//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/Cloning.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Instructions.h"
-#include "llvm/IntrinsicInst.h"
-#include "llvm/GlobalVariable.h"
-#include "llvm/Function.h"
-#include "llvm/LLVMContext.h"
-#include "llvm/Metadata.h"
-#include "llvm/Support/CFG.h"
-#include "llvm/Transforms/Utils/ValueMapper.h"
-#include "llvm/Analysis/ConstantFolding.h"
-#include "llvm/Analysis/DebugInfo.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;
-// CloneBasicBlock - See comments in Cloning.h
+/// See comments in Cloning.h.
BasicBlock *llvm::CloneBasicBlock(const BasicBlock *BB,
ValueToValueMapTy &VMap,
const Twine &NameSuffix, Function *F,
if (II->hasName())
NewInst->setName(II->getName()+NameSuffix);
NewBB->getInstList().push_back(NewInst);
- VMap[II] = NewInst; // Add instruction map to value.
-
+ 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()))
if (CodeInfo) {
CodeInfo->ContainsCalls |= hasCalls;
- CodeInfo->ContainsUnwinds |= isa<UnwindInst>(BB->getTerminator());
CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas &&
BB != &BB->getParent()->getEntryBlock();
ValueToValueMapTy &VMap,
bool ModuleLevelChanges,
SmallVectorImpl<ReturnInst*> &Returns,
- const char *NameSuffix, ClonedCodeInfo *CodeInfo) {
+ const char *NameSuffix, ClonedCodeInfo *CodeInfo,
+ ValueMapTypeRemapper *TypeMapper,
+ ValueMaterializer *Materializer) {
assert(NameSuffix && "NameSuffix cannot be null!");
#ifndef NDEBUG
- for (Function::const_arg_iterator I = OldFunc->arg_begin(),
- E = OldFunc->arg_end(); I != E; ++I)
- assert(VMap.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
- // Clone any attributes.
- if (NewFunc->arg_size() == OldFunc->arg_size())
- NewFunc->copyAttributesFrom(OldFunc);
- else {
- //Some arguments were deleted with the VMap. Copy arguments one by one
- for (Function::const_arg_iterator I = OldFunc->arg_begin(),
- E = OldFunc->arg_end(); I != E; ++I)
- if (Argument* Anew = dyn_cast<Argument>(VMap[I]))
- Anew->addAttr( OldFunc->getAttributes()
- .getParamAttributes(I->getArgNo() + 1));
- NewFunc->setAttributes(NewFunc->getAttributes()
- .addAttr(0, OldFunc->getAttributes()
- .getRetAttributes()));
- NewFunc->setAttributes(NewFunc->getAttributes()
- .addAttr(~0, OldFunc->getAttributes()
- .getFnAttributes()));
+ // 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
// Create a new basic block and copy instructions into it!
BasicBlock *CBB = CloneBasicBlock(&BB, VMap, NameSuffix, NewFunc, CodeInfo);
- VMap[&BB] = CBB; // Add basic block mapping.
+ // 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 VMap to do all the hard work.
- for (Function::iterator BB = cast<BasicBlock>(VMap[OldFunc->begin()]),
- BE = NewFunc->end(); BB != BE; ++BB)
+ 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 = BB->begin(); II != BB->end(); ++II)
- RemapInstruction(II, VMap,
- ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
+ 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 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 user might be deleting arguments to the function by specifying them in
// the VMap. If so, we need to not add the arguments to the arg ty vector
//
- for (Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
- I != E; ++I)
- if (VMap.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(),
// Loop over the arguments, copying the names of the mapped arguments over...
Function::arg_iterator DestI = NewF->arg_begin();
- for (Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
- I != E; ++I)
- if (VMap.count(I) == 0) { // Is this argument preserved?
- DestI->setName(I->getName()); // Copy the name over...
- VMap[I] = DestI++; // Add mapping to VMap
+ 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 {
- /// PruningFunctionCloner - This class is a private class used to implement
- /// the CloneAndPruneFunctionInto method.
