//===- CloneFunction.cpp - Clone a function into another function ---------===//
//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
// This file implements the CloneFunctionInto interface, which is used as the
// low-level function cloner. This is used by the CloneFunction and function
// inliner to do the dirty work of copying the body of a function around.
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/Cloning.h"
-#include "llvm/iTerminators.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Function.h"
-#include "ValueMapper.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/IR/CFG.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DebugInfo.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Utils/ValueMapper.h"
+#include <map>
+using namespace llvm;
-// RemapInstruction - Convert the instruction operands from referencing the
-// current values into those specified by ValueMap.
-//
-static inline void RemapInstruction(Instruction *I,
- std::map<const Value *, Value*> &ValueMap) {
- for (unsigned op = 0, E = I->getNumOperands(); op != E; ++op) {
- const Value *Op = I->getOperand(op);
- Value *V = MapValue(Op, ValueMap);
-#ifndef NDEBUG
- if (!V) {
- std::cerr << "Val = \n" << Op << "Addr = " << (void*)Op;
- std::cerr << "\nInst = " << I;
+/// See comments in Cloning.h.
+BasicBlock *llvm::CloneBasicBlock(const BasicBlock *BB,
+ ValueToValueMapTy &VMap,
+ const Twine &NameSuffix, Function *F,
+ ClonedCodeInfo *CodeInfo) {
+ BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), "", F);
+ if (BB->hasName()) NewBB->setName(BB->getName()+NameSuffix);
+
+ bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;
+
+ // Loop over all instructions, and copy them over.
+ for (BasicBlock::const_iterator II = BB->begin(), IE = BB->end();
+ II != IE; ++II) {
+ Instruction *NewInst = II->clone();
+ if (II->hasName())
+ NewInst->setName(II->getName()+NameSuffix);
+ NewBB->getInstList().push_back(NewInst);
+ VMap[&*II] = NewInst; // Add instruction map to value.
+
+ hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));
+ if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
+ if (isa<ConstantInt>(AI->getArraySize()))
+ hasStaticAllocas = true;
+ else
+ hasDynamicAllocas = true;
}
-#endif
- assert(V && "Referenced value not in value map!");
- I->setOperand(op, V);
}
+
+ if (CodeInfo) {
+ CodeInfo->ContainsCalls |= hasCalls;
+ CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
+ CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas &&
+ BB != &BB->getParent()->getEntryBlock();
+ }
+ return NewBB;
}
// Clone OldFunc into NewFunc, transforming the old arguments into references to
-// ArgMap values.
+// VMap values.
//
-void CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
- std::map<const Value*, Value*> &ValueMap,
- std::vector<ReturnInst*> &Returns,
- const char *NameSuffix) {
+void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
+ ValueToValueMapTy &VMap,
+ bool ModuleLevelChanges,
+ SmallVectorImpl<ReturnInst*> &Returns,
+ const char *NameSuffix, ClonedCodeInfo *CodeInfo,
+ ValueMapTypeRemapper *TypeMapper,
+ ValueMaterializer *Materializer) {
assert(NameSuffix && "NameSuffix cannot be null!");
-
+
#ifndef NDEBUG
- for (Function::const_aiterator I = OldFunc->abegin(), E = OldFunc->aend();
- I != E; ++I)
- assert(ValueMap.count(I) && "No mapping from source argument specified!");
+ for (const Argument &I : OldFunc->args())
+ assert(VMap.count(&I) && "No mapping from source argument specified!");
#endif
+ // Copy all attributes other than those stored in the AttributeSet. We need
+ // to remap the parameter indices of the AttributeSet.
+ AttributeSet NewAttrs = NewFunc->getAttributes();
+ NewFunc->copyAttributesFrom(OldFunc);
+ NewFunc->setAttributes(NewAttrs);
+
+ // Fix up the personality function that got copied over.
+ if (OldFunc->hasPersonalityFn())
+ NewFunc->setPersonalityFn(
+ MapValue(OldFunc->getPersonalityFn(), VMap,
+ ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges,
+ TypeMapper, Materializer));
+
+ AttributeSet OldAttrs = OldFunc->getAttributes();
+ // Clone any argument attributes that are present in the VMap.
