[Attributor] Indicate optimistic fixed point if an instruction already has non-zero address space (#101589)

Author: shiltian

llvm/lib/Transforms/IPO/AttributorAttributes.cpp

@@ -12491,6 +12491,9 @@ struct AAAddressSpaceImpl : public AAAddressSpace {
   void initialize(Attributor &A) override {
     assert(getAssociatedType()->isPtrOrPtrVectorTy() &&
            "Associated value is not a pointer");
+    auto *PtrTy = cast<PointerType>(getAssociatedType());
+    if (PtrTy->getAddressSpace())
+      indicateOptimisticFixpoint();
   }
 
   ChangeStatus updateImpl(Attributor &A) override {

llvm/test/Transforms/Attributor/memory_locations_gpu.ll

@@ -55,7 +55,8 @@ define i32 @test_const_as_call2() {
 ; CHECK-LABEL: define {{[^@]+}}@test_const_as_call2
 ; CHECK-SAME: () #[[ATTR3:[0-9]+]] {
 ; CHECK-NEXT:    [[P2:%.*]] = call ptr @ptr() #[[ATTR4]]
-; CHECK-NEXT:    [[L2:%.*]] = load i32, ptr [[P2]], align 4
+; CHECK-NEXT:    [[C2:%.*]] = addrspacecast ptr [[P2]] to ptr addrspace(4)
+; CHECK-NEXT:    [[L2:%.*]] = load i32, ptr addrspace(4) [[C2]], align 4
 ; CHECK-NEXT:    ret i32 [[L2]]
 ;
   %p2 = call ptr @ptr()
@@ -84,7 +85,8 @@ define i32 @test_shared_as_call2() {
 ; CHECK-LABEL: define {{[^@]+}}@test_shared_as_call2
 ; CHECK-SAME: () #[[ATTR2]] {
 ; CHECK-NEXT:    [[P2:%.*]] = call ptr @ptr() #[[ATTR4]]
-; CHECK-NEXT:    [[L2:%.*]] = load i32, ptr [[P2]], align 4
+; CHECK-NEXT:    [[C2:%.*]] = addrspacecast ptr [[P2]] to ptr addrspace(3)
+; CHECK-NEXT:    [[L2:%.*]] = load i32, ptr addrspace(3) [[C2]], align 4
 ; CHECK-NEXT:    ret i32 [[L2]]
 ;
   %p2 = call ptr @ptr()