[X86] Use X86AS::GS and X86AS::FS instead of 256 and 257. NFC (#109342)

Author: topperc

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -18925,7 +18925,7 @@ static SDValue LowerToTLSExecModel(GlobalAddressSDNode *GA, SelectionDAG &DAG,
 
   // Get the Thread Pointer, which is %gs:0 (32-bit) or %fs:0 (64-bit).
   Value *Ptr = Constant::getNullValue(
-      PointerType::get(*DAG.getContext(), is64Bit ? 257 : 256));
+      PointerType::get(*DAG.getContext(), is64Bit ? X86AS::FS : X86AS::GS));
 
   SDValue ThreadPointer =
       DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), DAG.getIntPtrConstant(0, dl),
@@ -19070,8 +19070,8 @@ X86TargetLowering::LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {
     // %gs:0x58 (64-bit). On MinGW, __tls_array is not available, so directly
     // use its literal value of 0x2C.
     Value *Ptr = Constant::getNullValue(
-        Subtarget.is64Bit() ? PointerType::get(*DAG.getContext(), 256)
-                            : PointerType::get(*DAG.getContext(), 257));
+        Subtarget.is64Bit() ? PointerType::get(*DAG.getContext(), X86AS::GS)
+                            : PointerType::get(*DAG.getContext(), X86AS::FS));
 
     SDValue TlsArray = Subtarget.is64Bit()
                            ? DAG.getIntPtrConstant(0x58, dl)

llvm/lib/Target/X86/X86ISelLoweringCall.cpp

@@ -524,8 +524,9 @@ X86TargetLowering::findRepresentativeClass(const TargetRegisterInfo *TRI,
 
 unsigned X86TargetLowering::getAddressSpace() const {
   if (Subtarget.is64Bit())
-    return (getTargetMachine().getCodeModel() == CodeModel::Kernel) ? 256 : 257;
-  return 256;
+    return (getTargetMachine().getCodeModel() == CodeModel::Kernel) ? X86AS::GS
+                                                                    : X86AS::FS;
+  return X86AS::GS;
 }
 
 static bool hasStackGuardSlotTLS(const Triple &TargetTriple) {

llvm/lib/Target/X86/X86WinEHState.cpp

@@ -423,7 +423,7 @@ void WinEHStatePass::linkExceptionRegistration(IRBuilder<> &Builder,
   // Handler = Handler
   Builder.CreateStore(Handler, Builder.CreateStructGEP(LinkTy, Link, 1));
   // Next = [fs:00]
-  Constant *FSZero = Constant::getNullValue(PointerType::get(C, 257));
+  Constant *FSZero = Constant::getNullValue(PointerType::get(C, X86AS::FS));
   Value *Next = Builder.CreateLoad(PointerType::getUnqual(C), FSZero);
   Builder.CreateStore(Next, Builder.CreateStructGEP(LinkTy, Link, 0));
   // [fs:00] = Link
@@ -443,7 +443,7 @@ void WinEHStatePass::unlinkExceptionRegistration(IRBuilder<> &Builder) {
   // [fs:00] = Link->Next
   Value *Next = Builder.CreateLoad(PointerType::getUnqual(C),
                                    Builder.CreateStructGEP(LinkTy, Link, 0));
-  Constant *FSZero = Constant::getNullValue(PointerType::get(C, 257));
+  Constant *FSZero = Constant::getNullValue(PointerType::get(C, X86AS::FS));
   Builder.CreateStore(Next, FSZero);
 }