CodeGen: Remove overrides of getSSPStackGuardCheck

All 3 implementations are just checking if this has the
windows check function, so merge that as the only implementation.

Author: arsenm

llvm/include/llvm/CodeGen/TargetLowering.h

@@ -2127,7 +2127,7 @@ class LLVM_ABI TargetLoweringBase {
   /// performs validation and error handling, returns the function. Otherwise,
   /// returns nullptr. Must be previously inserted by insertSSPDeclarations.
   /// Should be used only when getIRStackGuard returns nullptr.
-  virtual Function *getSSPStackGuardCheck(const Module &M) const;
+  Function *getSSPStackGuardCheck(const Module &M) const;
 
 protected:
   Value *getDefaultSafeStackPointerLocation(IRBuilderBase &IRB,

llvm/lib/CodeGen/TargetLoweringBase.cpp

@@ -2097,6 +2097,11 @@ Value *TargetLoweringBase::getSDagStackGuard(const Module &M) const {
 }
 
 Function *TargetLoweringBase::getSSPStackGuardCheck(const Module &M) const {
+  // MSVC CRT has a function to validate security cookie.
+  RTLIB::LibcallImpl SecurityCheckCookieLibcall =
+      getLibcallImpl(RTLIB::SECURITY_CHECK_COOKIE);
+  if (SecurityCheckCookieLibcall != RTLIB::Unsupported)
+    return M.getFunction(getLibcallImplName(SecurityCheckCookieLibcall));
   return nullptr;
 }
 

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -29422,15 +29422,6 @@ void AArch64TargetLowering::insertSSPDeclarations(Module &M) const {
   TargetLowering::insertSSPDeclarations(M);
 }
 
-Function *AArch64TargetLowering::getSSPStackGuardCheck(const Module &M) const {
-  // MSVC CRT has a function to validate security cookie.
-  RTLIB::LibcallImpl SecurityCheckCookieLibcall =
-      getLibcallImpl(RTLIB::SECURITY_CHECK_COOKIE);
-  if (SecurityCheckCookieLibcall != RTLIB::Unsupported)
-    return M.getFunction(getLibcallImplName(SecurityCheckCookieLibcall));
-  return TargetLowering::getSSPStackGuardCheck(M);
-}
-
 Value *
 AArch64TargetLowering::getSafeStackPointerLocation(IRBuilderBase &IRB) const {
   // Android provides a fixed TLS slot for the SafeStack pointer. See the

llvm/lib/Target/AArch64/AArch64ISelLowering.h

@@ -366,7 +366,6 @@ class AArch64TargetLowering : public TargetLowering {
   Value *getIRStackGuard(IRBuilderBase &IRB) const override;
 
   void insertSSPDeclarations(Module &M) const override;
-  Function *getSSPStackGuardCheck(const Module &M) const override;
 
   /// If the target has a standard location for the unsafe stack pointer,
   /// returns the address of that location. Otherwise, returns nullptr.

llvm/lib/Target/ARM/ARMISelLowering.cpp

@@ -21311,15 +21311,6 @@ void ARMTargetLowering::insertSSPDeclarations(Module &M) const {
   TargetLowering::insertSSPDeclarations(M);
 }
 
-Function *ARMTargetLowering::getSSPStackGuardCheck(const Module &M) const {
-  // MSVC CRT has a function to validate security cookie.
-  RTLIB::LibcallImpl SecurityCheckCookie =
-      getLibcallImpl(RTLIB::SECURITY_CHECK_COOKIE);
-  if (SecurityCheckCookie != RTLIB::Unsupported)
-    return M.getFunction(getLibcallImplName(SecurityCheckCookie));
-  return TargetLowering::getSSPStackGuardCheck(M);
-}
-
 bool ARMTargetLowering::canCombineStoreAndExtract(Type *VectorTy, Value *Idx,
                                                   unsigned &Cost) const {
   // If we do not have NEON, vector types are not natively supported.

llvm/lib/Target/ARM/ARMISelLowering.h

@@ -702,7 +702,6 @@ class VectorType;
     bool useLoadStackGuardNode(const Module &M) const override;
 
     void insertSSPDeclarations(Module &M) const override;
-    Function *getSSPStackGuardCheck(const Module &M) const override;
 
     bool canCombineStoreAndExtract(Type *VectorTy, Value *Idx,
                                    unsigned &Cost) const override;

llvm/lib/Target/X86/X86ISelLowering.h

@@ -1592,7 +1592,6 @@ namespace llvm {
     bool useLoadStackGuardNode(const Module &M) const override;
     bool useStackGuardXorFP() const override;
     void insertSSPDeclarations(Module &M) const override;
-    Function *getSSPStackGuardCheck(const Module &M) const override;
     SDValue emitStackGuardXorFP(SelectionDAG &DAG, SDValue Val,
                                 const SDLoc &DL) const override;
 

llvm/lib/Target/X86/X86ISelLoweringCall.cpp

@@ -640,15 +640,6 @@ void X86TargetLowering::insertSSPDeclarations(Module &M) const {
   TargetLowering::insertSSPDeclarations(M);
 }
 
-Function *X86TargetLowering::getSSPStackGuardCheck(const Module &M) const {
-  // MSVC CRT has a function to validate security cookie.
-  if (Subtarget.getTargetTriple().isWindowsMSVCEnvironment() ||
-      Subtarget.getTargetTriple().isWindowsItaniumEnvironment()) {
-    return M.getFunction("__security_check_cookie");
-  }
-  return TargetLowering::getSSPStackGuardCheck(M);
-}
-
 Value *
 X86TargetLowering::getSafeStackPointerLocation(IRBuilderBase &IRB) const {
   // Android provides a fixed TLS slot for the SafeStack pointer. See the