1 files changed, 22 insertions, 0 deletions
diff --git a/test/CodeGen/MIR/X86/unknown-register.mir b/test/CodeGen/MIR/X86/unknown-register.mir
new file mode 100644
index 0000000000000..ce40ee809bf3f
--- /dev/null
+++ b/test/CodeGen/MIR/X86/unknown-register.mir
@@ -0,0 +1,22 @@
+# RUN: not llc -march=x86-64 -start-after branch-folder -stop-after branch-folder -o /dev/null %s 2>&1 | FileCheck %s
+# This test ensures that an error is reported when an unknown register is
+# encountered.
+
+--- |
+
+  define i32 @foo() {
+  entry:
+    ret i32 0
+  }
+
+...
+---
+name:            foo
+body:
+ - id:           0
+   name:         entry
+   instructions:
+     # CHECK: [[@LINE+1]]:9: unknown register name 'xax'
+     - '%xax = MOV32r0'
+     - 'RETQ %xax'
+...