diff --git a/src/xenia/cpu/frontend/test/instr_addis.s b/src/xenia/cpu/frontend/test/instr_addis.s
new file mode 100644
index 000000000..bb5219ba5
--- /dev/null
+++ b/src/xenia/cpu/frontend/test/instr_addis.s
@@ -0,0 +1,77 @@
+test_addis_1:
+  #_ REGISTER_IN r0 1234
+  #_ REGISTER_IN r4 1
+  addis r3, r0, 1
+  blr
+  #_ REGISTER_OUT r0 1234
+  #_ REGISTER_OUT r3 0x10000
+  #_ REGISTER_OUT r4 1
+
+test_addis_1_constant:
+  li r0, 1234
+  li r4, 1
+  addis r3, r0, 1
+  blr
+  #_ REGISTER_OUT r0 1234
+  #_ REGISTER_OUT r3 0x10000
+  #_ REGISTER_OUT r4 1
+
+test_addis_2:
+  #_ REGISTER_IN r4 1234
+  #_ REGISTER_IN r5 1
+  addis r3, r4, 1
+  blr
+  #_ REGISTER_OUT r3 0x104D2
+  #_ REGISTER_OUT r4 1234
+
+test_addis_2_constant:
+  li r4, 1234
+  li r5, 1
+  addis r3, r4, 1
+  blr
+  #_ REGISTER_OUT r3 0x104D2
+  #_ REGISTER_OUT r4 1234
+
+test_lis_1:
+  #_ REGISTER_IN r0 1234
+  lis r3, 1
+  blr
+  #_ REGISTER_OUT r0 1234
+  #_ REGISTER_OUT r3 0x10000
+
+test_lis_1_constant:
+  li r0, 1234
+  lis r3, 1
+  blr
+  #_ REGISTER_OUT r0 1234
+  #_ REGISTER_OUT r3 0x10000
+
+test_lis_2:
+  #_ REGISTER_IN r0 1234
+  lis r3, -1
+  blr
+  #_ REGISTER_OUT r0 1234
+  #_ REGISTER_OUT r3 0xFFFFFFFFFFFF0000
+
+test_lis_2_constant:
+  li r0, 1234
+  lis r3, -1
+  blr
+  #_ REGISTER_OUT r0 1234
+  #_ REGISTER_OUT r3 0xFFFFFFFFFFFF0000
+
+test_subis_1:
+  #_ REGISTER_IN r4 1234
+  #_ REGISTER_IN r5 1
+  subis r3, r4, 1
+  blr
+  #_ REGISTER_OUT r3 0xFFFFFFFFFFFF04D2
+  #_ REGISTER_OUT r4 1234
+
+test_subis_1_constant:
+  li r4, 1234
+  li r5, 1
+  subis r3, r4, 1
+  blr
+  #_ REGISTER_OUT r3 0xFFFFFFFFFFFF04D2
+  #_ REGISTER_OUT r4 1234