[llvm] [InferAS] Infer the address space of inttoptr (PR #173244)

[Matt Arsenault via llvm-commits]

================
@@ -45,8 +45,9 @@ define void @test_xor_smem(ptr addrspace(3) %sp) {
 ; CHECK-NEXT:    [[GP:%.*]] = addrspacecast ptr addrspace(3) [[SP]] to ptr
 ; CHECK-NEXT:    [[A:%.*]] = ptrtoint ptr [[GP]] to i64
 ; CHECK-NEXT:    [[B:%.*]] = xor i64 4095, [[A]]
-; CHECK-NEXT:    [[GP2:%.*]] = inttoptr i64 [[B]] to ptr addrspace(3)
-; CHECK-NEXT:    store i16 0, ptr addrspace(3) [[GP2]], align 2
+; CHECK-NEXT:    [[GP2:%.*]] = inttoptr i64 [[B]] to ptr
+; CHECK-NEXT:    [[TMP1:%.*]] = addrspacecast ptr [[GP2]] to ptr addrspace(3)
+; CHECK-NEXT:    store i16 0, ptr addrspace(3) [[TMP1]], align 2
----------------
arsenm wrote:

The two separate casts is probably better and more canonical. InstCombine prefers to keep ptrtoint results as the no-op pointer width, and separate the integer cast to the final result type 

https://github.com/llvm/llvm-project/pull/173244