diff --git a/llvm/lib/Target/AArch64/AArch64InstrFormats.td b/llvm/lib/Target/AArch64/AArch64InstrFormats.td
--- a/llvm/lib/Target/AArch64/AArch64InstrFormats.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrFormats.td
@@ -1447,6 +1447,7 @@
                        "mrs", "\t$Rt, $systemreg"> {
   bits<16> systemreg;
   let Inst{20-5} = systemreg;
+  let DecoderNamespace = "Fallback";
 }
 
 // FIXME: Some of these def NZCV, others don't. Best way to model that?
@@ -1456,6 +1457,7 @@
                        "msr", "\t$systemreg, $Rt"> {
   bits<16> systemreg;
   let Inst{20-5} = systemreg;
+  let DecoderNamespace = "Fallback";
 }
 
 def SystemPStateFieldWithImm0_15Operand : AsmOperandClass {
diff --git a/llvm/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp b/llvm/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
--- a/llvm/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
+++ b/llvm/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
@@ -267,8 +267,16 @@
   uint32_t Insn =
       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
 
-  // Calling the auto-generated decoder function.
-  return decodeInstruction(DecoderTable32, MI, Insn, Address, this, STI);
+  const uint8_t *Tables[] = {DecoderTable32, DecoderTableFallback32};
+
+  for (auto Table : Tables) {
+    DecodeStatus Result =
+        decodeInstruction(Table, MI, Insn, Address, this, STI);
+    if (Result != MCDisassembler::Fail)
+      return Result;
+  }
+
+  return MCDisassembler::Fail;
 }
 
 static MCSymbolizer *