diff --git a/test/t/codegen.rb b/test/t/codegen.rb
new file mode 100644
index 000000000..29f5ad525
--- /dev/null
+++ b/test/t/codegen.rb
@@ -0,0 +1,75 @@
+##
+# Codegen tests
+
+assert('peephole optimization does not eliminate move whose result is reused') do
+  assert_raise LocalJumpError do
+    def method
+      yield
+    end
+    method(&a &&= 0)
+  end
+end
+
+assert('empty condition in ternary expression parses correctly') do
+  assert_equal(() ? 1 : 2, 2)
+end
+
+assert('method call with exactly 127 arguments') do
+  def args_to_ary(*args)
+    args
+  end
+
+  assert_equal [0]*127, args_to_ary(
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, \
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, \
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, \
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, \
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, \
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+  )
+end
+
+assert('nested empty heredoc') do
+  _, a = nil, <<B
+#{<<A}
+A
+B
+  assert_equal "\n", a
+end
+
+assert('splat in case splat') do
+  a = *case
+    when 0
+      * = 1
+  end
+
+  assert_equal [1], a
+end
+
+assert('undef with 127 or more arguments') do
+  assert_raise NameError do
+    undef
+      a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a,
+      a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a,
+      a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a,
+      a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a
+  end
+end
+
+assert('next in normal loop with 127 arguments') do
+  assert_raise NameError do
+    while true
+      next A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A,A
+    end
+  end
+end
+
+assert('negate literal register alignment') do
+  a = *case
+  when 0
+    -0.0
+    2
+  end
+
+  assert_equal [2], a
+end