forked from OSchip/llvm-project
1457 lines
60 KiB
C++
1457 lines
60 KiB
C++
//===- InlineFunction.cpp - Code to perform function inlining -------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements inlining of a function into a call site, resolving
|
|
// parameters and the return value as appropriate.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Transforms/Utils/Cloning.h"
|
|
#include "llvm/ADT/SmallSet.h"
|
|
#include "llvm/ADT/SmallVector.h"
|
|
#include "llvm/ADT/SetVector.h"
|
|
#include "llvm/ADT/StringExtras.h"
|
|
#include "llvm/Analysis/AliasAnalysis.h"
|
|
#include "llvm/Analysis/AssumptionCache.h"
|
|
#include "llvm/Analysis/CallGraph.h"
|
|
#include "llvm/Analysis/CaptureTracking.h"
|
|
#include "llvm/Analysis/InstructionSimplify.h"
|
|
#include "llvm/Analysis/ValueTracking.h"
|
|
#include "llvm/IR/Attributes.h"
|
|
#include "llvm/IR/CallSite.h"
|
|
#include "llvm/IR/CFG.h"
|
|
#include "llvm/IR/Constants.h"
|
|
#include "llvm/IR/DataLayout.h"
|
|
#include "llvm/IR/DebugInfo.h"
|
|
#include "llvm/IR/DerivedTypes.h"
|
|
#include "llvm/IR/DIBuilder.h"
|
|
#include "llvm/IR/Dominators.h"
|
|
#include "llvm/IR/IRBuilder.h"
|
|
#include "llvm/IR/Instructions.h"
|
|
#include "llvm/IR/IntrinsicInst.h"
|
|
#include "llvm/IR/Intrinsics.h"
|
|
#include "llvm/IR/MDBuilder.h"
|
|
#include "llvm/IR/Module.h"
|
|
#include "llvm/Transforms/Utils/Local.h"
|
|
#include "llvm/Support/CommandLine.h"
|
|
#include <algorithm>
|
|
using namespace llvm;
|
|
|
|
static cl::opt<bool>
|
|
EnableNoAliasConversion("enable-noalias-to-md-conversion", cl::init(true),
|
|
cl::Hidden,
|
|
cl::desc("Convert noalias attributes to metadata during inlining."));
|
|
|
|
static cl::opt<bool>
|
|
PreserveAlignmentAssumptions("preserve-alignment-assumptions-during-inlining",
|
|
cl::init(true), cl::Hidden,
|
|
cl::desc("Convert align attributes to assumptions during inlining."));
|
|
|
|
bool llvm::InlineFunction(CallInst *CI, InlineFunctionInfo &IFI,
|
|
bool InsertLifetime) {
|
|
return InlineFunction(CallSite(CI), IFI, InsertLifetime);
|
|
}
|
|
bool llvm::InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI,
|
|
bool InsertLifetime) {
|
|
return InlineFunction(CallSite(II), IFI, InsertLifetime);
|
|
}
|
|
|
|
namespace {
|
|
/// A class for recording information about inlining through an invoke.
|
|
class InvokeInliningInfo {
|
|
BasicBlock *OuterResumeDest; ///< Destination of the invoke's unwind.
|
|
BasicBlock *InnerResumeDest; ///< Destination for the callee's resume.
|
|
LandingPadInst *CallerLPad; ///< LandingPadInst associated with the invoke.
|
|
PHINode *InnerEHValuesPHI; ///< PHI for EH values from landingpad insts.
|
|
SmallVector<Value*, 8> UnwindDestPHIValues;
|
|
|
|
public:
|
|
InvokeInliningInfo(InvokeInst *II)
|
|
: OuterResumeDest(II->getUnwindDest()), InnerResumeDest(nullptr),
|
|
CallerLPad(nullptr), InnerEHValuesPHI(nullptr) {
|
|
// If there are PHI nodes in the unwind destination block, we need to keep
|
|
// track of which values came into them from the invoke before removing
|
|
// the edge from this block.
|
|
llvm::BasicBlock *InvokeBB = II->getParent();
|
|
BasicBlock::iterator I = OuterResumeDest->begin();
|
|
for (; isa<PHINode>(I); ++I) {
|
|
// Save the value to use for this edge.
|
|
PHINode *PHI = cast<PHINode>(I);
|
|
UnwindDestPHIValues.push_back(PHI->getIncomingValueForBlock(InvokeBB));
|
|
}
|
|
|
|
CallerLPad = cast<LandingPadInst>(I);
|
|
}
|
|
|
|
/// getOuterResumeDest - The outer unwind destination is the target of
|
|
/// unwind edges introduced for calls within the inlined function.
|
|
BasicBlock *getOuterResumeDest() const {
|
|
return OuterResumeDest;
|
|
}
|
|
|
|
BasicBlock *getInnerResumeDest();
|
|
|
|
LandingPadInst *getLandingPadInst() const { return CallerLPad; }
|
|
|
|
/// forwardResume - Forward the 'resume' instruction to the caller's landing
|
|
/// pad block. When the landing pad block has only one predecessor, this is
|
|
/// a simple branch. When there is more than one predecessor, we need to
|
|
/// split the landing pad block after the landingpad instruction and jump
|
|
/// to there.
|
|
void forwardResume(ResumeInst *RI,
|
|
SmallPtrSetImpl<LandingPadInst*> &InlinedLPads);
|
|
|
|
/// addIncomingPHIValuesFor - Add incoming-PHI values to the unwind
|
|
/// destination block for the given basic block, using the values for the
|
|
/// original invoke's source block.
|
|
void addIncomingPHIValuesFor(BasicBlock *BB) const {
|
|
addIncomingPHIValuesForInto(BB, OuterResumeDest);
|
|
}
|
|
|
|
void addIncomingPHIValuesForInto(BasicBlock *src, BasicBlock *dest) const {
|
|
BasicBlock::iterator I = dest->begin();
|
|
for (unsigned i = 0, e = UnwindDestPHIValues.size(); i != e; ++i, ++I) {
|
|
PHINode *phi = cast<PHINode>(I);
|
|
phi->addIncoming(UnwindDestPHIValues[i], src);
|
|
}
|
|
}
|
|
};
|
|
}
|
|
|
|
/// getInnerResumeDest - Get or create a target for the branch from ResumeInsts.
|
|
BasicBlock *InvokeInliningInfo::getInnerResumeDest() {
|
|
if (InnerResumeDest) return InnerResumeDest;
|
|
|
|
// Split the landing pad.
|
|
BasicBlock::iterator SplitPoint = CallerLPad; ++SplitPoint;
|
|
InnerResumeDest =
|
|
OuterResumeDest->splitBasicBlock(SplitPoint,
|
|
OuterResumeDest->getName() + ".body");
|
|
|
|
// The number of incoming edges we expect to the inner landing pad.
|
|
const unsigned PHICapacity = 2;
|
|
|
|
// Create corresponding new PHIs for all the PHIs in the outer landing pad.
|
|
BasicBlock::iterator InsertPoint = InnerResumeDest->begin();
|
|
BasicBlock::iterator I = OuterResumeDest->begin();
|
|
for (unsigned i = 0, e = UnwindDestPHIValues.size(); i != e; ++i, ++I) {
|
|
PHINode *OuterPHI = cast<PHINode>(I);
|
|
PHINode *InnerPHI = PHINode::Create(OuterPHI->getType(), PHICapacity,
|
|
OuterPHI->getName() + ".lpad-body",
|
|
InsertPoint);
|
|
OuterPHI->replaceAllUsesWith(InnerPHI);
|
|
InnerPHI->addIncoming(OuterPHI, OuterResumeDest);
|
|
}
|
|
|
|
// Create a PHI for the exception values.
|
|
InnerEHValuesPHI = PHINode::Create(CallerLPad->getType(), PHICapacity,
|
|
"eh.lpad-body", InsertPoint);
|
|
CallerLPad->replaceAllUsesWith(InnerEHValuesPHI);
|
|
InnerEHValuesPHI->addIncoming(CallerLPad, OuterResumeDest);
|
|
|
|
// All done.
|
|
return InnerResumeDest;
|
|
}
|
|
|
|
/// forwardResume - Forward the 'resume' instruction to the caller's landing pad
|
|
/// block. When the landing pad block has only one predecessor, this is a simple
|
|
/// branch. When there is more than one predecessor, we need to split the
|
|
/// landing pad block after the landingpad instruction and jump to there.
|
|
void InvokeInliningInfo::forwardResume(ResumeInst *RI,
|
|
SmallPtrSetImpl<LandingPadInst*> &InlinedLPads) {
|
|
BasicBlock *Dest = getInnerResumeDest();
|
|
BasicBlock *Src = RI->getParent();
|
|
|
|
BranchInst::Create(Dest, Src);
|
|
|
|
// Update the PHIs in the destination. They were inserted in an order which
|
|
// makes this work.
