmp
// because, although it does clobber the counter register, the
// control can't then return to inside the loop unless there is also
// an eh_sjlj_setjmp.
case Intrinsic::eh_sjlj_setjmp:
case Intrinsic::memcpy:
case Intrinsic::memmove:
case Intrinsic::memset:
case Intrinsic::powi:
case Intrinsic::log:
case Intrinsic::log2:
case Intrinsic::log10:
case Intrinsic::exp:
case Intrinsic::exp2:
case Intrinsic::pow:
case Intrinsic::sin:
case Intrinsic::cos:
return true;
case Intrinsic::copysign:
if (CI->getArgOperand(0)->getType()->getScalarType()->
isPPC_FP128Ty())
return true;
else
continue; // ISD::FCOPYSIGN is never a library call.
case Intrinsic::sqrt: Opcode = ISD::FSQRT; break;
case Intrinsic::floor: Opcode = ISD::FFLOOR; break;
case Intrinsic::ceil: Opcode = ISD::FCEIL; break;
case Intrinsic::trunc: Opcode = ISD::FTRUNC; break;
case Intrinsic::rint: Opcode = ISD::FRINT; break;
case Intrinsic::nearbyint: Opcode = ISD::FNEARBYINT; break;
case Intrinsic::round: Opcode = ISD::FROUND; break;
}
}
// PowerPC does not use [US]DIVREM or other library calls for
// operations on regular types which are not otherwise library calls
// (i.e. soft float or atomics). If adapting for targets that do,
// additional care is required here.
LibFunc::Func Func;
if (!F->hasLocalLinkage() && F->hasName() && LibInfo &&
LibInfo->getLibFunc(F->getName(), Func) &&
LibInfo->hasOptimizedCodeGen(Func)) {
// Non-read-only functions are never treated as intrinsics.
if (!CI->onlyReadsMemory())
return true;
// Conversion happens only for FP calls.
if (!CI->getArgOperand(0)->getType()->isFloatingPointTy())
return true;
switch (Func) {
default: return true;
case LibFunc::copysign:
case LibFunc::copysignf:
continue; // ISD::FCOPYSIGN is never a library call.
case LibFunc::copysignl:
return true;
case LibFunc::fabs:
case LibFunc::fabsf:
case LibFunc::fabsl:
continue; // ISD::FABS is never a library call.
case LibFunc::sqrt:
case LibFunc::sqrtf:
case LibFunc::sqrtl:
Opcode = ISD::FSQRT; break;
case LibFunc::floor:
case LibFunc::floorf:
case LibFunc::floorl:
Opcode = ISD::FFLOOR; break;
case LibFunc::nearbyint:
case LibFunc::nearbyintf:
case LibFunc::nearbyintl:
Opcode = ISD::FNEARBYINT; break;
case LibFunc::ceil:
case LibFunc::ceilf:
case LibFunc::ceill:
Opcode = ISD::FCEIL; break;
case LibFunc::rint:
case LibFunc::rintf:
case LibFunc::rintl:
Opcode = ISD::FRINT; break;
case LibFunc::round:
case LibFunc::roundf:
case LibFunc::roundl:
Opcode = ISD::FROUND; break;
case LibFunc::trunc:
case LibFunc::truncf:
case LibFunc::truncl:
Opcode = ISD::FTRUNC; break;
}
MVT VTy =
TLI->getSimpleValueType(CI->getArgOperand(0)->getType(), true);
if (VTy == MVT::Other)
return true;
if (TLI->isOperationLegalOrCustom(Opcode, VTy))
continue;
else if (VTy.isVector() &&
TLI->isOperationLegalOrCustom(Opcode, VTy.getScalarType()))
continue;
return true;
}
}
return true;
} else if (isa<BinaryOperator>(J) &&
J->getType()->getScalarType()->isPPC_FP128Ty()) {
// Most operations on ppc_f128 values become calls.
return true;
} else if (isa<UIToFPInst>(J) || isa<SIToFPInst>(J) ||
isa<FPToUIInst>(J) || isa<FPToSIInst>(J)) {
CastInst *CI = cast<CastInst>(J);
if (CI->getSrcTy()->getScalarType()->isPPC_FP128Ty() ||
CI->getDestTy()->getScalarType()->isPPC_FP128Ty() ||
isLargeIntegerTy(TT.isArch32Bit(), CI->getSrcTy()->getScalarType()) ||
isLargeIntegerTy(TT.isArch32Bit(), CI->getDestTy()->getScalarType()))
return true;
} else if (isLargeIntegerTy(TT.isArch32Bit(),
J->getType()->getScalarType()) &&
(J->getOpcode() == Instruction::UDiv ||
J->getOpcode() == Instruction::SDiv ||
J->getOpcode() == Instruction::URem ||
J->getOpcode() == Instruction::SRem)) {
return true;
} else if (TT.isArch32Bit() &&
isLargeIntegerTy(false, J->getType()->getScalarType()) &&
(J->getOpcode() == Instruction::Shl ||
J->getOpcode() == Instruction::AShr ||
J->getOpcode() == Instruction::LShr)) {
// Only on PPC32, for 128-bit integers (specifically not 64-bit
// integers), these might be runtime calls.
return true;
} else if (isa<IndirectBrInst>(J) || isa<InvokeInst>(J)) {
// On PowerPC, indirect jumps use the counter register.
return true;
} else if (SwitchInst *SI = dyn_cast<SwitchInst>(J)) {
if (!TM)
return true;
const TargetLowering *TLI = TM->getTargetLowering();
if (TLI->supportJumpTables() &&
SI->getNumCases()+1 >= (unsigned) TLI->getMinimumJumpTableEntries())
return true;
}
}
return false;
}
string getOperandName(BasicBlock::iterator inst)
{
return (inst->getOperand(1))->getName().str();
}
void StatsTracker::computeReachableUncovered() {
KModule *km = executor.kmodule;
Module *m = km->module;
static bool init = true;
const InstructionInfoTable &infos = *km->infos;
StatisticManager &sm = *theStatisticManager;
if (init) {
init = false;
// Compute call targets. It would be nice to use alias information
// instead of assuming all indirect calls hit all escaping
// functions, eh?
for (Module::iterator fnIt = m->begin(), fn_ie = m->end();
fnIt != fn_ie; ++fnIt) {
for (Function::iterator bbIt = fnIt->begin(), bb_ie = fnIt->end();
bbIt != bb_ie; ++bbIt) {
for (BasicBlock::iterator it = bbIt->begin(), ie = bbIt->end();
it != ie; ++it) {
if (isa<CallInst>(it) || isa<InvokeInst>(it)) {
if (isa<InlineAsm>(it->getOperand(0))) {
// We can never call through here so assume no targets
// (which should be correct anyhow).
callTargets.insert(std::make_pair(it,
std::vector<Function*>()));
} else if (Function *target = getDirectCallTarget(it)) {
callTargets[it].push_back(target);
} else {
callTargets[it] =
std::vector<Function*>(km->escapingFunctions.begin(),
km->escapingFunctions.end());
}
}
}
}
}
// Compute function callers as reflexion of callTargets.
for (calltargets_ty::iterator it = callTargets.begin(),
ie = callTargets.end(); it != ie; ++it)
for (std::vector<Function*>::iterator fit = it->second.begin(),
fie = it->second.end(); fit != fie; ++fit)
functionCallers[*fit].push_back(it->first);
// Initialize minDistToReturn to shortest paths through
// functions. 0 is unreachable.
std::vector<Instruction *> instructions;
for (Module::iterator fnIt = m->begin(), fn_ie = m->end();
fnIt != fn_ie; ++fnIt) {
if (fnIt->isDeclaration()) {
if (fnIt->doesNotReturn()) {
functionShortestPath[fnIt] = 0;
} else {
functionShortestPath[fnIt] = 1; // whatever
}
continue;
} else {
functionShortestPath[fnIt] = 0;
}
KFunction *kf = km->functionMap[fnIt];
for (unsigned i = 0; i < kf->numInstructions; ++i) {
Instruction *inst = kf->instrPostOrder[i]->inst;
instructions.push_back(inst);
sm.setIndexedValue(stats::minDistToReturn,
kf->instrPostOrder[i]->info->id,
isa<ReturnInst>(inst));
}
}
// I'm so lazy it's not even worklisted.
bool changed;
do {
changed = false;
for (std::vector<Instruction*>::iterator it = instructions.begin(),
ie = instructions.end(); it != ie; ++it) {
Instruction *inst = *it;
unsigned bestThrough = 0;
if (isa<CallInst>(inst) || isa<InvokeInst>(inst)) {
std::vector<Function*> &targets = callTargets[inst];
for (std::vector<Function*>::iterator fnIt = targets.begin(),
ie = targets.end(); fnIt != ie; ++fnIt) {
uint64_t dist = functionShortestPath[*fnIt];
if (dist) {
dist = 1+dist; // count instruction itself
if (bestThrough==0 || dist<bestThrough)
bestThrough = dist;
}
}
} else {
bestThrough = 1;
}
if (bestThrough) {
unsigned id = infos.getInfo(*it).id;
uint64_t best, cur = best = sm.getIndexedValue(stats::minDistToReturn, id);
std::vector<Instruction*> succs = getSuccs(*it);
for (std::vector<Instruction*>::iterator it2 = succs.begin(),
ie = succs.end(); it2 != ie; ++it2) {
uint64_t dist = sm.getIndexedValue(stats::minDistToReturn,
infos.getInfo(*it2).id);
if (dist) {
uint64_t val = bestThrough + dist;
if (best==0 || val<best)
best = val;
}
}
if (best != cur) {
sm.setIndexedValue(stats::minDistToReturn, id, best);
changed = true;
// Update shortest path if this is the entry point.
Function *f = inst->getParent()->getParent();
if (inst==f->begin()->begin())
functionShortestPath[f] = best;
}
}
}
} while (changed);
}
// compute minDistToUncovered, 0 is unreachable
std::vector<Instruction *> instructions;
std::vector<unsigned> ids;
for (Module::iterator fnIt = m->begin(), fn_ie = m->end();
fnIt != fn_ie; ++fnIt) {
if (fnIt->isDeclaration())
continue;
KFunction *kf = km->functionMap[fnIt];
for (unsigned i = 0; i < kf->numInstructions; ++i) {
Instruction *inst = kf->instrPostOrder[i]->inst;
unsigned id = kf->instrPostOrder[i]->info->id;
instructions.push_back(inst);
ids.push_back(id);
sm.setIndexedValue(stats::minDistToGloballyUncovered,
id,
sm.getIndexedValue(stats::globallyUncoveredInstructions, id));
}
}
// I'm so lazy it's not even worklisted.
