//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "argpromotion"
#include "llvm/Transforms/IPO.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Module.h"
-#include "llvm/CallGraphSCCPass.h"
-#include "llvm/Instructions.h"
-#include "llvm/LLVMContext.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/StringExtras.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/CallGraph.h"
-#include "llvm/Support/CallSite.h"
-#include "llvm/Support/CFG.h"
+#include "llvm/Analysis/CallGraphSCCPass.h"
+#include "llvm/IR/CFG.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/ADT/StringExtras.h"
#include <set>
using namespace llvm;
+#define DEBUG_TYPE "argpromotion"
+
STATISTIC(NumArgumentsPromoted , "Number of pointer arguments promoted");
STATISTIC(NumAggregatesPromoted, "Number of aggregate arguments promoted");
STATISTIC(NumByValArgsPromoted , "Number of byval arguments promoted");
/// ArgPromotion - The 'by reference' to 'by value' argument promotion pass.
///
struct ArgPromotion : public CallGraphSCCPass {
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequired<AliasAnalysis>();
CallGraphSCCPass::getAnalysisUsage(AU);
}
- virtual bool runOnSCC(CallGraphSCC &SCC);
+ bool runOnSCC(CallGraphSCC &SCC) override;
static char ID; // Pass identification, replacement for typeid
explicit ArgPromotion(unsigned maxElements = 3)
: CallGraphSCCPass(ID), maxElements(maxElements) {
INITIALIZE_PASS_BEGIN(ArgPromotion, "argpromotion",
"Promote 'by reference' arguments to scalars", false, false)
INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
-INITIALIZE_AG_DEPENDENCY(CallGraph)
+INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
INITIALIZE_PASS_END(ArgPromotion, "argpromotion",
"Promote 'by reference' arguments to scalars", false, false)
if (!F || !F->hasLocalLinkage()) return 0;
// First check: see if there are any pointer arguments! If not, quick exit.
- SmallVector<std::pair<Argument*, unsigned>, 16> PointerArgs;
- unsigned ArgNo = 0;
- for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end();
- I != E; ++I, ++ArgNo)
+ SmallVector<Argument*, 16> PointerArgs;
+ for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
if (I->getType()->isPointerTy())
- PointerArgs.push_back(std::pair<Argument*, unsigned>(I, ArgNo));
+ PointerArgs.push_back(I);
if (PointerArgs.empty()) return 0;
// Second check: make sure that all callers are direct callers. We can't
// transform functions that have indirect callers. Also see if the function
// is self-recursive.
bool isSelfRecursive = false;
- for (Value::use_iterator UI = F->use_begin(), E = F->use_end();
- UI != E; ++UI) {
- CallSite CS(*UI);
+ for (Use &U : F->uses()) {
+ CallSite CS(U.getUser());
// Must be a direct call.
- if (CS.getInstruction() == 0 || !CS.isCallee(UI)) return 0;
+ if (CS.getInstruction() == 0 || !CS.isCallee(&U)) return 0;
if (CS.getInstruction()->getParent()->getParent() == F)
isSelfRecursive = true;
// add it to ArgsToPromote.
SmallPtrSet<Argument*, 8> ArgsToPromote;
SmallPtrSet<Argument*, 8> ByValArgsToTransform;
- for (unsigned i = 0; i != PointerArgs.size(); ++i) {
- bool isByVal = F->paramHasAttr(PointerArgs[i].second+1, Attribute::ByVal);
- Argument *PtrArg = PointerArgs[i].first;
+ for (unsigned i = 0, e = PointerArgs.size(); i != e; ++i) {
+ Argument *PtrArg = PointerArgs[i];
Type *AgTy = cast<PointerType>(PtrArg->getType())->getElementType();
// If this is a byval argument, and if the aggregate type is small, just
- // pass the elements, which is always safe.
- if (isByVal) {
+ // pass the elements, which is always safe. This does not apply to
+ // inalloca.
