target-xtensa: add regression testsuite

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/tests/xtensa/test_mul32.S b/tests/xtensa/test_mul32.S
new file mode 100644
index 0000000..fdaf573
--- /dev/null
+++ b/tests/xtensa/test_mul32.S
@@ -0,0 +1,20 @@
+.include "macros.inc"
+
+test_suite mul32
+
+test mull
+    movi    a2, 0x137f5a5a
+    mov     a3, a2
+    movi    a4, 0xa5a5137f
+    movi    a6, 0x5de480a6
+    mull    a5, a2, a4
+    assert  eq, a5, a6
+    mull    a2, a2, a4
+    assert  eq, a2, a6
+    mull    a3, a4, a3
+    assert  eq, a3, a6
+test_end
+
+/* unfortunately dc232b doesn't have muluh/mulsh*/
+
+test_suite_end