diff --git a/compiler-rt/test/hwasan/TestCases/exported-tagged-global.c b/compiler-rt/test/hwasan/TestCases/exported-tagged-global.c
new file mode 100644
--- /dev/null
+++ b/compiler-rt/test/hwasan/TestCases/exported-tagged-global.c
@@ -0,0 +1,16 @@
+// RUN: %clang_hwasan %s -o %t
+// RUN: %run %t
+// RUN: %clang_hwasan -O1 %s -o %t
+// RUN: %run %t
+// RUN: %clang_hwasan -O1 -mllvm --aarch64-enable-global-isel-at-O=1 %s -o %t
+// RUN: %run %t
+
+static int global;
+
+__attribute__((optnone)) int *address_of_global() { return &global; }
+
+int main(int argc, char **argv) {
+  int *global_address = address_of_global();
+  *global_address = 13;
+  return 0;
+}
diff --git a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
--- a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
@@ -351,7 +351,7 @@
 
     if (DstSize == 128 && !Query.Types[0].isVector())
       return false; // Extending to a scalar s128 needs narrowing.
-    
+
     // Make sure that we have something that will fit in a register, and
     // make sure it's a power of 2.
     if (DstSize < 8 || DstSize > 128 || !isPowerOf2_32(DstSize))
@@ -676,6 +676,28 @@
   // Set the regclass on the dest reg too.
   MRI.setRegClass(ADRP.getReg(0), &AArch64::GPR64RegClass);
 
+  // MO_TAGGED on the page indicates a tagged address. Set the tag now. We do so
+  // by creating a MOVK that sets bits 48-63 of the register to (global address
+  // + 0x100000000 - PC) >> 48. The additional 0x100000000 offset here is to
+  // prevent an incorrect tag being generated during relocation when the the
+  // global appears before the code section. Without the offset, a global at
+  // `0x0f00'0000'0000'1000` (i.e. at `0x1000` with tag `0xf`) that's referenced
+  // by code at `0x2000` would result in `0x0f00'0000'0000'1000 - 0x2000 =
+  // 0x0eff'ffff'ffff'f000`, meaning the tag would be incorrectly set to `0xe`
+  // instead of `0xf`.
+  // This assumes that we're in the small code model so we can assume a binary
+  // size of <= 4GB, which makes the untagged PC relative offset positive. The
+  // binary must also be loaded into address range [0, 2^48). Both of these
+  // properties need to be ensured at runtime when using tagged addresses.
+  if (OpFlags & AArch64II::MO_TAGGED) {
+    auto Tag = MI.getOperand(1);
+    Tag.setTargetFlags(AArch64II::MO_PREL | AArch64II::MO_G3);
+    Tag.setOffset(0x100000000);
+    ADRP = MIRBuilder.buildInstr(AArch64::MOVKXi, {LLT::pointer(0, 64)}, {ADRP})
+               .addGlobalAddress(GV, 0x100000000,
+                                 AArch64II::MO_PREL | AArch64II::MO_G3);
+  }
+
   MIRBuilder.buildInstr(AArch64::G_ADD_LOW, {DstReg}, {ADRP})
       .addGlobalAddress(GV, 0,
                         OpFlags | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
diff --git a/llvm/test/CodeGen/AArch64/tagged-globals.ll b/llvm/test/CodeGen/AArch64/tagged-globals.ll
--- a/llvm/test/CodeGen/AArch64/tagged-globals.ll
+++ b/llvm/test/CodeGen/AArch64/tagged-globals.ll
@@ -1,31 +1,105 @@
-; RUN: llc < %s | FileCheck %s
+; RUN: llc --relocation-model=static < %s \
+; RUN:   | FileCheck %s --check-prefixes=CHECK-STATIC,CHECK-SELECTIONDAGISEL
+; RUN: llc --relocation-model=pic < %s \
+; RUN:   | FileCheck %s --check-prefix=CHECK-PIC
+
+; Ensure that GlobalISel lowers correctly. GlobalISel is the default ISel for
+; -O0 on aarch64. GlobalISel lowers the instruction sequence in the static
+; relocation model different to SelectionDAGISel. GlobalISel does the lowering
+; of AddLow *after* legalization, and thus doesn't differentiate between
+; address-taken-only vs. address-taken-for-loadstore. Hence, we generate a movk
+; instruction for load/store instructions as well with GlobalISel. GlobalISel
+; also doesn't have the scaffolding to correctly check the bounds of the global
+; offset, and cannot fold the lo12 bits into the load/store. Neither of these
+; things are a problem as GlobalISel is only used by default at -O0, so we don't
+; mind the code size and performance increase.
+
+; RUN: llc --aarch64-enable-global-isel-at-O=0 -O0 < %s \
+; RUN:   | FileCheck %s --check-prefixes=CHECK-STATIC,CHECK-GLOBALISEL
+; RUN: llc --aarch64-enable-global-isel-at-O=0 -O0 --relocation-model=pic < %s \
+; RUN:   | FileCheck %s --check-prefix=CHECK-PIC
 
 target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
 target triple = "aarch64-unknown-linux-android"
 
