[BUG] Fix bug in cast in quantization (#480)

[BUG] Fix bug in `cast` in quantization

python/hidet/graph/ops/quant/symmetric.py

@@ -11,7 +11,7 @@
 # limitations under the License.
 from typing import Union, List
 from hidet import ir
-from hidet.ir.type import DataType
+from hidet.ir.type import DataType, int32
 from hidet.ir.expr import cast, if_then_else
 from hidet.ir.compute.primitives import TensorNode, compute
 from hidet.ir import primitives as prim
@@ -36,7 +36,9 @@ def __init__(self, w: TensorNode, quant_type: DataType, dims: Union[int, List[in
 
         def scale_weight(*indices):
             scale_indices = [indices[i] for i in range(len(indices)) if not i in dims]
-            return cast(prim.round(w[indices] / scale[scale_indices]), quant_type)
+            # Have to cast to int32 first because there are several ways convert bf16 to int8
+            cast_to_int = cast(prim.round(w[indices] / scale[scale_indices]), int32)
+            return cast(cast_to_int, quant_type)
 
         wq = compute(name='quantize', shape=w.shape, fcompute=scale_weight)
         super().__init__(

python/hidet/version.py

@@ -10,4 +10,3 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 __version__ = "0.5.0"
-