bool changed;
do {
changed = false;
for (unsigned i = 0; i < instructions.size(); ++i) {
Instruction *inst = instructions[i];
unsigned id = ids[i];
uint64_t best, cur = best = sm.getIndexedValue(stats::minDistToGloballyUncovered,
id);
unsigned bestThrough = 0;
if (isa<CallInst>(inst) || isa<InvokeInst>(inst)) {
std::vector<Function*> &targets = callTargets[inst];
for (std::vector<Function*>::iterator fnIt = targets.begin(),
ie = targets.end(); fnIt != ie; ++fnIt) {
uint64_t dist = functionShortestPath[*fnIt];
if (dist) {
dist = 1+dist; // count instruction itself
if (bestThrough==0 || dist<bestThrough)
bestThrough = dist;
}
if (!(*fnIt)->isDeclaration()) {
uint64_t calleeDist = sm.getIndexedValue(stats::minDistToGloballyUncovered,
infos.getFunctionInfo(*fnIt).id);
if (calleeDist) {
calleeDist = 1+calleeDist; // count instruction itself
if (best==0 || calleeDist<best)
best = calleeDist;
}
}
}
} else {
bestThrough = 1;
}
if (bestThrough) {
std::vector<Instruction*> succs = getSuccs(inst);
for (std::vector<Instruction*>::iterator it2 = succs.begin(),
ie = succs.end(); it2 != ie; ++it2) {
uint64_t dist = sm.getIndexedValue(stats::minDistToGloballyUncovered,
infos.getInfo(*it2).id);
if (dist) {
uint64_t val = bestThrough + dist;
if (best==0 || val<best)
best = val;
}
}
}
if (best != cur) {
sm.setIndexedValue(stats::minDistToGloballyUncovered,
infos.getInfo(inst).id,
best);
changed = true;
}
}
} while (changed);
for (std::set<ExecutionState*>::iterator it = executor.states.begin(),
ie = executor.states.end(); it != ie; ++it) {
ExecutionState *es = *it;
uint64_t currentFrameMinDist = 0;
for (ExecutionState::stack_ty::iterator sfIt = es->stack().begin(),
sf_ie = es->stack().end(); sfIt != sf_ie; ++sfIt) {
ExecutionState::stack_ty::iterator next = sfIt + 1;
KInstIterator kii;
if (next==es->stack().end()) {
kii = es->pc();
} else {
kii = next->caller;
++kii;
}
sfIt->minDistToUncoveredOnReturn = currentFrameMinDist;
currentFrameMinDist = computeMinDistToUncovered(kii, currentFrameMinDist);
}
}
LOG(INFO) << "Processed " << instructions.size() << " instructions in static analysis";
}
/// processModule - Process entire module and collect debug info.
void DebugInfoFinder::processModule(Module &M) {
if (NamedMDNode *CU_Nodes = M.getNamedMetadata("llvm.dbg.cu")) {
for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
DICompileUnit CU(CU_Nodes->getOperand(i));
addCompileUnit(CU);
if (CU.getVersion() > LLVMDebugVersion10) {
DIArray GVs = CU.getGlobalVariables();
for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i) {
DIGlobalVariable DIG(GVs.getElement(i));
if (addGlobalVariable(DIG))
processType(DIG.getType());
}
DIArray SPs = CU.getSubprograms();
for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
processSubprogram(DISubprogram(SPs.getElement(i)));
DIArray EnumTypes = CU.getEnumTypes();
for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
processType(DIType(EnumTypes.getElement(i)));
DIArray RetainedTypes = CU.getRetainedTypes();
for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i)
processType(DIType(RetainedTypes.getElement(i)));
return;
}
}
}
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
for (Function::iterator FI = (*I).begin(), FE = (*I).end(); FI != FE; ++FI)
for (BasicBlock::iterator BI = (*FI).begin(), BE = (*FI).end(); BI != BE;
++BI) {
if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(BI))
processDeclare(DDI);
DebugLoc Loc = BI->getDebugLoc();
if (Loc.isUnknown())
continue;
LLVMContext &Ctx = BI->getContext();
DIDescriptor Scope(Loc.getScope(Ctx));
if (Scope.isCompileUnit())
addCompileUnit(DICompileUnit(Scope));
else if (Scope.isSubprogram())
processSubprogram(DISubprogram(Scope));
else if (Scope.isLexicalBlockFile()) {
DILexicalBlockFile DBF = DILexicalBlockFile(Scope);
processLexicalBlock(DILexicalBlock(DBF.getScope()));
}
else if (Scope.isLexicalBlock())
processLexicalBlock(DILexicalBlock(Scope));
if (MDNode *IA = Loc.getInlinedAt(Ctx))
processLocation(DILocation(IA));
}
if (NamedMDNode *NMD = M.getNamedMetadata("llvm.dbg.gv")) {
for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
DIGlobalVariable DIG(cast<MDNode>(NMD->getOperand(i)));
if (addGlobalVariable(DIG)) {
if (DIG.getVersion() <= LLVMDebugVersion10)
addCompileUnit(DIG.getCompileUnit());
processType(DIG.getType());
}
}
}
if (NamedMDNode *NMD = M.getNamedMetadata("llvm.dbg.sp"))
for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
processSubprogram(DISubprogram(NMD->getOperand(i)));
}
bool CopyMinimizationPass::runOnFunction(Function& f)
{
CurrentFile::set(__FILE__);
bool changed = false ;
if (f.isDeclaration() || f.getDFFunction() == NULL)
{
return changed ;
}
std::vector<Node<DFBasicBlock*>*> graph;
//We need to start with an acyclic graph to do retiming on -
//the analyzeCopyPass conveniently provides a function that returns the
//blocks reachable by the sink. These are the same blocks that the
//detectLoopsPass goes through, so they should be acyclical.
std::map<DFBasicBlock*, bool> pipeBlocks = getPipelineBlocks(f);
std::map<DFBasicBlock*,Node<DFBasicBlock*>*> nodeMap;
//for each block in the DFG, create a Node for it.
//this means we need to provide a weight for the block,
//and we also want to save it in a map for later
for(std::map<DFBasicBlock*, bool>::iterator BB = pipeBlocks.begin(); BB != pipeBlocks.end(); ++BB)
{
if( BB->second == false )
continue;
Node<DFBasicBlock*>* node = new Node<DFBasicBlock*>(BB->first, BB->first->getPipelineLevel(), BB->first->getDelay());
nodeMap[BB->first] = node;
graph.push_back(node);
}
//for each edge in the DFG, we need to create an Edge in the graph
for(std::map<DFBasicBlock*, bool>::iterator BB = pipeBlocks.begin(); BB != pipeBlocks.end(); ++BB)
{
if( BB->second == false )
continue;
CallInst* CI = dynamic_cast<CallInst*>(BB->first->getFirstNonPHI());
if( isROCCCFunctionCall(CI, ROCCCNames::LoadPrevious) )
continue;
for(pred_iterator pred = pred_begin(BB->first); pred != pred_end(BB->first); ++pred)
{
assert( (*pred)->getDFBasicBlock() );
std::map<DFBasicBlock*,Node<DFBasicBlock*>*>::iterator predNode = nodeMap.find((*pred)->getDFBasicBlock());
if( predNode != nodeMap.end() )
{
assert( nodeMap[BB->first] );
int weight = 0;
std::map<llvm::Value*,bool> valsUsed;
for(BasicBlock::iterator II = BB->first->begin(); II != BB->first->end(); ++II)
{
for(User::op_iterator OP = II->op_begin(); OP != II->op_end(); ++OP)
{
valsUsed[*OP] = true;
}
}
for(BasicBlock::iterator PII = (*pred)->begin(); PII != (*pred)->end(); ++PII)
{
for(std::map<llvm::Value*,bool>::iterator VUI = valsUsed.begin(); VUI != valsUsed.end(); ++VUI)
{
if( isDefinition(PII, VUI->first) )
{
weight += getSizeInBits(VUI->first);
}
}
}
predNode->second->flowsInto(*nodeMap[BB->first], weight);
}
else
{
INTERNAL_WARNING((*pred)->getName() << " was not found!\n");
}
}
}
int minimum_copies = getTotalCopiedBits(graph);
int num_original_copied_bits = minimum_copies;
std::vector< Node<DFBasicBlock*>* > min_graph = createCopyOfGraph(graph);
int iterationCount = 0;
int minIterationCount = 0;
LOG_MESSAGE2("Pipelining", "Register Minimization", "Bit registers needed to pipeline original graph, including both copies and pipeline boundaries: " << minimum_copies << ".\n");
while(maxTripCount(graph) < 10)
{
//cout << iterationCount << " - " << maxTripCount(graph) << "\n";
++iterationCount;
//display(graph);
Edge< Node<DFBasicBlock*> >* largest = selectEdgeWithLargestWeight(graph);
if( largest )
{
//LOG_MESSAGE2("Pipelining", "Register Minimization", "Edge with most bit registers needed: " << largest->source->getData() << " -> " << largest->sink->getData() << "\n");
tightenEdge(largest);
largest->tripCount++;
}
else
{
LOG_MESSAGE2("Pipelining", "Register Minimization", "Completely reduced.\n");
break;
}
//LOG_MESSAGE2("Pipelining", "Register Minimization", "Iteration " << iterationCount << " - total number of bits registers needed: " << getTotalCopiedBits(graph) << ".\n");
if( getTotalCopiedBits(graph) < minimum_copies )
{
min_graph = createCopyOfGraph(graph);
minimum_copies = getTotalCopiedBits(graph);
++minIterationCount;
}
}
LOG_MESSAGE2("Pipelining", "Register Minimization", "Tested " << iterationCount << " total iterations of minimizing; minimum number of bit registers needed, " << minimum_copies << ", was found after " << minIterationCount << " iterations.\n");
//display(min_graph);
if( minimum_copies != num_original_copied_bits )
{
for(std::vector<Node<DFBasicBlock*>*>::const_iterator GI = graph.begin(); GI != graph.end(); ++GI)
{
int level = (*GI)->getPosition();
(*GI)->getData()->setPipelineLevel(level);
(*GI)->getData()->setDataflowLevel(level);
std::stringstream ss;
ss << (*GI)->getData()->getName() << "_" << (*GI)->getData()->getPipelineLevel();
(*GI)->getData()->setName(ss.str());
}
changed = true;
}
return changed ;
}
/// When scanning forward over instructions, we look for some other patterns to
/// fold away. In particular, this looks for stores to neighboring locations of
/// memory. If it sees enough consecutive ones, it attempts to merge them
/// together into a memcpy/memset.
Instruction *MemCpyOpt::tryMergingIntoMemset(Instruction *StartInst,
Value *StartPtr, Value *ByteVal) {
const DataLayout &DL = StartInst->getModule()->getDataLayout();
// Okay, so we now have a single store that can be splatable. Scan to find
// all subsequent stores of the same value to offset from the same pointer.
// Join these together into ranges, so we can decide whether contiguous blocks
// are stored.
MemsetRanges Ranges(DL);
BasicBlock::iterator BI = StartInst;
for (++BI; !isa<TerminatorInst>(BI); ++BI) {
if (!isa<StoreInst>(BI) && !isa<MemSetInst>(BI)) {
// If the instruction is readnone, ignore it, otherwise bail out. We
// don't even allow readonly here because we don't want something like:
// A[1] = 2; strlen(A); A[2] = 2; -> memcpy(A, ...); strlen(A).
if (BI->mayWriteToMemory() || BI->mayReadFromMemory())
break;
continue;
}
if (StoreInst *NextStore = dyn_cast<StoreInst>(BI)) {
// If this is a store, see if we can merge it in.
if (!NextStore->isSimple()) break;
// Check to see if this stored value is of the same byte-splattable value.
if (ByteVal != isBytewiseValue(NextStore->getOperand(0)))
break;
// Check to see if this store is to a constant offset from the start ptr.
int64_t Offset;
if (!IsPointerOffset(StartPtr, NextStore->getPointerOperand(), Offset,
DL))
break;
Ranges.addStore(Offset, NextStore);
} else {
MemSetInst *MSI = cast<MemSetInst>(BI);
if (MSI->isVolatile() || ByteVal != MSI->getValue() ||
!isa<ConstantInt>(MSI->getLength()))
break;
// Check to see if this store is to a constant offset from the start ptr.
int64_t Offset;
if (!IsPointerOffset(StartPtr, MSI->getDest(), Offset, DL))
break;
Ranges.addMemSet(Offset, MSI);
}
}
// If we have no ranges, then we just had a single store with nothing that
// could be merged in. This is a very common case of course.
if (Ranges.empty())
return nullptr;
// If we had at least one store that could be merged in, add the starting
// store as well. We try to avoid this unless there is at least something
// interesting as a small compile-time optimization.
Ranges.addInst(0, StartInst);
// If we create any memsets, we put it right before the first instruction that
// isn't part of the memset block. This ensure that the memset is dominated
// by any addressing instruction needed by the start of the block.