|
|
addIncomingPHIValuesForInto(Src, Dest);
|
|
|
|
InnerEHValuesPHI->addIncoming(RI->getOperand(0), Src);
|
|
RI->eraseFromParent();
|
|
}
|
|
|
|
/// HandleCallsInBlockInlinedThroughInvoke - When we inline a basic block into
|
|
/// an invoke, we have to turn all of the calls that can throw into
|
|
/// invokes. This function analyze BB to see if there are any calls, and if so,
|
|
/// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI
|
|
/// nodes in that block with the values specified in InvokeDestPHIValues.
|
|
static void HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB,
|
|
InvokeInliningInfo &Invoke) {
|
|
for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
|
|
Instruction *I = BBI++;
|
|
|
|
// We only need to check for function calls: inlined invoke
|
|
// instructions require no special handling.
|
|
CallInst *CI = dyn_cast<CallInst>(I);
|
|
|
|
// If this call cannot unwind, don't convert it to an invoke.
|
|
// Inline asm calls cannot throw.
|
|
if (!CI || CI->doesNotThrow() || isa<InlineAsm>(CI->getCalledValue()))
|
|
continue;
|
|
|
|
// Convert this function call into an invoke instruction. First, split the
|
|
// basic block.
|
|
BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");
|
|
|
|
// Delete the unconditional branch inserted by splitBasicBlock
|
|
BB->getInstList().pop_back();
|
|
|
|
// Create the new invoke instruction.
|
|
ImmutableCallSite CS(CI);
|
|
SmallVector<Value*, 8> InvokeArgs(CS.arg_begin(), CS.arg_end());
|
|
InvokeInst *II = InvokeInst::Create(CI->getCalledValue(), Split,
|
|
Invoke.getOuterResumeDest(),
|
|
InvokeArgs, CI->getName(), BB);
|
|
II->setDebugLoc(CI->getDebugLoc());
|
|
II->setCallingConv(CI->getCallingConv());
|
|
II->setAttributes(CI->getAttributes());
|
|
|
|
// Make sure that anything using the call now uses the invoke! This also
|
|
// updates the CallGraph if present, because it uses a WeakVH.
|
|
CI->replaceAllUsesWith(II);
|
|
|
|
// Delete the original call
|
|
Split->getInstList().pop_front();
|
|
|
|
// Update any PHI nodes in the exceptional block to indicate that there is
|
|
// now a new entry in them.
|
|
Invoke.addIncomingPHIValuesFor(BB);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/// HandleInlinedInvoke - If we inlined an invoke site, we need to convert calls
|
|
/// in the body of the inlined function into invokes.
|
|
///
|
|
/// II is the invoke instruction being inlined. FirstNewBlock is the first
|
|
/// block of the inlined code (the last block is the end of the function),
|
|
/// and InlineCodeInfo is information about the code that got inlined.
|
|
static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock,
|
|
ClonedCodeInfo &InlinedCodeInfo) {
|
|
BasicBlock *InvokeDest = II->getUnwindDest();
|
|
|
|
Function *Caller = FirstNewBlock->getParent();
|
|
|
|
// The inlined code is currently at the end of the function, scan from the
|
|
// start of the inlined code to its end, checking for stuff we need to
|
|
// rewrite.
|
|
InvokeInliningInfo Invoke(II);
|
|
|
|
// Get all of the inlined landing pad instructions.
|
|
SmallPtrSet<LandingPadInst*, 16> InlinedLPads;
|
|
for (Function::iterator I = FirstNewBlock, E = Caller->end(); I != E; ++I)
|
|
if (InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator()))
|
|
InlinedLPads.insert(II->getLandingPadInst());
|
|
|
|
// Append the clauses from the outer landing pad instruction into the inlined
|
|
// landing pad instructions.
|
|
LandingPadInst *OuterLPad = Invoke.getLandingPadInst();
|
|
for (LandingPadInst *InlinedLPad : InlinedLPads) {
|
|
unsigned OuterNum = OuterLPad->getNumClauses();
|
|
InlinedLPad->reserveClauses(OuterNum);
|
|
for (unsigned OuterIdx = 0; OuterIdx != OuterNum; ++OuterIdx)
|
|
InlinedLPad->addClause(OuterLPad->getClause(OuterIdx));
|
|
if (OuterLPad->isCleanup())
|
|
InlinedLPad->setCleanup(true);
|
|
}
|
|
|
|
for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E; ++BB){
|
|
if (InlinedCodeInfo.ContainsCalls)
|
|
HandleCallsInBlockInlinedThroughInvoke(BB, Invoke);
|
|
|
|
// Forward any resumes that are remaining here.
|
|
if (ResumeInst *RI = dyn_cast<ResumeInst>(BB->getTerminator()))
|
|
Invoke.forwardResume(RI, InlinedLPads);
|
|
}
|
|
|
|
// Now that everything is happy, we have one final detail. The PHI nodes in
|
|
// the exception destination block still have entries due to the original
|
|
// invoke instruction. Eliminate these entries (which might even delete the
|
|
// PHI node) now.
|
|
InvokeDest->removePredecessor(II->getParent());
|
|
}
|
|
|
|
/// CloneAliasScopeMetadata - When inlining a function that contains noalias
|
|
/// scope metadata, this metadata needs to be cloned so that the inlined blocks
|
|
/// have different "unqiue scopes" at every call site. Were this not done, then
|
|
/// aliasing scopes from a function inlined into a caller multiple times could
|
|
/// not be differentiated (and this would lead to miscompiles because the
|
|
/// non-aliasing property communicated by the metadata could have
|
|
/// call-site-specific control dependencies).
|
|
static void CloneAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap) {
|
|
const Function *CalledFunc = CS.getCalledFunction();
|
|
SetVector<const MDNode *> MD;
|
|
|
|
// Note: We could only clone the metadata if it is already used in the
|
|
// caller. I'm omitting that check here because it might confuse
|
|
// inter-procedural alias analysis passes. We can revisit this if it becomes
|
|
// an efficiency or overhead problem.
|
|
|
|
for (Function::const_iterator I = CalledFunc->begin(), IE = CalledFunc->end();
|
|
I != IE; ++I)
|
|
for (BasicBlock::const_iterator J = I->begin(), JE = I->end(); J != JE; ++J) {
|
|
if (const MDNode *M = J->getMetadata(LLVMContext::MD_alias_scope))
|
|
MD.insert(M);
|
|
if (const MDNode *M = J->getMetadata(LLVMContext::MD_noalias))
|
|
MD.insert(M);
|
|
}
|
|
|
|
if (MD.empty())
|
|
return;
|
|
|
|
// Walk the existing metadata, adding the complete (perhaps cyclic) chain to
|
|
// the set.
|
|
SmallVector<const Metadata *, 16> Queue(MD.begin(), MD.end());
|
|
while (!Queue.empty()) {
|
|
const MDNode *M = cast<MDNode>(Queue.pop_back_val());
|
|
for (unsigned i = 0, ie = M->getNumOperands(); i != ie; ++i)
|
|
if (const MDNode *M1 = dyn_cast<MDNode>(M->getOperand(i)))
|
|
if (MD.insert(M1))
|
|
Queue.push_back(M1);
|
|
}
|
|
|
|
// Now we have a complete set of all metadata in the chains used to specify
|
|
// the noalias scopes and the lists of those scopes.
|
|
SmallVector<TempMDTuple, 16> DummyNodes;
|
|
DenseMap<const MDNode *, TrackingMDNodeRef> MDMap;
|
|
for (SetVector<const MDNode *>::iterator I = MD.begin(), IE = MD.end();
|
|
I != IE; ++I) {
|
|
DummyNodes.push_back(MDTuple::getTemporary(CalledFunc->getContext(), None));
|
|
MDMap[*I].reset(DummyNodes.back().get());
|
|
}
|
|
|
|
// Create new metadata nodes to replace the dummy nodes, replacing old
|
|
// metadata references with either a dummy node or an already-created new
|
|
// node.
|
|
for (SetVector<const MDNode *>::iterator I = MD.begin(), IE = MD.end();
|
|
I != IE; ++I) {
|
|
SmallVector<Metadata *, 4> NewOps;
|
|
for (unsigned i = 0, ie = (*I)->getNumOperands(); i != ie; ++i) {
|
|
const Metadata *V = (*I)->getOperand(i);
|
|
if (const MDNode *M = dyn_cast<MDNode>(V))
|
|
NewOps.push_back(MDMap[M]);
|
|
else
|
|
NewOps.push_back(const_cast<Metadata *>(V));
|
|
}
|
|
|
|
MDNode *NewM = MDNode::get(CalledFunc->getContext(), NewOps);
|
|
MDTuple *TempM = cast<MDTuple>(MDMap[*I]);
|
|
assert(TempM->isTemporary() && "Expected temporary node");
|
|
|
|
TempM->replaceAllUsesWith(NewM);
|
|
}
|
|
|
|
// Now replace the metadata in the new inlined instructions with the
|
|
// repacements from the map.
