[OpenVINO] ReverseSequence returns zeros for batch with sequence length 0

[ALinrunrun]

Describe the issue

ONNX Runtime CPUExecutionProvider produces incorrect output for ReverseSequence when one sequence length is 0.

In the reproducer below, time_axis=0, batch_axis=1, and sequence_lens=[4, 0, 2].

For the second batch, the sequence length is 0, so no elements should be reversed and the original column should remain unchanged. However, ORT returns zeros for the entire second batch column.

OpenVINO keeps that column unchanged, which matches the expected behavior.

To reproduce

import numpy as np
import onnxruntime as ort
from onnx import TensorProto, helper

node = helper.make_node(
    "ReverseSequence",
    ["x", "lens"],
    ["y"],
    time_axis=0,
    batch_axis=1,
)

graph = helper.make_graph(
    [node],
    "g",
    [
        helper.make_tensor_value_info("x", TensorProto.FLOAT, [5, 3]),
        helper.make_tensor_value_info("lens", TensorProto.INT64, [3]),
    ],
    [helper.make_tensor_value_info("y", TensorProto.FLOAT, [5, 3])],
)

model = helper.make_model(graph, opset_imports=[helper.make_opsetid("", 18)])
model.ir_version = 9

x = np.array(
    [
        [10, 20, 30],
        [11, 21, 31],
        [12, 22, 32],
        [13, 23, 33],
        [14, 24, 34],
    ],
    dtype=np.float32,
)

lens = np.array([4, 0, 2], dtype=np.int64)

sess = ort.InferenceSession(
    model.SerializeToString(),
    providers=["CPUExecutionProvider"],
)

y = sess.run(None, {"x": x, "lens": lens})[0]

expected = np.array(
    [
        [13, 20, 31],
        [12, 21, 30],
        [11, 22, 32],
        [10, 23, 33],
        [14, 24, 34],
    ],
    dtype=np.float32,
)

print("x:")
print(x)
print("lens:", lens)
print("expected column for length-0 batch:", expected[:, 1])
print("ORT column for length-0 batch:     ", y[:, 1])
print("PASS=", np.array_equal(y, expected))

Urgency

Expected output

lens: [4 0 2]
expected column for length-0 batch: [20. 21. 22. 23. 24.]
ORT column for length-0 batch:      [20. 21. 22. 23. 24.]
PASS=True

Actual output

lens: [4 0 2]
expected column for length-0 batch: [20. 21. 22. 23. 24.]
ORT column for length-0 batch:      [0. 0. 0. 0. 0.]
PASS=False

Platform

Linux

OS Version

Linux-6.17.0-20-generic-x86_64-with-glibc2.39

ONNX Runtime Installation

Released Package

ONNX Runtime Version or Commit ID

1.25.1

ONNX Runtime API

Python

Architecture

X86

Execution Provider

Default CPU

Execution Provider Library Version

No response