X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=lib%2FTransforms%2FUtils%2FCloneFunction.cpp;h=6454afb8bc42d3fa6803ce1a32e6f4d317f0f4d1;hp=7ecb103090b40f073b86c805e65aa2cf5cf025c9;hb=da92e119096b6e2e93efbf44ed07ea0a715cef9c;hpb=d04a8d4b33ff316ca4cf961e06c9e312eff8e64f diff --git a/lib/Transforms/Utils/CloneFunction.cpp b/lib/Transforms/Utils/CloneFunction.cpp index 7ecb103090b..6454afb8bc4 100644 --- a/lib/Transforms/Utils/CloneFunction.cpp +++ b/lib/Transforms/Utils/CloneFunction.cpp @@ -17,23 +17,25 @@ #include "llvm/ADT/SmallVector.h" #include "llvm/Analysis/ConstantFolding.h" #include "llvm/Analysis/InstructionSimplify.h" -#include "llvm/Constants.h" -#include "llvm/DebugInfo.h" -#include "llvm/DerivedTypes.h" -#include "llvm/Function.h" -#include "llvm/GlobalVariable.h" -#include "llvm/Instructions.h" -#include "llvm/IntrinsicInst.h" -#include "llvm/LLVMContext.h" -#include "llvm/Metadata.h" -#include "llvm/Support/CFG.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 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, @@ -50,8 +52,8 @@ BasicBlock *llvm::CloneBasicBlock(const BasicBlock *BB, 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(II) && !isa(II)); if (const AllocaInst *AI = dyn_cast(II)) { if (isa(AI->getArraySize())) @@ -78,37 +80,44 @@ void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc, bool ModuleLevelChanges, SmallVectorImpl &Returns, const char *NameSuffix, ClonedCodeInfo *CodeInfo, - ValueMapTypeRemapper *TypeMapper) { + 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(VMap[I])) - Anew->addAttr( OldFunc->getAttributes() - .getParamAttributes(I->getArgNo() + 1)); - NewFunc->setAttributes(NewFunc->getAttributes() - .addAttr(NewFunc->getContext(), - AttrListPtr::ReturnIndex, - OldFunc->getAttributes() - .getRetAttributes())); - NewFunc->setAttributes(NewFunc->getAttributes() - .addAttr(NewFunc->getContext(), - AttrListPtr::FunctionIndex, - 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(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 @@ -133,7 +142,7 @@ void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc, if (BB.hasAddressTaken()) { Constant *OldBBAddr = BlockAddress::get(const_cast(OldFunc), const_cast(&BB)); - VMap[OldBBAddr] = BlockAddress::get(NewFunc, CBB); + VMap[OldBBAddr] = BlockAddress::get(NewFunc, CBB); } // Note return instructions for the caller. @@ -143,16 +152,67 @@ void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc, // 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(VMap[OldFunc->begin()]), - BE = NewFunc->end(); BB != BE; ++BB) + for (Function::iterator BB = + cast(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, + for (Instruction &II : *BB) + RemapInstruction(&II, VMap, ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges, - TypeMapper); + 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; +} + +// 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 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)); } -/// CloneFunction - Return a copy of the specified function, but without +// 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(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, @@ -168,10 +228,9 @@ Function *llvm::CloneFunction(const Function *F, ValueToValueMapTy &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(), @@ -182,13 +241,15 @@ Function *llvm::CloneFunction(const Function *F, ValueToValueMapTy &VMap, // 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 Returns; // Ignore returns cloned. CloneFunctionInto(NewF, F, VMap, ModuleLevelChanges, Returns, "", CodeInfo); return NewF; @@ -197,8 +258,7 @@ Function *llvm::CloneFunction(const Function *F, ValueToValueMapTy &VMap, 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; @@ -206,29 +266,27 @@ namespace { bool ModuleLevelChanges; const char *NameSuffix; ClonedCodeInfo *CodeInfo; - const DataLayout *TD; + public: PruningFunctionCloner(Function *newFunc, const Function *oldFunc, - ValueToValueMapTy &valueMap, - bool moduleLevelChanges, - const char *nameSuffix, - ClonedCodeInfo *codeInfo, - const DataLayout *td) - : NewFunc(newFunc), OldFunc(oldFunc), - VMap(valueMap), ModuleLevelChanges(moduleLevelChanges), - 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 &ToClone); }; } -/// 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 &ToClone){ WeakVH &BBEntry = VMap[BB]; @@ -254,14 +312,14 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB, const_cast(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) { + Instruction *NewInst = II->clone(); // Eagerly