llvm/test/MC/AArch64/armv9.6a-mpam-diagnostics.s - llvm-project - Git at Google

 // RUN: not llvm-mc -triple=aarch64 -show-encoding < %s 2>&1 \
 // RUN:        | FileCheck %s --check-prefixes=CHECK-ERROR

 msr MPAMBWIDR_EL1, x0
 // CHECK-ERROR: error: expected writable system register or pstate
	// RUN: not llvm-mc -triple=aarch64 -show-encoding < %s 2>&1 \
	// RUN: \| FileCheck %s --check-prefixes=CHECK-ERROR

	msr MPAMBWIDR_EL1, x0
	// CHECK-ERROR: error: expected writable system register or pstate