diff --git a/clang/lib/Lex/HeaderSearch.cpp b/clang/lib/Lex/HeaderSearch.cpp
index a0ac0eaf2f900..0f1090187734f 100644
--- a/clang/lib/Lex/HeaderSearch.cpp
+++ b/clang/lib/Lex/HeaderSearch.cpp
@@ -1671,7 +1671,7 @@ static OptionalFileEntryRef getPrivateModuleMap(FileEntryRef File,
     if (Filename == "module.map")
       Diags.Report(diag::warn_deprecated_module_dot_map)
           << PrivateFilename << 1
-          << File.getDir().getName().endswith(".framework");
+          << File.getDir().getName().ends_with(".framework");
   }
   return PMMFile;
 }
diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp
index 738ec301d1479..6b54047020a05 100644
--- a/llvm/lib/IR/AutoUpgrade.cpp
+++ b/llvm/lib/IR/AutoUpgrade.cpp
@@ -5220,7 +5220,7 @@ std::string llvm::UpgradeDataLayoutString(StringRef DL, StringRef TT) {
       Res.append("-p7:160:256:256:32");
     if (!DL.contains("-p8") && !DL.starts_with("p8"))
       Res.append("-p8:128:128");
-    if (!DL.contains("-p9") && !DL.startswith("p9"))
+    if (!DL.contains("-p9") && !DL.starts_with("p9"))
       Res.append("-p9:192:256:256:32");
 
     return Res;
diff --git a/llvm/lib/Target/DirectX/DXILResource.cpp b/llvm/lib/Target/DirectX/DXILResource.cpp
index 92306d907e054..d3ff12a1f7b34 100644
--- a/llvm/lib/Target/DirectX/DXILResource.cpp
+++ b/llvm/lib/Target/DirectX/DXILResource.cpp
@@ -261,7 +261,7 @@ void UAVResource::parseSourceType(StringRef S) {
   S = S.substr(S.find("<") + 1);
 
   constexpr size_t PrefixLen = StringRef("vector<").size();
-  if (S.startswith("vector<"))
+  if (S.starts_with("vector<"))
     S = S.substr(PrefixLen, S.find(",") - PrefixLen);
   else
     S = S.substr(0, S.find(">"));
diff --git a/llvm/lib/Target/SPIRV/MCTargetDesc/SPIRVBaseInfo.cpp b/llvm/lib/Target/SPIRV/MCTargetDesc/SPIRVBaseInfo.cpp
index 1af7b7a5d7845..b69031adb1673 100644
--- a/llvm/lib/Target/SPIRV/MCTargetDesc/SPIRVBaseInfo.cpp
+++ b/llvm/lib/Target/SPIRV/MCTargetDesc/SPIRVBaseInfo.cpp
@@ -177,7 +177,7 @@ std::string getLinkStringForBuiltIn(SPIRV::BuiltIn::BuiltIn BuiltInValue) {
 bool getSpirvBuiltInIdByName(llvm::StringRef Name,
                              SPIRV::BuiltIn::BuiltIn &BI) {
   const std::string Prefix = "__spirv_BuiltIn";
-  if (!Name.startswith(Prefix))
+  if (!Name.starts_with(Prefix))
     return false;
 
   const SPIRV::SymbolicOperand *Lookup =
diff --git a/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp b/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
index ae9e801f8f50b..5ac45079bd002 100644
--- a/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
@@ -872,8 +872,8 @@ static bool generateGroupInst(const SPIRV::IncomingCall *Call,
     std::tie(GroupResultRegister, GroupResultType) =
         buildBoolRegister(MIRBuilder, Call->ReturnType, GR);
 
-  auto Scope = Builtin->Name.startswith("sub_group") ? SPIRV::Scope::Subgroup
-                                                     : SPIRV::Scope::Workgroup;
+  auto Scope = Builtin->Name.starts_with("sub_group") ? SPIRV::Scope::Subgroup
+                                                      : SPIRV::Scope::Workgroup;
   Register ScopeRegister = buildConstantIntReg(Scope, MIRBuilder, GR);
 
   // Build work/sub group instruction.
@@ -1999,13 +1999,13 @@ struct OpenCLType {
 //===----------------------------------------------------------------------===//
 
 static Type *parseTypeString(const StringRef Name, LLVMContext &Context) {
-  if (Name.startswith("void"))
+  if (Name.starts_with("void"))
     return Type::getVoidTy(Context);
-  else if (Name.startswith("int") || Name.startswith("uint"))
+  else if (Name.starts_with("int") || Name.starts_with("uint"))
     return Type::getInt32Ty(Context);
-  else if (Name.startswith("float"))
+  else if (Name.starts_with("float"))
     return Type::getFloatTy(Context);
-  else if (Name.startswith("half"))
+  else if (Name.starts_with("half"))
     return Type::getHalfTy(Context);
   llvm_unreachable("Unable to recognize type!");
 }
@@ -2081,7 +2081,7 @@ parseBuiltinTypeNameToTargetExtType(std::string TypeName,
   // Pointers-to-opaque-structs representing OpenCL types are first translated
   // to equivalent SPIR-V types. OpenCL builtin type names should have the
   // following format: e.g. %opencl.event_t
-  if (NameWithParameters.startswith("opencl.")) {
+  if (NameWithParameters.starts_with("opencl.")) {
     const SPIRV::OpenCLType *OCLTypeRecord =
         SPIRV::lookupOpenCLType(NameWithParameters);
     if (!OCLTypeRecord)
@@ -2093,7 +2093,7 @@ parseBuiltinTypeNameToTargetExtType(std::string TypeName,
 