|
|
for (ValueToValueMapTy::iterator VMI = VMap.begin(), VMIE = VMap.end();
|
|
VMI != VMIE; ++VMI) {
|
|
if (!VMI->second)
|
|
continue;
|
|
|
|
Instruction *NI = dyn_cast<Instruction>(VMI->second);
|
|
if (!NI)
|
|
continue;
|
|
|
|
if (MDNode *M = NI->getMetadata(LLVMContext::MD_alias_scope)) {
|
|
MDNode *NewMD = MDMap[M];
|
|
// If the call site also had alias scope metadata (a list of scopes to
|
|
// which instructions inside it might belong), propagate those scopes to
|
|
// the inlined instructions.
|
|
if (MDNode *CSM =
|
|
CS.getInstruction()->getMetadata(LLVMContext::MD_alias_scope))
|
|
NewMD = MDNode::concatenate(NewMD, CSM);
|
|
NI->setMetadata(LLVMContext::MD_alias_scope, NewMD);
|
|
} else if (NI->mayReadOrWriteMemory()) {
|
|
if (MDNode *M =
|
|
CS.getInstruction()->getMetadata(LLVMContext::MD_alias_scope))
|
|
NI->setMetadata(LLVMContext::MD_alias_scope, M);
|
|
}
|
|
|
|
if (MDNode *M = NI->getMetadata(LLVMContext::MD_noalias)) {
|
|
MDNode *NewMD = MDMap[M];
|
|
// If the call site also had noalias metadata (a list of scopes with
|
|
// which instructions inside it don't alias), propagate those scopes to
|
|
// the inlined instructions.
|
|
if (MDNode *CSM =
|
|
CS.getInstruction()->getMetadata(LLVMContext::MD_noalias))
|
|
NewMD = MDNode::concatenate(NewMD, CSM);
|
|
NI->setMetadata(LLVMContext::MD_noalias, NewMD);
|
|
} else if (NI->mayReadOrWriteMemory()) {
|
|
if (MDNode *M = CS.getInstruction()->getMetadata(LLVMContext::MD_noalias))
|
|
NI->setMetadata(LLVMContext::MD_noalias, M);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// AddAliasScopeMetadata - If the inlined function has noalias arguments, then
|
|
/// add new alias scopes for each noalias argument, tag the mapped noalias
|
|
/// parameters with noalias metadata specifying the new scope, and tag all
|
|
/// non-derived loads, stores and memory intrinsics with the new alias scopes.
|
|
static void AddAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap,
|
|
const DataLayout *DL, AliasAnalysis *AA) {
|
|
if (!EnableNoAliasConversion)
|
|
return;
|
|
|
|
const Function *CalledFunc = CS.getCalledFunction();
|
|
SmallVector<const Argument *, 4> NoAliasArgs;
|
|
|
|
for (Function::const_arg_iterator I = CalledFunc->arg_begin(),
|
|
E = CalledFunc->arg_end(); I != E; ++I) {
|
|
if (I->hasNoAliasAttr() && !I->hasNUses(0))
|
|
NoAliasArgs.push_back(I);
|
|
}
|
|
|
|
if (NoAliasArgs.empty())
|
|
return;
|
|
|
|
// To do a good job, if a noalias variable is captured, we need to know if
|
|
// the capture point dominates the particular use we're considering.
|
|
DominatorTree DT;
|
|
DT.recalculate(const_cast<Function&>(*CalledFunc));
|
|
|
|
// noalias indicates that pointer values based on the argument do not alias
|
|
// pointer values which are not based on it. So we add a new "scope" for each
|
|
// noalias function argument. Accesses using pointers based on that argument
|
|
// become part of that alias scope, accesses using pointers not based on that
|
|
// argument are tagged as noalias with that scope.
|
|
|
|
DenseMap<const Argument *, MDNode *> NewScopes;
|
|
MDBuilder MDB(CalledFunc->getContext());
|
|
|
|
// Create a new scope domain for this function.
|
|
MDNode *NewDomain =
|
|
MDB.createAnonymousAliasScopeDomain(CalledFunc->getName());
|
|
for (unsigned i = 0, e = NoAliasArgs.size(); i != e; ++i) {
|
|
const Argument *A = NoAliasArgs[i];
|
|
|
|
std::string Name = CalledFunc->getName();
|
|
if (A->hasName()) {
|
|
Name += ": %";
|
|
Name += A->getName();
|
|
} else {
|
|
Name += ": argument ";
|
|
Name += utostr(i);
|
|
}
|
|
|
|
// Note: We always create a new anonymous root here. This is true regardless
|
|
// of the linkage of the callee because the aliasing "scope" is not just a
|
|
// property of the callee, but also all control dependencies in the caller.
|
|
MDNode *NewScope = MDB.createAnonymousAliasScope(NewDomain, Name);
|
|
NewScopes.insert(std::make_pair(A, NewScope));
|
|
}
|
|
|
|
// Iterate over all new instructions in the map; for all memory-access
|
|
// instructions, add the alias scope metadata.
|
|
for (ValueToValueMapTy::iterator VMI = VMap.begin(), VMIE = VMap.end();
|
|
VMI != VMIE; ++VMI) {
|
|
if (const Instruction *I = dyn_cast<Instruction>(VMI->first)) {
|
|
if (!VMI->second)
|
|
continue;
|
|
|
|
Instruction *NI = dyn_cast<Instruction>(VMI->second);
|
|
if (!NI)
|
|
continue;
|
|
|
|
bool IsArgMemOnlyCall = false, IsFuncCall = false;
|
|
SmallVector<const Value *, 2> PtrArgs;
|
|
|
|
if (const LoadInst *LI = dyn_cast<LoadInst>(I))
|
|
PtrArgs.push_back(LI->getPointerOperand());
|
|
else if (const StoreInst *SI = dyn_cast<StoreInst>(I))
|
|
PtrArgs.push_back(SI->getPointerOperand());
|
|
else if (const VAArgInst *VAAI = dyn_cast<VAArgInst>(I))
|
|
PtrArgs.push_back(VAAI->getPointerOperand());
|
|
else if (const AtomicCmpXchgInst *CXI = dyn_cast<AtomicCmpXchgInst>(I))
|
|
PtrArgs.push_back(CXI->getPointerOperand());
|
|
else if (const AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I))
|
|
PtrArgs.push_back(RMWI->getPointerOperand());
|
|
else if (ImmutableCallSite ICS = ImmutableCallSite(I)) {
|
|
// If we know that the call does not access memory, then we'll still
|
|
// know that about the inlined clone of this call site, and we don't
|
|
// need to add metadata.
|
|
if (ICS.doesNotAccessMemory())
|
|
continue;
|
|
|
|
IsFuncCall = true;
|
|
if (AA) {
|
|
AliasAnalysis::ModRefBehavior MRB = AA->getModRefBehavior(ICS);
|
|
if (MRB == AliasAnalysis::OnlyAccessesArgumentPointees ||
|
|
MRB == AliasAnalysis::OnlyReadsArgumentPointees)
|
|
IsArgMemOnlyCall = true;
|
|
}
|
|
|
|
for (ImmutableCallSite::arg_iterator AI = ICS.arg_begin(),
|
|
AE = ICS.arg_end(); AI != AE; ++AI) {
|
|
// We need to check the underlying objects of all arguments, not just
|
|
// the pointer arguments, because we might be passing pointers as
|
|
// integers, etc.
|
|
// However, if we know that the call only accesses pointer arguments,
|
|
// then we only need to check the pointer arguments.
|
|
if (IsArgMemOnlyCall && !(*AI)->getType()->isPointerTy())
|
|
continue;
|
|
|
|
PtrArgs.push_back(*AI);
|
|
}
|
|
}
|
|
|
|
// If we found no pointers, then this instruction is not suitable for
|
|
// pairing with an instruction to receive aliasing metadata.
|
|
// However, if this is a call, this we might just alias with none of the
|
|
// noalias arguments.
|
|
if (PtrArgs.empty() && !IsFuncCall)
|
|
continue;
|
|
|
|
// It is possible that there is only one underlying object, but you
|
|
// need to go through several PHIs to see it, and thus could be
|
|
// repeated in the Objects list.
|
|
SmallPtrSet<const Value *, 4> ObjSet;
|
|
SmallVector<Metadata *, 4> Scopes, NoAliases;
|
|
|
|
SmallSetVector<const Argument *, 4> NAPtrArgs;
|
|
for (unsigned i = 0, ie = PtrArgs.size(); i != ie; ++i) {
|
|
SmallVector<Value *, 4> Objects;
|
|
GetUnderlyingObjects(const_cast<Value*>(PtrArgs[i]),
|
|
Objects, DL, /* MaxLookup = */ 0);
|
|
|
|
for (Value *O : Objects)
|
|
ObjSet.insert(O);
|
|
}
|
|
|
|
// Figure out if we're derived from anything that is not a noalias
|
|
// argument.