+ for (const Argument &OldArg : OldFunc->args())
+ if (Argument *NewArg = dyn_cast<Argument>(VMap[&OldArg])) {
+ AttributeSet attrs =
+ OldAttrs.getParamAttributes(OldArg.getArgNo() + 1);
+ if (attrs.getNumSlots() > 0)
+ NewArg->addAttr(attrs);
+ }
+
+ NewFunc->setAttributes(
+ NewFunc->getAttributes()
+ .addAttributes(NewFunc->getContext(), AttributeSet::ReturnIndex,
+ OldAttrs.getRetAttributes())
+ .addAttributes(NewFunc->getContext(), AttributeSet::FunctionIndex,
+ OldAttrs.getFnAttributes()));
+
// Loop over all of the basic blocks in the function, cloning them as
// appropriate. Note that we save BE this way in order to handle cloning of
// recursive functions into themselves.
for (Function::const_iterator BI = OldFunc->begin(), BE = OldFunc->end();
BI != BE; ++BI) {
const BasicBlock &BB = *BI;
-
- // Create a new basic block to copy instructions into!
- BasicBlock *CBB = new BasicBlock("", NewFunc);
- if (BB.hasName()) CBB->setName(BB.getName()+NameSuffix);
- ValueMap[&BB] = CBB; // Add basic block mapping.
- // Loop over all instructions copying them over...
- for (BasicBlock::const_iterator II = BB.begin(), IE = BB.end();
- II != IE; ++II) {
- Instruction *NewInst = II->clone();
- if (II->hasName())
- NewInst->setName(II->getName()+NameSuffix); // Name is not cloned...
- CBB->getInstList().push_back(NewInst);
- ValueMap[II] = NewInst; // Add instruction map to value.
+ // Create a new basic block and copy instructions into it!
+ BasicBlock *CBB = CloneBasicBlock(&BB, VMap, NameSuffix, NewFunc, CodeInfo);
+
+ // Add basic block mapping.
+ VMap[&BB] = CBB;
+
+ // It is only legal to clone a function if a block address within that
+ // function is never referenced outside of the function. Given that, we
+ // want to map block addresses from the old function to block addresses in
+ // the clone. (This is different from the generic ValueMapper
+ // implementation, which generates an invalid blockaddress when
+ // cloning a function.)
+ if (BB.hasAddressTaken()) {
+ Constant *OldBBAddr = BlockAddress::get(const_cast<Function*>(OldFunc),
+ const_cast<BasicBlock*>(&BB));
+ VMap[OldBBAddr] = BlockAddress::get(NewFunc, CBB);
}
+ // Note return instructions for the caller.
if (ReturnInst *RI = dyn_cast<ReturnInst>(CBB->getTerminator()))
Returns.push_back(RI);
}
- // Loop over all of the instructions in the function, fixing up operand
- // references as we go. This uses ValueMap to do all the hard work.
- //
- for (Function::const_iterator BB = OldFunc->begin(), BE = OldFunc->end();
- BB != BE; ++BB) {
- BasicBlock *NBB = cast<BasicBlock>(ValueMap[BB]);
-
+ // Loop over all of the instructions in the function, fixing up operand
+ // references as we go. This uses VMap to do all the hard work.
+ for (Function::iterator BB =
+ cast<BasicBlock>(VMap[&OldFunc->front()])->getIterator(),
+ BE = NewFunc->end();
+ BB != BE; ++BB)
// Loop over all instructions, fixing each one as we find it...
- for (BasicBlock::iterator II = NBB->begin(); II != NBB->end(); ++II)
- RemapInstruction(II, ValueMap);
+ for (Instruction &II : *BB)
+ RemapInstruction(&II, VMap,
+ ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges,
+ TypeMapper, Materializer);
+}
+
+// Find the MDNode which corresponds to the subprogram data that described F.
+static DISubprogram *FindSubprogram(const Function *F,
+ DebugInfoFinder &Finder) {
+ for (DISubprogram *Subprogram : Finder.subprograms()) {
+ if (Subprogram->describes(F))
+ return Subprogram;
}
+ return nullptr;
}
-/// CloneFunction - Return a copy of the specified function, but without
+// Add an operand to an existing MDNode. The new operand will be added at the
+// back of the operand list.
+static void AddOperand(DICompileUnit *CU, DISubprogramArray SPs,
+ Metadata *NewSP) {
+ SmallVector<Metadata *, 16> NewSPs;
+ NewSPs.reserve(SPs.size() + 1);
+ for (auto *SP : SPs)
+ NewSPs.push_back(SP);
+ NewSPs.push_back(NewSP);
+ CU->replaceSubprograms(MDTuple::get(CU->getContext(), NewSPs));
+}
+
+// Clone the module-level debug info associated with OldFunc. The cloned data
+// will point to NewFunc instead.
