[Lang] MatrixField refactor 6/n: Add tests for MatrixField scalarizat…

…ion (#6137)

Issue: #5959

### Brief Summary

This PR demonstrates that the following path of #5959 can also run
end-to-end:


![MatrixField_Part6](https://user-images.githubusercontent.com/3251060/191686873-839fd9c2-11fb-4fea-b648-3350a3992779.png)

python/taichi/lang/ast/ast_transformer.py

@@ -115,11 +115,8 @@ def build_Assign(ctx, node):
     @staticmethod
     def build_assign_slice(ctx, node_target, values, is_static_assign):
         target = ASTTransformer.build_Subscript(ctx, node_target, get_ref=True)
-        if current_cfg().real_matrix:
-            if isinstance(node_target.value.ptr,
-                          any_array.AnyArray) and isinstance(
-                              values, (list, tuple)):
-                values = make_matrix(values)
+        if current_cfg().real_matrix and isinstance(values, (list, tuple)):
+            values = make_matrix(values)
 
         if isinstance(node_target.value.ptr, Matrix):
             if isinstance(node_target.value.ptr._impl, _TiScopeMatrixImpl):

tests/python/test_matrix.py

@@ -828,63 +828,84 @@ def foo() -> ti.types.matrix(2, 2, ti.f32):
     assert foo() == [[1.0, 2.0], [2.0, 4.0]]
 
 
+def _test_field_and_ndarray(field, ndarray, func, verify):
+    @ti.kernel
+    def kern_field(a: ti.template()):
+        func(a)
+
+    @ti.kernel
+    def kern_ndarray(a: ti.types.ndarray()):
+        func(a)
+
+    kern_field(field)
+    verify(field)
+    kern_ndarray(ndarray)
+    verify(ndarray)
+
+
 @test_utils.test(arch=[ti.cuda, ti.cpu],
                  real_matrix=True,
                  real_matrix_scalarize=True)
 def test_store_scalarize():
-    @ti.kernel
-    def func(a: ti.types.ndarray()):
+    @ti.func
+    def func(a: ti.template()):
         for i in range(5):
             a[i] = [[i, i + 1], [i + 2, i + 3]]
 
-    x = ti.Matrix.ndarray(2, 2, ti.i32, shape=5)
-    func(x)
+    def verify(x):
+        assert (x[0] == [[0, 1], [2, 3]]).all()
+        assert (x[1] == [[1, 2], [3, 4]]).all()
+        assert (x[2] == [[2, 3], [4, 5]]).all()
+        assert (x[3] == [[3, 4], [5, 6]]).all()
+        assert (x[4] == [[4, 5], [6, 7]]).all()
 
-    assert (x[0] == [[0, 1], [2, 3]]).all()
-    assert (x[1] == [[1, 2], [3, 4]]).all()
-    assert (x[2] == [[2, 3], [4, 5]]).all()
-    assert (x[3] == [[3, 4], [5, 6]]).all()
-    assert (x[4] == [[4, 5], [6, 7]]).all()
+    field = ti.Matrix.field(2, 2, ti.i32, shape=5)
+    ndarray = ti.Matrix.ndarray(2, 2, ti.i32, shape=5)
+    _test_field_and_ndarray(field, ndarray, func, verify)
 
 
 @test_utils.test(arch=[ti.cuda, ti.cpu],
                  real_matrix=True,
                  real_matrix_scalarize=True)
 def test_load_store_scalarize():
-    @ti.kernel
-    def func(a: ti.types.ndarray()):
+    @ti.func
+    def func(a: ti.template()):
         for i in range(3):
             a[i] = [[i, i + 1], [i + 2, i + 3]]
 
         a[3] = a[1]
         a[4] = a[2]
 
-    x = ti.Matrix.ndarray(2, 2, ti.i32, shape=5)
-    func(x)
+    def verify(x):
+        assert (x[3] == [[1, 2], [3, 4]]).all()
+        assert (x[4] == [[2, 3], [4, 5]]).all()
 
-    assert (x[3] == [[1, 2], [3, 4]]).all()
-    assert (x[4] == [[2, 3], [4, 5]]).all()
+    field = ti.Matrix.field(2, 2, ti.i32, shape=5)
+    ndarray = ti.Matrix.ndarray(2, 2, ti.i32, shape=5)
+    _test_field_and_ndarray(field, ndarray, func, verify)
 
 
 @test_utils.test(arch=[ti.cuda, ti.cpu],
                  real_matrix=True,
                  real_matrix_scalarize=True)
 def test_unary_op_scalarize():
-    @ti.kernel
-    def func(a: ti.types.ndarray()):
+    @ti.func
+    def func(a: ti.template()):
         a[0] = [[0, 1], [2, 3]]
         a[1] = [[3, 4], [5, 6]]
         a[2] = -a[0]
         a[3] = ti.exp(a[1])
         a[4] = ti.sqrt(a[3])
 
-    x = ti.Matrix.ndarray(2, 2, ti.f32, shape=5)
-    func(x)
-
-    assert (x[0] == [[0., 1.], [2., 3.]]).all()
-    assert (x[1] == [[3., 4.], [5., 6.]]).all()
-    assert (x[2] == [[-0., -1.], [-2., -3.]]).all()
-    assert (x[3] < [[20.086, 54.60], [148.42, 403.43]]).all()
-    assert (x[3] > [[20.085, 54.59], [148.41, 403.42]]).all()
-    assert (x[4] < [[4.49, 7.39], [12.19, 20.09]]).all()
-    assert (x[4] > [[4.48, 7.38], [12.18, 20.08]]).all()
+    def verify(x):
+        assert (x[0] == [[0., 1.], [2., 3.]]).all()
+        assert (x[1] == [[3., 4.], [5., 6.]]).all()
+        assert (x[2] == [[-0., -1.], [-2., -3.]]).all()
+        assert (x[3] < [[20.086, 54.60], [148.42, 403.43]]).all()
+        assert (x[3] > [[20.085, 54.59], [148.41, 403.42]]).all()
+        assert (x[4] < [[4.49, 7.39], [12.19, 20.09]]).all()
+        assert (x[4] > [[4.48, 7.38], [12.18, 20.08]]).all()
+
+    field = ti.Matrix.field(2, 2, ti.f32, shape=5)
+    ndarray = ti.Matrix.ndarray(2, 2, ti.f32, shape=5)
+    _test_field_and_ndarray(field, ndarray, func, verify)