[AMD] fix moriep quant kernel not implemented issue (#27855)

python/sglang/srt/layers/moe/moe_runner/aiter.py

@@ -18,7 +18,7 @@ from sglang.srt.layers.moe.moe_runner.base import (
     register_pre_permute,
 )
 from sglang.srt.layers.moe.utils import MoeRunnerBackend
-from sglang.srt.utils import get_int_env_var
+from sglang.srt.utils import get_bool_env_var, get_int_env_var
 
 if TYPE_CHECKING:
     from sglang.srt.layers.moe.token_dispatcher.base import CombineInput
@@ -327,6 +327,13 @@ def _pre_permute_deepep_to_aiter(
         is_w4a4 = weight_quant == AiterQuantType.PER_1X32
         is_fp4_dispatch = hidden_states.dtype == torch.float4_e2m1fn_x2
 
+        # AITER fused_moe Clamped-SwiGLU is dispatched with
+        # gate_mode=INTERLEAVE, for which AITER picks a bf16/fp8 `q_dtype_a`
+        # Refer to https://github.com/ROCm/aiter/blob/a2617c366dc7271a1662ecda2023d19f6ccefcec/aiter/fused_moe.py#L406-L412
+        swiglu_interleave = quant_info.swiglu_limit > 0 and get_bool_env_var(
+            "SGLANG_USE_AITER_MOE_GU_ITLV", "true"
+        )
+
         if is_w4a4 and a1_scale is not None and not is_fp4_dispatch:
             # W4A4 weights with FP8 dispatch: dequant FP8->BF16 first; the
             # FP4 per_1x32 path needs BF16 input.
@@ -334,6 +341,14 @@ def _pre_permute_deepep_to_aiter(
                 hidden_states, a1_scale, num_local_tokens, output_dtype
             )
             a1_scale = None
+        elif is_w4a4 and is_fp4_dispatch and a1_scale is not None and swiglu_interleave:
+            # W4A4 weights + FP4 dispatch on the clamped-SwiGLU/INTERLEAVE
+            # path: AITER expects a bf16/fp8 activation here, not fp4x2.
+            # Dequant FP4->BF16 and let fused_moe re-quantize internally.
+            hidden_states = upscale_mxfp4(
+                hidden_states, a1_scale, num_local_tokens, output_dtype
+            )
+            a1_scale = None
         elif is_fp8_quant and is_fp4_dispatch and a1_scale is not None:
             # FP8 weights + FP4 dispatch: no kernel for the fp4x2/fp8 pair;
             # dequant FP4->BF16 and let fused_moe re-quantize to FP8.