|
|
bool CanDeriveViaCapture = false, UsesAliasingPtr = false;
|
|
for (const Value *V : ObjSet) {
|
|
// Is this value a constant that cannot be derived from any pointer
|
|
// value (we need to exclude constant expressions, for example, that
|
|
// are formed from arithmetic on global symbols).
|
|
bool IsNonPtrConst = isa<ConstantInt>(V) || isa<ConstantFP>(V) ||
|
|
isa<ConstantPointerNull>(V) ||
|
|
isa<ConstantDataVector>(V) || isa<UndefValue>(V);
|
|
if (IsNonPtrConst)
|
|
continue;
|
|
|
|
// If this is anything other than a noalias argument, then we cannot
|
|
// completely describe the aliasing properties using alias.scope
|
|
// metadata (and, thus, won't add any).
|
|
if (const Argument *A = dyn_cast<Argument>(V)) {
|
|
if (!A->hasNoAliasAttr())
|
|
UsesAliasingPtr = true;
|
|
} else {
|
|
UsesAliasingPtr = true;
|
|
}
|
|
|
|
// If this is not some identified function-local object (which cannot
|
|
// directly alias a noalias argument), or some other argument (which,
|
|
// by definition, also cannot alias a noalias argument), then we could
|
|
// alias a noalias argument that has been captured).
|
|
if (!isa<Argument>(V) &&
|
|
!isIdentifiedFunctionLocal(const_cast<Value*>(V)))
|
|
CanDeriveViaCapture = true;
|
|
}
|
|
|
|
// A function call can always get captured noalias pointers (via other
|
|
// parameters, globals, etc.).
|
|
if (IsFuncCall && !IsArgMemOnlyCall)
|
|
CanDeriveViaCapture = true;
|
|
|
|
// First, we want to figure out all of the sets with which we definitely
|
|
// don't alias. Iterate over all noalias set, and add those for which:
|
|
// 1. The noalias argument is not in the set of objects from which we
|
|
// definitely derive.
|
|
// 2. The noalias argument has not yet been captured.
|
|
// An arbitrary function that might load pointers could see captured
|
|
// noalias arguments via other noalias arguments or globals, and so we
|
|
// must always check for prior capture.
|
|
for (const Argument *A : NoAliasArgs) {
|
|
if (!ObjSet.count(A) && (!CanDeriveViaCapture ||
|
|
// It might be tempting to skip the
|
|
// PointerMayBeCapturedBefore check if
|
|
// A->hasNoCaptureAttr() is true, but this is
|
|
// incorrect because nocapture only guarantees
|
|
// that no copies outlive the function, not
|
|
// that the value cannot be locally captured.
|
|
!PointerMayBeCapturedBefore(A,
|
|
/* ReturnCaptures */ false,
|
|
/* StoreCaptures */ false, I, &DT)))
|
|
NoAliases.push_back(NewScopes[A]);
|
|
}
|
|
|
|
if (!NoAliases.empty())
|
|
NI->setMetadata(LLVMContext::MD_noalias,
|
|
MDNode::concatenate(
|
|
NI->getMetadata(LLVMContext::MD_noalias),
|
|
MDNode::get(CalledFunc->getContext(), NoAliases)));
|
|
|
|
// Next, we want to figure out all of the sets to which we might belong.
|
|
// We might belong to a set if the noalias argument is in the set of
|
|
// underlying objects. If there is some non-noalias argument in our list
|
|
// of underlying objects, then we cannot add a scope because the fact
|
|
// that some access does not alias with any set of our noalias arguments
|
|
// cannot itself guarantee that it does not alias with this access
|
|
// (because there is some pointer of unknown origin involved and the
|
|
// other access might also depend on this pointer). We also cannot add
|
|
// scopes to arbitrary functions unless we know they don't access any
|
|
// non-parameter pointer-values.
|
|
bool CanAddScopes = !UsesAliasingPtr;
|
|
if (CanAddScopes && IsFuncCall)
|
|
CanAddScopes = IsArgMemOnlyCall;
|
|
|
|
if (CanAddScopes)
|
|
for (const Argument *A : NoAliasArgs) {
|
|
if (ObjSet.count(A))
|
|
Scopes.push_back(NewScopes[A]);
|
|
}
|
|
|
|
if (!Scopes.empty())
|
|
NI->setMetadata(
|
|
LLVMContext::MD_alias_scope,
|
|
MDNode::concatenate(NI->getMetadata(LLVMContext::MD_alias_scope),
|
|
MDNode::get(CalledFunc->getContext(), Scopes)));
|
|
}
|
|
}
|
|
}
|
|
|
|
/// If the inlined function has non-byval align arguments, then
|
|
/// add @llvm.assume-based alignment assumptions to preserve this information.
|
|
static void AddAlignmentAssumptions(CallSite CS, InlineFunctionInfo &IFI) {
|
|
if (!PreserveAlignmentAssumptions || !IFI.DL)
|
|
return;
|
|
|
|
// To avoid inserting redundant assumptions, we should check for assumptions
|
|
// already in the caller. To do this, we might need a DT of the caller.
|
|
DominatorTree DT;
|
|
bool DTCalculated = false;
|
|
|
|
Function *CalledFunc = CS.getCalledFunction();
|
|
for (Function::arg_iterator I = CalledFunc->arg_begin(),
|
|
E = CalledFunc->arg_end();
|
|
I != E; ++I) {
|
|
unsigned Align = I->getType()->isPointerTy() ? I->getParamAlignment() : 0;
|
|
if (Align && !I->hasByValOrInAllocaAttr() && !I->hasNUses(0)) {
|
|
if (!DTCalculated) {
|
|
DT.recalculate(const_cast<Function&>(*CS.getInstruction()->getParent()
|
|
->getParent()));
|
|
DTCalculated = true;
|
|
}
|
|
|
|
// If we can already prove the asserted alignment in the context of the
|
|
// caller, then don't bother inserting the assumption.
|
|
Value *Arg = CS.getArgument(I->getArgNo());
|
|
if (getKnownAlignment(Arg, IFI.DL,
|
|
&IFI.ACT->getAssumptionCache(*CalledFunc),
|
|
CS.getInstruction(), &DT) >= Align)
|
|
continue;
|
|
|
|
IRBuilder<>(CS.getInstruction()).CreateAlignmentAssumption(*IFI.DL, Arg,
|
|
Align);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// UpdateCallGraphAfterInlining - Once we have cloned code over from a callee
|
|
/// into the caller, update the specified callgraph to reflect the changes we
|
|
/// made. Note that it's possible that not all code was copied over, so only
|
|
/// some edges of the callgraph may remain.
|
|
static void UpdateCallGraphAfterInlining(CallSite CS,
|
|
Function::iterator FirstNewBlock,
|
|
ValueToValueMapTy &VMap,
|
|
InlineFunctionInfo &IFI) {
|
|
CallGraph &CG = *IFI.CG;
|
|
const Function *Caller = CS.getInstruction()->getParent()->getParent();
|
|
const Function *Callee = CS.getCalledFunction();
|
|
CallGraphNode *CalleeNode = CG[Callee];
|
|
CallGraphNode *CallerNode = CG[Caller];
|
|
|
|
// Since we inlined some uninlined call sites in the callee into the caller,
|
|
// add edges from the caller to all of the callees of the callee.
|
|
CallGraphNode::iterator I = CalleeNode->begin(), E = CalleeNode->end();
|
|
|
|
// Consider the case where CalleeNode == CallerNode.
|
|
CallGraphNode::CalledFunctionsVector CallCache;
|
|
if (CalleeNode == CallerNode) {
|
|
CallCache.assign(I, E);
|
|
I = CallCache.begin();
|
|
E = CallCache.end();
|
|
}
|
|
|
|
for (; I != E; ++I) {
|
|
const Value *OrigCall = I->first;
|
|
|
|
ValueToValueMapTy::iterator VMI = VMap.find(OrigCall);
|
|
// Only copy the edge if the call was inlined!
|
|
if (VMI == VMap.end() || VMI->second == nullptr)
|
|
continue;
|
|
|
|
// If the call was inlined, but then constant folded, there is no edge to
|
|
// add. Check for this case.
|
|
Instruction *NewCall = dyn_cast<Instruction>(VMI->second);
|
|
if (!NewCall) continue;
|
|
|
|
// Remember that this call site got inlined for the client of
|
|
// InlineFunction.
|
|
IFI.InlinedCalls.push_back(NewCall);
|
|
|
|
// It's possible that inlining the callsite will cause it to go from an
|
|
// indirect to a direct call by resolving a function pointer. If this
|
|
// happens, set the callee of the new call site to a more precise
|
|
// destination. This can also happen if the call graph node of the caller
|
|
// was just unnecessarily imprecise.