+ if (PtrArg->hasByValAttr()) {
if (StructType *STy = dyn_cast<StructType>(AgTy)) {
if (maxElements > 0 && STy->getNumElements() > maxElements) {
DEBUG(dbgs() << "argpromotion disable promoting argument '"
}
// Otherwise, see if we can promote the pointer to its value.
- if (isSafeToPromoteArgument(PtrArg, isByVal))
+ if (isSafeToPromoteArgument(PtrArg, PtrArg->hasByValOrInAllocaAttr()))
ArgsToPromote.insert(PtrArg);
}
static bool AllCallersPassInValidPointerForArgument(Argument *Arg) {
Function *Callee = Arg->getParent();
- unsigned ArgNo = std::distance(Callee->arg_begin(),
- Function::arg_iterator(Arg));
+ unsigned ArgNo = Arg->getArgNo();
// Look at all call sites of the function. At this pointer we know we only
// have direct callees.
- for (Value::use_iterator UI = Callee->use_begin(), E = Callee->use_end();
- UI != E; ++UI) {
- CallSite CS(*UI);
+ for (User *U : Callee->users()) {
+ CallSite CS(U);
assert(CS && "Should only have direct calls!");
if (!CS.getArgument(ArgNo)->isDereferenceablePointer())
const ArgPromotion::IndicesVector &Longer) {
if (Prefix.size() > Longer.size())
return false;
- for (unsigned i = 0, e = Prefix.size(); i != e; ++i)
- if (Prefix[i] != Longer[i])
- return false;
- return true;
+ return std::equal(Prefix.begin(), Prefix.end(), Longer.begin());
}
/// This method limits promotion of aggregates to only promote up to three
/// elements of the aggregate in order to avoid exploding the number of
/// arguments passed in.
-bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
+bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg,
+ bool isByValOrInAlloca) const {
typedef std::set<IndicesVector> GEPIndicesSet;
// Quick exit for unused arguments
//
// This set will contain all sets of indices that are loaded in the entry
// block, and thus are safe to unconditionally load in the caller.
+ //
+ // This optimization is also safe for InAlloca parameters, because it verifies
+ // that the address isn't captured.
GEPIndicesSet SafeToUnconditionallyLoad;
// This set contains all the sets of indices that we are planning to promote.
GEPIndicesSet ToPromote;
// If the pointer is always valid, any load with first index 0 is valid.
- if (isByVal || AllCallersPassInValidPointerForArgument(Arg))
+ if (isByValOrInAlloca || AllCallersPassInValidPointerForArgument(Arg))
SafeToUnconditionallyLoad.insert(IndicesVector(1, 0));
// First, iterate the entry block and mark loads of (geps of) arguments as
// not (GEP+)loads, or any (GEP+)loads that are not safe to promote.
SmallVector<LoadInst*, 16> Loads;
IndicesVector Operands;
- for (Value::use_iterator UI = Arg->use_begin(), E = Arg->use_end();
- UI != E; ++UI) {
- User *U = *UI;
+ for (Use &U : Arg->uses()) {
+ User *UR = U.getUser();
Operands.clear();
- if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
+ if (LoadInst *LI = dyn_cast<LoadInst>(UR)) {
// Don't hack volatile/atomic loads
if (!LI->isSimple()) return false;
Loads.push_back(LI);
// Direct loads are equivalent to a GEP with a zero index and then a load.
Operands.push_back(0);
- } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(U)) {
+ } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(UR)) {
if (GEP->use_empty()) {
// Dead GEP's cause trouble later. Just remove them if we run into
// them.
// TODO: This runs the above loop over and over again for dead GEPs
// Couldn't we just do increment the UI iterator earlier and erase the
// use?
- return isSafeToPromoteArgument(Arg, isByVal);
+ return isSafeToPromoteArgument(Arg, isByValOrInAlloca);
}
// Ensure that all of the indices are constants.
return false; // Not a constant operand GEP!
// Ensure that the only users of the GEP are load instructions.