   // Names of the opaque structs representing a SPIR-V builtins without
   // parameters should have the following format: e.g. %spirv.Event
-  assert(NameWithParameters.startswith("spirv.") &&
+  assert(NameWithParameters.starts_with("spirv.") &&
          "Unknown builtin opaque type!");
 
   // Parameterized SPIR-V builtins names follow this format:
diff --git a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
index d450613196f3e..b8a6784ff3c62 100644
--- a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
@@ -962,35 +962,35 @@ SPIRVType *SPIRVGlobalRegistry::getOrCreateSPIRVTypeByName(
   if (TypeStr.starts_with("atomic_"))
     TypeStr = TypeStr.substr(strlen("atomic_"));
 
-  if (TypeStr.startswith("void")) {
+  if (TypeStr.starts_with("void")) {
     Ty = Type::getVoidTy(Ctx);
     TypeStr = TypeStr.substr(strlen("void"));
-  } else if (TypeStr.startswith("bool")) {
+  } else if (TypeStr.starts_with("bool")) {
     Ty = Type::getIntNTy(Ctx, 1);
     TypeStr = TypeStr.substr(strlen("bool"));
-  } else if (TypeStr.startswith("char") || TypeStr.startswith("uchar")) {
+  } else if (TypeStr.starts_with("char") || TypeStr.starts_with("uchar")) {
     Ty = Type::getInt8Ty(Ctx);
-    TypeStr = TypeStr.startswith("char") ? TypeStr.substr(strlen("char"))
-                                         : TypeStr.substr(strlen("uchar"));
-  } else if (TypeStr.startswith("short") || TypeStr.startswith("ushort")) {
+    TypeStr = TypeStr.starts_with("char") ? TypeStr.substr(strlen("char"))
+                                          : TypeStr.substr(strlen("uchar"));
+  } else if (TypeStr.starts_with("short") || TypeStr.starts_with("ushort")) {
     Ty = Type::getInt16Ty(Ctx);
-    TypeStr = TypeStr.startswith("short") ? TypeStr.substr(strlen("short"))
-                                          : TypeStr.substr(strlen("ushort"));
-  } else if (TypeStr.startswith("int") || TypeStr.startswith("uint")) {
+    TypeStr = TypeStr.starts_with("short") ? TypeStr.substr(strlen("short"))
+                                           : TypeStr.substr(strlen("ushort"));
+  } else if (TypeStr.starts_with("int") || TypeStr.starts_with("uint")) {
     Ty = Type::getInt32Ty(Ctx);
-    TypeStr = TypeStr.startswith("int") ? TypeStr.substr(strlen("int"))
-                                        : TypeStr.substr(strlen("uint"));
+    TypeStr = TypeStr.starts_with("int") ? TypeStr.substr(strlen("int"))
+                                         : TypeStr.substr(strlen("uint"));
   } else if (TypeStr.starts_with("long") || TypeStr.starts_with("ulong")) {
     Ty = Type::getInt64Ty(Ctx);
-    TypeStr = TypeStr.startswith("long") ? TypeStr.substr(strlen("long"))
-                                         : TypeStr.substr(strlen("ulong"));
-  } else if (TypeStr.startswith("half")) {
+    TypeStr = TypeStr.starts_with("long") ? TypeStr.substr(strlen("long"))
+                                          : TypeStr.substr(strlen("ulong"));
+  } else if (TypeStr.starts_with("half")) {
     Ty = Type::getHalfTy(Ctx);
     TypeStr = TypeStr.substr(strlen("half"));
-  } else if (TypeStr.startswith("float")) {
+  } else if (TypeStr.starts_with("float")) {
     Ty = Type::getFloatTy(Ctx);
     TypeStr = TypeStr.substr(strlen("float"));
-  } else if (TypeStr.startswith("double")) {
+  } else if (TypeStr.starts_with("double")) {
     Ty = Type::getDoubleTy(Ctx);
     TypeStr = TypeStr.substr(strlen("double"));
   } else
@@ -1007,7 +1007,7 @@ SPIRVType *SPIRVGlobalRegistry::getOrCreateSPIRVTypeByName(
   // Handle "typeN*" or  "type vector[N]*".
   bool IsPtrToVec = TypeStr.consume_back("*");
 