|
|
if (!I->second->getFunction())
|
|
if (Function *F = CallSite(NewCall).getCalledFunction()) {
|
|
// Indirect call site resolved to direct call.
|
|
CallerNode->addCalledFunction(CallSite(NewCall), CG[F]);
|
|
|
|
continue;
|
|
}
|
|
|
|
CallerNode->addCalledFunction(CallSite(NewCall), I->second);
|
|
}
|
|
|
|
// Update the call graph by deleting the edge from Callee to Caller. We must
|
|
// do this after the loop above in case Caller and Callee are the same.
|
|
CallerNode->removeCallEdgeFor(CS);
|
|
}
|
|
|
|
static void HandleByValArgumentInit(Value *Dst, Value *Src, Module *M,
|
|
BasicBlock *InsertBlock,
|
|
InlineFunctionInfo &IFI) {
|
|
Type *AggTy = cast<PointerType>(Src->getType())->getElementType();
|
|
IRBuilder<> Builder(InsertBlock->begin());
|
|
|
|
Value *Size;
|
|
if (IFI.DL == nullptr)
|
|
Size = ConstantExpr::getSizeOf(AggTy);
|
|
else
|
|
Size = Builder.getInt64(IFI.DL->getTypeStoreSize(AggTy));
|
|
|
|
// Always generate a memcpy of alignment 1 here because we don't know
|
|
// the alignment of the src pointer. Other optimizations can infer
|
|
// better alignment.
|
|
Builder.CreateMemCpy(Dst, Src, Size, /*Align=*/1);
|
|
}
|
|
|
|
/// HandleByValArgument - When inlining a call site that has a byval argument,
|
|
/// we have to make the implicit memcpy explicit by adding it.
|
|
static Value *HandleByValArgument(Value *Arg, Instruction *TheCall,
|
|
const Function *CalledFunc,
|
|
InlineFunctionInfo &IFI,
|
|
unsigned ByValAlignment) {
|
|
PointerType *ArgTy = cast<PointerType>(Arg->getType());
|
|
Type *AggTy = ArgTy->getElementType();
|
|
|
|
Function *Caller = TheCall->getParent()->getParent();
|
|
|
|
// If the called function is readonly, then it could not mutate the caller's
|
|
// copy of the byval'd memory. In this case, it is safe to elide the copy and
|
|
// temporary.
|
|
if (CalledFunc->onlyReadsMemory()) {
|
|
// If the byval argument has a specified alignment that is greater than the
|
|
// passed in pointer, then we either have to round up the input pointer or
|
|
// give up on this transformation.
|
|
if (ByValAlignment <= 1) // 0 = unspecified, 1 = no particular alignment.
|
|
return Arg;
|
|
|
|
// If the pointer is already known to be sufficiently aligned, or if we can
|
|
// round it up to a larger alignment, then we don't need a temporary.
|
|
if (getOrEnforceKnownAlignment(Arg, ByValAlignment, IFI.DL,
|
|
&IFI.ACT->getAssumptionCache(*Caller),
|
|
TheCall) >= ByValAlignment)
|
|
return Arg;
|
|
|
|
// Otherwise, we have to make a memcpy to get a safe alignment. This is bad
|
|
// for code quality, but rarely happens and is required for correctness.
|
|
}
|
|
|
|
// Create the alloca. If we have DataLayout, use nice alignment.
|
|
unsigned Align = 1;
|
|
if (IFI.DL)
|
|
Align = IFI.DL->getPrefTypeAlignment(AggTy);
|
|
|
|
// If the byval had an alignment specified, we *must* use at least that
|
|
// alignment, as it is required by the byval argument (and uses of the
|
|
// pointer inside the callee).
|
|
Align = std::max(Align, ByValAlignment);
|
|
|
|
Value *NewAlloca = new AllocaInst(AggTy, nullptr, Align, Arg->getName(),
|
|
&*Caller->begin()->begin());
|
|
IFI.StaticAllocas.push_back(cast<AllocaInst>(NewAlloca));
|
|
|
|
// Uses of the argument in the function should use our new alloca
|
|
// instead.
|
|
return NewAlloca;
|
|
}
|
|
|
|
// isUsedByLifetimeMarker - Check whether this Value is used by a lifetime
|
|
// intrinsic.
|
|
static bool isUsedByLifetimeMarker(Value *V) {
|
|
for (User *U : V->users()) {
|
|
if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U)) {
|
|
switch (II->getIntrinsicID()) {
|
|
default: break;
|
|
case Intrinsic::lifetime_start:
|
|
case Intrinsic::lifetime_end:
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// hasLifetimeMarkers - Check whether the given alloca already has
|
|
// lifetime.start or lifetime.end intrinsics.
|
|
static bool hasLifetimeMarkers(AllocaInst *AI) {
|
|
Type *Ty = AI->getType();
|
|
Type *Int8PtrTy = Type::getInt8PtrTy(Ty->getContext(),
|
|
Ty->getPointerAddressSpace());
|
|
if (Ty == Int8PtrTy)
|
|
return isUsedByLifetimeMarker(AI);
|
|
|
|
// Do a scan to find all the casts to i8*.
|
|
for (User *U : AI->users()) {
|
|
if (U->getType() != Int8PtrTy) continue;
|
|
if (U->stripPointerCasts() != AI) continue;
|
|
if (isUsedByLifetimeMarker(U))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/// Rebuild the entire inlined-at chain for this instruction so that the top of
|
|
/// the chain now is inlined-at the new call site.
|
|
static DebugLoc
|
|
updateInlinedAtInfo(DebugLoc DL, MDLocation *InlinedAtNode,
|
|
LLVMContext &Ctx,
|
|
DenseMap<const MDLocation *, MDLocation *> &IANodes) {
|
|
SmallVector<MDLocation*, 3> InlinedAtLocations;
|
|
MDLocation *Last = InlinedAtNode;
|
|
DebugLoc CurInlinedAt = DL;
|
|
|
|
// Gather all the inlined-at nodes
|
|
while (MDLocation *IA =
|
|
cast_or_null<MDLocation>(CurInlinedAt.getInlinedAt(Ctx))) {
|
|
// Skip any we've already built nodes for
|
|
if (MDLocation *Found = IANodes[IA]) {
|
|
Last = Found;
|
|
break;
|
|
}
|
|
|
|
InlinedAtLocations.push_back(IA);
|
|
CurInlinedAt = DebugLoc::getFromDILocation(IA);
|
|
}
|
|
|
|
// Starting from the top, rebuild the nodes to point to the new inlined-at
|
|
// location (then rebuilding the rest of the chain behind it) and update the
|
|
// map of already-constructed inlined-at nodes.
|
|
for (auto I = InlinedAtLocations.rbegin(), E = InlinedAtLocations.rend();
|
|
I != E; ++I) {
|
|
const MDLocation *MD = *I;
|
|
Last = IANodes[MD] = MDLocation::getDistinct(
|
|
Ctx, MD->getLine(), MD->getColumn(), MD->getScope(), Last);
|
|
}
|
|
|
|
// And finally create the normal location for this instruction, referring to
|
|
// the new inlined-at chain.
|
|
return DebugLoc::get(DL.getLine(), DL.getCol(), DL.getScope(Ctx), Last);
|
|
}
|
|
|
|
/// fixupLineNumbers - Update inlined instructions' line numbers to
|
|
/// to encode location where these instructions are inlined.
|
|
static void fixupLineNumbers(Function *Fn, Function::iterator FI,
|
|
Instruction *TheCall) {
|
|
DebugLoc TheCallDL = TheCall->getDebugLoc();
|
|
if (TheCallDL.isUnknown())
|
|
return;
|
|
|
|
auto &Ctx = Fn->getContext();
|
|
auto *InlinedAtNode = cast<MDLocation>(TheCallDL.getAsMDNode(Ctx));
|
|
|
|
// Create a unique call site, not to be confused with any other call from the
|
|
// same location.
|
|
InlinedAtNode = MDLocation::getDistinct(
|
|
Ctx, InlinedAtNode->getLine(), InlinedAtNode->getColumn(),
|
|
InlinedAtNode->getScope(), InlinedAtNode->getInlinedAt());
|
|
|
|
// Cache the inlined-at nodes as they're built so they are reused, without
|
|
// this every instruction's inlined-at chain would become distinct from each
|
|
// other.
|
|
DenseMap<const MDLocation *, MDLocation *> IANodes;
|
|
|
|
for (; FI != Fn->end(); ++FI) {
|
|
for (BasicBlock::iterator BI = FI->begin(), BE = FI->end();
|
|
BI != BE; ++BI) {
|
|
DebugLoc DL = BI->getDebugLoc();
|
|
if (DL.isUnknown()) {
|
|
// If the inlined instruction has no line number, make it look as if it
|
|
// originates from the call location. This is important for
|
|
// ((__always_inline__, __nodebug__)) functions which must use caller
|
|
// location for all instructions in their function body.
|
|
|
|
// Don't update static allocas, as they may get moved later.
