Index: include/llvm/Support/LowLevelTypeImpl.h
===================================================================
--- include/llvm/Support/LowLevelTypeImpl.h
+++ include/llvm/Support/LowLevelTypeImpl.h
@@ -45,8 +45,8 @@
                SizeInBits, /*AddressSpace=*/0};
   }
 
-  /// Get a low-level pointer in the given address space (defaulting to 0).
-  static LLT pointer(uint16_t AddressSpace, unsigned SizeInBits) {
+  /// Get a low-level pointer in the given address space.
+  static LLT pointer(unsigned AddressSpace, unsigned SizeInBits) {
     assert(SizeInBits > 0 && "invalid pointer size");
     return LLT{/*isPointer=*/true, /*isVector=*/false, /*NumElements=*/0,
                SizeInBits, AddressSpace};
@@ -181,10 +181,10 @@
   static const constexpr BitFieldInfo ScalarSizeFieldInfo{32, 0};
   /// * Pointer (isPointer == 1 && isVector == 0):
   ///   SizeInBits: 16;
-  ///   AddressSpace: 23;
+  ///   AddressSpace: 24;
   static const constexpr BitFieldInfo PointerSizeFieldInfo{16, 0};
   static const constexpr BitFieldInfo PointerAddressSpaceFieldInfo{
-      23, PointerSizeFieldInfo[0] + PointerSizeFieldInfo[1]};
+      24, PointerSizeFieldInfo[0] + PointerSizeFieldInfo[1]};
   /// * Vector-of-non-pointer (isPointer == 0 && isVector == 1):
   ///   NumElements: 16;
   ///   SizeOfElement: 32;
@@ -194,13 +194,13 @@
   /// * Vector-of-pointer (isPointer == 1 && isVector == 1):
   ///   NumElements: 16;
   ///   SizeOfElement: 16;
-  ///   AddressSpace: 23;
+  ///   AddressSpace: 24;
   static const constexpr BitFieldInfo PointerVectorElementsFieldInfo{16, 0};
   static const constexpr BitFieldInfo PointerVectorSizeFieldInfo{
       16,
       PointerVectorElementsFieldInfo[1] + PointerVectorElementsFieldInfo[0]};
   static const constexpr BitFieldInfo PointerVectorAddressSpaceFieldInfo{
-      23, PointerVectorSizeFieldInfo[1] + PointerVectorSizeFieldInfo[0]};
+      24, PointerVectorSizeFieldInfo[1] + PointerVectorSizeFieldInfo[0]};
 
   uint64_t IsPointer : 1;
   uint64_t IsVector : 1;
Index: test/CodeGen/AArch64/GlobalISel/irtranslator-max-address-space.ll
===================================================================
--- /dev/null
+++ test/CodeGen/AArch64/GlobalISel/irtranslator-max-address-space.ll
@@ -0,0 +1,26 @@
+; RUN: llc -O0 -mtriple=aarch64-apple-ios -global-isel -stop-after=irtranslator %s -o - | FileCheck %s
+
+; CHECK-LABEL: name: store_max_address_space
+; CHECK: %0:_(p16777215) = COPY $x0
+; CHECK: G_STORE %1(s32), %0(p16777215) :: (store 4 into %ir.ptr, addrspace 16777215)
+define void @store_max_address_space(i32 addrspace(16777215)* %ptr) {
+  store i32 0, i32 addrspace(16777215)* %ptr
+  ret void
+}
+
+; CHECK-LABEL: name: store_max_address_space_vector
+; CHECK: %0:_(<2 x p16777215>) = COPY $q0
+; CHECK: %1:_(p16777215) = G_EXTRACT_VECTOR_ELT %0(<2 x p16777215>), %2(s64)
+; CHECK: %1(p16777215) :: (store 4 into %ir.elt0, addrspace 16777215)
+define void @store_max_address_space_vector(<2 x i32 addrspace(16777215)*> %vptr) {
+  %elt0 = extractelement <2 x i32 addrspace(16777215)*> %vptr, i32 0
+  store i32 0, i32 addrspace(16777215)* %elt0
+  ret void
+}
+
+; CHECK-LABEL: name: max_address_space_vector_max_num_elts
+; CHECK: %0:_(<65535 x p16777215>) = G_LOAD %1(p0) :: (volatile load 524280 from `<65535 x i32 addrspace(16777215)*>* undef`, align 524288)
+define void @max_address_space_vector_max_num_elts() {
+  %load = load volatile <65535 x i32 addrspace(16777215)*>, <65535 x i32 addrspace(16777215)*>* undef
+  ret void
+}
Index: unittests/CodeGen/LowLevelTypeTest.cpp
===================================================================
--- unittests/CodeGen/LowLevelTypeTest.cpp
+++ unittests/CodeGen/LowLevelTypeTest.cpp
@@ -120,39 +120,46 @@
 