-  if (TypeStr.startswith(" vector[")) {
+  if (TypeStr.starts_with(" vector[")) {
     TypeStr = TypeStr.substr(strlen(" vector["));
     TypeStr = TypeStr.substr(0, TypeStr.find(']'));
   }
diff --git a/llvm/lib/Target/SPIRV/SPIRVRegularizer.cpp b/llvm/lib/Target/SPIRV/SPIRVRegularizer.cpp
index 3a51e29dcf161..322e051a87db1 100644
--- a/llvm/lib/Target/SPIRV/SPIRVRegularizer.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVRegularizer.cpp
@@ -177,8 +177,8 @@ void SPIRVRegularizer::visitCallInst(CallInst &CI) {
   StringRef DemangledName(NameStr);
 
   // TODO: add support for other builtins.
-  if (DemangledName.startswith("fmin") || DemangledName.startswith("fmax") ||
-      DemangledName.startswith("min") || DemangledName.startswith("max"))
+  if (DemangledName.starts_with("fmin") || DemangledName.starts_with("fmax") ||
+      DemangledName.starts_with("min") || DemangledName.starts_with("max"))
     visitCallScalToVec(&CI, MangledName, DemangledName);
   free(NameStr);
 }
diff --git a/llvm/lib/Target/SPIRV/SPIRVUtils.cpp b/llvm/lib/Target/SPIRV/SPIRVUtils.cpp
index 0bd51436082d5..1c0e8d84e2fd1 100644
--- a/llvm/lib/Target/SPIRV/SPIRVUtils.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVUtils.cpp
@@ -279,7 +279,7 @@ static bool isKernelQueryBI(const StringRef MangledName) {
 }
 
 static bool isNonMangledOCLBuiltin(StringRef Name) {
-  if (!Name.startswith("__"))
+  if (!Name.starts_with("__"))
     return false;
 
   return isEnqueueKernelBI(Name) || isKernelQueryBI(Name) ||
@@ -289,8 +289,8 @@ static bool isNonMangledOCLBuiltin(StringRef Name) {
 
 std::string getOclOrSpirvBuiltinDemangledName(StringRef Name) {
   bool IsNonMangledOCL = isNonMangledOCLBuiltin(Name);
-  bool IsNonMangledSPIRV = Name.startswith("__spirv_");
-  bool IsMangled = Name.startswith("_Z");
+  bool IsNonMangledSPIRV = Name.starts_with("__spirv_");
+  bool IsMangled = Name.starts_with("_Z");
 
   if (!IsNonMangledOCL && !IsNonMangledSPIRV && !IsMangled)
     return std::string();
@@ -311,7 +311,7 @@ std::string getOclOrSpirvBuiltinDemangledName(StringRef Name) {
   // Similar to ::std:: in C++.
   size_t Start, Len = 0;
   size_t DemangledNameLenStart = 2;
-  if (Name.startswith("_ZN")) {
+  if (Name.starts_with("_ZN")) {
     // Skip CV and ref qualifiers.
     size_t NameSpaceStart = Name.find_first_not_of("rVKRO", 3);
     // All built-ins are in the ::cl:: namespace.
diff --git a/llvm/lib/Target/Xtensa/AsmParser/XtensaAsmParser.cpp b/llvm/lib/Target/Xtensa/AsmParser/XtensaAsmParser.cpp
index 76c7328b547cd..3f808298527f8 100644
--- a/llvm/lib/Target/Xtensa/AsmParser/XtensaAsmParser.cpp
+++ b/llvm/lib/Target/Xtensa/AsmParser/XtensaAsmParser.cpp
@@ -598,8 +598,8 @@ bool XtensaAsmParser::parseOperand(OperandVector &Operands, StringRef Mnemonic,
 bool XtensaAsmParser::ParseInstructionWithSR(ParseInstructionInfo &Info,
                                              StringRef Name, SMLoc NameLoc,
                                              OperandVector &Operands) {
-  if ((Name.startswith("wsr.") || Name.startswith("rsr.") ||
-       Name.startswith("xsr.")) &&
+  if ((Name.starts_with("wsr.") || Name.starts_with("rsr.") ||
+       Name.starts_with("xsr.")) &&
       (Name.size() > 4)) {
     // Parse case when instruction name is concatenated with SR register
     // name, like "wsr.sar a1"
@@ -655,8 +655,8 @@ bool XtensaAsmParser::ParseInstructionWithSR(ParseInstructionInfo &Info,
 bool XtensaAsmParser::ParseInstruction(ParseInstructionInfo &Info,
                                        StringRef Name, SMLoc NameLoc,
                                        OperandVector &Operands) {
-  if (Name.startswith("wsr") || Name.startswith("rsr") ||
-      Name.startswith("xsr")) {
+  if (Name.starts_with("wsr") || Name.starts_with("rsr") ||
+      Name.starts_with("xsr")) {
     return ParseInstructionWithSR(Info, Name, NameLoc, Operands);
   }