|
|
if (auto *AI = dyn_cast<AllocaInst>(BI))
|
|
if (isa<Constant>(AI->getArraySize()))
|
|
continue;
|
|
|
|
BI->setDebugLoc(TheCallDL);
|
|
} else {
|
|
BI->setDebugLoc(updateInlinedAtInfo(DL, InlinedAtNode, BI->getContext(), IANodes));
|
|
if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(BI)) {
|
|
LLVMContext &Ctx = BI->getContext();
|
|
MDNode *InlinedAt = BI->getDebugLoc().getInlinedAt(Ctx);
|
|
DVI->setOperand(2, MetadataAsValue::get(
|
|
Ctx, createInlinedVariable(DVI->getVariable(),
|
|
InlinedAt, Ctx)));
|
|
} else if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(BI)) {
|
|
LLVMContext &Ctx = BI->getContext();
|
|
MDNode *InlinedAt = BI->getDebugLoc().getInlinedAt(Ctx);
|
|
DDI->setOperand(1, MetadataAsValue::get(
|
|
Ctx, createInlinedVariable(DDI->getVariable(),
|
|
InlinedAt, Ctx)));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// InlineFunction - This function inlines the called function into the basic
|
|
/// block of the caller. This returns false if it is not possible to inline
|
|
/// this call. The program is still in a well defined state if this occurs
|
|
/// though.
|
|
///
|
|
/// Note that this only does one level of inlining. For example, if the
|
|
/// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now
|
|
/// exists in the instruction stream. Similarly this will inline a recursive
|
|
/// function by one level.
|
|
bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
|
|
bool InsertLifetime) {
|
|
Instruction *TheCall = CS.getInstruction();
|
|
assert(TheCall->getParent() && TheCall->getParent()->getParent() &&
|
|
"Instruction not in function!");
|
|
|
|
// If IFI has any state in it, zap it before we fill it in.
|
|
IFI.reset();
|
|
|
|
const Function *CalledFunc = CS.getCalledFunction();
|
|
if (!CalledFunc || // Can't inline external function or indirect
|
|
CalledFunc->isDeclaration() || // call, or call to a vararg function!
|
|
CalledFunc->getFunctionType()->isVarArg()) return false;
|
|
|
|
// If the call to the callee cannot throw, set the 'nounwind' flag on any
|
|
// calls that we inline.
|
|
bool MarkNoUnwind = CS.doesNotThrow();
|
|
|
|
BasicBlock *OrigBB = TheCall->getParent();
|
|
Function *Caller = OrigBB->getParent();
|
|
|
|
// GC poses two hazards to inlining, which only occur when the callee has GC:
|
|
// 1. If the caller has no GC, then the callee's GC must be propagated to the
|
|
// caller.
|
|
// 2. If the caller has a differing GC, it is invalid to inline.
|
|
if (CalledFunc->hasGC()) {
|
|
if (!Caller->hasGC())
|
|
Caller->setGC(CalledFunc->getGC());
|
|
else if (CalledFunc->getGC() != Caller->getGC())
|
|
return false;
|
|
}
|
|
|
|
// Get the personality function from the callee if it contains a landing pad.
|
|
Value *CalleePersonality = nullptr;
|
|
for (Function::const_iterator I = CalledFunc->begin(), E = CalledFunc->end();
|
|
I != E; ++I)
|
|
if (const InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) {
|
|
const BasicBlock *BB = II->getUnwindDest();
|
|
const LandingPadInst *LP = BB->getLandingPadInst();
|
|
CalleePersonality = LP->getPersonalityFn();
|
|
break;
|
|
}
|
|
|
|
// Find the personality function used by the landing pads of the caller. If it
|
|
// exists, then check to see that it matches the personality function used in
|
|
// the callee.
|
|
if (CalleePersonality) {
|
|
for (Function::const_iterator I = Caller->begin(), E = Caller->end();
|
|
I != E; ++I)
|
|
if (const InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) {
|
|
const BasicBlock *BB = II->getUnwindDest();
|
|
const LandingPadInst *LP = BB->getLandingPadInst();
|
|
|
|
// If the personality functions match, then we can perform the
|
|
// inlining. Otherwise, we can't inline.
|
|
// TODO: This isn't 100% true. Some personality functions are proper
|
|
// supersets of others and can be used in place of the other.
|
|
if (LP->getPersonalityFn() != CalleePersonality)
|
|
return false;
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Get an iterator to the last basic block in the function, which will have
|
|
// the new function inlined after it.
|
|
Function::iterator LastBlock = &Caller->back();
|
|
|
|
// Make sure to capture all of the return instructions from the cloned
|
|
// function.
|
|
SmallVector<ReturnInst*, 8> Returns;
|
|
ClonedCodeInfo InlinedFunctionInfo;
|
|
Function::iterator FirstNewBlock;
|
|
|
|
{ // Scope to destroy VMap after cloning.
|
|
ValueToValueMapTy VMap;
|
|
// Keep a list of pair (dst, src) to emit byval initializations.
|
|
SmallVector<std::pair<Value*, Value*>, 4> ByValInit;
|
|
|
|
assert(CalledFunc->arg_size() == CS.arg_size() &&
|
|
"No varargs calls can be inlined!");
|
|
|
|
// Calculate the vector of arguments to pass into the function cloner, which
|
|
// matches up the formal to the actual argument values.
|
|
CallSite::arg_iterator AI = CS.arg_begin();
|
|
unsigned ArgNo = 0;
|
|
for (Function::const_arg_iterator I = CalledFunc->arg_begin(),
|
|
E = CalledFunc->arg_end(); I != E; ++I, ++AI, ++ArgNo) {
|
|
Value *ActualArg = *AI;
|
|
|
|
// When byval arguments actually inlined, we need to make the copy implied
|
|
// by them explicit. However, we don't do this if the callee is readonly
|
|
// or readnone, because the copy would be unneeded: the callee doesn't
|
|
// modify the struct.
|
|
if (CS.isByValArgument(ArgNo)) {
|
|
ActualArg = HandleByValArgument(ActualArg, TheCall, CalledFunc, IFI,
|
|
CalledFunc->getParamAlignment(ArgNo+1));
|
|
if (ActualArg != *AI)
|
|
ByValInit.push_back(std::make_pair(ActualArg, (Value*) *AI));
|
|
}
|
|
|
|
VMap[I] = ActualArg;
|
|
}
|
|
|
|
// Add alignment assumptions if necessary. We do this before the inlined
|
|
// instructions are actually cloned into the caller so that we can easily
|
|
// check what will be known at the start of the inlined code.
|
|
AddAlignmentAssumptions(CS, IFI);
|
|
|
|
// We want the inliner to prune the code as it copies. We would LOVE to
|
|
// have no dead or constant instructions leftover after inlining occurs
|
|
// (which can happen, e.g., because an argument was constant), but we'll be
|
|
// happy with whatever the cloner can do.
|
|
CloneAndPruneFunctionInto(Caller, CalledFunc, VMap,
|
|
/*ModuleLevelChanges=*/false, Returns, ".i",
|
|
&InlinedFunctionInfo, IFI.DL, TheCall);
|
|
|
|
// Remember the first block that is newly cloned over.
|
|
FirstNewBlock = LastBlock; ++FirstNewBlock;
|
|
|
|
// Inject byval arguments initialization.
|
|
for (std::pair<Value*, Value*> &Init : ByValInit)
|
|
HandleByValArgumentInit(Init.first, Init.second, Caller->getParent(),
|
|
FirstNewBlock, IFI);
|
|
|
|
// Update the callgraph if requested.
|
|
if (IFI.CG)
|
|
UpdateCallGraphAfterInlining(CS, FirstNewBlock, VMap, IFI);
|
|
|
|
// Update inlined instructions' line number information.
|
|
fixupLineNumbers(Caller, FirstNewBlock, TheCall);
|
|
|
|
// Clone existing noalias metadata if necessary.
|
|
CloneAliasScopeMetadata(CS, VMap);
|
|
|
|
// Add noalias metadata if necessary.
|
|
AddAliasScopeMetadata(CS, VMap, IFI.DL, IFI.AA);
|
|
|
|
// FIXME: We could register any cloned assumptions instead of clearing the
|
|
// whole function's cache.
|
|
if (IFI.ACT)
|
|
IFI.ACT->getAssumptionCache(*Caller).clear();
|
|
}
|
|
|
|
// If there are any alloca instructions in the block that used to be the entry
|
|
// block for the callee, move them to the entry block of the caller. First
|
|
// calculate which instruction they should be inserted before. We insert the
|
|
// instructions at the end of the current alloca list.
|
|
{
|
|
BasicBlock::iterator InsertPoint = Caller->begin()->begin();
|
|
for (BasicBlock::iterator I = FirstNewBlock->begin(),
|
|
E = FirstNewBlock->end(); I != E; ) {
|
|
AllocaInst *AI = dyn_cast<AllocaInst>(I++);
|
|
if (!AI) continue;
|
|
|
|
// If the alloca is now dead, remove it. This often occurs due to code
|
|
// specialization.
