ConstantMerge.cpp Source File (original) (raw)

34#include

35#include

36#include

38using namespace llvm;

40#define DEBUG_TYPE "constmerge"

42 STATISTIC(NumIdenticalMerged, "Number of identical global constants merged");

47 if (!LLVMUsed) return;

50 for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i) {

53 UsedValues.insert(GV);

54 }

55}

60 if (.hasLocalLinkage() && B.hasLocalLinkage())

61 return true;

63 if (A.hasLocalLinkage() && .hasLocalLinkage())

64 return false;

66 return A.hasGlobalUnnamedAddr();

67}

72 for (const auto &V : MDs)

73 if (V.first != LLVMContext::MD_dbg)

74 return true;

75 return false;

76}

82 for (auto *MD : MDs)

84}

91static bool

100 UsedGlobals.count(GV);

101}

102

114

117

119 << New->getName() << "\n");

120

121

122 if (Old->getAlign() || New->getAlign())

124

127

128

130 "Refusing to delete an externally visible global variable.");

132}

133

135

137 FindUsedValues(M.getGlobalVariable("llvm.used"), UsedGlobals);

138 FindUsedValues(M.getGlobalVariable("llvm.compiler.used"), UsedGlobals);

139

140

142

144 SameContentReplacements;

145

146 size_t ChangesMade = 0;

147 size_t OldChangesMade = 0;

148

149

150

151

152

153 while (true) {

154

156

157 GV.removeDeadConstantUsers();

158 if (GV.use_empty() && GV.hasLocalLinkage()) {

159 GV.eraseFromParent();

160 ++ChangesMade;

161 continue;

162 }

163

165 continue;

166

167

168

169

170

171 if (GV.isWeakForLinker())

172 continue;

173

174

176 continue;

177

179

180

182

183

184

185

186 bool FirstConstantFound = !Slot;

188 Slot = &GV;

190 << (FirstConstantFound ? "\n" : " (updated)\n"));

191 }

192 }

193

194

195

196

197

200 continue;

201

202

203 if (!GV.hasLocalLinkage())

204 continue;

205

207

208

209 auto Found = CMap.find(Init);

210 if (Found == CMap.end())

211 continue;

212

214 if (Slot == &GV)

215 continue;

216

218 continue;

219

220

221 LLVM_DEBUG(dbgs() << "Will replace: @" << GV.getName() << " -> @"

222 << Slot->getName() << "\n");

223 SameContentReplacements.push_back(std::make_pair(&GV, Slot));

224 }

225

226

227

228

229 for (const auto &[Old, New] : SameContentReplacements) {

231 ++ChangesMade;

232 ++NumIdenticalMerged;

233 }

234

235 if (ChangesMade == OldChangesMade)

236 break;

237 OldChangesMade = ChangesMade;

238

239 SameContentReplacements.clear();

241 }

242

243 return ChangesMade;

244}

245

assert(UImm &&(UImm !=~static_cast< T >(0)) &&"Invalid immediate!")

static GCRegistry::Add< ErlangGC > A("erlang", "erlang-compatible garbage collector")

static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")

static bool IsBetterCanonical(const GlobalVariable &A, const GlobalVariable &B)

Definition ConstantMerge.cpp:58

static bool hasMetadataOtherThanDebugLoc(const GlobalVariable *GV)

Definition ConstantMerge.cpp:69

static void copyDebugLocMetadata(const GlobalVariable *From, GlobalVariable *To)

Definition ConstantMerge.cpp:78

static bool mergeConstants(Module &M)

Definition ConstantMerge.cpp:134

static bool isUnmergeableGlobal(GlobalVariable *GV, const SmallPtrSetImpl< const GlobalValue * > &UsedGlobals)

Definition ConstantMerge.cpp:92

static void FindUsedValues(GlobalVariable *LLVMUsed, SmallPtrSetImpl< const GlobalValue * > &UsedValues)

Find values that are marked as llvm.used.

Definition ConstantMerge.cpp:45

CanMerge

Definition ConstantMerge.cpp:103

@ Yes

Definition ConstantMerge.cpp:103

@ No

Definition ConstantMerge.cpp:103

static CanMerge makeMergeable(GlobalVariable *Old, GlobalVariable *New)

Definition ConstantMerge.cpp:104

This file contains the declarations for the subclasses of Constant, which represent the different fla...

