[Core] Move test utility to test file (#35672)

Signed-off-by: Turner Jabbour <doubleujabbour@gmail.com>

tests/kernels/moe/test_gpt_oss_triton_kernels.py

@@ -26,9 +26,10 @@ from vllm.model_executor.layers.fused_moe.config import mxfp4_w4a16_moe_quant_co
 from vllm.model_executor.layers.fused_moe.gpt_oss_triton_kernels_moe import (
     triton_kernel_moe_forward,
 )
-from vllm.model_executor.layers.utils import shuffle_weight
 from vllm.utils.math_utils import round_up
 
+from .utils import shuffle_weight
+
 
 def deshuffle(w: torch.Tensor):
     first = w[..., ::2]

tests/kernels/moe/test_modular_oai_triton_moe.py

@@ -33,11 +33,10 @@ from vllm.model_executor.layers.fused_moe.modular_kernel import FusedMoEModularK
 from vllm.model_executor.layers.fused_moe.prepare_finalize import (
     MoEPrepareAndFinalizeNoEP,
 )
-from vllm.model_executor.layers.utils import shuffle_weight
 from vllm.platforms import current_platform
 from vllm.utils.torch_utils import set_random_seed
 
-from .utils import make_dummy_moe_config
+from .utils import make_dummy_moe_config, shuffle_weight
 
 MNK = [
     (1, 512, 384),

tests/kernels/moe/utils.py

@@ -33,6 +33,16 @@ from vllm.utils.deep_gemm import per_block_cast_to_fp8
 from vllm.utils.math_utils import round_up
 
 
+def shuffle_weight(w: torch.Tensor) -> torch.Tensor:
+    """Fold weights to adjacent locations for Triton MoE / SwiGLU kernel layout."""
+    shape = w.shape
+    n = shape[-1]
+    first = w[..., : n // 2]
+    second = w[..., n // 2 :]
+    stacked = torch.stack((first, second), dim=-1)
+    return stacked.reshape(shape)
+
+
 def make_dummy_moe_config(
     num_experts: int = 1,
     experts_per_token: int = 1,