|
|
if (AI->use_empty()) {
|
|
AI->eraseFromParent();
|
|
continue;
|
|
}
|
|
|
|
if (!isa<Constant>(AI->getArraySize()))
|
|
continue;
|
|
|
|
// Keep track of the static allocas that we inline into the caller.
|
|
IFI.StaticAllocas.push_back(AI);
|
|
|
|
// Scan for the block of allocas that we can move over, and move them
|
|
// all at once.
|
|
while (isa<AllocaInst>(I) &&
|
|
isa<Constant>(cast<AllocaInst>(I)->getArraySize())) {
|
|
IFI.StaticAllocas.push_back(cast<AllocaInst>(I));
|
|
++I;
|
|
}
|
|
|
|
// Transfer all of the allocas over in a block. Using splice means
|
|
// that the instructions aren't removed from the symbol table, then
|
|
// reinserted.
|
|
Caller->getEntryBlock().getInstList().splice(InsertPoint,
|
|
FirstNewBlock->getInstList(),
|
|
AI, I);
|
|
}
|
|
// Move any dbg.declares describing the allocas into the entry basic block.
|
|
DIBuilder DIB(*Caller->getParent());
|
|
for (auto &AI : IFI.StaticAllocas)
|
|
replaceDbgDeclareForAlloca(AI, AI, DIB, /*Deref=*/false);
|
|
}
|
|
|
|
bool InlinedMustTailCalls = false;
|
|
if (InlinedFunctionInfo.ContainsCalls) {
|
|
CallInst::TailCallKind CallSiteTailKind = CallInst::TCK_None;
|
|
if (CallInst *CI = dyn_cast<CallInst>(TheCall))
|
|
CallSiteTailKind = CI->getTailCallKind();
|
|
|
|
for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E;
|
|
++BB) {
|
|
for (Instruction &I : *BB) {
|
|
CallInst *CI = dyn_cast<CallInst>(&I);
|
|
if (!CI)
|
|
continue;
|
|
|
|
// We need to reduce the strength of any inlined tail calls. For
|
|
// musttail, we have to avoid introducing potential unbounded stack
|
|
// growth. For example, if functions 'f' and 'g' are mutually recursive
|
|
// with musttail, we can inline 'g' into 'f' so long as we preserve
|
|
// musttail on the cloned call to 'f'. If either the inlined call site
|
|
// or the cloned call site is *not* musttail, the program already has
|
|
// one frame of stack growth, so it's safe to remove musttail. Here is
|
|
// a table of example transformations:
|
|
//
|
|
// f -> musttail g -> musttail f ==> f -> musttail f
|
|
// f -> musttail g -> tail f ==> f -> tail f
|
|
// f -> g -> musttail f ==> f -> f
|
|
// f -> g -> tail f ==> f -> f
|
|
CallInst::TailCallKind ChildTCK = CI->getTailCallKind();
|
|
ChildTCK = std::min(CallSiteTailKind, ChildTCK);
|
|
CI->setTailCallKind(ChildTCK);
|
|
InlinedMustTailCalls |= CI->isMustTailCall();
|
|
|
|
// Calls inlined through a 'nounwind' call site should be marked
|
|
// 'nounwind'.
|
|
if (MarkNoUnwind)
|
|
CI->setDoesNotThrow();
|
|
}
|
|
}
|
|
}
|
|
|
|
// Leave lifetime markers for the static alloca's, scoping them to the
|
|
// function we just inlined.
|
|
if (InsertLifetime && !IFI.StaticAllocas.empty()) {
|
|
IRBuilder<> builder(FirstNewBlock->begin());
|
|
for (unsigned ai = 0, ae = IFI.StaticAllocas.size(); ai != ae; ++ai) {
|
|
AllocaInst *AI = IFI.StaticAllocas[ai];
|
|
|
|
// If the alloca is already scoped to something smaller than the whole
|
|
// function then there's no need to add redundant, less accurate markers.
|
|
if (hasLifetimeMarkers(AI))
|
|
continue;
|
|
|
|
// Try to determine the size of the allocation.
|
|
ConstantInt *AllocaSize = nullptr;
|
|
if (ConstantInt *AIArraySize =
|
|
dyn_cast<ConstantInt>(AI->getArraySize())) {
|
|
if (IFI.DL) {
|
|
Type *AllocaType = AI->getAllocatedType();
|
|
uint64_t AllocaTypeSize = IFI.DL->getTypeAllocSize(AllocaType);
|
|
uint64_t AllocaArraySize = AIArraySize->getLimitedValue();
|
|
assert(AllocaArraySize > 0 && "array size of AllocaInst is zero");
|
|
// Check that array size doesn't saturate uint64_t and doesn't
|
|
// overflow when it's multiplied by type size.
|
|
if (AllocaArraySize != ~0ULL &&
|
|
UINT64_MAX / AllocaArraySize >= AllocaTypeSize) {
|
|
AllocaSize = ConstantInt::get(Type::getInt64Ty(AI->getContext()),
|
|
AllocaArraySize * AllocaTypeSize);
|
|
}
|
|
}
|
|
}
|
|
|
|
builder.CreateLifetimeStart(AI, AllocaSize);
|
|
for (ReturnInst *RI : Returns) {
|
|
// Don't insert llvm.lifetime.end calls between a musttail call and a
|
|
// return. The return kills all local allocas.
|
|
if (InlinedMustTailCalls &&
|
|
RI->getParent()->getTerminatingMustTailCall())
|
|
continue;
|
|
IRBuilder<>(RI).CreateLifetimeEnd(AI, AllocaSize);
|
|
}
|
|
}
|
|
}
|
|
|
|
// If the inlined code contained dynamic alloca instructions, wrap the inlined
|
|
// code with llvm.stacksave/llvm.stackrestore intrinsics.
|
|
if (InlinedFunctionInfo.ContainsDynamicAllocas) {
|
|
Module *M = Caller->getParent();
|
|
// Get the two intrinsics we care about.
|
|
Function *StackSave = Intrinsic::getDeclaration(M, Intrinsic::stacksave);
|
|
Function *StackRestore=Intrinsic::getDeclaration(M,Intrinsic::stackrestore);
|
|
|
|
// Insert the llvm.stacksave.
|
|
CallInst *SavedPtr = IRBuilder<>(FirstNewBlock, FirstNewBlock->begin())
|
|
.CreateCall(StackSave, "savedstack");
|
|
|
|
// Insert a call to llvm.stackrestore before any return instructions in the
|
|
// inlined function.
|
|
for (ReturnInst *RI : Returns) {
|
|
// Don't insert llvm.stackrestore calls between a musttail call and a
|
|
// return. The return will restore the stack pointer.
|
|
if (InlinedMustTailCalls && RI->getParent()->getTerminatingMustTailCall())
|
|
continue;
|
|
IRBuilder<>(RI).CreateCall(StackRestore, SavedPtr);
|
|
}
|
|
}
|
|
|
|
// If we are inlining for an invoke instruction, we must make sure to rewrite
|
|
// any call instructions into invoke instructions.
|
|
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall))
|
|
HandleInlinedInvoke(II, FirstNewBlock, InlinedFunctionInfo);
|
|
|
|
// Handle any inlined musttail call sites. In order for a new call site to be
|
|
// musttail, the source of the clone and the inlined call site must have been
|
|
// musttail. Therefore it's safe to return without merging control into the
|
|
// phi below.
|
|
if (InlinedMustTailCalls) {
|
|
// Check if we need to bitcast the result of any musttail calls.
|
|
Type *NewRetTy = Caller->getReturnType();
|
|
bool NeedBitCast = !TheCall->use_empty() && TheCall->getType() != NewRetTy;
|
|
|
|
// Handle the returns preceded by musttail calls separately.
|
|
SmallVector<ReturnInst *, 8> NormalReturns;
|
|
for (ReturnInst *RI : Returns) {
|
|
CallInst *ReturnedMustTail =
|
|
RI->getParent()->getTerminatingMustTailCall();
|
|
if (!ReturnedMustTail) {
|
|
NormalReturns.push_back(RI);
|
|
continue;
|
|
}
|
|
if (!NeedBitCast)
|
|
continue;
|
|
|
|
// Delete the old return and any preceding bitcast.
|
|
BasicBlock *CurBB = RI->getParent();
|
|
auto *OldCast = dyn_cast_or_null<BitCastInst>(RI->getReturnValue());
|
|
RI->eraseFromParent();
|
|
if (OldCast)
|
|
OldCast->eraseFromParent();
|
|
|
|
// Insert a new bitcast and return with the right type.
|
|
IRBuilder<> Builder(CurBB);
|
|
Builder.CreateRet(Builder.CreateBitCast(ReturnedMustTail, NewRetTy));
|
|
}
|
|
|
|
// Leave behind the normal returns so we can merge control flow.