+ /// This is a private class used to implement CloneAndPruneFunctionInto.
struct PruningFunctionCloner {
Function *NewFunc;
const Function *OldFunc;
ValueToValueMapTy &VMap;
bool ModuleLevelChanges;
- SmallVectorImpl<ReturnInst*> &Returns;
const char *NameSuffix;
ClonedCodeInfo *CodeInfo;
- const TargetData *TD;
+
public:
PruningFunctionCloner(Function *newFunc, const Function *oldFunc,
- ValueToValueMapTy &valueMap,
- bool moduleLevelChanges,
- SmallVectorImpl<ReturnInst*> &returns,
- const char *nameSuffix,
- ClonedCodeInfo *codeInfo,
- const TargetData *td)
- : NewFunc(newFunc), OldFunc(oldFunc),
- VMap(valueMap), ModuleLevelChanges(moduleLevelChanges),
- Returns(returns), NameSuffix(nameSuffix), CodeInfo(codeInfo), TD(td) {
- }
+ ValueToValueMapTy &valueMap, bool moduleLevelChanges,
+ const char *nameSuffix, ClonedCodeInfo *codeInfo)
+ : NewFunc(newFunc), OldFunc(oldFunc), VMap(valueMap),
+ ModuleLevelChanges(moduleLevelChanges), NameSuffix(nameSuffix),
+ CodeInfo(codeInfo) {}
- /// CloneBlock - The specified block is found to be reachable, clone it and
+ /// The specified block is found to be reachable, clone it and
/// anything that it can reach.
- void CloneBlock(const BasicBlock *BB,
+ void CloneBlock(const BasicBlock *BB,
+ BasicBlock::const_iterator StartingInst,
std::vector<const BasicBlock*> &ToClone);
-
- public:
- /// ConstantFoldMappedInstruction - Constant fold the specified instruction,
- /// mapping its operands through VMap if they are available.
- Constant *ConstantFoldMappedInstruction(const Instruction *I);
};
}
-/// CloneBlock - The specified block is found to be reachable, clone it and
+/// 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){
- TrackingVH<Value> &BBEntry = VMap[BB];
+ WeakVH &BBEntry = VMap[BB];
// Have we already cloned this block?
if (BBEntry) return;
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 = BB->begin(), IE = --BB->end();
+ for (BasicBlock::const_iterator II = StartingInst, IE = --BB->end();
II != IE; ++II) {
- // If this instruction constant folds, don't bother cloning the instruction,
- // instead, just add the constant to the value map.
- if (Constant *C = ConstantFoldMappedInstruction(II)) {
- VMap[II] = C;
- continue;
- }
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);
- VMap[II] = NewInst; // Add instruction map to value.
-
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;
// 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 == 0) {
+ if (!Cond) {
Value *V = VMap[BI->getCondition()];
Cond = dyn_cast_or_null<ConstantInt>(V);
}
} 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 == 0) { // Or known constant after constant prop in the callee...
+ 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!
- BasicBlock *Dest = SI->getSuccessor(SI->findCaseValue(Cond));
+ 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;
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 (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
- ToClone.push_back(TI->getSuccessor(i));
+ for (const BasicBlock *Succ : TI->successors())
+ ToClone.push_back(Succ);
}
if (CodeInfo) {
CodeInfo->ContainsCalls |= hasCalls;
- CodeInfo->ContainsUnwinds |= isa<UnwindInst>(OldTI);
CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas &&
BB != &BB->getParent()->front();
}
-
- if (ReturnInst *RI = dyn_cast<ReturnInst>(NewBB->getTerminator()))
- Returns.push_back(RI);
-}
-
-/// ConstantFoldMappedInstruction - Constant fold the specified instruction,
-/// mapping its operands through VMap if they are available.
-Constant *PruningFunctionCloner::
-ConstantFoldMappedInstruction(const Instruction *I) {
- SmallVector<Constant*, 8> Ops;
- for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
- if (Constant *Op = dyn_cast_or_null<Constant>(MapValue(I->getOperand(i),
- VMap,
- ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges)))
- Ops.push_back(Op);
- else
- return 0; // All operands not constant!