+static void CloneDebugInfoMetadata(Function *NewFunc, const Function *OldFunc,
+ ValueToValueMapTy &VMap) {
+ DebugInfoFinder Finder;
+ Finder.processModule(*OldFunc->getParent());
+
+ const DISubprogram *OldSubprogramMDNode = FindSubprogram(OldFunc, Finder);
+ if (!OldSubprogramMDNode) return;
+
+ auto *NewSubprogram =
+ cast<DISubprogram>(MapMetadata(OldSubprogramMDNode, VMap));
+ NewFunc->setSubprogram(NewSubprogram);
+
+ for (auto *CU : Finder.compile_units()) {
+ auto Subprograms = CU->getSubprograms();
+ // If the compile unit's function list contains the old function, it should
+ // also contain the new one.
+ for (auto *SP : Subprograms) {
+ if (SP == OldSubprogramMDNode) {
+ AddOperand(CU, Subprograms, NewSubprogram);
+ break;
+ }
+ }
+ }
+}
+
+/// Return a copy of the specified function, but without
/// embedding the function into another module. Also, any references specified
-/// in the ValueMap are changed to refer to their mapped value instead of the
-/// original one. If any of the arguments to the function are in the ValueMap,
-/// the arguments are deleted from the resultant function. The ValueMap is
+/// in the VMap are changed to refer to their mapped value instead of the
+/// original one. If any of the arguments to the function are in the VMap,
+/// the arguments are deleted from the resultant function. The VMap is
/// updated to include mappings from all of the instructions and basicblocks in
/// the function from their old to new values.
///
-Function *CloneFunction(const Function *F,
- std::map<const Value*, Value*> &ValueMap) {
- std::vector<const Type*> ArgTypes;
+Function *llvm::CloneFunction(const Function *F, ValueToValueMapTy &VMap,
+ bool ModuleLevelChanges,
+ ClonedCodeInfo *CodeInfo) {
+ std::vector<Type*> ArgTypes;
// The user might be deleting arguments to the function by specifying them in
- // the ValueMap. If so, we need to not add the arguments to the arg ty vector
+ // the VMap. If so, we need to not add the arguments to the arg ty vector
//
- for (Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
- if (ValueMap.count(I) == 0) // Haven't mapped the argument to anything yet?
- ArgTypes.push_back(I->getType());
+ for (const Argument &I : F->args())
+ if (VMap.count(&I) == 0) // Haven't mapped the argument to anything yet?
+ ArgTypes.push_back(I.getType());
// Create a new function type...
FunctionType *FTy = FunctionType::get(F->getFunctionType()->getReturnType(),
ArgTypes, F->getFunctionType()->isVarArg());
// Create the new function...
- Function *NewF = new Function(FTy, F->hasInternalLinkage(), F->getName());
-
+ Function *NewF = Function::Create(FTy, F->getLinkage(), F->getName());
+
// Loop over the arguments, copying the names of the mapped arguments over...
- Function::aiterator DestI = NewF->abegin();
- for (Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
- if (ValueMap.count(I) == 0) { // Is this argument preserved?
- DestI->setName(I->getName()); // Copy the name over...
- ValueMap[I] = DestI++; // Add mapping to ValueMap
+ Function::arg_iterator DestI = NewF->arg_begin();
+ for (const Argument & I : F->args())
+ if (VMap.count(&I) == 0) { // Is this argument preserved?
+ DestI->setName(I.getName()); // Copy the name over...
+ VMap[&I] = &*DestI++; // Add mapping to VMap
+ }
+
+ if (ModuleLevelChanges)
+ CloneDebugInfoMetadata(NewF, F, VMap);
+
+ SmallVector<ReturnInst*, 8> Returns; // Ignore returns cloned.
+ CloneFunctionInto(NewF, F, VMap, ModuleLevelChanges, Returns, "", CodeInfo);
+ return NewF;
+}
+
+
+
+namespace {
+ /// This is a private class used to implement CloneAndPruneFunctionInto.
