[llvm] Use nullptr instead of 0 or NULL (NFC) (#165396)

Identified with modernize-use-nullptr.

Author: kazutakahirata

llvm/include/llvm/CodeGen/TargetLowering.h

@@ -3761,7 +3761,7 @@ class LLVM_ABI TargetLoweringBase {
   /// register class is the largest legal super-reg register class of the
   /// register class of the specified type. e.g. On x86, i8, i16, and i32's
   /// representative class would be GR32.
-  const TargetRegisterClass *RepRegClassForVT[MVT::VALUETYPE_SIZE] = {0};
+  const TargetRegisterClass *RepRegClassForVT[MVT::VALUETYPE_SIZE] = {nullptr};
 
   /// This indicates the "cost" of the "representative" register class for each
   /// ValueType. The cost is used by the scheduler to approximate register

llvm/lib/DebugInfo/GSYM/GsymCreator.cpp

@@ -552,7 +552,7 @@ llvm::Error GsymCreator::saveSegments(StringRef Path,
         createSegment(SegmentSize, FuncIdx);
     if (ExpectedGC) {
       GsymCreator *GC = ExpectedGC->get();
-      if (GC == NULL)
+      if (!GC)
         break; // We had not more functions to encode.
       // Don't collect any messages at all
       OutputAggregator Out(nullptr);

llvm/lib/ExecutionEngine/Orc/TargetProcess/JITLoaderPerf.cpp

@@ -55,7 +55,7 @@ struct PerfState {
   std::unique_ptr<raw_fd_ostream> Dumpstream;
 
   // perf mmap marker
-  void *MarkerAddr = NULL;
+  void *MarkerAddr = nullptr;
 };
 
 // prevent concurrent dumps from messing up the output file

llvm/lib/SandboxIR/Context.cpp

@@ -443,7 +443,7 @@ Argument *Context::getOrCreateArgument(llvm::Argument *LLVMArg) {
 }
 
 Constant *Context::getOrCreateConstant(llvm::Constant *LLVMC) {
-  return cast<Constant>(getOrCreateValueInternal(LLVMC, 0));
+  return cast<Constant>(getOrCreateValueInternal(LLVMC, nullptr));
 }
 
 BasicBlock *Context::createBasicBlock(llvm::BasicBlock *LLVMBB) {

llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp

@@ -745,7 +745,7 @@ Register SPIRVGlobalRegistry::buildGlobalVariable(
                  .addDef(ResVReg)
                  .addUse(getSPIRVTypeID(BaseType))
                  .addImm(static_cast<uint32_t>(Storage));
-  if (Init != 0)
+  if (Init)
     MIB.addUse(Init->getOperand(0).getReg());
   // ISel may introduce a new register on this step, so we need to add it to
   // DT and correct its type avoiding fails on the next stage.

llvm/lib/TargetParser/Host.cpp

@@ -1179,7 +1179,7 @@ static const char *getAMDProcessorTypeAndSubtype(unsigned Family,
                                                  const unsigned *Features,
                                                  unsigned *Type,
                                                  unsigned *Subtype) {
-  const char *CPU = 0;
+  const char *CPU = nullptr;
 
   switch (Family) {
   case 4:

llvm/lib/Transforms/IPO/ExpandVariadics.cpp

@@ -380,7 +380,7 @@ bool ExpandVariadics::runOnModule(Module &M) {
           if (CB->isIndirectCall()) {
             FunctionType *FTy = CB->getFunctionType();
             if (FTy->isVarArg())
-              Changed |= expandCall(M, Builder, CB, FTy, 0);
+              Changed |= expandCall(M, Builder, CB, FTy, /*NF=*/nullptr);
           }
         }
       }

llvm/unittests/ProfileData/InstrProfTest.cpp

@@ -914,7 +914,7 @@ TEST_P(MaybeSparseInstrProfTest, annotate_vp_data) {
   ASSERT_THAT(ValueData, SizeIs(0));
 
   // Remove the MD_prof metadata
-  Inst->setMetadata(LLVMContext::MD_prof, 0);
+  Inst->setMetadata(LLVMContext::MD_prof, nullptr);
   // Annotate 5 records this time.
   annotateValueSite(*M, *Inst, R.get(), IPVK_IndirectCallTarget, 0, 5);
   ValueData = getValueProfDataFromInst(*Inst, IPVK_IndirectCallTarget, 5, T);
@@ -932,7 +932,7 @@ TEST_P(MaybeSparseInstrProfTest, annotate_vp_data) {
   ASSERT_EQ(2U, ValueData[4].Count);
 
   // Remove the MD_prof metadata
-  Inst->setMetadata(LLVMContext::MD_prof, 0);
+  Inst->setMetadata(LLVMContext::MD_prof, nullptr);
   // Annotate with 4 records.
   InstrProfValueData VD0Sorted[] = {{1000, 6}, {2000, 5}, {3000, 4}, {4000, 3},
                               {5000, 2}, {6000, 1}};