//===----------------------------------------------------------------------===//
#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/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;
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
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);
+
+ 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 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);
+ ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges,
+ TypeMapper, Materializer);
+}
+
+// Find the MDNode which corresponds to the DISubprogram data that described F.
+static MDNode* 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, DIArray SPs, Metadata *NewSP) {
+ SmallVector<Metadata *, 16> NewSPs;
+ NewSPs.reserve(SPs->getNumOperands() + 1);
+ for (unsigned I = 0, E = SPs->getNumOperands(); I != E; ++I)
+ NewSPs.push_back(SPs->getOperand(I));
+ NewSPs.push_back(NewSP);
+ CU.replaceSubprograms(DIArray(MDNode::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 MDNode *OldSubprogramMDNode = FindSubprogram(OldFunc, Finder);
+ if (!OldSubprogramMDNode) return;
+
+ // Ensure that OldFunc appears in the map.
+ // (if it's already there it must point to NewFunc anyway)
+ VMap[OldFunc] = NewFunc;
+ DISubprogram NewSubprogram(MapMetadata(OldSubprogramMDNode, VMap));
+
+ for (DICompileUnit CU : Finder.compile_units()) {
+ DIArray Subprograms(CU.getSubprograms());
+
+ // If the compile unit's function list contains the old function, it should
+ // also contain the new one.
+ for (unsigned i = 0; i < Subprograms.getNumElements(); i++) {
+ if ((MDNode*)Subprograms.getElement(i) == OldSubprogramMDNode) {
+ AddOperand(CU, Subprograms, NewSubprogram);
+ break;
+ }
+ }
+ }
}
/// CloneFunction - Return a copy of the specified function, but without
Function *llvm::CloneFunction(const Function *F, ValueToValueMapTy &VMap,
bool ModuleLevelChanges,
ClonedCodeInfo *CodeInfo) {
- std::vector<const Type*> ArgTypes;
+ std::vector<Type*> ArgTypes;
// 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
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;
const Function *OldFunc;
ValueToValueMapTy &VMap;
bool ModuleLevelChanges;
- SmallVectorImpl<ReturnInst*> &Returns;
const char *NameSuffix;
ClonedCodeInfo *CodeInfo;
- const TargetData *TD;
+ CloningDirector *Director;
+ ValueMapTypeRemapper *TypeMapper;
+ ValueMaterializer *Materializer;
+
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,
+ CloningDirector *Director)
+ : NewFunc(newFunc), OldFunc(oldFunc), VMap(valueMap),
+ ModuleLevelChanges(moduleLevelChanges), NameSuffix(nameSuffix),
+ CodeInfo(codeInfo), Director(Director) {
+ // These are optional components. The Director may return null.
+ if (Director) {
+ TypeMapper = Director->getTypeRemapper();
+ Materializer = Director->getValueMaterializer();
+ } else {
+ TypeMapper = nullptr;
+ Materializer = nullptr;
+ }
}
/// CloneBlock - 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
/// 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;
+ // If the "Director" remaps the instruction, don't clone it.
+ if (Director) {
+ CloningDirector::CloningAction Action
+ = Director->handleInstruction(VMap, II, NewBB);
+ // If the cloning director says stop, we want to stop everything, not
+ // just break out of the loop (which would cause the terminator to be
+ // cloned). The cloning director is responsible for inserting a proper
+ // terminator into the new basic block in this case.
+ if (Action == CloningDirector::StopCloningBB)
+ return;
+ // If the cloning director says skip, continue to the next instruction.
+ // In this case, the cloning director is responsible for mapping the
+ // skipped instruction to some value that is defined in the new
+ // basic block.
+ if (Action == CloningDirector::SkipInstruction)
+ 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,
+ TypeMapper, Materializer);
+
+ // 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);
- NewBB->getInstList().push_back(NewInst);
VMap[II] = NewInst; // Add instruction map to value.
-
+ NewBB->getInstList().push_back(NewInst);
hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));
if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
if (isa<ConstantInt>(AI->getArraySize()))
// Finally, clone over the terminator.
const TerminatorInst *OldTI = BB->getTerminator();
bool TerminatorDone = false;
+ if (Director) {
+ CloningDirector::CloningAction Action
+ = Director->handleInstruction(VMap, OldTI, NewBB);
+ // If the cloning director says stop, we want to stop everything, not
+ // just break out of the loop (which would cause the terminator to be
+ // cloned). The cloning director is responsible for inserting a proper
+ // terminator into the new basic block in this case.