+ struct PruningFunctionCloner {
+ Function *NewFunc;
+ const Function *OldFunc;
+ ValueToValueMapTy &VMap;
+ bool ModuleLevelChanges;
+ const char *NameSuffix;
+ ClonedCodeInfo *CodeInfo;
+
+ public:
+ PruningFunctionCloner(Function *newFunc, const Function *oldFunc,
+ ValueToValueMapTy &valueMap, bool moduleLevelChanges,
+ const char *nameSuffix, ClonedCodeInfo *codeInfo)
+ : NewFunc(newFunc), OldFunc(oldFunc), VMap(valueMap),
+ ModuleLevelChanges(moduleLevelChanges), NameSuffix(nameSuffix),
+ CodeInfo(codeInfo) {}
+
+ /// The specified block is found to be reachable, clone it and
+ /// anything that it can reach.
+ void CloneBlock(const BasicBlock *BB,
+ BasicBlock::const_iterator StartingInst,
+ std::vector<const BasicBlock*> &ToClone);
+ };
+}
+
+/// The specified block is found to be reachable, clone it and
+/// anything that it can reach.
+void PruningFunctionCloner::CloneBlock(const BasicBlock *BB,
+ BasicBlock::const_iterator StartingInst,
+ std::vector<const BasicBlock*> &ToClone){
+ WeakVH &BBEntry = VMap[BB];
+
+ // Have we already cloned this block?
+ if (BBEntry) return;
+
+ // Nope, clone it now.
+ BasicBlock *NewBB;
+ BBEntry = NewBB = BasicBlock::Create(BB->getContext());
+ if (BB->hasName()) NewBB->setName(BB->getName()+NameSuffix);
+
+ // It is only legal to clone a function if a block address within that
+ // function is never referenced outside of the function. Given that, we
+ // want to map block addresses from the old function to block addresses in
+ // the clone. (This is different from the generic ValueMapper
+ // implementation, which generates an invalid blockaddress when
+ // cloning a function.)
+ //
+ // Note that we don't need to fix the mapping for unreachable blocks;
+ // the default mapping there is safe.
+ if (BB->hasAddressTaken()) {
+ Constant *OldBBAddr = BlockAddress::get(const_cast<Function*>(OldFunc),
+ const_cast<BasicBlock*>(BB));
+ VMap[OldBBAddr] = BlockAddress::get(NewFunc, NewBB);
+ }
+
+ bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;
+
+ // Loop over all instructions, and copy them over, DCE'ing as we go. This
+ // loop doesn't include the terminator.
+ for (BasicBlock::const_iterator II = StartingInst, IE = --BB->end();
+ II != IE; ++II) {
+
+ Instruction *NewInst = II->clone();
+
+ // Eagerly remap operands to the newly cloned instruction, except for PHI
+ // nodes for which we defer processing until we update the CFG.
+ if (!isa<PHINode>(NewInst)) {
+ RemapInstruction(NewInst, VMap,
+ ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
+
+ // If we can simplify this instruction to some other value, simply add
+ // a mapping to that value rather than inserting a new instruction into
+ // the basic block.
+ if (Value *V =
+ SimplifyInstruction(NewInst, BB->getModule()->getDataLayout())) {
+ // On the off-chance that this simplifies to an instruction in the old
+ // function, map it back into the new function.
+ if (Value *MappedV = VMap.lookup(V))
+ V = MappedV;
+
+ VMap[&*II] = V;
+ delete NewInst;
+ continue;
+ }
+ }
+
+ if (II->hasName())
+ NewInst->setName(II->getName()+NameSuffix);
+ VMap[&*II] = NewInst; // Add instruction map to value.
+ NewBB->getInstList().push_back(NewInst);
+ hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));
+
+ if (CodeInfo)
+ if (auto CS = ImmutableCallSite(&*II))
+ if (CS.hasOperandBundles())
+ CodeInfo->OperandBundleCallSites.push_back(NewInst);
+
+ if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
+ if (isa<ConstantInt>(AI->getArraySize()))
+ hasStaticAllocas = true;
+ else
+ hasDynamicAllocas = true;
+ }
+ }
+
+ // Finally, clone over the terminator.
+ const TerminatorInst *OldTI = BB->getTerminator();
+ bool TerminatorDone = false;
+ if (const BranchInst *BI = dyn_cast<BranchInst>(OldTI)) {
+ if (BI->isConditional()) {
+ // If the condition was a known constant in the callee...
+ ConstantInt *Cond = dyn_cast<ConstantInt>(BI->getCondition());
+ // Or is a known constant in the caller...