IRBuilder<> Builder(BI);
// Now that we have full information about ranges, loop over the ranges and
// emit memset's for anything big enough to be worthwhile.
Instruction *AMemSet = nullptr;
for (MemsetRanges::const_iterator I = Ranges.begin(), E = Ranges.end();
I != E; ++I) {
const MemsetRange &Range = *I;
if (Range.TheStores.size() == 1) continue;
// If it is profitable to lower this range to memset, do so now.
if (!Range.isProfitableToUseMemset(DL))
continue;
// Otherwise, we do want to transform this! Create a new memset.
// Get the starting pointer of the block.
StartPtr = Range.StartPtr;
// Determine alignment
unsigned Alignment = Range.Alignment;
if (Alignment == 0) {
Type *EltType =
cast<PointerType>(StartPtr->getType())->getElementType();
Alignment = DL.getABITypeAlignment(EltType);
}
AMemSet =
Builder.CreateMemSet(StartPtr, ByteVal, Range.End-Range.Start, Alignment);
DEBUG(dbgs() << "Replace stores:\n";
for (unsigned i = 0, e = Range.TheStores.size(); i != e; ++i)
dbgs() << *Range.TheStores[i] << '\n';
dbgs() << "With: " << *AMemSet << '\n');
if (!Range.TheStores.empty())
AMemSet->setDebugLoc(Range.TheStores[0]->getDebugLoc());
// Zap all the stores.
for (SmallVectorImpl<Instruction *>::const_iterator
SI = Range.TheStores.begin(),
SE = Range.TheStores.end(); SI != SE; ++SI) {
MD->removeInstruction(*SI);
(*SI)->eraseFromParent();
}
++NumMemSetInfer;
}
return AMemSet;
}
/// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto,
/// except that it does some simple constant prop and DCE on the fly. The
/// effect of this is to copy significantly less code in cases where (for
/// example) a function call with constant arguments is inlined, and those
/// constant arguments cause a significant amount of code in the callee to be
/// dead. Since this doesn't produce an exact copy of the input, it can't be
/// used for things like CloneFunction or CloneModule.
void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc,
DenseMap<const Value*, Value*> &ValueMap,
SmallVectorImpl<ReturnInst*> &Returns,
const char *NameSuffix,
ClonedCodeInfo *CodeInfo,
const TargetData *TD,
Instruction *TheCall) {
assert(NameSuffix && "NameSuffix cannot be null!");
#ifndef NDEBUG
for (Function::const_arg_iterator II = OldFunc->arg_begin(),
E = OldFunc->arg_end(); II != E; ++II)
assert(ValueMap.count(II) && "No mapping from source argument specified!");
#endif
PruningFunctionCloner PFC(NewFunc, OldFunc, ValueMap, Returns,
NameSuffix, CodeInfo, TD);
// Clone the entry block, and anything recursively reachable from it.
std::vector<const BasicBlock*> CloneWorklist;
CloneWorklist.push_back(&OldFunc->getEntryBlock());
while (!CloneWorklist.empty()) {
const BasicBlock *BB = CloneWorklist.back();
CloneWorklist.pop_back();
PFC.CloneBlock(BB, CloneWorklist);
}
// Loop over all of the basic blocks in the old function. If the block was
// reachable, we have cloned it and the old block is now in the value map:
// insert it into the new function in the right order. If not, ignore it.
//
// Defer PHI resolution until rest of function is resolved.
SmallVector<const PHINode*, 16> PHIToResolve;
for (Function::const_iterator BI = OldFunc->begin(), BE = OldFunc->end();
BI != BE; ++BI) {
BasicBlock *NewBB = cast_or_null<BasicBlock>(ValueMap[BI]);
if (NewBB == 0) continue; // Dead block.
// Add the new block to the new function.
NewFunc->getBasicBlockList().push_back(NewBB);
// Loop over all of the instructions in the block, fixing up operand
// references as we go. This uses ValueMap to do all the hard work.
//
BasicBlock::iterator I = NewBB->begin();
LLVMContext &Context = OldFunc->getContext();
unsigned DbgKind = Context.getMetadata().getMDKind("dbg");
MDNode *TheCallMD = NULL;
SmallVector<Value *, 4> MDVs;
if (TheCall && TheCall->hasMetadata())
TheCallMD = Context.getMetadata().getMD(DbgKind, TheCall);
// Handle PHI nodes specially, as we have to remove references to dead
// blocks.
if (PHINode *PN = dyn_cast<PHINode>(I)) {
// Skip over all PHI nodes, remembering them for later.
BasicBlock::const_iterator OldI = BI->begin();
for (; (PN = dyn_cast<PHINode>(I)); ++I, ++OldI) {
if (I->hasMetadata()) {
if (TheCallMD) {
if (MDNode *IMD = Context.getMetadata().getMD(DbgKind, I)) {
MDNode *NewMD = UpdateInlinedAtInfo(IMD, TheCallMD, Context);
Context.getMetadata().addMD(DbgKind, NewMD, I);
}
} else {
// The cloned instruction has dbg info but the call instruction
// does not have dbg info. Remove dbg info from cloned instruction.
Context.getMetadata().removeMD(DbgKind, I);
}
}
PHIToResolve.push_back(cast<PHINode>(OldI));
}
}
// Otherwise, remap the rest of the instructions normally.
for (; I != NewBB->end(); ++I) {
if (I->hasMetadata()) {
if (TheCallMD) {
if (MDNode *IMD = Context.getMetadata().getMD(DbgKind, I)) {
MDNode *NewMD = UpdateInlinedAtInfo(IMD, TheCallMD, Context);
Context.getMetadata().addMD(DbgKind, NewMD, I);
}
} else {
// The cloned instruction has dbg info but the call instruction
// does not have dbg info. Remove dbg info from cloned instruction.
Context.getMetadata().removeMD(DbgKind, I);
}
}
RemapInstruction(I, ValueMap);
}
}
// Defer PHI resolution until rest of function is resolved, PHI resolution
// requires the CFG to be up-to-date.
for (unsigned phino = 0, e = PHIToResolve.size(); phino != e; ) {
const PHINode *OPN = PHIToResolve[phino];
unsigned NumPreds = OPN->getNumIncomingValues();
const BasicBlock *OldBB = OPN->getParent();
BasicBlock *NewBB = cast<BasicBlock>(ValueMap[OldBB]);
// Map operands for blocks that are live and remove operands for blocks
// that are dead.
for (; phino != PHIToResolve.size() &&
PHIToResolve[phino]->getParent() == OldBB; ++phino) {
OPN = PHIToResolve[phino];
PHINode *PN = cast<PHINode>(ValueMap[OPN]);
for (unsigned pred = 0, e = NumPreds; pred != e; ++pred) {
if (BasicBlock *MappedBlock =
cast_or_null<BasicBlock>(ValueMap[PN->getIncomingBlock(pred)])) {
Value *InVal = MapValue(PN->getIncomingValue(pred),
ValueMap);
assert(InVal && "Unknown input value?");
PN->setIncomingValue(pred, InVal);
PN->setIncomingBlock(pred, MappedBlock);
} else {
PN->removeIncomingValue(pred, false);
--pred, --e; // Revisit the next entry.
}
}
}
// The loop above has removed PHI entries for those blocks that are dead
// and has updated others. However, if a block is live (i.e. copied over)
// but its terminator has been changed to not go to this block, then our
// phi nodes will have invalid entries. Update the PHI nodes in this
// case.
PHINode *PN = cast<PHINode>(NewBB->begin());
NumPreds = std::distance(pred_begin(NewBB), pred_end(NewBB));
if (NumPreds != PN->getNumIncomingValues()) {
assert(NumPreds < PN->getNumIncomingValues());
// Count how many times each predecessor comes to this block.
std::map<BasicBlock*, unsigned> PredCount;
for (pred_iterator PI = pred_begin(NewBB), E = pred_end(NewBB);
PI != E; ++PI)
--PredCount[*PI];
// Figure out how many entries to remove from each PHI.
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
++PredCount[PN->getIncomingBlock(i)];
// At this point, the excess predecessor entries are positive in the
// map. Loop over all of the PHIs and remove excess predecessor
// entries.
BasicBlock::iterator I = NewBB->begin();
for (; (PN = dyn_cast<PHINode>(I)); ++I) {
for (std::map<BasicBlock*, unsigned>::iterator PCI =PredCount.begin(),
E = PredCount.end(); PCI != E; ++PCI) {
BasicBlock *Pred = PCI->first;
for (unsigned NumToRemove = PCI->second; NumToRemove; --NumToRemove)
PN->removeIncomingValue(Pred, false);
}
}
}
// If the loops above have made these phi nodes have 0 or 1 operand,
// replace them with undef or the input value. We must do this for
// correctness, because 0-operand phis are not valid.
PN = cast<PHINode>(NewBB->begin());
if (PN->getNumIncomingValues() == 0) {
BasicBlock::iterator I = NewBB->begin();
BasicBlock::const_iterator OldI = OldBB->begin();
while ((PN = dyn_cast<PHINode>(I++))) {
Value *NV = UndefValue::get(PN->getType());
PN->replaceAllUsesWith(NV);
assert(ValueMap[OldI] == PN && "ValueMap mismatch");
ValueMap[OldI] = NV;
PN->eraseFromParent();
++OldI;
}
}
// NOTE: We cannot eliminate single entry phi nodes here, because of
// ValueMap. Single entry phi nodes can have multiple ValueMap entries
// pointing at them. Thus, deleting one would require scanning the ValueMap
// to update any entries in it that would require that. This would be
// really slow.
}
// Now that the inlined function body has been fully constructed, go through
// and zap unconditional fall-through branches. This happen all the time when
// specializing code: code specialization turns conditional branches into
// uncond branches, and this code folds them.
Function::iterator I = cast<BasicBlock>(ValueMap[&OldFunc->getEntryBlock()]);
while (I != NewFunc->end()) {
BranchInst *BI = dyn_cast<BranchInst>(I->getTerminator());
if (!BI || BI->isConditional()) { ++I; continue; }
// Note that we can't eliminate uncond branches if the destination has
// single-entry PHI nodes. Eliminating the single-entry phi nodes would
// require scanning the ValueMap to update any entries that point to the phi
// node.
BasicBlock *Dest = BI->getSuccessor(0);
if (!Dest->getSinglePredecessor() || isa<PHINode>(Dest->begin())) {
++I; continue;
}
// We know all single-entry PHI nodes in the inlined function have been
// removed, so we just need to splice the blocks.
BI->eraseFromParent();
// Move all the instructions in the succ to the pred.
I->getInstList().splice(I->end(), Dest->getInstList());
// Make all PHI nodes that referred to Dest now refer to I as their source.
Dest->replaceAllUsesWith(I);
// Remove the dest block.
Dest->eraseFromParent();
// Do not increment I, iteratively merge all things this block branches to.
