//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/Cloning.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Instructions.h"
-#include "llvm/Function.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/DebugInfo.h"
+#include "llvm/IR/Constants.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/Support/CFG.h"
-#include "llvm/Support/Compiler.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/ValueMapper.h"
-#include "llvm/Analysis/ConstantFolding.h"
-#include "llvm/ADT/SmallVector.h"
#include <map>
using namespace llvm;
// CloneBasicBlock - See comments in Cloning.h
BasicBlock *llvm::CloneBasicBlock(const BasicBlock *BB,
- DenseMap<const Value*, Value*> &ValueMap,
- const char *NameSuffix, Function *F,
+ ValueToValueMapTy &VMap,
+ const Twine &NameSuffix, Function *F,
ClonedCodeInfo *CodeInfo) {
- BasicBlock *NewBB = new BasicBlock("", F);
+ BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), "", F);
if (BB->hasName()) NewBB->setName(BB->getName()+NameSuffix);
bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;
if (II->hasName())
NewInst->setName(II->getName()+NameSuffix);
NewBB->getInstList().push_back(NewInst);
- ValueMap[II] = NewInst; // Add instruction map to value.
+ VMap[II] = NewInst; // Add instruction map to value.
- hasCalls |= isa<CallInst>(II);
+ hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));
if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
if (isa<ConstantInt>(AI->getArraySize()))
hasStaticAllocas = true;
if (CodeInfo) {
CodeInfo->ContainsCalls |= hasCalls;
- CodeInfo->ContainsUnwinds |= isa<UnwindInst>(BB->getTerminator());
CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas &&
BB != &BB->getParent()->getEntryBlock();
}
// Clone OldFunc into NewFunc, transforming the old arguments into references to
-// ArgMap values.
+// VMap values.
//
void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
- DenseMap<const Value*, Value*> &ValueMap,
- std::vector<ReturnInst*> &Returns,
- const char *NameSuffix, ClonedCodeInfo *CodeInfo) {
+ ValueToValueMapTy &VMap,
+ bool ModuleLevelChanges,
+ SmallVectorImpl<ReturnInst*> &Returns,
+ const char *NameSuffix, ClonedCodeInfo *CodeInfo,
+ ValueMapTypeRemapper *TypeMapper) {
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(ValueMap.count(I) && "No mapping from source argument specified!");
+ 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(NewFunc->getContext(),
+ AttributeSet::ReturnIndex,
+ OldFunc->getAttributes()
+ .getRetAttributes()));
+ NewFunc->setAttributes(NewFunc->getAttributes()
+ .addAttr(NewFunc->getContext(),
+ AttributeSet::FunctionIndex,
+ OldFunc->getAttributes()
+ .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.
const BasicBlock &BB = *BI;
// Create a new basic block and copy instructions into it!
- BasicBlock *CBB = CloneBasicBlock(&BB, ValueMap, NameSuffix, NewFunc,
- CodeInfo);
- ValueMap[&BB] = CBB; // Add basic block mapping.
+ 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::iterator BB = cast<BasicBlock>(ValueMap[OldFunc->begin()]),
+ // 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)
// Loop over all instructions, fixing each one as we find it...
for (BasicBlock::iterator II = BB->begin(); II != BB->end(); ++II)
- RemapInstruction(II, ValueMap);
+ RemapInstruction(II, VMap,
+ ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges,
+ TypeMapper);
}
/// CloneFunction - 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 *llvm::CloneFunction(const Function *F,
- DenseMap<const Value*, Value*> &ValueMap,
+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 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_arg_iterator I = F->arg_begin(), E = F->arg_end();
I != E; ++I)
- if (ValueMap.count(I) == 0) // Haven't mapped the argument to anything yet?
+ if (VMap.count(I) == 0) // Haven't mapped the argument to anything yet?
ArgTypes.push_back(I->getType());
// Create a new function type...
ArgTypes, F->getFunctionType()->isVarArg());
// Create the new function...
- Function *NewF = new Function(FTy, F->getLinkage(), F->getName());
+ Function *NewF = Function::Create(FTy, F->getLinkage(), F->getName());
// 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 (ValueMap.count(I) == 0) { // Is this argument preserved?