- for (Value::use_iterator UI = GEP->use_begin(), E = GEP->use_end();
- UI != E; ++UI)
- if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) {
+ for (User *GEPU : GEP->users())
+ if (LoadInst *LI = dyn_cast<LoadInst>(GEPU)) {
// Don't hack volatile/atomic loads
if (!LI->isSimple()) return false;
Loads.push_back(LI);
// OriginalLoads - Keep track of a representative load instruction from the
// original function so that we can tell the alias analysis implementation
// what the new GEP/Load instructions we are inserting look like.
- std::map<IndicesVector, LoadInst*> OriginalLoads;
+ // We need to keep the original loads for each argument and the elements
+ // of the argument that are accessed.
+ std::map<std::pair<Argument*, IndicesVector>, LoadInst*> OriginalLoads;
- // Attributes - Keep track of the parameter attributes for the arguments
+ // Attribute - Keep track of the parameter attributes for the arguments
// that we are *not* promoting. For the ones that we do promote, the parameter
// attributes are lost
- SmallVector<AttributeWithIndex, 8> AttributesVec;
- const AttrListPtr &PAL = F->getAttributes();
+ SmallVector<AttributeSet, 8> AttributesVec;
+ const AttributeSet &PAL = F->getAttributes();
// Add any return attributes.
- if (Attributes attrs = PAL.getRetAttributes())
- AttributesVec.push_back(AttributeWithIndex::get(0, attrs));
+ if (PAL.hasAttributes(AttributeSet::ReturnIndex))
+ AttributesVec.push_back(AttributeSet::get(F->getContext(),
+ PAL.getRetAttributes()));
// First, determine the new argument list
unsigned ArgIndex = 1;
} else if (!ArgsToPromote.count(I)) {
// Unchanged argument
Params.push_back(I->getType());
- if (Attributes attrs = PAL.getParamAttributes(ArgIndex))
- AttributesVec.push_back(AttributeWithIndex::get(Params.size(), attrs));
+ AttributeSet attrs = PAL.getParamAttributes(ArgIndex);
+ if (attrs.hasAttributes(ArgIndex)) {
+ AttrBuilder B(attrs, ArgIndex);
+ AttributesVec.
+ push_back(AttributeSet::get(F->getContext(), Params.size(), B));
+ }
} else if (I->use_empty()) {
// Dead argument (which are always marked as promotable)
++NumArgumentsDead;
// In this table, we will track which indices are loaded from the argument
// (where direct loads are tracked as no indices).
ScalarizeTable &ArgIndices = ScalarizedElements[I];
- for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E;
- ++UI) {
- Instruction *User = cast<Instruction>(*UI);
- assert(isa<LoadInst>(User) || isa<GetElementPtrInst>(User));
+ for (User *U : I->users()) {
+ Instruction *UI = cast<Instruction>(U);
+ assert(isa<LoadInst>(UI) || isa<GetElementPtrInst>(UI));
IndicesVector Indices;
- Indices.reserve(User->getNumOperands() - 1);
+ Indices.reserve(UI->getNumOperands() - 1);
// Since loads will only have a single operand, and GEPs only a single
// non-index operand, this will record direct loads without any indices,
// and gep+loads with the GEP indices.
- for (User::op_iterator II = User->op_begin() + 1, IE = User->op_end();
+ for (User::op_iterator II = UI->op_begin() + 1, IE = UI->op_end();
II != IE; ++II)
Indices.push_back(cast<ConstantInt>(*II)->getSExtValue());
// GEPs with a single 0 index can be merged with direct loads
Indices.clear();
ArgIndices.insert(Indices);
LoadInst *OrigLoad;
- if (LoadInst *L = dyn_cast<LoadInst>(User))
+ if (LoadInst *L = dyn_cast<LoadInst>(UI))
OrigLoad = L;
else
// Take any load, we will use it only to update Alias Analysis
- OrigLoad = cast<LoadInst>(User->use_back());
- OriginalLoads[Indices] = OrigLoad;
+ OrigLoad = cast<LoadInst>(UI->user_back());
+ OriginalLoads[std::make_pair(I, Indices)] = OrigLoad;
}
// Add a parameter to the function for each element passed in.