-
- if (const CmpInst *CI = dyn_cast<CmpInst>(I))
- return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1],
- TD);
-
- if (const LoadInst *LI = dyn_cast<LoadInst>(I))
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0]))
- if (!LI->isVolatile() && CE->getOpcode() == Instruction::GetElementPtr)
- if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
- if (GV->isConstant() && GV->hasDefinitiveInitializer())
- return ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(),
- CE);
-
- return ConstantFoldInstOperands(I->getOpcode(), I->getType(), Ops, TD);
}
-/// 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,
+/// 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,
- const TargetData *TD,
- Instruction *TheCall) {
+ SmallVectorImpl<ReturnInst *> &Returns,
+ const char *NameSuffix,
+ ClonedCodeInfo *CodeInfo) {
assert(NameSuffix && "NameSuffix cannot be null!");
-
+
+ ValueMapTypeRemapper *TypeMapper = nullptr;
+ ValueMaterializer *Materializer = nullptr;
+
#ifndef NDEBUG
- for (Function::const_arg_iterator II = OldFunc->arg_begin(),
- E = OldFunc->arg_end(); II != E; ++II)
- assert(VMap.count(II) && "No mapping from source argument specified!");
+ // 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,
- Returns, NameSuffix, CodeInfo, TD);
+ 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;
- CloneWorklist.push_back(&OldFunc->getEntryBlock());
+ PFC.CloneBlock(StartingBB, StartingInst->getIterator(), CloneWorklist);
while (!CloneWorklist.empty()) {
const BasicBlock *BB = CloneWorklist.back();
CloneWorklist.pop_back();
- PFC.CloneBlock(BB, CloneWorklist);
+ PFC.CloneBlock(BB, BB->begin(), CloneWorklist);
}
// Loop over all of the basic blocks in the old function. If the block was
//
// 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) {
- Value *V = VMap[BI];
+ for (const BasicBlock &BI : *OldFunc) {
+ Value *V = VMap[&BI];
BasicBlock *NewBB = cast_or_null<BasicBlock>(V);
- if (NewBB == 0) continue; // Dead block.
+ if (!NewBB) 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 VMap to do all the hard work.
- //
- BasicBlock::iterator I = NewBB->begin();
-
- DebugLoc TheCallDL;
- if (TheCall)
- TheCallDL = TheCall->getDebugLoc();
-
+
// 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)
- PHIToResolve.push_back(cast<PHINode>(OldI));
+ 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;
+ }
}
-
- // Otherwise, remap the rest of the instructions normally.
- for (; I != NewBB->end(); ++I)
- RemapInstruction(I, VMap,
- ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
+
+ // 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
while ((PN = dyn_cast<PHINode>(I++))) {
Value *NV = UndefValue::get(PN->getType());
PN->replaceAllUsesWith(NV);
- assert(VMap[OldI] == PN && "VMap mismatch");
- VMap[OldI] = NV;
+ assert(VMap[&*OldI] == PN && "VMap mismatch");
+ VMap[&*OldI] = NV;
PN->eraseFromParent();
++OldI;
}
}
- // NOTE: We cannot eliminate single entry phi nodes here, because of
- // VMap. Single entry phi nodes can have multiple VMap entries
- // pointing at them. Thus, deleting one would require scanning the VMap
- // to update any entries in it that would require that. This would be
- // really slow.
}
-
+
+ // 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 happen all the time when
+ // 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 I = cast<BasicBlock>(VMap[&OldFunc->getEntryBlock()]);
+ 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; }
- // 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 VMap to update any entries that point to the phi
- // node.
BasicBlock *Dest = BI->getSuccessor(0);
- if (!Dest->getSinglePredecessor() || isa<PHINode>(Dest->begin())) {
+ 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);
+ Dest->replaceAllUsesWith(&*I);
// Move all the instructions in the succ to the pred.
I->getInstList().splice(I->end(), Dest->getInstList());
// 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());
+
+ return NewLoop;
}