+ if (!Cond) {
+ Value *V = VMap[BI->getCondition()];
+ Cond = dyn_cast_or_null<ConstantInt>(V);
+ }
+
+ // Constant fold to uncond branch!
+ if (Cond) {
+ BasicBlock *Dest = BI->getSuccessor(!Cond->getZExtValue());
+ VMap[OldTI] = BranchInst::Create(Dest, NewBB);
+ ToClone.push_back(Dest);
+ TerminatorDone = true;
+ }
+ }
+ } else if (const SwitchInst *SI = dyn_cast<SwitchInst>(OldTI)) {
+ // If switching on a value known constant in the caller.
+ ConstantInt *Cond = dyn_cast<ConstantInt>(SI->getCondition());
+ if (!Cond) { // Or known constant after constant prop in the callee...
+ Value *V = VMap[SI->getCondition()];
+ Cond = dyn_cast_or_null<ConstantInt>(V);
}
+ if (Cond) { // Constant fold to uncond branch!
+ SwitchInst::ConstCaseIt Case = SI->findCaseValue(Cond);
+ BasicBlock *Dest = const_cast<BasicBlock*>(Case.getCaseSuccessor());
+ VMap[OldTI] = BranchInst::Create(Dest, NewBB);
+ ToClone.push_back(Dest);
+ TerminatorDone = true;
+ }
+ }
+
+ if (!TerminatorDone) {
+ Instruction *NewInst = OldTI->clone();
+ if (OldTI->hasName())
+ NewInst->setName(OldTI->getName()+NameSuffix);
+ NewBB->getInstList().push_back(NewInst);
+ VMap[OldTI] = NewInst; // Add instruction map to value.
+
+ if (CodeInfo)
+ if (auto CS = ImmutableCallSite(OldTI))
+ if (CS.hasOperandBundles())
+ CodeInfo->OperandBundleCallSites.push_back(NewInst);
+
+ // Recursively clone any reachable successor blocks.
+ const TerminatorInst *TI = BB->getTerminator();
+ for (const BasicBlock *Succ : TI->successors())
+ ToClone.push_back(Succ);
+ }
+
+ if (CodeInfo) {
+ CodeInfo->ContainsCalls |= hasCalls;
+ CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
+ CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas &&
+ BB != &BB->getParent()->front();
+ }
+}
+
+/// This works like CloneAndPruneFunctionInto, except that it does not clone the
+/// entire function. Instead it starts at an instruction provided by the caller
+/// and copies (and prunes) only the code reachable from that instruction.
+void llvm::CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc,
+ const Instruction *StartingInst,
+ ValueToValueMapTy &VMap,
+ bool ModuleLevelChanges,
+ SmallVectorImpl<ReturnInst *> &Returns,
+ const char *NameSuffix,
+ ClonedCodeInfo *CodeInfo) {
+ assert(NameSuffix && "NameSuffix cannot be null!");
+
+ ValueMapTypeRemapper *TypeMapper = nullptr;
+ ValueMaterializer *Materializer = nullptr;
+
+#ifndef NDEBUG
+ // If the cloning starts at the beginning of the function, verify that
+ // the function arguments are mapped.
+ if (!StartingInst)
+ for (const Argument &II : OldFunc->args())
+ assert(VMap.count(&II) && "No mapping from source argument specified!");
+#endif
+
+ PruningFunctionCloner PFC(NewFunc, OldFunc, VMap, ModuleLevelChanges,
+ NameSuffix, CodeInfo);
+ const BasicBlock *StartingBB;
+ if (StartingInst)
+ StartingBB = StartingInst->getParent();
+ else {
+ StartingBB = &OldFunc->getEntryBlock();
+ StartingInst = &StartingBB->front();
+ }
+
+ // Clone the entry block, and anything recursively reachable from it.
+ std::vector<const BasicBlock*> CloneWorklist;
+ PFC.CloneBlock(StartingBB, StartingInst->getIterator(), CloneWorklist);
+ while (!CloneWorklist.empty()) {
+ const BasicBlock *BB = CloneWorklist.back();
+ CloneWorklist.pop_back();
+ PFC.CloneBlock(BB, BB->begin(), 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 (const BasicBlock &BI : *OldFunc) {
+ Value *V = VMap[&BI];
+ BasicBlock *NewBB = cast_or_null<BasicBlock>(V);
+ if (!NewBB) continue; // Dead block.