}
// Add any function attributes.
- if (Attributes attrs = PAL.getFnAttributes())
- AttributesVec.push_back(AttributeWithIndex::get(~0, attrs));
+ if (PAL.hasAttributes(AttributeSet::FunctionIndex))
+ AttributesVec.push_back(AttributeSet::get(FTy->getContext(),
+ PAL.getFnAttributes()));
Type *RetTy = FTy->getReturnType();
- // Work around LLVM bug PR56: the CWriter cannot emit varargs functions which
- // have zero fixed arguments.
- bool ExtraArgHack = false;
- if (Params.empty() && FTy->isVarArg()) {
- ExtraArgHack = true;
- Params.push_back(Type::getInt32Ty(F->getContext()));
- }
-
// Construct the new function type using the new arguments.
FunctionType *NFTy = FunctionType::get(RetTy, Params, FTy->isVarArg());
// Recompute the parameter attributes list based on the new arguments for
// the function.
- NF->setAttributes(AttrListPtr::get(AttributesVec.begin(),
- AttributesVec.end()));
+ NF->setAttributes(AttributeSet::get(F->getContext(), AttributesVec));
AttributesVec.clear();
F->getParent()->getFunctionList().insert(F, NF);
// Get the callgraph information that we need to update to reflect our
// changes.
- CallGraph &CG = getAnalysis<CallGraph>();
-
+ CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
+
// Get a new callgraph node for NF.
CallGraphNode *NF_CGN = CG.getOrInsertFunction(NF);
//
SmallVector<Value*, 16> Args;
while (!F->use_empty()) {
- CallSite CS(F->use_back());
+ CallSite CS(F->user_back());
assert(CS.getCalledFunction() == F);
Instruction *Call = CS.getInstruction();
- const AttrListPtr &CallPAL = CS.getAttributes();
+ const AttributeSet &CallPAL = CS.getAttributes();
// Add any return attributes.
- if (Attributes attrs = CallPAL.getRetAttributes())
- AttributesVec.push_back(AttributeWithIndex::get(0, attrs));
+ if (CallPAL.hasAttributes(AttributeSet::ReturnIndex))
+ AttributesVec.push_back(AttributeSet::get(F->getContext(),
+ CallPAL.getRetAttributes()));
// Loop over the operands, inserting GEP and loads in the caller as
// appropriate.
if (!ArgsToPromote.count(I) && !ByValArgsToTransform.count(I)) {
Args.push_back(*AI); // Unmodified argument
- if (Attributes Attrs = CallPAL.getParamAttributes(ArgIndex))
- AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs));
-
+ if (CallPAL.hasAttributes(ArgIndex)) {
+ AttrBuilder B(CallPAL, ArgIndex);
+ AttributesVec.
+ push_back(AttributeSet::get(F->getContext(), Args.size(), B));
+ }
} else if (ByValArgsToTransform.count(I)) {
// Emit a GEP and load for each element of the struct.
Type *AgTy = cast<PointerType>(I->getType())->getElementType();
for (ScalarizeTable::iterator SI = ArgIndices.begin(),
E = ArgIndices.end(); SI != E; ++SI) {
Value *V = *AI;
- LoadInst *OrigLoad = OriginalLoads[*SI];
+ LoadInst *OrigLoad = OriginalLoads[std::make_pair(I, *SI)];
if (!SI->empty()) {
Ops.reserve(SI->size());
Type *ElTy = V->getType();
}
}
- if (ExtraArgHack)
- Args.push_back(Constant::getNullValue(Type::getInt32Ty(F->getContext())));
-
// Push any varargs arguments on the list.
for (; AI != CS.arg_end(); ++AI, ++ArgIndex) {
Args.push_back(*AI);
- if (Attributes Attrs = CallPAL.getParamAttributes(ArgIndex))
- AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs));
+ if (CallPAL.hasAttributes(ArgIndex)) {
+ AttrBuilder B(CallPAL, ArgIndex);
+ AttributesVec.