+ if (Action == CloningDirector::StopCloningBB)
+ return;
+ assert(Action != CloningDirector::SkipInstruction &&
+ "SkipInstruction is not valid for terminators.");
+ }
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 == 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;
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[0],
- Ops.size(), TD);
-}
-
-static DebugLoc
-UpdateInlinedAtInfo(const DebugLoc &InsnDL, const DebugLoc &TheCallDL,
- LLVMContext &Ctx) {
- DebugLoc NewLoc = TheCallDL;
- if (MDNode *IA = InsnDL.getInlinedAt(Ctx))
- NewLoc = UpdateInlinedAtInfo(DebugLoc::getFromDILocation(IA), TheCallDL,
- Ctx);
-
- return DebugLoc::get(InsnDL.getLine(), InsnDL.getCol(),
- InsnDL.getScope(Ctx), NewLoc.getAsMDNode(Ctx));
}
-/// 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,
+/// CloneAndPruneIntoFromInst - 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,
+ SmallVectorImpl<ReturnInst *> &Returns,
const char *NameSuffix,
ClonedCodeInfo *CodeInfo,
- const TargetData *TD,
- Instruction *TheCall) {
+ CloningDirector *Director) {
assert(NameSuffix && "NameSuffix cannot be null!");
-
+
+ ValueMapTypeRemapper *TypeMapper = nullptr;
+ ValueMaterializer *Materializer = nullptr;
+
+ if (Director) {
+ TypeMapper = Director->getTypeRemapper();
+ Materializer = Director->getValueMaterializer();
+ }
+
#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 begining of the function, verify that
+ // the function arguments are mapped.
+ if (!StartingInst)
+ 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!");
#endif
PruningFunctionCloner PFC(NewFunc, OldFunc, VMap, ModuleLevelChanges,
- Returns, NameSuffix, CodeInfo, TD);
+ NameSuffix, CodeInfo, Director);
+ const BasicBlock *StartingBB;
+ if (StartingInst)
+ StartingBB = StartingInst->getParent();
+ else {
+ StartingBB = &OldFunc->getEntryBlock();
+ StartingInst = StartingBB->begin();
+ }
// Clone the entry block, and anything recursively reachable from it.
std::vector<const BasicBlock*> CloneWorklist;
- CloneWorklist.push_back(&OldFunc->getEntryBlock());
+ PFC.CloneBlock(StartingBB, StartingInst, 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
BI != BE; ++BI) {
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) {
- if (I->hasMetadata()) {
- if (!TheCallDL.isUnknown()) {
- DebugLoc IDL = I->getDebugLoc();
- if (!IDL.isUnknown()) {
- DebugLoc NewDL = UpdateInlinedAtInfo(IDL, TheCallDL,
- I->getContext());
- I->setDebugLoc(NewDL);
- }
- } else {
- // The cloned instruction has dbg info but the call instruction
- // does not have dbg info. Remove dbg info from cloned instruction.
- I->setDebugLoc(DebugLoc());
- }
- }
- PHIToResolve.push_back(cast<PHINode>(OldI));
- }
- }
-
- // FIXME:
- // FIXME:
- // FIXME: Unclone all this metadata stuff.
- // FIXME:
- // FIXME:
-
- // Otherwise, remap the rest of the instructions normally.
- for (; I != NewBB->end(); ++I) {
- if (I->hasMetadata()) {
- if (!TheCallDL.isUnknown()) {
- DebugLoc IDL = I->getDebugLoc();
- if (!IDL.isUnknown()) {
- DebugLoc NewDL = UpdateInlinedAtInfo(IDL, TheCallDL,
- I->getContext());
- I->setDebugLoc(NewDL);
- }
- } else {
- // The cloned instruction has dbg info but the call instruction
- // does not have dbg info. Remove dbg info from cloned instruction.
- I->setDebugLoc(DebugLoc());
- }
- }
- RemapInstruction(I, VMap,
- ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
- }
+ for (BasicBlock::const_iterator I = BI->begin(), E = BI->end(); I != E; ++I)
+ if (const PHINode *PN = dyn_cast<PHINode>(I))
+ PHIToResolve.push_back(PN);
+ 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
++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
// 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]);
+ 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();
- // 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);
+ // 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 theh 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]),
+ E = NewFunc->end();
+ I != E; ++I)
+ if (ReturnInst *RI = dyn_cast<ReturnInst>(I->getTerminator()))
+ Returns.push_back(RI);
+}
+
+
+/// 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,
+ ValueToValueMapTy &VMap,
+ bool ModuleLevelChanges,
+ SmallVectorImpl<ReturnInst*> &Returns,
+ const char *NameSuffix,
+ ClonedCodeInfo *CodeInfo,
+ Instruction *TheCall) {
+ CloneAndPruneIntoFromInst(NewFunc, OldFunc, OldFunc->front().begin(), VMap,
+ ModuleLevelChanges, Returns, NameSuffix, CodeInfo,
+ nullptr);
}
projects / oota-llvm.git / blobdiff