+
+ // Add the new block to the new function.
+ NewFunc->getBasicBlockList().push_back(NewBB);
+
+ // Handle PHI nodes specially, as we have to remove references to dead
+ // blocks.
+ for (BasicBlock::const_iterator I = BI.begin(), E = BI.end(); I != E; ++I) {
+ // PHI nodes may have been remapped to non-PHI nodes by the caller or
+ // during the cloning process.
+ if (const PHINode *PN = dyn_cast<PHINode>(I)) {
+ if (isa<PHINode>(VMap[PN]))
+ PHIToResolve.push_back(PN);
+ else
+ break;
+ } else {
+ break;
+ }
+ }
+
+ // Finally, remap the terminator instructions, as those can't be remapped
+ // until all BBs are mapped.
+ RemapInstruction(NewBB->getTerminator(), VMap,
+ ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges,
+ TypeMapper, Materializer);
+ }
+
+ // 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>(VMap[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>(VMap[OPN]);
+ for (unsigned pred = 0, e = NumPreds; pred != e; ++pred) {
+ Value *V = VMap[PN->getIncomingBlock(pred)];
+ if (BasicBlock *MappedBlock = cast_or_null<BasicBlock>(V)) {
+ Value *InVal = MapValue(PN->getIncomingValue(pred),
+ VMap,
+ ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
+ 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(VMap[&*OldI] == PN && "VMap mismatch");
+ VMap[&*OldI] = NV;
+ PN->eraseFromParent();
+ ++OldI;
+ }
+ }
+ }
+
+ // Make a second pass over the PHINodes now that all of them have been
+ // remapped into the new function, simplifying the PHINode and performing any
+ // recursive simplifications exposed. This will transparently update the
+ // WeakVH in the VMap. Notably, we rely on that so that if we coalesce
+ // two PHINodes, the iteration over the old PHIs remains valid, and the
+ // mapping will just map us to the new node (which may not even be a PHI
+ // node).
+ for (unsigned Idx = 0, Size = PHIToResolve.size(); Idx != Size; ++Idx)
+ if (PHINode *PN = dyn_cast<PHINode>(VMap[PHIToResolve[Idx]]))
+ recursivelySimplifyInstruction(PN);
+
+ // Now that the inlined function body has been fully constructed, go through
+ // and zap unconditional fall-through branches. This happens all the time when
+ // specializing code: code specialization turns conditional branches into
+ // uncond branches, and this code folds them.
+ Function::iterator Begin = cast<BasicBlock>(VMap[StartingBB])->getIterator();
+ Function::iterator I = Begin;
+ while (I != NewFunc->end()) {
+ // Check if this block has become dead during inlining or other
+ // simplifications. Note that the first block will appear dead, as it has
+ // not yet been wired up properly.
+ if (I != Begin && (pred_begin(&*I) == pred_end(&*I) ||
+ I->getSinglePredecessor() == &*I)) {
+ BasicBlock *DeadBB = &*I++;
+ DeleteDeadBlock(DeadBB);
+ continue;
+ }
+
+ // We need to simplify conditional branches and switches with a constant
+ // operand. We try to prune these out when cloning, but if the
+ // simplification required looking through PHI nodes, those are only
+ // available after forming the full basic block. That may leave some here,
+ // and we still want to prune the dead code as early as possible.
+ ConstantFoldTerminator(&*I);
+
+ BranchInst *BI = dyn_cast<BranchInst>(I->getTerminator());
+ if (!BI || BI->isConditional()) { ++I; continue; }
+
+ BasicBlock *Dest = BI->getSuccessor(0);
+ if (!Dest->getSinglePredecessor()) {
+ ++I; continue;
+ }
+
+ // We shouldn't be able to get single-entry PHI nodes here, as instsimplify
+ // above should have zapped all of them..
+ assert(!isa<PHINode>(Dest->begin()));
+
+ // We know all single-entry PHI nodes in the inlined function have been
+ // removed, so we just need to splice the blocks.
+ BI->eraseFromParent();
+
+ // Make all PHI nodes that referred to Dest now refer to I as their source.
+ Dest->replaceAllUsesWith(&*I);
+
+ // Move all the instructions in the succ to the pred.
+ I->getInstList().splice(I->end(), Dest->getInstList());
+
+ // Remove the dest block.
