Module &M, bool isConst, unsigned AddrSpace) const;
/// \brief Merge everything in \p Globals for which the corresponding bit
/// in \p GlobalSet is set.
- bool doMerge(SmallVectorImpl<GlobalVariable *> &Globals,
+ bool doMerge(const SmallVectorImpl<GlobalVariable *> &Globals,
const BitVector &GlobalSet, Module &M, bool isConst,
unsigned AddrSpace) const;
Module &M, bool isConst, unsigned AddrSpace) const {
auto &DL = M.getDataLayout();
// FIXME: Find better heuristics
- std::stable_sort(
- Globals.begin(), Globals.end(),
- [&DL](const GlobalVariable *GV1, const GlobalVariable *GV2) {
- Type *Ty1 = cast<PointerType>(GV1->getType())->getElementType();
- Type *Ty2 = cast<PointerType>(GV2->getType())->getElementType();
-
- return (DL.getTypeAllocSize(Ty1) < DL.getTypeAllocSize(Ty2));
- });
+ std::stable_sort(Globals.begin(), Globals.end(),
+ [&DL](const GlobalVariable *GV1, const GlobalVariable *GV2) {
+ return DL.getTypeAllocSize(GV1->getValueType()) <
+ DL.getTypeAllocSize(GV2->getValueType());
+ });
// If we want to just blindly group all globals together, do so.
if (!GlobalMergeGroupByUse) {
Function *ParentFn = I->getParent()->getParent();
// If we're only optimizing for size, ignore non-minsize functions.
- if (OnlyOptimizeForSize &&
- !ParentFn->hasFnAttribute(Attribute::MinSize))
+ if (OnlyOptimizeForSize && !ParentFn->optForMinSize())
continue;
size_t UGSIdx = GlobalUsesByFunction[ParentFn];
return Changed;
}
-bool GlobalMerge::doMerge(SmallVectorImpl<GlobalVariable *> &Globals,
+bool GlobalMerge::doMerge(const SmallVectorImpl<GlobalVariable *> &Globals,
const BitVector &GlobalSet, Module &M, bool isConst,
unsigned AddrSpace) const {
+ assert(Globals.size() > 1);
Type *Int32Ty = Type::getInt32Ty(M.getContext());
auto &DL = M.getDataLayout();
- assert(Globals.size() > 1);
-
DEBUG(dbgs() << " Trying to merge set, starts with #"
<< GlobalSet.find_first() << "\n");
std::vector<Type*> Tys;
std::vector<Constant*> Inits;
- bool HasExternal = false;
- GlobalVariable *TheFirstExternal = 0;
for (j = i; j != -1; j = GlobalSet.find_next(j)) {
- Type *Ty = Globals[j]->getType()->getElementType();
+ Type *Ty = Globals[j]->getValueType();
MergedSize += DL.getTypeAllocSize(Ty);
if (MergedSize > MaxOffset) {
break;
}
Tys.push_back(Ty);
Inits.push_back(Globals[j]->getInitializer());
-
- if (Globals[j]->hasExternalLinkage() && !HasExternal) {
- HasExternal = true;
- TheFirstExternal = Globals[j];
- }
}
- // If merged variables doesn't have external linkage, we needn't to expose
- // the symbol after merging.
- GlobalValue::LinkageTypes Linkage = HasExternal
- ? GlobalValue::ExternalLinkage
- : GlobalValue::InternalLinkage;
-
StructType *MergedTy = StructType::get(M.getContext(), Tys);
Constant *MergedInit = ConstantStruct::get(MergedTy, Inits);
- // If merged variables have external linkage, we use symbol name of the
- // first variable merged as the suffix of global symbol name. This would
- // be able to avoid the link-time naming conflict for globalm symbols.
GlobalVariable *MergedGV = new GlobalVariable(
- M, MergedTy, isConst, Linkage, MergedInit,
- HasExternal ? "_MergedGlobals_" + TheFirstExternal->getName()
- : "_MergedGlobals",
- nullptr, GlobalVariable::NotThreadLocal, AddrSpace);
+ M, MergedTy, isConst, GlobalValue::PrivateLinkage, MergedInit,
+ "_MergedGlobals", nullptr, GlobalVariable::NotThreadLocal, AddrSpace);
for (ssize_t k = i, idx = 0; k != j; k = GlobalSet.find_next(k)) {
GlobalValue::LinkageTypes Linkage = Globals[k]->getLinkage();
Globals[k]->replaceAllUsesWith(GEP);
Globals[k]->eraseFromParent();
- if (Linkage != GlobalValue::InternalLinkage) {
- // Generate a new alias...
+ // When the linkage is not internal we must emit an alias for the original
+ // variable name as it may be accessed from another object. On non-Mach-O
+ // we can also emit an alias for internal linkage as it's safe to do so.
+ // It's not safe on Mach-O as the alias (and thus the portion of the
+ // MergedGlobals variable) may be dead stripped at link time.
+ if (Linkage != GlobalValue::InternalLinkage ||
+ !TM->getTargetTriple().isOSBinFormatMachO()) {
auto *PTy = cast<PointerType>(GEP->getType());
GlobalAlias::create(PTy, Linkage, Name, GEP, &M);
}
// Ignore fancy-aligned globals for now.
unsigned Alignment = DL.getPreferredAlignment(I);
- Type *Ty = I->getType()->getElementType();
+ Type *Ty = I->getValueType();
if (Alignment > DL.getABITypeAlignment(Ty))
continue;
}
}
- for (DenseMap<unsigned, SmallVector<GlobalVariable*, 16> >::iterator
- I = Globals.begin(), E = Globals.end(); I != E; ++I)
- if (I->second.size() > 1)
- Changed |= doMerge(I->second, M, false, I->first);
-
- for (DenseMap<unsigned, SmallVector<GlobalVariable*, 16> >::iterator
- I = BSSGlobals.begin(), E = BSSGlobals.end(); I != E; ++I)
- if (I->second.size() > 1)
- Changed |= doMerge(I->second, M, false, I->first);
-
- if (EnableGlobalMergeOnConst)
- for (DenseMap<unsigned, SmallVector<GlobalVariable*, 16> >::iterator
- I = ConstGlobals.begin(), E = ConstGlobals.end(); I != E; ++I)
- if (I->second.size() > 1)
- Changed |= doMerge(I->second, M, true, I->first);
+ for (auto &P : Globals)
+ if (P.second.size() > 1)
+ Changed |= doMerge(P.second, M, false, P.first);
+
+ for (auto &P : BSSGlobals)
+ if (P.second.size() > 1)
+ Changed |= doMerge(P.second, M, false, P.first);
+
+ for (auto &P : ConstGlobals)
+ if (P.second.size() > 1)
+ Changed |= doMerge(P.second, M, true, P.first);
return Changed;
}
projects / oota-llvm.git / blobdiff