}
}
void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
bool UseCalls) {
BasicBlock::iterator IP = BB.getFirstInsertionPt(), BE = BB.end();
// Skip static allocas at the top of the entry block so they don't become
// dynamic when we split the block. If we used our optimized stack layout,
// then there will only be one alloca and it will come first.
for (; IP != BE; ++IP) {
AllocaInst *AI = dyn_cast<AllocaInst>(IP);
if (!AI || !AI->isStaticAlloca())
break;
}
bool IsEntryBB = &BB == &F.getEntryBlock();
DebugLoc EntryLoc;
if (IsEntryBB) {
if (auto SP = getDISubprogram(&F))
EntryLoc = DebugLoc::get(SP->getScopeLine(), 0, SP);
} else {
EntryLoc = IP->getDebugLoc();
}
IRBuilder<> IRB(IP);
IRB.SetCurrentDebugLocation(EntryLoc);
SmallVector<Value *, 1> Indices;
Value *GuardP = IRB.CreateAdd(
IRB.CreatePointerCast(GuardArray, IntptrTy),
ConstantInt::get(IntptrTy, (1 + NumberOfInstrumentedBlocks()) * 4));
Type *Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty());
GuardP = IRB.CreateIntToPtr(GuardP, Int32PtrTy);
if (UseCalls) {
IRB.CreateCall(SanCovWithCheckFunction, GuardP);
} else {
LoadInst *Load = IRB.CreateLoad(GuardP);
Load->setAtomic(Monotonic);
Load->setAlignment(4);
SetNoSanitizeMetadata(Load);
Value *Cmp = IRB.CreateICmpSGE(Constant::getNullValue(Load->getType()), Load);
Instruction *Ins = SplitBlockAndInsertIfThen(
Cmp, IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
IRB.SetInsertPoint(Ins);
IRB.SetCurrentDebugLocation(EntryLoc);
// __sanitizer_cov gets the PC of the instruction using GET_CALLER_PC.
IRB.CreateCall(SanCovFunction, GuardP);
IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge.
}
if (Options.Use8bitCounters) {
IRB.SetInsertPoint(IP);
Value *P = IRB.CreateAdd(
IRB.CreatePointerCast(EightBitCounterArray, IntptrTy),
ConstantInt::get(IntptrTy, NumberOfInstrumentedBlocks() - 1));
P = IRB.CreateIntToPtr(P, IRB.getInt8PtrTy());
LoadInst *LI = IRB.CreateLoad(P);
Value *Inc = IRB.CreateAdd(LI, ConstantInt::get(IRB.getInt8Ty(), 1));
StoreInst *SI = IRB.CreateStore(Inc, P);
SetNoSanitizeMetadata(LI);
SetNoSanitizeMetadata(SI);
}
if (Options.TraceBB) {
// Experimental support for tracing.
// Insert a callback with the same guard variable as used for coverage.
IRB.SetInsertPoint(IP);
IRB.CreateCall(IsEntryBB ? SanCovTraceEnter : SanCovTraceBB, GuardP);
}
}
/// isSafeToLoadUnconditionally - Return true if we know that executing a load
/// from this value cannot trap. If it is not obviously safe to load from the
/// specified pointer, we do a quick local scan of the basic block containing
/// ScanFrom, to determine if the address is already accessed.
bool llvm::isSafeToLoadUnconditionally(Value *V, Instruction *ScanFrom,
unsigned Align, const TargetData *TD) {
uint64_t ByteOffset = 0;
Value *Base = V;
if (TD)
Base = getUnderlyingObjectWithOffset(V, TD, ByteOffset);
const Type *BaseType = 0;
unsigned BaseAlign = 0;
if (const AllocaInst *AI = dyn_cast<AllocaInst>(Base)) {
// An alloca is safe to load from as load as it is suitably aligned.
BaseType = AI->getAllocatedType();
BaseAlign = AI->getAlignment();
} else if (const GlobalValue *GV = dyn_cast<GlobalValue>(Base)) {
// Global variables are safe to load from but their size cannot be
// guaranteed if they are overridden.
if (!isa<GlobalAlias>(GV) && !GV->mayBeOverridden()) {
BaseType = GV->getType()->getElementType();
BaseAlign = GV->getAlignment();
}
}
if (BaseType && BaseType->isSized()) {
if (TD && BaseAlign == 0)
BaseAlign = TD->getPrefTypeAlignment(BaseType);
if (Align <= BaseAlign) {
if (!TD)
return true; // Loading directly from an alloca or global is OK.
// Check if the load is within the bounds of the underlying object.
const PointerType *AddrTy = cast<PointerType>(V->getType());
uint64_t LoadSize = TD->getTypeStoreSize(AddrTy->getElementType());
if (ByteOffset + LoadSize <= TD->getTypeAllocSize(BaseType) &&
(Align == 0 || (ByteOffset % Align) == 0))
return true;
}
}
// Otherwise, be a little bit aggressive by scanning the local block where we
// want to check to see if the pointer is already being loaded or stored
// from/to. If so, the previous load or store would have already trapped,
// so there is no harm doing an extra load (also, CSE will later eliminate
// the load entirely).
BasicBlock::iterator BBI = ScanFrom, E = ScanFrom->getParent()->begin();
while (BBI != E) {
--BBI;
// If we see a free or a call which may write to memory (i.e. which might do
// a free) the pointer could be marked invalid.
if (isa<CallInst>(BBI) && BBI->mayWriteToMemory() &&
!isa<DbgInfoIntrinsic>(BBI))
return false;
if (LoadInst *LI = dyn_cast<LoadInst>(BBI)) {
if (AreEquivalentAddressValues(LI->getOperand(0), V)) return true;
} else if (StoreInst *SI = dyn_cast<StoreInst>(BBI)) {
if (AreEquivalentAddressValues(SI->getOperand(1), V)) return true;
}
}
return false;
}
/// Evaluate all instructions in block BB, returning true if successful, false
/// if we can't evaluate it. NewBB returns the next BB that control flows into,
/// or null upon return.
bool Evaluator::EvaluateBlock(BasicBlock::iterator CurInst,
BasicBlock *&NextBB) {
// This is the main evaluation loop.
while (1) {
Constant *InstResult = nullptr;
DEBUG(dbgs() << "Evaluating Instruction: " << *CurInst << "\n");
if (StoreInst *SI = dyn_cast<StoreInst>(CurInst)) {
if (!SI->isSimple()) {
DEBUG(dbgs() << "Store is not simple! Can not evaluate.\n");
return false; // no volatile/atomic accesses.
}
Constant *Ptr = getVal(SI->getOperand(1));
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
DEBUG(dbgs() << "Folding constant ptr expression: " << *Ptr);
Ptr = ConstantFoldConstantExpression(CE, DL, TLI);
DEBUG(dbgs() << "; To: " << *Ptr << "\n");
}
if (!isSimpleEnoughPointerToCommit(Ptr)) {
// If this is too complex for us to commit, reject it.
DEBUG(dbgs() << "Pointer is too complex for us to evaluate store.");
return false;
}
Constant *Val = getVal(SI->getOperand(0));
// If this might be too difficult for the backend to handle (e.g. the addr
// of one global variable divided by another) then we can't commit it.
if (!isSimpleEnoughValueToCommit(Val, SimpleConstants, DL)) {
DEBUG(dbgs() << "Store value is too complex to evaluate store. " << *Val
<< "\n");
return false;
}
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
if (CE->getOpcode() == Instruction::BitCast) {
DEBUG(dbgs() << "Attempting to resolve bitcast on constant ptr.\n");
// If we're evaluating a store through a bitcast, then we need
// to pull the bitcast off the pointer type and push it onto the
// stored value.
Ptr = CE->getOperand(0);
Type *NewTy = cast<PointerType>(Ptr->getType())->getElementType();
// In order to push the bitcast onto the stored value, a bitcast
// from NewTy to Val's type must be legal. If it's not, we can try
// introspecting NewTy to find a legal conversion.
while (!Val->getType()->canLosslesslyBitCastTo(NewTy)) {
// If NewTy is a struct, we can convert the pointer to the struct
// into a pointer to its first member.
// FIXME: This could be extended to support arrays as well.
if (StructType *STy = dyn_cast<StructType>(NewTy)) {
NewTy = STy->getTypeAtIndex(0U);
IntegerType *IdxTy = IntegerType::get(NewTy->getContext(), 32);
Constant *IdxZero = ConstantInt::get(IdxTy, 0, false);
Constant * const IdxList[] = {IdxZero, IdxZero};
Ptr = ConstantExpr::getGetElementPtr(nullptr, Ptr, IdxList);
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
Ptr = ConstantFoldConstantExpression(CE, DL, TLI);
// If we can't improve the situation by introspecting NewTy,
// we have to give up.
} else {
DEBUG(dbgs() << "Failed to bitcast constant ptr, can not "
"evaluate.\n");
return false;
}
}
// If we found compatible types, go ahead and push the bitcast
// onto the stored value.
Val = ConstantExpr::getBitCast(Val, NewTy);
DEBUG(dbgs() << "Evaluated bitcast: " << *Val << "\n");
}
}
MutatedMemory[Ptr] = Val;
} else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CurInst)) {
InstResult = ConstantExpr::get(BO->getOpcode(),
getVal(BO->getOperand(0)),
getVal(BO->getOperand(1)));
DEBUG(dbgs() << "Found a BinaryOperator! Simplifying: " << *InstResult
<< "\n");
} else if (CmpInst *CI = dyn_cast<CmpInst>(CurInst)) {
InstResult = ConstantExpr::getCompare(CI->getPredicate(),
getVal(CI->getOperand(0)),
getVal(CI->getOperand(1)));
DEBUG(dbgs() << "Found a CmpInst! Simplifying: " << *InstResult
<< "\n");
} else if (CastInst *CI = dyn_cast<CastInst>(CurInst)) {
InstResult = ConstantExpr::getCast(CI->getOpcode(),
getVal(CI->getOperand(0)),
CI->getType());
DEBUG(dbgs() << "Found a Cast! Simplifying: " << *InstResult
<< "\n");
} else if (SelectInst *SI = dyn_cast<SelectInst>(CurInst)) {
InstResult = ConstantExpr::getSelect(getVal(SI->getOperand(0)),
getVal(SI->getOperand(1)),
getVal(SI->getOperand(2)));
DEBUG(dbgs() << "Found a Select! Simplifying: " << *InstResult
<< "\n");
} else if (auto *EVI = dyn_cast<ExtractValueInst>(CurInst)) {
InstResult = ConstantExpr::getExtractValue(
getVal(EVI->getAggregateOperand()), EVI->getIndices());
DEBUG(dbgs() << "Found an ExtractValueInst! Simplifying: " << *InstResult
<< "\n");
} else if (auto *IVI = dyn_cast<InsertValueInst>(CurInst)) {
InstResult = ConstantExpr::getInsertValue(
getVal(IVI->getAggregateOperand()),
getVal(IVI->getInsertedValueOperand()), IVI->getIndices());
DEBUG(dbgs() << "Found an InsertValueInst! Simplifying: " << *InstResult
<< "\n");
} else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(CurInst)) {
Constant *P = getVal(GEP->getOperand(0));
SmallVector<Constant*, 8> GEPOps;
for (User::op_iterator i = GEP->op_begin() + 1, e = GEP->op_end();
i != e; ++i)
GEPOps.push_back(getVal(*i));
InstResult =
ConstantExpr::getGetElementPtr(GEP->getSourceElementType(), P, GEPOps,
cast<GEPOperator>(GEP)->isInBounds());
DEBUG(dbgs() << "Found a GEP! Simplifying: " << *InstResult
<< "\n");
} else if (LoadInst *LI = dyn_cast<LoadInst>(CurInst)) {
if (!LI->isSimple()) {
DEBUG(dbgs() << "Found a Load! Not a simple load, can not evaluate.\n");
return false; // no volatile/atomic accesses.
}
Constant *Ptr = getVal(LI->getOperand(0));
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
Ptr = ConstantFoldConstantExpression(CE, DL, TLI);
DEBUG(dbgs() << "Found a constant pointer expression, constant "
"folding: " << *Ptr << "\n");
}
InstResult = ComputeLoadResult(Ptr);
if (!InstResult) {
DEBUG(dbgs() << "Failed to compute load result. Can not evaluate load."
"\n");
return false; // Could not evaluate load.
}
DEBUG(dbgs() << "Evaluated load: " << *InstResult << "\n");
} else if (AllocaInst *AI = dyn_cast<AllocaInst>(CurInst)) {
if (AI->isArrayAllocation()) {
DEBUG(dbgs() << "Found an array alloca. Can not evaluate.\n");
return false; // Cannot handle array allocs.