+ Dest->eraseFromParent();
+
+ // Do not increment I, iteratively merge all things this block branches to.
+ }
+
+ // Make a final pass over the basic blocks from the old function to gather
+ // any return instructions which survived folding. We have to do this here
+ // because we can iteratively remove and merge returns above.
+ for (Function::iterator I = cast<BasicBlock>(VMap[StartingBB])->getIterator(),
+ E = NewFunc->end();
+ I != E; ++I)
+ if (ReturnInst *RI = dyn_cast<ReturnInst>(I->getTerminator()))
+ Returns.push_back(RI);
+}
+
+
+/// 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,
+ ValueToValueMapTy &VMap,
+ bool ModuleLevelChanges,
+ SmallVectorImpl<ReturnInst*> &Returns,
+ const char *NameSuffix,
+ ClonedCodeInfo *CodeInfo,
+ Instruction *TheCall) {
+ CloneAndPruneIntoFromInst(NewFunc, OldFunc, &OldFunc->front().front(), VMap,
+ ModuleLevelChanges, Returns, NameSuffix, CodeInfo);
+}
+
+/// \brief Remaps instructions in \p Blocks using the mapping in \p VMap.
+void llvm::remapInstructionsInBlocks(
+ const SmallVectorImpl<BasicBlock *> &Blocks, ValueToValueMapTy &VMap) {
+ // Rewrite the code to refer to itself.
+ for (auto *BB : Blocks)
+ for (auto &Inst : *BB)
+ RemapInstruction(&Inst, VMap,
+ RF_NoModuleLevelChanges | RF_IgnoreMissingEntries);
+}
+
+/// \brief Clones a loop \p OrigLoop. Returns the loop and the blocks in \p
+/// Blocks.
+///
+/// Updates LoopInfo and DominatorTree assuming the loop is dominated by block
+/// \p LoopDomBB. Insert the new blocks before block specified in \p Before.
+Loop *llvm::cloneLoopWithPreheader(BasicBlock *Before, BasicBlock *LoopDomBB,
+ Loop *OrigLoop, ValueToValueMapTy &VMap,
+ const Twine &NameSuffix, LoopInfo *LI,
+ DominatorTree *DT,
+ SmallVectorImpl<BasicBlock *> &Blocks) {
+ Function *F = OrigLoop->getHeader()->getParent();
+ Loop *ParentLoop = OrigLoop->getParentLoop();
+
+ Loop *NewLoop = new Loop();
+ if (ParentLoop)
+ ParentLoop->addChildLoop(NewLoop);
+ else
+ LI->addTopLevelLoop(NewLoop);
+
+ BasicBlock *OrigPH = OrigLoop->getLoopPreheader();
+ assert(OrigPH && "No preheader");
+ BasicBlock *NewPH = CloneBasicBlock(OrigPH, VMap, NameSuffix, F);
+ // To rename the loop PHIs.
+ VMap[OrigPH] = NewPH;
+ Blocks.push_back(NewPH);
+
+ // Update LoopInfo.
+ if (ParentLoop)
+ ParentLoop->addBasicBlockToLoop(NewPH, *LI);
+
+ // Update DominatorTree.
+ DT->addNewBlock(NewPH, LoopDomBB);
+
+ for (BasicBlock *BB : OrigLoop->getBlocks()) {
+ BasicBlock *NewBB = CloneBasicBlock(BB, VMap, NameSuffix, F);
+ VMap[BB] = NewBB;
+
+ // Update LoopInfo.
+ NewLoop->addBasicBlockToLoop(NewBB, *LI);
+
+ // Update DominatorTree.
+ BasicBlock *IDomBB = DT->getNode(BB)->getIDom()->getBlock();
+ DT->addNewBlock(NewBB, cast<BasicBlock>(VMap[IDomBB]));
+
+ Blocks.push_back(NewBB);
+ }
+
+ // Move them physically from the end of the block list.
+ F->getBasicBlockList().splice(Before->getIterator(), F->getBasicBlockList(),
+ NewPH);
+ F->getBasicBlockList().splice(Before->getIterator(), F->getBasicBlockList(),
+ NewLoop->getHeader()->getIterator(), F->end());
- std::vector<ReturnInst*> Returns; // Ignore returns cloned...
- CloneFunctionInto(NewF, F, ValueMap, Returns);
- return NewF;
+ return NewLoop;
}
projects / oota-llvm.git / blobdiff