This file defines the DenseMap class.

Module.h This file contains the declarations for the Module class.

This file defines the SmallPtrSet class.

This file defines the SmallVector class.

This file defines the 'Statistic' class, which is designed to be an easy way to expose various metric...

#define STATISTIC(VARNAME, DESC)

ConstantArray - Constant Array Declarations.

PreservedAnalyses run(Module &M, ModuleAnalysisManager &)

Definition ConstantMerge.cpp:246

This is an important base class in LLVM.

LLVM_ABI Align getPreferredAlign(const GlobalVariable *GV) const

Returns the preferred alignment of the specified global.

iterator find(const_arg_type_t< KeyT > Val)

LLVM_ABI void getAllMetadata(SmallVectorImpl< std::pair< unsigned, MDNode * > > &MDs) const

Appends all metadata attached to this value to MDs, sorting by KindID.

bool hasSection() const

Check if this global has a custom object file section.

bool isThreadLocal() const

If the value is "Thread Local", its value isn't shared by the threads.

bool hasLocalLinkage() const

PointerType * getType() const

Global values are always pointers.

LLVM_ABI const DataLayout & getDataLayout() const

Get the data layout of the module this global belongs to.

bool hasGlobalUnnamedAddr() const

MaybeAlign getAlign() const

Returns the alignment of the given variable.

LLVM_ABI void getDebugInfo(SmallVectorImpl< DIGlobalVariableExpression * > &GVs) const

Fill the vector with all debug info attachements.

bool isConstant() const

If the value is a global constant, its value is immutable throughout the runtime execution of the pro...

LLVM_ABI void eraseFromParent()

eraseFromParent - This method unlinks 'this' from the containing module and deletes it.

LLVM_ABI void addDebugInfo(DIGlobalVariableExpression *GV)

Attach a DIGlobalVariableExpression.

bool hasDefinitiveInitializer() const

hasDefinitiveInitializer - Whether the global variable has an initializer, and any other instances of...

A Module instance is used to store all the information related to an LLVM module.

unsigned getAddressSpace() const

Return the address space of the Pointer type.

A set of analyses that are preserved following a run of a transformation pass.

static PreservedAnalyses none()

Convenience factory function for the empty preserved set.

static PreservedAnalyses all()

Construct a special preserved set that preserves all passes.

A templated base class for SmallPtrSet which provides the typesafe interface that is common across al...

size_type count(ConstPtrType Ptr) const

count - Return 1 if the specified pointer is in the set, 0 otherwise.

std::pair< iterator, bool > insert(PtrType Ptr)

Inserts Ptr if and only if there is no element in the container equal to Ptr.

SmallPtrSet - This class implements a set which is optimized for holding SmallSize or less elements.

void push_back(const T &Elt)

This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.

Value * getOperand(unsigned i) const

unsigned getNumOperands() const

LLVM Value Representation.

LLVM_ABI void replaceAllUsesWith(Value *V)

Change all uses of this to point to a new Value.

LLVM_ABI const Value * stripPointerCasts() const

Strip off pointer casts, all-zero GEPs and address space casts.

LLVM_ABI StringRef getName() const

Return a constant reference to the value's name.

This is an optimization pass for GlobalISel generic memory operations.

MaybeAlign getAlign(const CallInst &I, unsigned Index)

iterator_range< early_inc_iterator_impl< detail::IterOfRange< RangeT > > > make_early_inc_range(RangeT &&Range)

Make a range that does early increment to allow mutation of the underlying range without disrupting i...

LLVM_ABI raw_ostream & dbgs()

dbgs() - This returns a reference to a raw_ostream for debugging messages.

void replace(R &&Range, const T &OldValue, const T &NewValue)

Provide wrappers to std::replace which take ranges instead of having to pass begin/end explicitly.

decltype(auto) cast(const From &Val)

cast - Return the argument parameter cast to the specified type.

AnalysisManager< Module > ModuleAnalysisManager

Convenience typedef for the Module analysis manager.

This struct is a compact representation of a valid (non-zero power of two) alignment.