}
Type *Ty = AI->getAllocatedType();
AllocaTmps.push_back(
make_unique<GlobalVariable>(Ty, false, GlobalValue::InternalLinkage,
UndefValue::get(Ty), AI->getName()));
InstResult = AllocaTmps.back().get();
DEBUG(dbgs() << "Found an alloca. Result: " << *InstResult << "\n");
} else if (isa<CallInst>(CurInst) || isa<InvokeInst>(CurInst)) {
CallSite CS(&*CurInst);
// Debug info can safely be ignored here.
if (isa<DbgInfoIntrinsic>(CS.getInstruction())) {
DEBUG(dbgs() << "Ignoring debug info.\n");
++CurInst;
continue;
}
// Cannot handle inline asm.
if (isa<InlineAsm>(CS.getCalledValue())) {
DEBUG(dbgs() << "Found inline asm, can not evaluate.\n");
return false;
}
if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction())) {
if (MemSetInst *MSI = dyn_cast<MemSetInst>(II)) {
if (MSI->isVolatile()) {
DEBUG(dbgs() << "Can not optimize a volatile memset " <<
"intrinsic.\n");
return false;
}
Constant *Ptr = getVal(MSI->getDest());
Constant *Val = getVal(MSI->getValue());
Constant *DestVal = ComputeLoadResult(getVal(Ptr));
if (Val->isNullValue() && DestVal && DestVal->isNullValue()) {
// This memset is a no-op.
DEBUG(dbgs() << "Ignoring no-op memset.\n");
++CurInst;
continue;
}
}
if (II->getIntrinsicID() == Intrinsic::lifetime_start ||
II->getIntrinsicID() == Intrinsic::lifetime_end) {
DEBUG(dbgs() << "Ignoring lifetime intrinsic.\n");
++CurInst;
continue;
}
if (II->getIntrinsicID() == Intrinsic::invariant_start) {
// We don't insert an entry into Values, as it doesn't have a
// meaningful return value.
if (!II->use_empty()) {
DEBUG(dbgs() << "Found unused invariant_start. Can't evaluate.\n");
return false;
}
ConstantInt *Size = cast<ConstantInt>(II->getArgOperand(0));
Value *PtrArg = getVal(II->getArgOperand(1));
Value *Ptr = PtrArg->stripPointerCasts();
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Ptr)) {
Type *ElemTy = GV->getValueType();
if (!Size->isAllOnesValue() &&
Size->getValue().getLimitedValue() >=
DL.getTypeStoreSize(ElemTy)) {
Invariants.insert(GV);
DEBUG(dbgs() << "Found a global var that is an invariant: " << *GV
<< "\n");
} else {
DEBUG(dbgs() << "Found a global var, but can not treat it as an "
"invariant.\n");
}
}
// Continue even if we do nothing.
++CurInst;
continue;
} else if (II->getIntrinsicID() == Intrinsic::assume) {
DEBUG(dbgs() << "Skipping assume intrinsic.\n");
++CurInst;
continue;
}
DEBUG(dbgs() << "Unknown intrinsic. Can not evaluate.\n");
return false;
}
// Resolve function pointers.
Function *Callee = dyn_cast<Function>(getVal(CS.getCalledValue()));
if (!Callee || Callee->isInterposable()) {
DEBUG(dbgs() << "Can not resolve function pointer.\n");
return false; // Cannot resolve.
}
SmallVector<Constant*, 8> Formals;
for (User::op_iterator i = CS.arg_begin(), e = CS.arg_end(); i != e; ++i)
Formals.push_back(getVal(*i));
if (Callee->isDeclaration()) {
// If this is a function we can constant fold, do it.
if (Constant *C = ConstantFoldCall(Callee, Formals, TLI)) {
InstResult = C;
DEBUG(dbgs() << "Constant folded function call. Result: " <<
*InstResult << "\n");
} else {
DEBUG(dbgs() << "Can not constant fold function call.\n");
return false;
}
} else {
if (Callee->getFunctionType()->isVarArg()) {
DEBUG(dbgs() << "Can not constant fold vararg function call.\n");
return false;
}
Constant *RetVal = nullptr;
// Execute the call, if successful, use the return value.
ValueStack.emplace_back();
if (!EvaluateFunction(Callee, RetVal, Formals)) {
DEBUG(dbgs() << "Failed to evaluate function.\n");
return false;
}
ValueStack.pop_back();
InstResult = RetVal;
if (InstResult) {
DEBUG(dbgs() << "Successfully evaluated function. Result: "
<< *InstResult << "\n\n");
} else {
DEBUG(dbgs() << "Successfully evaluated function. Result: 0\n\n");
}
}
} else if (isa<TerminatorInst>(CurInst)) {
DEBUG(dbgs() << "Found a terminator instruction.\n");
if (BranchInst *BI = dyn_cast<BranchInst>(CurInst)) {
if (BI->isUnconditional()) {
NextBB = BI->getSuccessor(0);
} else {
ConstantInt *Cond =
dyn_cast<ConstantInt>(getVal(BI->getCondition()));
if (!Cond) return false; // Cannot determine.
NextBB = BI->getSuccessor(!Cond->getZExtValue());
}
} else if (SwitchInst *SI = dyn_cast<SwitchInst>(CurInst)) {
ConstantInt *Val =
dyn_cast<ConstantInt>(getVal(SI->getCondition()));
if (!Val) return false; // Cannot determine.
NextBB = SI->findCaseValue(Val).getCaseSuccessor();
} else if (IndirectBrInst *IBI = dyn_cast<IndirectBrInst>(CurInst)) {
Value *Val = getVal(IBI->getAddress())->stripPointerCasts();
if (BlockAddress *BA = dyn_cast<BlockAddress>(Val))
NextBB = BA->getBasicBlock();
else
return false; // Cannot determine.
} else if (isa<ReturnInst>(CurInst)) {
NextBB = nullptr;
} else {
// invoke, unwind, resume, unreachable.
DEBUG(dbgs() << "Can not handle terminator.");
return false; // Cannot handle this terminator.
}
// We succeeded at evaluating this block!
DEBUG(dbgs() << "Successfully evaluated block.\n");
return true;
} else {
// Did not know how to evaluate this!
DEBUG(dbgs() << "Failed to evaluate block due to unhandled instruction."
"\n");
return false;
}
if (!CurInst->use_empty()) {
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(InstResult))
InstResult = ConstantFoldConstantExpression(CE, DL, TLI);
setVal(&*CurInst, InstResult);
}
// If we just processed an invoke, we finished evaluating the block.
if (InvokeInst *II = dyn_cast<InvokeInst>(CurInst)) {
NextBB = II->getNormalDest();
DEBUG(dbgs() << "Found an invoke instruction. Finished Block.\n\n");
return true;
}
// Advance program counter.
++CurInst;
}
}
void GNUstep::IMPCacher::SpeculativelyInline(Instruction *call, Function
*function) {
BasicBlock *beforeCallBB = call->getParent();
BasicBlock *callBB = SplitBlock(beforeCallBB, call, Owner);
BasicBlock *inlineBB = BasicBlock::Create(Context, "inline",
callBB->getParent());
BasicBlock::iterator iter = call;
iter++;
BasicBlock *afterCallBB = SplitBlock(iter->getParent(), iter, Owner);
removeTerminator(beforeCallBB);
// Put a branch before the call, testing whether the callee really is the
// function
IRBuilder<> B = IRBuilder<>(beforeCallBB);
Value *callee = isa<CallInst>(call) ? cast<CallInst>(call)->getCalledValue()
: cast<InvokeInst>(call)->getCalledValue();
const FunctionType *FTy = function->getFunctionType();
const FunctionType *calleeTy = cast<FunctionType>(
cast<PointerType>(callee->getType())->getElementType());
if (calleeTy != FTy) {
callee = B.CreateBitCast(callee, function->getType());
}
Value *isInlineValid = B.CreateICmpEQ(callee, function);
B.CreateCondBr(isInlineValid, inlineBB, callBB);
// In the inline BB, add a copy of the call, but this time calling the real
// version.
Instruction *inlineCall = call->clone();
Value *inlineResult= inlineCall;
inlineBB->getInstList().push_back(inlineCall);
B.SetInsertPoint(inlineBB);
if (calleeTy != FTy) {
for (unsigned i=0 ; i<FTy->getNumParams() ; i++) {
LLVMType *callType = calleeTy->getParamType(i);
LLVMType *argType = FTy->getParamType(i);
if (callType != argType) {
inlineCall->setOperand(i, new
BitCastInst(inlineCall->getOperand(i), argType, "", inlineCall));
}
}
if (FTy->getReturnType() != calleeTy->getReturnType()) {
if (FTy->getReturnType() == Type::getVoidTy(Context)) {
inlineResult = Constant::getNullValue(calleeTy->getReturnType());
} else {
inlineResult =
new BitCastInst(inlineCall, calleeTy->getReturnType(), "", inlineBB);
}
}
}
B.CreateBr(afterCallBB);
// Unify the return values
if (call->getType() != Type::getVoidTy(Context)) {
PHINode *phi = CreatePHI(call->getType(), 2, "", afterCallBB->begin());
call->replaceAllUsesWith(phi);
phi->addIncoming(call, callBB);
phi->addIncoming(inlineResult, inlineBB);
}
// Really do the real inlining
InlineFunctionInfo IFI(0, 0);
if (CallInst *c = dyn_cast<CallInst>(inlineCall)) {
c->setCalledFunction(function);
InlineFunction(c, IFI);
} else if (InvokeInst *c = dyn_cast<InvokeInst>(inlineCall)) {
c->setCalledFunction(function);
InlineFunction(c, IFI);
}
}
/// \brief Check if executing a load of this pointer value cannot trap.
///
/// If DT and ScanFrom are specified this method performs context-sensitive
/// analysis and returns true if it is safe to load immediately before ScanFrom.
///
/// If it is not obviously safe to load from the specified pointer, we do
/// a quick local scan of the basic block containing \c ScanFrom, to determine
/// if the address is already accessed.
///
/// This uses the pointee type to determine how many bytes need to be safe to
/// load from the pointer.
bool llvm::isSafeToLoadUnconditionally(Value *V, unsigned Align,
const DataLayout &DL,
Instruction *ScanFrom,
const DominatorTree *DT) {
// Zero alignment means that the load has the ABI alignment for the target
if (Align == 0)
Align = DL.getABITypeAlignment(V->getType()->getPointerElementType());
assert(isPowerOf2_32(Align));
// If DT is not specified we can't make context-sensitive query
const Instruction* CtxI = DT ? ScanFrom : nullptr;
if (isDereferenceableAndAlignedPointer(V, Align, DL, CtxI, DT))
return true;
int64_t ByteOffset = 0;
Value *Base = V;
Base = GetPointerBaseWithConstantOffset(V, ByteOffset, DL);
if (ByteOffset < 0) // out of bounds
return false;
Type *BaseType = nullptr;
unsigned BaseAlign = 0;
if (const AllocaInst *AI = dyn_cast<AllocaInst>(Base)) {
// An alloca is safe to load from as load as it is suitably aligned.
