Fix and test the integral propery with np_vstack (#69)

* Unit test the integral property for atomic SecFxp

* Start unit testing integral for SecFxp arrays

* Fix integral property for np_vstack

* Shortened syntax for tests, mixed in extra cases.

---------

Co-authored-by: Berry Schoenmakers <l.a.m.schoenmakers@tue.nl>

mpyc/runtime.py

@@ -2640,9 +2640,16 @@ def block_shape(a):
     @mpc_coro_no_pc
     async def np_vstack(self, tup):
         a = tup[0]
+        stype = type(a)
         shape = list(a.shape) if a.ndim >= 2 else [1, a.shape[0]]
         shape[0] = sum(a.shape[0] if a.shape[1:] else 1 for a in tup)
-        await self.returnType((type(a), tuple(shape)))
+
+        shape = tuple(shape)
+        if issubclass(stype, self.SecureFixedPointArray):
+            integral = all(a.integral if isinstance(a, stype) else stype(a).integral for a in tup)
+            await self.returnType((stype, integral, shape))
+        else:
+            await self.returnType((stype, shape))
         tup = await self.gather(tup)
         return np.vstack(tup)
 

tests/test_runtime.py

@@ -298,6 +298,33 @@ def test_secfxp_array(self):
         u = mpc.np_unit_vector(secfxp(3), 7)
         self.assertEqual(mpc.run(mpc.output(np.argmax(u))), 3)
 
+        # Test the integral property
+        a1 = np.array([[-1.5, 2.5], [4.5, -8.5]])
+        a2 = np.array([[-1, 2], [4, -8]])
+        c1 = secfxp.array(a1)
+        c2 = secfxp.array(a2)
+        self.assertEqual(c1.integral, False)
+        self.assertEqual(c2.integral, True)
+        self.assertEqual((c1 + c2).integral, False)
+        self.assertEqual(np.add(c2, c2).integral, True)
+        self.assertEqual((c1 * c2).integral, False)
+        self.assertEqual(np.multiply(c2, c2).integral, True)
+        self.assertEqual(np.matmul(c1, c2).integral, False)
+        self.assertEqual((c2 @ c2).integral, True)
+
+        self.assertEqual(np.hstack((c1, c2)).integral, False)
+        self.assertEqual(np.hstack((c1, c1)).integral, False)
+        self.assertEqual(np.hstack((c2, c2)).integral, True)
+        self.assertEqual(np.column_stack((c1, c2)).integral, False)
+        self.assertEqual(np.column_stack((c1, a1)).integral, False)
+        self.assertEqual(np.column_stack((c2, c2)).integral, True)
+        self.assertEqual(np.stack((c1, c2)).integral, False)
+        self.assertEqual(np.stack((c2, a1)).integral, False)
+        self.assertEqual(np.stack((c2, c2, a2)).integral, True)
+        self.assertEqual(np.vstack((c1, a2)).integral, False)
+        self.assertEqual(np.vstack((c1, c1)).integral, False)
+        self.assertEqual(np.vstack((c2, c2)).integral, True)
+
     @unittest.skipIf(not np, 'NumPy not available or inside MPyC disabled')
     def test_secfld_array(self):
         np.assertEqual = np.testing.assert_array_equal
@@ -605,6 +632,18 @@ def test_secfxp(self):
         c = mpc.run(mpc.output(mpc.to_bits(secfxp(-2**15))))
         self.assertEqual(c, [0]*31 + [1])
 
+        # Test integral property
+        c1 = secfxp(8)
+        self.assertEqual(c1.integral, True)
+        self.assertEqual((c1*0.5).integral, False)
+        c2 = secfxp(1.5)
+        self.assertEqual(c2.integral, False)
+        self.assertEqual((c1*c2).integral, False)
+        self.assertEqual((c1+c2).integral, False)
+        c2 = secfxp(1)
+        self.assertEqual((c1*c2).integral, True)
+        self.assertEqual((c1+c2).integral, True)
+
         for f in [8, 16, 32, 64]:
             secfxp = mpc.SecFxp(2*f)
             c = mpc.run(mpc.output(secfxp(1) + secfxp(1)))