[BUG] The pass "eliminate_slice_after_shape" causes great output mismatch

The pass "eliminate_slice_after_shape" causes output mismatch

Issue
Running the single pass eliminate_slice_after_shape with onnxoptimizer 0.4.2 may change model outputs. This folder provides minimal repro cases and harnesses to compare original vs optimized models using stored oracle inputs.

Environment

• Ubuntu 20.04
• Python 3.10
• onnx==1.19.0
• onnxruntime==1.19.2
• onnxoptimizer==0.4.2 (latest)

Repro steps (run from this folder)

eliminate_slice_after_shape_repro.tar.gz

1. Create a Python 3.10 virtual environment and install dependencies:

python -m venv .venv
source .venv/bin/activate
pip install --upgrade pip
pip install -r requirements.txt

2. Optimize a case with only eliminate_slice_after_shape (writes model.opt.onnx next to model.onnx):

python optimize_model.py --case ./case_02084_seed36754215

3. Differential test original vs optimized outputs using stored oracle inputs :

python diff_test.py --case ./case_02084_seed36754215

4. Repeat Step 1 ~ 3 until all the models involved are tested.

Observed results

• Mismatches:
  • case_03361_seed46866778: output v52_0 drifts (max_abs=6.770e+00, max_rel=1.417e+00).
  • case_05414_seed63124485: output v26_0 drifts (max_abs=1.067e+19, max_rel=2.512e+00).
  • case_05714_seed65500185: output v10_0 drifts (max_abs=1.153e+00, max_rel=1.005e+00).

Expected
eliminate_slice_after_shape should be semantics-preserving. Applying this pass alone should not change any output values.

Differential Test Output Details

1. case_03361_seed46866778

Case: case_03361_seed46866778
Mismatched outputs (optimized vs reference):
	v52_0 (output[4]): max_abs=6.770e+00, max_rel=1.417e+00, shape=(34, 34, 1, 22)
Overall: max_abs=6.770e+00, max_rel=1.417e+00

1. case_05414_seed63124485

Case: case_05414_seed63124485
Mismatched outputs (optimized vs reference):
	v26_0 (output[10]): max_abs=1.067e+19, max_rel=2.512e+00, shape=(33, 52)
Overall: max_abs=1.067e+19, max_rel=2.512e+00

1. case_05714_seed65500185

Case: case_05714_seed65500185
Mismatched outputs (optimized vs reference):
	v10_0 (output[4]): max_abs=1.153e+00, max_rel=1.005e+00, shape=(1, 54)
Overall: max_abs=1.153e+00, max_rel=1.005e+00

Attachments

• README.md (this document)
• requirements.txt (dependency versions)
• optimize_model.py (runs only eliminate_slice_after_shape and saves model.opt.onnx)
• diff_test.py (runs original vs optimized with oracle inputs and reports max_abs/max_rel)
• run_optimized_model.py (runs the optimized model to inspect outputs)
• case_*/ (original models plus oracle inputs for reproduction)

Start with optimize_model.py and diff_test.py, following the documented virtual-environment setup and testing the listed case_* directories, especially the three cases with mismatches. Use run_optimized_model.py to inspect affected outputs; done means the optimized models preserve the reference outputs for all supplied oracle inputs when only eliminate_slice_after_shape runs.