diff --git a/llvm/test/MC/RISCV/rv32zicboz-invalid.s b/llvm/test/MC/RISCV/rv32zicboz-invalid.s
@@ -0,0 +1,19 @@
+# RUN: not llvm-mc -triple riscv32 -mattr=+zicboz < %s 2>&1 | FileCheck %s
+# RUN: not llvm-mc -triple riscv64 -mattr=+zicboz < %s 2>&1 | FileCheck %s
+
+# Must have a single register argument.
+cbo.zero # CHECK: :[[@LINE]]:1: error: too few operands for instruction
+cbo.zero 1 # CHECK: :[[@LINE]]:12: error: expected '(' after optional integer offset
+cbo.zero t0, t1 # CHECK: :[[@LINE]]:10: error: expected '(' or optional integer offset
+
+# Non-zero offsets are not supported.
+cbo.zero 1(t0) # CHECK: :[[@LINE]]:10: error: optional integer offset must be 0
+
+# Instructions from other zicbo* extensions aren't available without enabling
+# the appropriate -mattr flag.
+cbo.clean (t0) # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'Zicbom' (Cache-Block Management Instructions)
+cbo.flush (t1) # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'Zicbom' (Cache-Block Management Instructions)
+cbo.inval (t2) # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'Zicbom' (Cache-Block Management Instructions)
+prefetch.i 0(t3) # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'Zicbop' (Cache-Block Prefetch Instructions)
+prefetch.r 0(t4) # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'Zicbop' (Cache-Block Prefetch Instructions)
+prefetch.w 0(t5) # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'Zicbop' (Cache-Block Prefetch Instructions)
diff --git a/llvm/test/MC/RISCV/rv32zicboz-valid.s b/llvm/test/MC/RISCV/rv32zicboz-valid.s
@@ -0,0 +1,17 @@
+# RUN: llvm-mc %s -triple=riscv32 -mattr=+zicboz -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc %s -triple=riscv64 -mattr=+zicboz -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv32 -mattr=+zicboz < %s \
+# RUN:     | llvm-objdump --mattr=+zicboz -d -r - \
+# RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+zicboz < %s \
+# RUN:     | llvm-objdump --mattr=+zicboz -d -r - \
+# RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
+
+# CHECK-ASM-AND-OBJ: cbo.zero (t0)
+# CHECK-ASM: encoding: [0x0f,0xa0,0x42,0x00]
+cbo.zero (t0)
+# CHECK-ASM-AND-OBJ: cbo.zero (t0)
+# CHECK-ASM: encoding: [0x0f,0xa0,0x42,0x00]
+cbo.zero 0(t0)