[llvm] Use *Map::lookup (NFC)

include/llvm/ProfileData/SampleProf.h

@@ -796,10 +796,7 @@ public:
       return Name;
 
     assert(GUIDToFuncNameMap && "GUIDToFuncNameMap needs to be popluated first");
-    auto iter = GUIDToFuncNameMap->find(std::stoull(Name.data()));
-    if (iter == GUIDToFuncNameMap->end())
-      return StringRef();
-    return iter->second;
+    return GUIDToFuncNameMap->lookup(std::stoull(Name.data()));
   }
 
   /// Returns the line offset to the start line of the subprogram.

lib/Support/CommandLine.cpp

@@ -531,11 +531,7 @@ Option *CommandLineParser::LookupOption(SubCommand &Sub, StringRef &Arg,
   // If we have an equals sign, remember the value.
   if (EqualPos == StringRef::npos) {
     // Look up the option.
-    auto I = Sub.OptionsMap.find(Arg);
-    if (I == Sub.OptionsMap.end())
-      return nullptr;
-
-    return I != Sub.OptionsMap.end() ? I->second : nullptr;
+    return Sub.OptionsMap.lookup(Arg);
   }
 
   // If the argument before the = is a valid option name and the option allows

tools/llvm-objcopy/COFF/Object.cpp

@@ -31,10 +31,7 @@ void Object::updateSymbols() {
 }
 
 const Symbol *Object::findSymbol(size_t UniqueId) const {
-  auto It = SymbolMap.find(UniqueId);
-  if (It == SymbolMap.end())
-    return nullptr;
-  return It->second;
+  return SymbolMap.lookup(UniqueId);
 }
 
 Error Object::removeSymbols(
@@ -86,10 +83,7 @@ void Object::updateSections() {
 }
 
 const Section *Object::findSection(ssize_t UniqueId) const {
-  auto It = SectionMap.find(UniqueId);
-  if (It == SectionMap.end())
-    return nullptr;
-  return It->second;
+  return SectionMap.lookup(UniqueId);
 }
 
 void Object::removeSections(function_ref<bool(const Section &)> ToRemove) {

utils/TableGen/CodeGenRegisters.cpp

@@ -1238,8 +1238,7 @@ CodeGenSubRegIndex *CodeGenRegBank::getSubRegIdx(Record *Def) {
 
 const CodeGenSubRegIndex *
 CodeGenRegBank::findSubRegIdx(const Record* Def) const {
-  auto I = Def2SubRegIdx.find(Def);
-  return (I == Def2SubRegIdx.end()) ? nullptr : I->second;
+  return Def2SubRegIdx.lookup(Def);
 }
 
 CodeGenRegister *CodeGenRegBank::getReg(Record *Def) {

utils/TableGen/CodeGenTarget.cpp

@@ -393,11 +393,7 @@ void CodeGenTarget::ReadRegAltNameIndices() const {
 /// getRegisterByName - If there is a register with the specific AsmName,
 /// return it.
 const CodeGenRegister *CodeGenTarget::getRegisterByName(StringRef Name) const {
-  const StringMap<CodeGenRegister*> &Regs = getRegBank().getRegistersByName();
-  StringMap<CodeGenRegister*>::const_iterator I = Regs.find(Name);
-  if (I == Regs.end())
-    return nullptr;
-  return I->second;
+  return getRegBank().getRegistersByName().lookup(Name);
 }
 
 std::vector<ValueTypeByHwMode> CodeGenTarget::getRegisterVTs(Record *R)

utils/TableGen/GlobalISel/GIMatchTree.h

@@ -353,10 +353,7 @@ public:
   void declareOperand(unsigned InstrID, unsigned OpIdx);
 
   GIMatchTreeInstrInfo *getInstrInfo(unsigned ID) const {
-    auto I = InstrIDToInfo.find(ID);
-    if (I != InstrIDToInfo.end())
-      return I->second;
-    return nullptr;
+    return InstrIDToInfo.lookup(ID);
   }
 
   void dump(raw_ostream &OS) const {