MLBEDSW-7284: MLCE: Fix assert for faulty Split op

- An assert in Vela is triggered when the number of splits does
not evenly divide the input.shape[axis] value and the split offsets
are calculated wrongly.
- The fix is to add the same constraints as in the reference kernel
and only run the Split op on the NPU when the criterias are fulfilled.
- Modified test to reflect the new constraints
- Updated SUPPORTED_OPS.md

Change-Id: I4103ff4a3fdf9a813f5fcb7f51081b859e611100
Signed-off-by: Johan Alfven <johan.alfven@arm.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/ethosu/vela/test/test_tflite_model_semantic.py b/ethosu/vela/test/test_tflite_model_semantic.py
index 2e0936d0..e26a327f 100644
--- a/ethosu/vela/test/test_tflite_model_semantic.py
+++ b/ethosu/vela/test/test_tflite_model_semantic.py
@@ -191,6 +191,40 @@ def test_constraint_beta_value_range():
     assert semantic_checker.is_operator_semantic_valid(op)
 
 
+def test_constraint_split_axis():
+    # Axis value must be in the range [-<ifm_dimensions>, <ifm_dimensions>)"
+    attrs = {"num_splits": 2}
+    axis = create_const_tensor("axis", [1], DataType.int8, [3])
+    ifm = Tensor([1, 1, 4], DataType.int8, "ifm")
+    ifm.quantization = testutil.default_quant_params()
+    ofm = Tensor([1, 1, 4], DataType.int8, "ofm")
+    ofm.quantization = testutil.default_quant_params()
+    op = testutil.create_op(Op.Split, [axis, ifm], ofm, attrs)
+    # Check invalid axis value
+    assert not semantic_checker.is_operator_semantic_valid(op)
+    # Check valid axis value
+    axis = create_const_tensor("axis", [1], DataType.int8, [-1])
+    op = testutil.create_op(Op.Split, [axis, ifm], ofm, attrs)
+    assert semantic_checker.is_operator_semantic_valid(op)
+
+
+def test_constraint_split_num_splits():
+    # Check that split number is valid"
+    attrs = {"num_splits": 2}
+    axis = create_const_tensor("axis", [1], DataType.int8, [-1])
+    ifm = Tensor([1, 1, 3], DataType.int8, "ifm")
+    ifm.quantization = testutil.default_quant_params()
+    ofm = Tensor([1, 1, 3], DataType.int8, "ofm")
+    ofm.quantization = testutil.default_quant_params()
+    op = testutil.create_op(Op.Split, [axis, ifm], ofm, attrs)
+    # Check invalid split number 2
+    assert not semantic_checker.is_operator_semantic_valid(op)
+    # Check valid split number 3
+    attrs = {"num_splits": 3}
+    op = testutil.create_op(Op.Split, [axis, ifm], ofm, attrs)
+    assert semantic_checker.is_operator_semantic_valid(op)
+
+
 def test_constraint_splitv_inferred():
     # SplitV requires a maximum of one inferred shape (-1)
     qp = testutil.default_quant_params()