fix(mgb/dtype): enable TypeCvt for bool when trace(symbolic=True)

GitOrigin-RevId: 4e0fc63369b623e6e9e9eca396ec03f87b56452f

imperative/python/test/unit/test_tracing.py

@@ -16,6 +16,7 @@ import megengine
 import megengine.core.tensor.megbrain_graph as G
 import megengine.module as M
 from megengine import cgtools, tensor
+from megengine.core._trace_option import set_tensor_shape
 from megengine.core.ops import builtin as ops
 from megengine.core.tensor import megbrain_graph as G
 from megengine.core.tensor.core import apply
@@ -274,3 +275,15 @@ def test_optimize_for_inference():
     res = G.load_comp_graph_from_file(out)
     computing_input = res.output_vars_list[0].owner.inputs[0]
     assert computing_input.dtype == np.float16
+
+
+def test_trace_cvt_bool():
+    set_tensor_shape(True)
+    x = tensor([0], dtype=np.int32)
+
+    @trace(symbolic=True)
+    def f(x):
+        return x.shape[0] == 0
+
+    for i in range(3):
+        np.testing.assert_equal(f(x).numpy()[0], False)

src/core/impl/dtype.cpp

@@ -136,6 +136,7 @@ void mgb::static_cast_dtype(T* dest, DType src_type, const void* storage,
                 nr_elem, src_type);
         MEGDNN_FOREACH_COMPUTING_DTYPE(cb)
         MEGDNN_FOREACH_QUANTIZED_DTYPE(cb)
+        cb(::megdnn::dtype::Bool)
 #undef cb
 #define cb(_name, _bits)                                                    \
     case DTypeTrait<dtype::_name##_bits>::enumv:                            \