1 files changed, 33 insertions, 0 deletions
diff --git a/test/CodeGen/MIR/X86/subregister-operands.mir b/test/CodeGen/MIR/X86/subregister-operands.mir
new file mode 100644
index 000000000000..5e46fab4b058
--- /dev/null
+++ b/test/CodeGen/MIR/X86/subregister-operands.mir
@@ -0,0 +1,33 @@
+# RUN: llc -march=x86-64 -start-after machine-sink -stop-after machine-sink -o /dev/null %s | FileCheck %s
+# This test ensures that the MIR parser parses subregisters in register operands
+# correctly.
+
+--- |
+
+  define zeroext i1 @t(i1 %c) {
+  entry:
+    ret i1 %c
+  }
+
+...
+---
+name:            t
+isSSA:           true
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: gr32 }
+  - { id: 1, class: gr8 }
+  - { id: 2, class: gr8 }
+body:
+  - name:        entry
+    id:          0
+    instructions:
+      # CHECK:      %0 = COPY %edi
+      # CHECK-NEXT: %1 = COPY %0:sub_8bit
+      - '%0 = COPY %edi'
+      - '%1 = COPY %0:sub_8bit'
+      - '%2 = AND8ri %1, 1, implicit-def %eflags'
+      - '%al = COPY %2'
+      - 'RETQ %al'
+...
+