|
|
std::swap(Returns, NormalReturns);
|
|
}
|
|
|
|
// If we cloned in _exactly one_ basic block, and if that block ends in a
|
|
// return instruction, we splice the body of the inlined callee directly into
|
|
// the calling basic block.
|
|
if (Returns.size() == 1 && std::distance(FirstNewBlock, Caller->end()) == 1) {
|
|
// Move all of the instructions right before the call.
|
|
OrigBB->getInstList().splice(TheCall, FirstNewBlock->getInstList(),
|
|
FirstNewBlock->begin(), FirstNewBlock->end());
|
|
// Remove the cloned basic block.
|
|
Caller->getBasicBlockList().pop_back();
|
|
|
|
// If the call site was an invoke instruction, add a branch to the normal
|
|
// destination.
|
|
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) {
|
|
BranchInst *NewBr = BranchInst::Create(II->getNormalDest(), TheCall);
|
|
NewBr->setDebugLoc(Returns[0]->getDebugLoc());
|
|
}
|
|
|
|
// If the return instruction returned a value, replace uses of the call with
|
|
// uses of the returned value.
|
|
if (!TheCall->use_empty()) {
|
|
ReturnInst *R = Returns[0];
|
|
if (TheCall == R->getReturnValue())
|
|
TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType()));
|
|
else
|
|
TheCall->replaceAllUsesWith(R->getReturnValue());
|
|
}
|
|
// Since we are now done with the Call/Invoke, we can delete it.
|
|
TheCall->eraseFromParent();
|
|
|
|
// Since we are now done with the return instruction, delete it also.
|
|
Returns[0]->eraseFromParent();
|
|
|
|
// We are now done with the inlining.
|
|
return true;
|
|
}
|
|
|
|
// Otherwise, we have the normal case, of more than one block to inline or
|
|
// multiple return sites.
|
|
|
|
// We want to clone the entire callee function into the hole between the
|
|
// "starter" and "ender" blocks. How we accomplish this depends on whether
|
|
// this is an invoke instruction or a call instruction.
|
|
BasicBlock *AfterCallBB;
|
|
BranchInst *CreatedBranchToNormalDest = nullptr;
|
|
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) {
|
|
|
|
// Add an unconditional branch to make this look like the CallInst case...
|
|
CreatedBranchToNormalDest = BranchInst::Create(II->getNormalDest(), TheCall);
|
|
|
|
// Split the basic block. This guarantees that no PHI nodes will have to be
|
|
// updated due to new incoming edges, and make the invoke case more
|
|
// symmetric to the call case.
|
|
AfterCallBB = OrigBB->splitBasicBlock(CreatedBranchToNormalDest,
|
|
CalledFunc->getName()+".exit");
|
|
|
|
} else { // It's a call
|
|
// If this is a call instruction, we need to split the basic block that
|
|
// the call lives in.
|
|
//
|
|
AfterCallBB = OrigBB->splitBasicBlock(TheCall,
|
|
CalledFunc->getName()+".exit");
|
|
}
|
|
|
|
// Change the branch that used to go to AfterCallBB to branch to the first
|
|
// basic block of the inlined function.
|
|
//
|
|
TerminatorInst *Br = OrigBB->getTerminator();
|
|
assert(Br && Br->getOpcode() == Instruction::Br &&
|
|
"splitBasicBlock broken!");
|
|
Br->setOperand(0, FirstNewBlock);
|
|
|
|
|
|
// Now that the function is correct, make it a little bit nicer. In
|
|
// particular, move the basic blocks inserted from the end of the function
|
|
// into the space made by splitting the source basic block.
|
|
Caller->getBasicBlockList().splice(AfterCallBB, Caller->getBasicBlockList(),
|
|
FirstNewBlock, Caller->end());
|
|
|
|
// Handle all of the return instructions that we just cloned in, and eliminate
|
|
// any users of the original call/invoke instruction.
|
|
Type *RTy = CalledFunc->getReturnType();
|
|
|
|
PHINode *PHI = nullptr;
|
|
if (Returns.size() > 1) {
|
|
// The PHI node should go at the front of the new basic block to merge all
|
|
// possible incoming values.
|
|
if (!TheCall->use_empty()) {
|
|
PHI = PHINode::Create(RTy, Returns.size(), TheCall->getName(),
|
|
AfterCallBB->begin());
|
|
// Anything that used the result of the function call should now use the
|
|
// PHI node as their operand.
|
|
TheCall->replaceAllUsesWith(PHI);
|
|
}
|
|
|
|
// Loop over all of the return instructions adding entries to the PHI node
|
|
// as appropriate.
|
|
if (PHI) {
|
|
for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
|
|
ReturnInst *RI = Returns[i];
|
|
assert(RI->getReturnValue()->getType() == PHI->getType() &&
|
|
"Ret value not consistent in function!");
|
|
PHI->addIncoming(RI->getReturnValue(), RI->getParent());
|
|
}
|
|
}
|
|
|
|
|
|
// Add a branch to the merge points and remove return instructions.
|
|
DebugLoc Loc;
|
|
for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
|
|
ReturnInst *RI = Returns[i];
|
|
BranchInst* BI = BranchInst::Create(AfterCallBB, RI);
|
|
Loc = RI->getDebugLoc();
|
|
BI->setDebugLoc(Loc);
|
|
RI->eraseFromParent();
|
|
}
|
|
// We need to set the debug location to *somewhere* inside the
|
|
// inlined function. The line number may be nonsensical, but the
|
|
// instruction will at least be associated with the right
|
|
// function.
|
|
if (CreatedBranchToNormalDest)
|
|
CreatedBranchToNormalDest->setDebugLoc(Loc);
|
|
} else if (!Returns.empty()) {
|
|
// Otherwise, if there is exactly one return value, just replace anything
|
|
// using the return value of the call with the computed value.
|
|
if (!TheCall->use_empty()) {
|
|
if (TheCall == Returns[0]->getReturnValue())
|
|
TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType()));
|
|
else
|
|
TheCall->replaceAllUsesWith(Returns[0]->getReturnValue());
|
|
}
|
|
|
|
// Update PHI nodes that use the ReturnBB to use the AfterCallBB.
|
|
BasicBlock *ReturnBB = Returns[0]->getParent();
|
|
ReturnBB->replaceAllUsesWith(AfterCallBB);
|
|
|
|
// Splice the code from the return block into the block that it will return
|
|
// to, which contains the code that was after the call.
|
|
AfterCallBB->getInstList().splice(AfterCallBB->begin(),
|
|
ReturnBB->getInstList());
|
|
|
|
if (CreatedBranchToNormalDest)
|
|
CreatedBranchToNormalDest->setDebugLoc(Returns[0]->getDebugLoc());
|
|
|
|
// Delete the return instruction now and empty ReturnBB now.
|
|
Returns[0]->eraseFromParent();
|
|
ReturnBB->eraseFromParent();
|
|
} else if (!TheCall->use_empty()) {
|
|
// No returns, but something is using the return value of the call. Just
|
|
// nuke the result.
|
|
TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType()));
|
|
}
|
|
|
|
// Since we are now done with the Call/Invoke, we can delete it.
|
|
TheCall->eraseFromParent();
|
|
|
|
// If we inlined any musttail calls and the original return is now
|
|
// unreachable, delete it. It can only contain a bitcast and ret.
|
|
if (InlinedMustTailCalls && pred_begin(AfterCallBB) == pred_end(AfterCallBB))
|
|
AfterCallBB->eraseFromParent();
|
|
|
|
// We should always be able to fold the entry block of the function into the
|
|
// single predecessor of the block...
|
|
assert(cast<BranchInst>(Br)->isUnconditional() && "splitBasicBlock broken!");
|
|
BasicBlock *CalleeEntry = cast<BranchInst>(Br)->getSuccessor(0);
|
|
|
|
// Splice the code entry block into calling block, right before the
|
|
// unconditional branch.
|
|
CalleeEntry->replaceAllUsesWith(OrigBB); // Update PHI nodes
|
|
OrigBB->getInstList().splice(Br, CalleeEntry->getInstList());
|
|
|
|
// Remove the unconditional branch.
|
|
OrigBB->getInstList().erase(Br);
|
|
|
|
// Now we can remove the CalleeEntry block, which is now empty.
|
|
Caller->getBasicBlockList().erase(CalleeEntry);
|
|
|
|
// If we inserted a phi node, check to see if it has a single value (e.g. all
|
|
// the entries are the same or undef). If so, remove the PHI so it doesn't
|
|
// block other optimizations.
|
|
if (PHI) {
|
|
if (Value *V = SimplifyInstruction(PHI, IFI.DL, nullptr, nullptr,
|
|
&IFI.ACT->getAssumptionCache(*Caller))) {
|
|
PHI->replaceAllUsesWith(V);
|
|
PHI->eraseFromParent();
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|