-@global = external hidden global i32
+@global = external global i32
 declare void @func()
 
 define i32* @global_addr() #0 {
-  ; CHECK: global_addr:
-  ; CHECK: adrp x0, :pg_hi21_nc:global
-  ; CHECK: movk x0, #:prel_g3:global+4294967296
-  ; CHECK: add x0, x0, :lo12:global
+  ; Static relocation model has common codegen between SelectionDAGISel and
+  ; GlobalISel when the address-taken of a global isn't folded into a load or
+  ; store instruction.
+  ; CHECK-STATIC: global_addr:
+  ; CHECK-STATIC: adrp [[REG:x[0-9]+]], :pg_hi21_nc:global
+  ; CHECK-STATIC: movk [[REG]], #:prel_g3:global+4294967296
+  ; CHECK-STATIC: add x0, [[REG]], :lo12:global
+  ; CHECK-STATIC: ret
+
+  ; CHECK-PIC: global_addr:
+  ; CHECK-PIC: adrp [[REG:x[0-9]+]], :got:global
+  ; CHECK-PIC: ldr x0, {{\[}}[[REG]], :got_lo12:global]
+  ; CHECK-PIC: ret
+
   ret i32* @global
 }
 
 define i32 @global_load() #0 {
-  ; CHECK: global_load:
-  ; CHECK: adrp x8, :pg_hi21_nc:global
-  ; CHECK: ldr w0, [x8, :lo12:global]
+  ; CHECK-SELECTIONDAGISEL: global_load:
+  ; CHECK-SELECTIONDAGISEL: adrp [[REG:x[0-9]+]], :pg_hi21_nc:global
+  ; CHECK-SELECTIONDAGISEL: ldr w0, {{\[}}[[REG]], :lo12:global{{\]}}
+  ; CHECK-SELECTIONDAGISEL: ret
+
+  ; CHECK-GLOBALISEL: global_load:
+  ; CHECK-GLOBALISEL: adrp [[REG:x[0-9]+]], :pg_hi21_nc:global
+  ; CHECK-GLOBALISEL: movk [[REG]], #:prel_g3:global+4294967296
+  ; CHECK-GLOBALISEL: add [[REG]], [[REG]], :lo12:global
+  ; CHECK-GLOBALISEL: ldr w0, {{\[}}[[REG]]{{\]}}
+  ; CHECK-GLOBALISEL: ret
+
+  ; CHECK-PIC: global_load:
+  ; CHECK-PIC: adrp [[REG:x[0-9]+]], :got:global
+  ; CHECK-PIC: ldr  [[REG]], {{\[}}[[REG]], :got_lo12:global]
+  ; CHECK-PIC: ldr w0, {{\[}}[[REG]]{{\]}}
+  ; CHECK-PIC: ret
+
   %load = load i32, i32* @global
   ret i32 %load
 }
 
+define void @global_store() #0 {
+  ; CHECK-SELECTIONDAGISEL: global_store:
+  ; CHECK-SELECTIONDAGISEL: adrp [[REG:x[0-9]+]], :pg_hi21_nc:global
+  ; CHECK-SELECTIONDAGISEL: str wzr, {{\[}}[[REG]], :lo12:global{{\]}}
+  ; CHECK-SELECTIONDAGISEL: ret
+
+  ; CHECK-GLOBALISEL: global_store:
+  ; CHECK-GLOBALISEL: adrp [[REG:x[0-9]+]], :pg_hi21_nc:global
+  ; CHECK-GLOBALISEL: movk [[REG]], #:prel_g3:global+4294967296
+  ; CHECK-GLOBALISEL: add [[REG]], [[REG]], :lo12:global
+  ; CHECK-GLOBALISEL: str wzr, {{\[}}[[REG]]{{\]}}
+  ; CHECK-GLOBALISEL: ret
+
+  ; CHECK-PIC: global_store:
+  ; CHECK-PIC: adrp [[REG:x[0-9]+]], :got:global
+  ; CHECK-PIC: ldr  [[REG]], {{\[}}[[REG]], :got_lo12:global]
+  ; CHECK-PIC: str wzr, {{\[}}[[REG]]{{\]}}
+  ; CHECK-PIC: ret
+
+  store i32 0, i32* @global
+  ret void
+}
+
 define void ()* @func_addr() #0 {
-  ; CHECK: func_addr:
-  ; CHECK: adrp x0, func
-  ; CHECK: add x0, x0, :lo12:func
+  ; CHECK-STATIC: func_addr:
+  ; CHECK-STATIC: adrp [[REG:x[0-9]+]], func
+  ; CHECK-STATIC: add x0, [[REG]], :lo12:func
+  ; CHECK-STATIC: ret
+
+  ; CHECK-PIC: func_addr:
+  ; CHECK-PIC: adrp [[REG:x[0-9]+]], :got:func
+  ; CHECK-PIC: ldr  x0, {{\[}}[[REG]], :got_lo12:func]
+  ; CHECK-PIC: ret
+
   ret void ()* @func
 }