+ push_back(AttributeSet::get(F->getContext(), Args.size(), B));
+ }
}
// Add any function attributes.
- if (Attributes attrs = CallPAL.getFnAttributes())
- AttributesVec.push_back(AttributeWithIndex::get(~0, attrs));
+ if (CallPAL.hasAttributes(AttributeSet::FunctionIndex))
+ AttributesVec.push_back(AttributeSet::get(Call->getContext(),
+ CallPAL.getFnAttributes()));
Instruction *New;
if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
New = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(),
Args, "", Call);
cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv());
- cast<InvokeInst>(New)->setAttributes(AttrListPtr::get(AttributesVec.begin(),
- AttributesVec.end()));
+ cast<InvokeInst>(New)->setAttributes(AttributeSet::get(II->getContext(),
+ AttributesVec));
} else {
New = CallInst::Create(NF, Args, "", Call);
cast<CallInst>(New)->setCallingConv(CS.getCallingConv());
- cast<CallInst>(New)->setAttributes(AttrListPtr::get(AttributesVec.begin(),
- AttributesVec.end()));
+ cast<CallInst>(New)->setAttributes(AttributeSet::get(New->getContext(),
+ AttributesVec));
if (cast<CallInst>(Call)->isTailCall())
cast<CallInst>(New)->setTailCall();
}
I->replaceAllUsesWith(TheAlloca);
TheAlloca->takeName(I);
AA.replaceWithNewValue(I, TheAlloca);
+
+ // If the alloca is used in a call, we must clear the tail flag since
+ // the callee now uses an alloca from the caller.
+ for (User *U : TheAlloca->users()) {
+ CallInst *Call = dyn_cast<CallInst>(U);
+ if (!Call)
+ continue;
+ Call->setTailCall(false);
+ }
continue;
}
ScalarizeTable &ArgIndices = ScalarizedElements[I];
while (!I->use_empty()) {
- if (LoadInst *LI = dyn_cast<LoadInst>(I->use_back())) {
+ if (LoadInst *LI = dyn_cast<LoadInst>(I->user_back())) {
assert(ArgIndices.begin()->empty() &&
"Load element should sort to front!");
I2->setName(I->getName()+".val");
DEBUG(dbgs() << "*** Promoted load of argument '" << I->getName()
<< "' in function '" << F->getName() << "'\n");
} else {
- GetElementPtrInst *GEP = cast<GetElementPtrInst>(I->use_back());
+ GetElementPtrInst *GEP = cast<GetElementPtrInst>(I->user_back());
IndicesVector Operands;
Operands.reserve(GEP->getNumIndices());
for (User::op_iterator II = GEP->idx_begin(), IE = GEP->idx_end();
// All of the uses must be load instructions. Replace them all with
// the argument specified by ArgNo.
while (!GEP->use_empty()) {
- LoadInst *L = cast<LoadInst>(GEP->use_back());
+ LoadInst *L = cast<LoadInst>(GEP->user_back());
L->replaceAllUsesWith(TheArg);
AA.replaceWithNewValue(L, TheArg);
L->eraseFromParent();
}
// Increment I2 past all of the arguments added for this promoted pointer.
- for (unsigned i = 0, e = ArgIndices.size(); i != e; ++i)
- ++I2;
+ std::advance(I2, ArgIndices.size());
}
- // Notify the alias analysis implementation that we inserted a new argument.
- if (ExtraArgHack)
- AA.copyValue(Constant::getNullValue(Type::getInt32Ty(F->getContext())),
- NF->arg_begin());
-
-
// Tell the alias analysis that the old function is about to disappear.
AA.replaceWithNewValue(F, NF);
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