[NFC][Attributor] Use unsigned integer for address space tracking (llvm#108447)

Author: shiltian

llvm/include/llvm/Transforms/IPO/Attributor.h

@@ -6249,7 +6249,7 @@ struct AAAddressSpace : public StateWrapper<BooleanState, AbstractAttribute> {
   /// Return the address space of the associated value. \p NoAddressSpace is
   /// returned if the associated value is dead. This functions is not supposed
   /// to be called if the AA is invalid.
-  virtual int32_t getAddressSpace() const = 0;
+  virtual uint32_t getAddressSpace() const = 0;
 
   /// Create an abstract attribute view for the position \p IRP.
   static AAAddressSpace &createForPosition(const IRPosition &IRP,
@@ -6268,7 +6268,7 @@ struct AAAddressSpace : public StateWrapper<BooleanState, AbstractAttribute> {
   }
 
   // No address space which indicates the associated value is dead.
-  static const int32_t NoAddressSpace = -1;
+  static const uint32_t NoAddressSpace = ~0U;
 
   /// Unique ID (due to the unique address)
   static const char ID;

llvm/lib/Transforms/IPO/AttributorAttributes.cpp

@@ -12562,7 +12562,7 @@ struct AAAddressSpaceImpl : public AAAddressSpace {
   AAAddressSpaceImpl(const IRPosition &IRP, Attributor &A)
       : AAAddressSpace(IRP, A) {}
 
-  int32_t getAddressSpace() const override {
+  uint32_t getAddressSpace() const override {
     assert(isValidState() && "the AA is invalid");
     return AssumedAddressSpace;
   }
@@ -12576,7 +12576,7 @@ struct AAAddressSpaceImpl : public AAAddressSpace {
   }
 
   ChangeStatus updateImpl(Attributor &A) override {
-    int32_t OldAddressSpace = AssumedAddressSpace;
+    uint32_t OldAddressSpace = AssumedAddressSpace;
     auto *AUO = A.getOrCreateAAFor<AAUnderlyingObjects>(getIRPosition(), this,
                                                         DepClassTy::REQUIRED);
     auto Pred = [&](Value &Obj) {
@@ -12597,16 +12597,13 @@ struct AAAddressSpaceImpl : public AAAddressSpace {
     Value *AssociatedValue = &getAssociatedValue();
     Value *OriginalValue = peelAddrspacecast(AssociatedValue);
     if (getAddressSpace() == NoAddressSpace ||
-        static_cast<uint32_t>(getAddressSpace()) ==
-            getAssociatedType()->getPointerAddressSpace())
+        getAddressSpace() == getAssociatedType()->getPointerAddressSpace())
       return ChangeStatus::UNCHANGED;
 
     PointerType *NewPtrTy =
-        PointerType::get(getAssociatedType()->getContext(),
-                         static_cast<uint32_t>(getAddressSpace()));
+        PointerType::get(getAssociatedType()->getContext(), getAddressSpace());
     bool UseOriginalValue =
-        OriginalValue->getType()->getPointerAddressSpace() ==
-        static_cast<uint32_t>(getAddressSpace());
+        OriginalValue->getType()->getPointerAddressSpace() == getAddressSpace();
 
     bool Changed = false;
 
@@ -12656,9 +12653,9 @@ struct AAAddressSpaceImpl : public AAAddressSpace {
   }
 
 private:
-  int32_t AssumedAddressSpace = NoAddressSpace;
+  uint32_t AssumedAddressSpace = NoAddressSpace;
 
-  bool takeAddressSpace(int32_t AS) {
+  bool takeAddressSpace(uint32_t AS) {
     if (AssumedAddressSpace == NoAddressSpace) {
       AssumedAddressSpace = AS;
       return true;