Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
===================================================================
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
@@ -621,7 +621,6 @@
         break;
       }
       case MCCFIInstruction::OpDefCfaOffset: {
-        assert(StackSize == 0 && "We already have the CFA offset!");
         StackSize = std::abs(Inst.getOffset());
         break;
       }
Index: llvm/test/CodeGen/AArch64/compact-unwind-async.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AArch64/compact-unwind-async.ll
@@ -0,0 +1,11 @@
+; RUN: llc -mtriple=arm64-apple-macosx %s -filetype=obj -o - | llvm-objdump --unwind-info - | FileCheck %s
+
+; CHECK: Contents of __compact_unwind section
+; CHECK: compact encoding: 0x02021010
+
+; 0x02|021|010 => frameless, stack size 0x21 * 16 = 528, x27 & x28 saved
+
+define void @func() {
+  alloca i8, i32 512
+  ret void
+}