remap operands to the newly cloned instruction, except for PHI @@ -273,13 +331,14 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB, // 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, TD)) { + 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; + VMap[&*II] = V; delete NewInst; continue; } @@ -287,9 +346,15 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB, if (II->hasName()) NewInst->setName(II->getName()+NameSuffix); - VMap[II] = NewInst; // Add instruction map to value. + VMap[&*II] = NewInst; // Add instruction map to value. NewBB->getInstList().push_back(NewInst); hasCalls |= (isa(II) && !isa(II)); + + if (CodeInfo) + if (auto CS = ImmutableCallSite(&*II)) + if (CS.hasOperandBundles()) + CodeInfo->OperandBundleCallSites.push_back(NewInst); + if (const AllocaInst *AI = dyn_cast(II)) { if (isa(AI->getArraySize())) hasStaticAllocas = true; @@ -306,7 +371,7 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB, // If the condition was a known constant in the callee... ConstantInt *Cond = dyn_cast(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(V); } @@ -322,7 +387,7 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB, } else if (const SwitchInst *SI = dyn_cast(OldTI)) { // If switching on a value known constant in the caller. ConstantInt *Cond = dyn_cast(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(V); } @@ -341,11 +406,16 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB, 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) { @@ -356,39 +426,46 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB, } } -/// 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 &Returns, - const char *NameSuffix, - ClonedCodeInfo *CodeInfo, - const DataLayout *TD, - Instruction *TheCall) { + SmallVectorImpl &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, - 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 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 @@ -397,27 +474,34 @@ void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, // // Defer PHI resolution until rest of function is resolved. SmallVector 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(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); // 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) - if (const PHINode *PN = dyn_cast(I)) - PHIToResolve.push_back(PN); - else + 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(I)) { + if (isa(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); + ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges, + TypeMapper, Materializer); } // Defer PHI resolution until rest of function is resolved, PHI resolution @@ -493,8 +577,8 @@ void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, while ((PN = dyn_cast(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; } @@ -510,21 +594,21 @@ void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, // node). for (unsigned Idx = 0, Size = PHIToResolve.size(); Idx != Size; ++Idx) if (PHINode *PN = dyn_cast(VMap[PHIToResolve[Idx]])) - recursivelySimplifyInstruction(PN, TD); + 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 Begin = cast(VMap[&OldFunc->getEntryBlock()]); + Function::iterator Begin = cast(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++; + if (I != Begin && (pred_begin(&*I) == pred_end(&*I) || + I->getSinglePredecessor() == &*I)) { + BasicBlock *DeadBB = &*I++; DeleteDeadBlock(DeadBB); continue; } @@ -534,7 +618,7 @@ void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, // 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); + ConstantFoldTerminator(&*I); BranchInst *BI = dyn_cast(I->getTerminator()); if (!BI || BI->isConditional()) { ++I; continue; } @@ -553,7 +637,7 @@ void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, 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()); @@ -564,12 +648,97 @@ void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, // Do not increment I, iteratively merge all things this block branches to. } - // Make a final pass over the basic blocks from theh old function to gather + // 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(VMap[&OldFunc->getEntryBlock()]), + for (Function::iterator I = cast(VMap[StartingBB])->getIterator(), E = NewFunc->end(); I != E; ++I) if (ReturnInst *RI = dyn_cast(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 &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 &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 &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(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; +}