+ if (VMap.count(I) == 0) { // Is this argument preserved?
DestI->setName(I->getName()); // Copy the name over...
- ValueMap[I] = DestI++; // Add mapping to ValueMap
+ VMap[I] = DestI++; // Add mapping to VMap
}
- std::vector<ReturnInst*> Returns; // Ignore returns cloned...
- CloneFunctionInto(NewF, F, ValueMap, Returns, "", CodeInfo);
+ 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.
- struct VISIBILITY_HIDDEN PruningFunctionCloner {
+ struct PruningFunctionCloner {
Function *NewFunc;
const Function *OldFunc;
- DenseMap<const Value*, Value*> &ValueMap;
- std::vector<ReturnInst*> &Returns;
+ ValueToValueMapTy &VMap;
+ bool ModuleLevelChanges;
const char *NameSuffix;
ClonedCodeInfo *CodeInfo;
- const TargetData *TD;
-
+ const DataLayout *TD;
public:
PruningFunctionCloner(Function *newFunc, const Function *oldFunc,
- DenseMap<const Value*, Value*> &valueMap,
- std::vector<ReturnInst*> &returns,
+ ValueToValueMapTy &valueMap,
+ bool moduleLevelChanges,
const char *nameSuffix,
ClonedCodeInfo *codeInfo,
- const TargetData *td)
- : NewFunc(newFunc), OldFunc(oldFunc), ValueMap(valueMap), Returns(returns),
+ const DataLayout *td)
+ : NewFunc(newFunc), OldFunc(oldFunc),
+ VMap(valueMap), ModuleLevelChanges(moduleLevelChanges),
NameSuffix(nameSuffix), CodeInfo(codeInfo), TD(td) {
}
/// anything that it can reach.
void CloneBlock(const BasicBlock *BB,
std::vector<const BasicBlock*> &ToClone);
-
- public:
- /// ConstantFoldMappedInstruction - Constant fold the specified instruction,
- /// mapping its operands through ValueMap if they are available.
- Constant *ConstantFoldMappedInstruction(const Instruction *I);
};
}
/// anything that it can reach.
void PruningFunctionCloner::CloneBlock(const BasicBlock *BB,
std::vector<const BasicBlock*> &ToClone){
- Value *&BBEntry = ValueMap[BB];
+ WeakVH &BBEntry = VMap[BB];
// Have we already cloned this block?
if (BBEntry) return;
// Nope, clone it now.
BasicBlock *NewBB;
- BBEntry = NewBB = new BasicBlock();
+ 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();
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)) {
- ValueMap[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, TD)) {
+ // 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);
- ValueMap[II] = NewInst; // Add instruction map to value.
-
- hasCalls |= isa<CallInst>(II);
+ hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));
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)
- Cond = dyn_cast_or_null<ConstantInt>(ValueMap[BI->getCondition()]);
+ if (Cond == 0) {
+ 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());
- ValueMap[OldTI] = new BranchInst(Dest, NewBB);
+ 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 == 0) // Or known constant after constant prop in the callee...
- Cond = dyn_cast_or_null<ConstantInt>(ValueMap[SI->getCondition()]);
+ if (Cond == 0) { // 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));
- ValueMap[OldTI] = new BranchInst(Dest, NewBB);
+ 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 (OldTI->hasName())
NewInst->setName(OldTI->getName()+NameSuffix);
NewBB->getInstList().push_back(NewInst);
- ValueMap[OldTI] = NewInst; // Add instruction map to value.
+ VMap[OldTI] = NewInst; // Add instruction map to value.
// Recursively clone any reachable successor blocks.
const TerminatorInst *TI = BB->getTerminator();
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 ValueMap 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),
- ValueMap)))
- Ops.push_back(Op);
- else
- return 0; // All operands not constant!
