[quantization] Enable aiter mxfp4 fused_moe for Quark (#10048)

Co-authored-by: HaiShaw <hixiao@gmail.com>

python/sglang/srt/layers/quantization/quark/quark_moe.py

@@ -12,7 +12,7 @@ from aiter.utility.fp4_utils import e8m0_shuffle
 
 from sglang.srt.layers.moe import MoeRunnerConfig
 from sglang.srt.layers.quantization.base_config import FusedMoEMethodBase
-from sglang.srt.utils import get_bool_env_var, mxfp_supported, set_weight_attrs
+from sglang.srt.utils import get_bool_env_var, is_hip, mxfp_supported, set_weight_attrs
 
 if TYPE_CHECKING:
     from sglang.srt.layers.moe.token_dispatcher import (
@@ -23,6 +23,8 @@ if TYPE_CHECKING:
 
 logger = logging.getLogger(__name__)
 
+_is_hip = is_hip()
+
 __all__ = ["QuarkMoEMethod", "QuarkW4A4MXFp4MoEMethod"]
 
 OCP_MX_BLOCK_SIZE = 32
@@ -182,6 +184,10 @@ class QuarkW4A4MXFp4MoEMethod(QuarkMoEMethod):
         topk_output = dispatch_output.topk_output
         moe_runner_config = self.moe_runner_config
         topk_weights, topk_ids, _ = topk_output
+        if _is_hip:
+            topk_weights = topk_weights.to(
+                torch.float32
+            )  # aiter's moe_sorting requires topk_weights to be FP32
 
         if hasattr(torch, "float4_e2m1fn_x2"):
             w13_weight = layer.w13_weight.view(torch.float4_e2m1fn_x2)