BaseType = AI->getAllocatedType();
BaseAlign = AI->getAlignment();
} else if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(Base)) {
// Global variables are not necessarily safe to load from if they are
// interposed arbitrarily. Their size may change or they may be weak and
// require a test to determine if they were in fact provided.
if (!GV->isInterposable()) {
BaseType = GV->getType()->getElementType();
BaseAlign = GV->getAlignment();
}
}
PointerType *AddrTy = cast<PointerType>(V->getType());
uint64_t LoadSize = DL.getTypeStoreSize(AddrTy->getElementType());
// If we found a base allocated type from either an alloca or global variable,
// try to see if we are definitively within the allocated region. We need to
// know the size of the base type and the loaded type to do anything in this
// case.
if (BaseType && BaseType->isSized()) {
if (BaseAlign == 0)
BaseAlign = DL.getPrefTypeAlignment(BaseType);
if (Align <= BaseAlign) {
// Check if the load is within the bounds of the underlying object.
if (ByteOffset + LoadSize <= DL.getTypeAllocSize(BaseType) &&
((ByteOffset % Align) == 0))
return true;
}
}
if (!ScanFrom)
return false;
// Otherwise, be a little bit aggressive by scanning the local block where we
// want to check to see if the pointer is already being loaded or stored
// from/to. If so, the previous load or store would have already trapped,
// so there is no harm doing an extra load (also, CSE will later eliminate
// the load entirely).
BasicBlock::iterator BBI = ScanFrom->getIterator(),
E = ScanFrom->getParent()->begin();
// We can at least always strip pointer casts even though we can't use the
// base here.
V = V->stripPointerCasts();
while (BBI != E) {
--BBI;
// If we see a free or a call which may write to memory (i.e. which might do
// a free) the pointer could be marked invalid.
if (isa<CallInst>(BBI) && BBI->mayWriteToMemory() &&
!isa<DbgInfoIntrinsic>(BBI))
return false;
Value *AccessedPtr;
unsigned AccessedAlign;
if (LoadInst *LI = dyn_cast<LoadInst>(BBI)) {
AccessedPtr = LI->getPointerOperand();
AccessedAlign = LI->getAlignment();
} else if (StoreInst *SI = dyn_cast<StoreInst>(BBI)) {
AccessedPtr = SI->getPointerOperand();
AccessedAlign = SI->getAlignment();
} else
continue;
Type *AccessedTy = AccessedPtr->getType()->getPointerElementType();
if (AccessedAlign == 0)
AccessedAlign = DL.getABITypeAlignment(AccessedTy);
if (AccessedAlign < Align)
continue;
// Handle trivial cases.
if (AccessedPtr == V)
return true;
if (AreEquivalentAddressValues(AccessedPtr->stripPointerCasts(), V) &&
LoadSize <= DL.getTypeStoreSize(AccessedTy))
return true;
}
return false;
}
void GNUstep::IMPCacher::CacheLookup(Instruction *lookup, Value *slot, Value
*version, bool isSuperMessage) {
// If this IMP is already cached, don't cache it again.
if (lookup->getMetadata(IMPCacheFlagKind)) {
return;
}
lookup->setMetadata(IMPCacheFlagKind, AlreadyCachedFlag);
bool isInvoke = false;
BasicBlock *beforeLookupBB = lookup->getParent();
BasicBlock *lookupBB = SplitBlock(beforeLookupBB, lookup, Owner);
BasicBlock *lookupFinishedBB = lookupBB;
BasicBlock *afterLookupBB;
if (InvokeInst *inv = dyn_cast<InvokeInst>(lookup)) {
afterLookupBB = inv->getNormalDest();
lookupFinishedBB =
BasicBlock::Create(Context, "done_lookup", lookupBB->getParent());
CGBuilder B(lookupFinishedBB);
B.CreateBr(afterLookupBB);
inv->setNormalDest(lookupFinishedBB);
isInvoke = true;
} else {
BasicBlock::iterator iter = lookup;
iter++;
afterLookupBB = SplitBlock(iter->getParent(), iter, Owner);
}
removeTerminator(beforeLookupBB);
CGBuilder B = CGBuilder(beforeLookupBB);
// Load the slot and check that neither it nor the version is 0.
Value *versionValue = B.CreateLoad(version);
Value *receiverPtr = lookup->getOperand(0);
Value *receiver = receiverPtr;
if (!isSuperMessage) {
receiver = B.CreateLoad(receiverPtr);
}
// For small objects, we skip the cache entirely.
// FIXME: Class messages are never to small objects...
bool is64Bit = llvm::Module::Pointer64 ==
B.GetInsertBlock()->getParent()->getParent()->getPointerSize();
LLVMType *intPtrTy = is64Bit ? Type::getInt64Ty(Context) :
Type::getInt32Ty(Context);
// Receiver as an integer
Value *receiverSmallObject = B.CreatePtrToInt(receiver, intPtrTy);
// Receiver is a small object...
receiverSmallObject =
B.CreateAnd(receiverSmallObject, is64Bit ? 7 : 1);
// Receiver is not a small object.
receiverSmallObject =
B.CreateICmpNE(receiverSmallObject, Constant::getNullValue(intPtrTy));
// Ideally, we'd call objc_msgSend() here, but for now just skip the cache
// lookup
Value *isCacheEmpty =
B.CreateICmpEQ(versionValue, Constant::getNullValue(IntTy));
Value *receiverNil =
B.CreateICmpEQ(receiver, Constant::getNullValue(receiver->getType()));
isCacheEmpty = B.CreateOr(isCacheEmpty, receiverNil);
isCacheEmpty = B.CreateOr(isCacheEmpty, receiverSmallObject);
BasicBlock *cacheLookupBB = BasicBlock::Create(Context, "cache_check",
lookupBB->getParent());
B.CreateCondBr(isCacheEmpty, lookupBB, cacheLookupBB);
// Check the cache node is current
B.SetInsertPoint(cacheLookupBB);
Value *slotValue = B.CreateLoad(slot, "slot_value");
Value *slotVersion = B.CreateStructGEP(slotValue, 3);
// Note: Volatile load because the slot version might have changed in
// another thread.
slotVersion = B.CreateLoad(slotVersion, true, "slot_version");
Value *slotCachedFor = B.CreateStructGEP(slotValue, 1);
slotCachedFor = B.CreateLoad(slotCachedFor, true, "slot_owner");
Value *cls = B.CreateLoad(B.CreateBitCast(receiver, IdTy));
Value *isVersionCorrect = B.CreateICmpEQ(slotVersion, versionValue);
Value *isOwnerCorrect = B.CreateICmpEQ(slotCachedFor, cls);
Value *isSlotValid = B.CreateAnd(isVersionCorrect, isOwnerCorrect);
// If this slot is still valid, skip the lookup.
B.CreateCondBr(isSlotValid, afterLookupBB, lookupBB);
// Perform the real lookup and cache the result
removeTerminator(lookupFinishedBB);
// Replace the looked up slot with the loaded one
B.SetInsertPoint(afterLookupBB, afterLookupBB->begin());
PHINode *newLookup = IRBuilderCreatePHI(&B, lookup->getType(), 3, "new_lookup");
// Not volatile, so a redundant load elimination pass can do some phi
// magic with this later.
lookup->replaceAllUsesWith(newLookup);
B.SetInsertPoint(lookupFinishedBB);
Value * newReceiver = receiver;
if (!isSuperMessage) {
newReceiver = B.CreateLoad(receiverPtr);
}
BasicBlock *storeCacheBB = BasicBlock::Create(Context, "cache_store",
lookupBB->getParent());
// Don't store the cached lookup if we are doing forwarding tricks.
// Also skip caching small object messages for now
Value *skipCacheWrite =
B.CreateOr(B.CreateICmpNE(receiver, newReceiver), receiverSmallObject);
skipCacheWrite = B.CreateOr(skipCacheWrite, receiverNil);
B.CreateCondBr(skipCacheWrite, afterLookupBB, storeCacheBB);
B.SetInsertPoint(storeCacheBB);
// Store it even if the version is 0, because we always check that the
// version is not 0 at the start and an occasional redundant store is
// probably better than a branch every time.
B.CreateStore(lookup, slot);
B.CreateStore(B.CreateLoad(B.CreateStructGEP(lookup, 3)), version);
cls = B.CreateLoad(B.CreateBitCast(receiver, IdTy));
B.CreateStore(cls, B.CreateStructGEP(lookup, 1));
B.CreateBr(afterLookupBB);
newLookup->addIncoming(lookup, lookupFinishedBB);
newLookup->addIncoming(slotValue, cacheLookupBB);
newLookup->addIncoming(lookup, storeCacheBB);
}
bool Substitution::substitute(Function *f) {
Function *tmp = f;
// Loop for the number of time we run the pass on the function
int times = ObfTimes;
do {
for (Function::iterator bb = tmp->begin(); bb != tmp->end(); ++bb) {
for (BasicBlock::iterator inst = bb->begin(); inst != bb->end(); ++inst) {
if (inst->isBinaryOp()) {
switch (inst->getOpcode()) {
case BinaryOperator::Add:
// case BinaryOperator::FAdd:
// Substitute with random add operation
(this->*funcAdd[llvm::cryptoutils->get_range(NUMBER_ADD_SUBST)])(
cast<BinaryOperator>(inst));
++Add;
break;
case BinaryOperator::Sub:
// case BinaryOperator::FSub:
// Substitute with random sub operation
(this->*funcSub[llvm::cryptoutils->get_range(NUMBER_SUB_SUBST)])(
cast<BinaryOperator>(inst));
++Sub;
break;
case BinaryOperator::Mul:
case BinaryOperator::FMul:
//++Mul;
break;
case BinaryOperator::UDiv:
case BinaryOperator::SDiv:
case BinaryOperator::FDiv:
//++Div;
break;
case BinaryOperator::URem:
case BinaryOperator::SRem:
case BinaryOperator::FRem:
//++Rem;
break;
case Instruction::Shl:
//++Shi;
break;
case Instruction::LShr:
//++Shi;
break;
case Instruction::AShr:
//++Shi;
break;
case Instruction::And:
(this->*
funcAnd[llvm::cryptoutils->get_range(2)])(cast<BinaryOperator>(inst));
++And;
break;
case Instruction::Or:
(this->*
funcOr[llvm::cryptoutils->get_range(2)])(cast<BinaryOperator>(inst));
++Or;
break;
case Instruction::Xor:
(this->*
funcXor[llvm::cryptoutils->get_range(2)])(cast<BinaryOperator>(inst));
++Xor;
break;
default:
break;
} // End switch
} // End isBinaryOp
} // End for basickblock
} // End for Function
} while (--times > 0); // for times
return false;
}
void transform(Module &M,Function &f,vector <BasicBlock*> &BB1,vector <BasicBlock*> &BB2,vector<Instruction*>I1,vector<Instruction*>I2)
{
LLVMContext &context = M.getContext();
Instruction *br,*I;
Type* Int1= Type::getInt8PtrTy(context);
Type *typpe=Type::getInt32Ty(context);
Type* voidd= Type::getVoidTy(context);
vector <BasicBlock*> BB3,BB4,contt,tran;
vector<Instruction*>inst1,inst2;
BasicBlock *bt;
Instruction *in;
unsigned i=0;
Function *under_over = cast<Function>(M.getOrInsertFunction ("llvm.x86.sse.stmxcsr",voidd,Int1,nullptr));//function how test condition(overflow,underflow...)