-
- return ConstantFoldInstOperands(I, &Ops[0], Ops.size(), TD);
}
/// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto,
/// 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 exactly copy of the input, it can't be
+/// dead. Since this doesn't produce an exact copy of the input, it can't be
/// used for things like CloneFunction or CloneModule.
void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc,
- DenseMap<const Value*, Value*> &ValueMap,
- std::vector<ReturnInst*> &Returns,
+ ValueToValueMapTy &VMap,
+ bool ModuleLevelChanges,
+ SmallVectorImpl<ReturnInst*> &Returns,
const char *NameSuffix,
ClonedCodeInfo *CodeInfo,
- const TargetData *TD) {
+ const DataLayout *TD,
+ Instruction *TheCall) {
assert(NameSuffix && "NameSuffix cannot be null!");
#ifndef NDEBUG
for (Function::const_arg_iterator II = OldFunc->arg_begin(),
E = OldFunc->arg_end(); II != E; ++II)
- assert(ValueMap.count(II) && "No mapping from source argument specified!");
+ assert(VMap.count(II) && "No mapping from source argument specified!");
#endif
-
- PruningFunctionCloner PFC(NewFunc, OldFunc, ValueMap, Returns,
+
+ PruningFunctionCloner PFC(NewFunc, OldFunc, VMap, ModuleLevelChanges,
NameSuffix, CodeInfo, TD);
// Clone the entry block, and anything recursively reachable from it.
// insert it into the new function in the right order. If not, ignore it.
//
// Defer PHI resolution until rest of function is resolved.
- std::vector<const PHINode*> PHIToResolve;
+ SmallVector<const PHINode*, 16> PHIToResolve;
for (Function::const_iterator BI = OldFunc->begin(), BE = OldFunc->end();
BI != BE; ++BI) {
- BasicBlock *NewBB = cast_or_null<BasicBlock>(ValueMap[BI]);
+ Value *V = VMap[BI];
+ BasicBlock *NewBB = cast_or_null<BasicBlock>(V);
if (NewBB == 0) continue; // Dead block.
// Add the new block to the new function.
NewFunc->getBasicBlockList().push_back(NewBB);
-
- // Loop over all of the instructions in the block, fixing up operand
- // references as we go. This uses ValueMap to do all the hard work.
- //
- BasicBlock::iterator I = NewBB->begin();
-
+
// 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));
- }
-
- // Otherwise, remap the rest of the instructions normally.
- for (; I != NewBB->end(); ++I)
- RemapInstruction(I, ValueMap);
+ 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);
}
// Defer PHI resolution until rest of function is resolved, PHI resolution
const PHINode *OPN = PHIToResolve[phino];
unsigned NumPreds = OPN->getNumIncomingValues();
const BasicBlock *OldBB = OPN->getParent();
- BasicBlock *NewBB = cast<BasicBlock>(ValueMap[OldBB]);
+ 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>(ValueMap[OPN]);
+ PHINode *PN = cast<PHINode>(VMap[OPN]);
for (unsigned pred = 0, e = NumPreds; pred != e; ++pred) {
- if (BasicBlock *MappedBlock =
- cast_or_null<BasicBlock>(ValueMap[PN->getIncomingBlock(pred)])) {
- Value *InVal = MapValue(PN->getIncomingValue(pred), ValueMap);
+ 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);
while ((PN = dyn_cast<PHINode>(I++))) {
Value *NV = UndefValue::get(PN->getType());
PN->replaceAllUsesWith(NV);
- assert(ValueMap[OldI] == PN && "ValueMap mismatch");
- ValueMap[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
- // ValueMap. Single entry phi nodes can have multiple ValueMap entries
- // pointing at them. Thus, deleting one would require scanning the ValueMap
- // to update any entries in it that would require that. This would be
- // really slow.
}
-
+
+ // 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, TD);
+
// Now that the inlined function body has been fully constructed, go through
// and zap unconditional fall-through branches. This happen all the time when
// specializing code: code specialization turns conditional branches into
// uncond branches, and this code folds them.
- Function::iterator I = cast<BasicBlock>(ValueMap[&OldFunc->getEntryBlock()]);
+ Function::iterator Begin = cast<BasicBlock>(VMap[&OldFunc->getEntryBlock()]);
+ 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 ValueMap 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[&OldFunc->getEntryBlock()]),
+ E = NewFunc->end();
+ I != E; ++I)
+ if (ReturnInst *RI = dyn_cast<ReturnInst>(I->getTerminator()))
+ Returns.push_back(RI);
}
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