 TEST(LowLevelTypeTest, Pointer) {
   LLVMContext C;
-  DataLayout DL("");
+  DataLayout DL("p64:64:64-p127:512:512:512-p16777215:65528:8");
 
-  for (unsigned AS : {0U, 1U, 127U, 0xffffU}) {
-    const LLT Ty = LLT::pointer(AS, DL.getPointerSizeInBits(AS));
-    const LLT VTy = LLT::vector(4, Ty);
+  for (unsigned AS : {0U, 1U, 127U, 0xffffU,
+        static_cast<unsigned>(maxUIntN(23)),
+        static_cast<unsigned>(maxUIntN(24))}) {
+    for (unsigned NumElts : {2, 3, 4, 256, 65535}) {
+      const LLT Ty = LLT::pointer(AS, DL.getPointerSizeInBits(AS));
+      const LLT VTy = LLT::vector(NumElts, Ty);
 
-    // Test kind.
-    ASSERT_TRUE(Ty.isValid());
-    ASSERT_TRUE(Ty.isPointer());
+      // Test kind.
+      ASSERT_TRUE(Ty.isValid());
+      ASSERT_TRUE(Ty.isPointer());
 
-    ASSERT_FALSE(Ty.isScalar());
-    ASSERT_FALSE(Ty.isVector());
+      ASSERT_FALSE(Ty.isScalar());
+      ASSERT_FALSE(Ty.isVector());
 
-    ASSERT_TRUE(VTy.isValid());
-    ASSERT_TRUE(VTy.isVector());
-    ASSERT_TRUE(VTy.getElementType().isPointer());
+      ASSERT_TRUE(VTy.isValid());
+      ASSERT_TRUE(VTy.isVector());
+      ASSERT_TRUE(VTy.getElementType().isPointer());
 
-    // Test addressspace.
-    EXPECT_EQ(AS, Ty.getAddressSpace());
-    EXPECT_EQ(AS, VTy.getElementType().getAddressSpace());
+      EXPECT_EQ(Ty, VTy.getElementType());
+      EXPECT_EQ(Ty.getSizeInBits(), VTy.getScalarSizeInBits());
 
-    // Test equality operators.
-    EXPECT_TRUE(Ty == Ty);
-    EXPECT_FALSE(Ty != Ty);
-    EXPECT_TRUE(VTy == VTy);
-    EXPECT_FALSE(VTy != VTy);
+      // Test address space.
+      EXPECT_EQ(AS, Ty.getAddressSpace());
+      EXPECT_EQ(AS, VTy.getElementType().getAddressSpace());
 
-    // Test Type->LLT conversion.
-    Type *IRTy = PointerType::get(IntegerType::get(C, 8), AS);
-    EXPECT_EQ(Ty, getLLTForType(*IRTy, DL));
-    Type *IRVTy =
-        VectorType::get(PointerType::get(IntegerType::get(C, 8), AS), 4);
-    EXPECT_EQ(VTy, getLLTForType(*IRVTy, DL));
+      // Test equality operators.
+      EXPECT_TRUE(Ty == Ty);
+      EXPECT_FALSE(Ty != Ty);
+      EXPECT_TRUE(VTy == VTy);
+      EXPECT_FALSE(VTy != VTy);
+
+      // Test Type->LLT conversion.
+      Type *IRTy = PointerType::get(IntegerType::get(C, 8), AS);
+      EXPECT_EQ(Ty, getLLTForType(*IRTy, DL));
+      Type *IRVTy =
+        VectorType::get(PointerType::get(IntegerType::get(C, 8), AS), NumElts);
+      EXPECT_EQ(VTy, getLLTForType(*IRVTy, DL));
+    }
   }
 }