//*******************************take the basic block and his copy of the highest type********************
for (Function::iterator blocdebase = f.begin(), e = f.end(); blocdebase != e; ++blocdebase)
{
unsigned n=Search(BB1,blocdebase);
if(n<BB1.size())
{
BB3.push_back(BB1[n]);
BB4.push_back(BB2[n]);
}
}
//********************************take the instruction of each block *******************************
bt=f.begin();
for(unsigned i=0;i<BB3.size();i++)
{
for(BasicBlock::iterator instruction = BB3[i]->begin(), ee = BB3[i]->end(); instruction != ee; ++instruction)
{
if (dyn_cast<LoadInst>(instruction))
{
//from read instruction
unsigned n=Searchinst(I2,dyn_cast<Instruction>(instruction->getOperand(0)));
unsigned n1=Searchinst(inst2,dyn_cast<Instruction>(instruction->getOperand(0)));
if(n<I2.size()&&n1>inst2.size())
{
inst2.push_back(I2[n]);//copy instruction
inst1.push_back(I1[n]);//orginal instruction
}
}
if (dyn_cast<StoreInst>(instruction))
{
//from write instruction
unsigned n=Searchinst(I2,dyn_cast<Instruction>(instruction->getOperand(0)));
unsigned n1=Searchinst(inst2,dyn_cast<Instruction>(instruction->getOperand(0)));
unsigned n2=Searchinst(I2,dyn_cast<Instruction>(instruction->getOperand(1)));
unsigned n3=Searchinst(inst2,dyn_cast<Instruction>(instruction->getOperand(1)));
if(n<I2.size()&&n1>inst2.size()){inst2.push_back(I2[n]);inst1.push_back(I1[n]);}
else if(n2<I2.size()&&n3>inst2.size()){inst2.push_back(I2[n2]);inst1.push_back(I1[n2]);}
}
}
}
while(i<BB3.size())
{
BasicBlock *cont = BasicBlock::Create(context, "continue", BB3[i]->getParent());//block that allows to continue in the same way
BasicBlock *transforms = BasicBlock::Create(context, "transforms", BB3[i]->getParent());//block that do the transformation
I= BB3[i]->getTerminator();
br=I->clone();
I->eraseFromParent();
//*********************************test to choose what to do*************************
AllocaInst *test = new AllocaInst(typpe,0, "test",BB3[i]);
BitCastInst *newb= new BitCastInst(test,Int1," ",BB3[i]);
CallInst::Create(under_over, newb, "",BB3[i]);
LoadInst *Cov=new LoadInst(test,"",false,BB3[i]);
Value *one = ConstantInt::get(Type::getInt32Ty(context), 63);
Value *two = ConstantInt::get(Type::getInt32Ty(context), 16);
Value *three = ConstantInt::get(Type::getInt32Ty(context), 8);
BinaryOperator *te1 = BinaryOperator::Create(Instruction::And,Cov,one,"",BB3[i]);
BinaryOperator *te2 = BinaryOperator::Create(Instruction::And,te1,two,"",BB3[i]);
BinaryOperator *te3 = BinaryOperator::Create(Instruction::And,Cov,three,"",BB3[i]);
BinaryOperator *te4 = BinaryOperator::Create(Instruction::Or,te3,te2,"",BB3[i]);
Value *z = ConstantInt::get(Type::getInt32Ty(context), 0);
Value *CondI = new ICmpInst(*BB3[i], ICmpInst::ICMP_NE, te4,z , "cond");
//************************************************************************
BranchInst::Create (transforms,cont ,CondI,BB3[i]);// branch to the block of continue
BranchInst::Create(BB4[i],transforms);// branch to the block copy
cont->getInstList().push_back(br);// branch to the next block
contt.push_back(cont);//take all the continents blocks
tran.push_back(transforms);//take all the transformations blocks
i++;
}
BB3.clear();
BB4.clear();
i=0;
while(i<contt.size())
{
I= contt[i]->getTerminator();
int size= I1.size();
for(unsigned a=0;a<inst1.size();a++)
{
LoadInst *new_load = new LoadInst(inst2[a],"Nl",false,I);//load the copy value
new StoreInst(new_load,inst1[a] , false,I);//store the copy value in original value
//**********************************************************************
in= tran[i]->getTerminator();
LoadInst *new_load1 = new LoadInst(inst1[a],"e",false,in);//load the original value of original block
int id=Searchinst(I1,inst1[a]);
AllocaInst *t=dyn_cast<AllocaInst>(I1[(id+(size/3))]);
Type *T=t->getAllocatedType ();
if(inst1[a]->getType()==I1[(id+(size/3))]->getType())//same type of original value of copy block
{
new StoreInst(new_load1,I1[(id+(size/3))] , false,4,in);
}
else//different type
{
FPExtInst *c= new FPExtInst (new_load1,T , "",in);
new StoreInst(c,I1[(id+(size/3))] , false,in);
}
}
i++;
}
inst1.clear();
contt.clear();
}
void HeterotbbTransform::edit_template_function (Module &M,Function* F,Function* new_join,GlobalVariable *old_gb,Value *gb) {
SmallVector<Value*, 16> Args; // Argument lists to the new call
vector<Instruction *> toDelete;
// old_gb->dump();
// gb->dump();
Constant *Ids[2];
for (Function::iterator BI=F->begin(),BE = F->end(); BI != BE; ++BI) {
for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE; ++II) {
GetElementPtrInst *GEP;
GlobalVariable *op;
if (isa<CallInst>(II) || isa<InvokeInst>(II)) {
CallSite CI(cast<Instruction>(II));
//replace dummy reduce with new reduce
if(CI.getCalledFunction()->getName().equals("__join_reduce_hetero")) {
Args.clear();
CastInst *newarg1 = CastInst::Create(Instruction::BitCast, CI.getArgument(0), new_join->arg_begin()->getType(), "arg1",CI.getInstruction());
Args.push_back(newarg1);
CastInst *newarg2 = CastInst::Create(Instruction::BitCast, CI.getArgument(1), new_join->arg_begin()->getType(), "arg2", CI.getInstruction());
Args.push_back(newarg2);
//no need to set attributes
Instruction *NewCall = CallInst::Create(new_join, Args, "", CI.getInstruction());
cast<CallInst>(NewCall)->setCallingConv(CI.getCallingConv());
toDelete.push_back(CI.getInstruction());
DEBUG(dbgs()<<"Joins Replaced\n");
}
}
/*
%arrayidx18 = getelementptr inbounds i32 addrspace(3)* getelementptr
inbounds ([192 x i32] addrspace(3)* @opencl_kernel_join_name_local_arr, i32 0, i32 0),
i64 %idxprom1
*/
if((GEP = dyn_cast<GetElementPtrInst>(II)) /*&&
(op = dyn_cast<GlobalVariable>(GEP->getOperand(0)))*/ /*&&
(op->getName().equals("opencl_kernel_join_name_local_arr"))*/) {
//II->dump();
Value *val= II->getOperand(0);
if(Constant *op=dyn_cast<ConstantExpr>(val)) {
//II->dump();
//II->getOperand(1)->dump();
/*Ids[0]=cast<Constant>(op->getOperand(1));
Ids[1]=cast<Constant>(op->getOperand(1));
Constant *new_op = ConstantExpr::getInBoundsGetElementPtr(cast<Constant>(gb),Ids,2);
new_op->dump();
Instruction *inst = GetElementPtrInst::CreateInBounds(new_op, II->getOperand(1), II->getName()+"_temp",II);
Value *Elts[] = {MDString::get(M.getContext(), "local_access")};
MDNode *Node = MDNode::get(M.getContext(), Elts);
inst->setMetadata("local_access",Node);
inst->dump();
II->replaceAllUsesWith(inst);
toDelete.push_back(II);
*/
Value *Idxs[2] = {ConstantInt::get(Type::getInt32Ty(M.getContext()), 0),
ConstantInt::get(Type::getInt32Ty(M.getContext()), 0)
};
//gb->getType()->dump();
//gb->dump();
Instruction *inst_= GetElementPtrInst::CreateInBounds(gb, Idxs, /*Idxs+2,*/ II->getName()+"_temp_",II);
//inst_->dump();
Instruction *inst= GetElementPtrInst::CreateInBounds(inst_, II->getOperand(1), II->getName()+"_temp",II);
Value *Elts[] = {MDString::get(M.getContext(), inst->getName())};
MDNode *Node = MDNode::get(M.getContext(), Elts);
inst->setMetadata("local_access",Node);
//inst->dump();
II->replaceAllUsesWith(inst);
toDelete.push_back(II);
}
}
}
}
while(!toDelete.empty()) {
Instruction *g = toDelete.back();
toDelete.pop_back();
g->eraseFromParent();
}
}
// Reroll the provided loop with respect to the provided induction variable.
// Generally, we're looking for a loop like this:
//
// %iv = phi [ (preheader, ...), (body, %iv.next) ]
// f(%iv)
// %iv.1 = add %iv, 1 <-- a root increment
// f(%iv.1)
// %iv.2 = add %iv, 2 <-- a root increment
// f(%iv.2)
// %iv.scale_m_1 = add %iv, scale-1 <-- a root increment
// f(%iv.scale_m_1)
// ...
// %iv.next = add %iv, scale
// %cmp = icmp(%iv, ...)
// br %cmp, header, exit
//
// Notably, we do not require that f(%iv), f(%iv.1), etc. be isolated groups of
// instructions. In other words, the instructions in f(%iv), f(%iv.1), etc. can
// be intermixed with eachother. The restriction imposed by this algorithm is
// that the relative order of the isomorphic instructions in f(%iv), f(%iv.1),
// etc. be the same.
//
// First, we collect the use set of %iv, excluding the other increment roots.
// This gives us f(%iv). Then we iterate over the loop instructions (scale-1)
// times, having collected the use set of f(%iv.(i+1)), during which we:
// - Ensure that the next unmatched instruction in f(%iv) is isomorphic to
// the next unmatched instruction in f(%iv.(i+1)).
// - Ensure that both matched instructions don't have any external users
// (with the exception of last-in-chain reduction instructions).
// - Track the (aliasing) write set, and other side effects, of all
// instructions that belong to future iterations that come before the matched
// instructions. If the matched instructions read from that write set, then
// f(%iv) or f(%iv.(i+1)) has some dependency on instructions in
// f(%iv.(j+1)) for some j > i, and we cannot reroll the loop. Similarly,
// if any of these future instructions had side effects (could not be
// speculatively executed), and so do the matched instructions, when we
// cannot reorder those side-effect-producing instructions, and rerolling
// fails.
//
// Finally, we make sure that all loop instructions are either loop increment
// roots, belong to simple latch code, parts of validated reductions, part of
// f(%iv) or part of some f(%iv.i). If all of that is true (and all reductions
// have been validated), then we reroll the loop.
bool LoopReroll::reroll(Instruction *IV, Loop *L, BasicBlock *Header,
const SCEV *IterCount,
ReductionTracker &Reductions) {
const SCEVAddRecExpr *RealIVSCEV = cast<SCEVAddRecExpr>(SE->getSCEV(IV));
uint64_t Inc = cast<SCEVConstant>(RealIVSCEV->getOperand(1))->
getValue()->getZExtValue();
// The collection of loop increment instructions.
SmallInstructionVector LoopIncs;
uint64_t Scale = Inc;
// The effective induction variable, IV, is normally also the real induction
// variable. When we're dealing with a loop like:
// for (int i = 0; i < 500; ++i)
// x[3*i] = ...;
// x[3*i+1] = ...;
// x[3*i+2] = ...;
// then the real IV is still i, but the effective IV is (3*i).
Instruction *RealIV = IV;
if (Inc == 1 && !findScaleFromMul(RealIV, Scale, IV, LoopIncs))
return false;
assert(Scale <= MaxInc && "Scale is too large");
assert(Scale > 1 && "Scale must be at least 2");
// The set of increment instructions for each increment value.
SmallVector<SmallInstructionVector, 32> Roots(Scale-1);
SmallInstructionSet AllRoots;
if (!collectAllRoots(L, Inc, Scale, IV, Roots, AllRoots, LoopIncs))
return false;
DEBUG(dbgs() << "LRR: Found all root induction increments for: " <<
*RealIV << "\n");
// An array of just the possible reductions for this scale factor. When we
// collect the set of all users of some root instructions, these reduction
// instructions are treated as 'final' (their uses are not considered).
// This is important because we don't want the root use set to search down
// the reduction chain.
SmallInstructionSet PossibleRedSet;
SmallInstructionSet PossibleRedLastSet, PossibleRedPHISet;
Reductions.restrictToScale(Scale, PossibleRedSet, PossibleRedPHISet,
PossibleRedLastSet);
// We now need to check for equivalence of the use graph of each root with
// that of the primary induction variable (excluding the roots). Our goal
// here is not to solve the full graph isomorphism problem, but rather to
// catch common cases without a lot of work. As a result, we will assume
// that the relative order of the instructions in each unrolled iteration
// is the same (although we will not make an assumption about how the
// different iterations are intermixed). Note that while the order must be
// the same, the instructions may not be in the same basic block.
SmallInstructionSet Exclude(AllRoots);
Exclude.insert(LoopIncs.begin(), LoopIncs.end());
DenseSet<Instruction *> BaseUseSet;
collectInLoopUserSet(L, IV, Exclude, PossibleRedSet, BaseUseSet);
DenseSet<Instruction *> AllRootUses;
std::vector<DenseSet<Instruction *> > RootUseSets(Scale-1);
bool MatchFailed = false;
for (unsigned i = 0; i < Scale-1 && !MatchFailed; ++i) {
DenseSet<Instruction *> &RootUseSet = RootUseSets[i];
collectInLoopUserSet(L, Roots[i], SmallInstructionSet(),
PossibleRedSet, RootUseSet);
DEBUG(dbgs() << "LRR: base use set size: " << BaseUseSet.size() <<
" vs. iteration increment " << (i+1) <<
" use set size: " << RootUseSet.size() << "\n");
if (BaseUseSet.size() != RootUseSet.size()) {
MatchFailed = true;
break;
}
// In addition to regular aliasing information, we need to look for
// instructions from later (future) iterations that have side effects
// preventing us from reordering them past other instructions with side
// effects.
bool FutureSideEffects = false;
AliasSetTracker AST(*AA);
// The map between instructions in f(%iv.(i+1)) and f(%iv).
DenseMap<Value *, Value *> BaseMap;
assert(L->getNumBlocks() == 1 && "Cannot handle multi-block loops");
for (BasicBlock::iterator J1 = Header->begin(), J2 = Header->begin(),
JE = Header->end(); J1 != JE && !MatchFailed; ++J1) {
if (cast<Instruction>(J1) == RealIV)
continue;
if (cast<Instruction>(J1) == IV)
continue;
if (!BaseUseSet.count(J1))
continue;
if (PossibleRedPHISet.count(J1)) // Skip reduction PHIs.
continue;
while (J2 != JE && (!RootUseSet.count(J2) ||
std::find(Roots[i].begin(), Roots[i].end(), J2) !=
Roots[i].end())) {
// As we iterate through the instructions, instructions that don't
// belong to previous iterations (or the base case), must belong to
// future iterations. We want to track the alias set of writes from
// previous iterations.
if (!isa<PHINode>(J2) && !BaseUseSet.count(J2) &&
!AllRootUses.count(J2)) {
if (J2->mayWriteToMemory())
AST.add(J2);
// Note: This is specifically guarded by a check on isa<PHINode>,
// which while a valid (somewhat arbitrary) micro-optimization, is
// needed because otherwise isSafeToSpeculativelyExecute returns
// false on PHI nodes.
if (!isSimpleLoadStore(J2) && !isSafeToSpeculativelyExecute(J2, DL))
FutureSideEffects = true;
}
++J2;
}
if (!J1->isSameOperationAs(J2)) {
DEBUG(dbgs() << "LRR: iteration root match failed at " << *J1 <<
" vs. " << *J2 << "\n");
MatchFailed = true;
break;
}
// Make sure that this instruction, which is in the use set of this
// root instruction, does not also belong to the base set or the set of
// some previous root instruction.
if (BaseUseSet.count(J2) || AllRootUses.count(J2)) {
DEBUG(dbgs() << "LRR: iteration root match failed at " << *J1 <<
" vs. " << *J2 << " (prev. case overlap)\n");
MatchFailed = true;
break;
}
// Make sure that we don't alias with any instruction in the alias set
// tracker. If we do, then we depend on a future iteration, and we
// can't reroll.
if (J2->mayReadFromMemory()) {
for (AliasSetTracker::iterator K = AST.begin(), KE = AST.end();
K != KE && !MatchFailed; ++K) {
if (K->aliasesUnknownInst(J2, *AA)) {
DEBUG(dbgs() << "LRR: iteration root match failed at " << *J1 <<
" vs. " << *J2 << " (depends on future store)\n");
MatchFailed = true;
break;
}
}
}
// If we've past an instruction from a future iteration that may have
// side effects, and this instruction might also, then we can't reorder
// them, and this matching fails. As an exception, we allow the alias
// set tracker to handle regular (simple) load/store dependencies.
if (FutureSideEffects &&
((!isSimpleLoadStore(J1) && !isSafeToSpeculativelyExecute(J1)) ||
(!isSimpleLoadStore(J2) && !isSafeToSpeculativelyExecute(J2)))) {
DEBUG(dbgs() << "LRR: iteration root match failed at " << *J1 <<
" vs. " << *J2 <<
" (side effects prevent reordering)\n");
MatchFailed = true;
break;
}
// For instructions that are part of a reduction, if the operation is
// associative, then don't bother matching the operands (because we
// already know that the instructions are isomorphic, and the order
// within the iteration does not matter). For non-associative reductions,
// we do need to match the operands, because we need to reject
// out-of-order instructions within an iteration!
// For example (assume floating-point addition), we need to reject this:
// x += a[i]; x += b[i];
// x += a[i+1]; x += b[i+1];
// x += b[i+2]; x += a[i+2];
bool InReduction = Reductions.isPairInSame(J1, J2);
if (!(InReduction && J1->isAssociative())) {
bool Swapped = false, SomeOpMatched = false;;
for (unsigned j = 0; j < J1->getNumOperands() && !MatchFailed; ++j) {
Value *Op2 = J2->getOperand(j);
// If this is part of a reduction (and the operation is not
// associatve), then we match all operands, but not those that are
// part of the reduction.
if (InReduction)
if (Instruction *Op2I = dyn_cast<Instruction>(Op2))
if (Reductions.isPairInSame(J2, Op2I))
continue;
DenseMap<Value *, Value *>::iterator BMI = BaseMap.find(Op2);
if (BMI != BaseMap.end())
Op2 = BMI->second;
else if (std::find(Roots[i].begin(), Roots[i].end(),
(Instruction*) Op2) != Roots[i].end())
Op2 = IV;
if (J1->getOperand(Swapped ? unsigned(!j) : j) != Op2) {
// If we've not already decided to swap the matched operands, and
// we've not already matched our first operand (note that we could
// have skipped matching the first operand because it is part of a
// reduction above), and the instruction is commutative, then try
// the swapped match.
if (!Swapped && J1->isCommutative() && !SomeOpMatched &&
J1->getOperand(!j) == Op2) {
Swapped = true;
} else {
DEBUG(dbgs() << "LRR: iteration root match failed at " << *J1 <<
" vs. " << *J2 << " (operand " << j << ")\n");
MatchFailed = true;
break;
}
}
SomeOpMatched = true;
}
}
if ((!PossibleRedLastSet.count(J1) && hasUsesOutsideLoop(J1, L)) ||
(!PossibleRedLastSet.count(J2) && hasUsesOutsideLoop(J2, L))) {
DEBUG(dbgs() << "LRR: iteration root match failed at " << *J1 <<
" vs. " << *J2 << " (uses outside loop)\n");
MatchFailed = true;
break;
}
if (!MatchFailed)
BaseMap.insert(std::pair<Value *, Value *>(J2, J1));
AllRootUses.insert(J2);
Reductions.recordPair(J1, J2, i+1);
++J2;
}
}
if (MatchFailed)
return false;
DEBUG(dbgs() << "LRR: Matched all iteration increments for " <<
*RealIV << "\n");
DenseSet<Instruction *> LoopIncUseSet;
collectInLoopUserSet(L, LoopIncs, SmallInstructionSet(),
SmallInstructionSet(), LoopIncUseSet);
DEBUG(dbgs() << "LRR: Loop increment set size: " <<
LoopIncUseSet.size() << "\n");
// Make sure that all instructions in the loop have been included in some
// use set.
for (BasicBlock::iterator J = Header->begin(), JE = Header->end();
J != JE; ++J) {
if (isa<DbgInfoIntrinsic>(J))
continue;
if (cast<Instruction>(J) == RealIV)
continue;
if (cast<Instruction>(J) == IV)
continue;
if (BaseUseSet.count(J) || AllRootUses.count(J) ||
(LoopIncUseSet.count(J) && (J->isTerminator() ||
isSafeToSpeculativelyExecute(J, DL))))
continue;
if (AllRoots.count(J))
continue;
if (Reductions.isSelectedPHI(J))
continue;
DEBUG(dbgs() << "LRR: aborting reroll based on " << *RealIV <<
" unprocessed instruction found: " << *J << "\n");
MatchFailed = true;
break;
}
if (MatchFailed)
return false;
DEBUG(dbgs() << "LRR: all instructions processed from " <<
*RealIV << "\n");
if (!Reductions.validateSelected())
return false;
// At this point, we've validated the rerolling, and we're committed to
// making changes!
Reductions.replaceSelected();
// Remove instructions associated with non-base iterations.
for (BasicBlock::reverse_iterator J = Header->rbegin();
J != Header->rend();) {
if (AllRootUses.count(&*J)) {
Instruction *D = &*J;
DEBUG(dbgs() << "LRR: removing: " << *D << "\n");
D->eraseFromParent();
continue;
}
++J;
}
// Insert the new induction variable.
const SCEV *Start = RealIVSCEV->getStart();
if (Inc == 1)
Start = SE->getMulExpr(Start,
SE->getConstant(Start->getType(), Scale));
const SCEVAddRecExpr *H =
cast<SCEVAddRecExpr>(SE->getAddRecExpr(Start,
SE->getConstant(RealIVSCEV->getType(), 1),
L, SCEV::FlagAnyWrap));
{ // Limit the lifetime of SCEVExpander.
SCEVExpander Expander(*SE, "reroll");
Value *NewIV = Expander.expandCodeFor(H, IV->getType(), Header->begin());
for (DenseSet<Instruction *>::iterator J = BaseUseSet.begin(),
JE = BaseUseSet.end(); J != JE; ++J)
(*J)->replaceUsesOfWith(IV, NewIV);
if (BranchInst *BI = dyn_cast<BranchInst>(Header->getTerminator())) {
if (LoopIncUseSet.count(BI)) {
const SCEV *ICSCEV = RealIVSCEV->evaluateAtIteration(IterCount, *SE);
if (Inc == 1)
ICSCEV =
SE->getMulExpr(ICSCEV, SE->getConstant(ICSCEV->getType(), Scale));
// Iteration count SCEV minus 1
const SCEV *ICMinus1SCEV =
SE->getMinusSCEV(ICSCEV, SE->getConstant(ICSCEV->getType(), 1));
Value *ICMinus1; // Iteration count minus 1
if (isa<SCEVConstant>(ICMinus1SCEV)) {
ICMinus1 = Expander.expandCodeFor(ICMinus1SCEV, NewIV->getType(), BI);
} else {
BasicBlock *Preheader = L->getLoopPreheader();
if (!Preheader)
Preheader = InsertPreheaderForLoop(L, this);
ICMinus1 = Expander.expandCodeFor(ICMinus1SCEV, NewIV->getType(),
Preheader->getTerminator());
}
Value *Cond = new ICmpInst(BI, CmpInst::ICMP_EQ, NewIV, ICMinus1,
"exitcond");
BI->setCondition(Cond);
if (BI->getSuccessor(1) != Header)
BI->swapSuccessors();
}
}
}
SimplifyInstructionsInBlock(Header, DL, TLI);
DeleteDeadPHIs(Header, TLI);
++NumRerolledLoops;
return true;
}
