[ROCm][Bugfix] Fix accuracy issue on fmoe when...

[ROCm][Bugfix] Fix accuracy issue on fmoe when `VLLM_ROCM_USE_AITER_FUSION_SHARED_EXPERTS` enabled (#31523)
Signed-off-by: ganyi <ygan@amd.com>

vllm/platforms/rocm.py

@@ -407,8 +407,10 @@ class RocmPlatform(Platform):
         compilation_config = vllm_config.compilation_config
         parallel_config = vllm_config.parallel_config
         is_eager_execution = compilation_config == CUDAGraphMode.NONE
+        use_aiter_fused_moe = rocm_aiter_ops.is_fused_moe_enabled()
         use_aiter_rms_norm = rocm_aiter_ops.is_rmsnorm_enabled()
         use_aiter_fp8_linear = rocm_aiter_ops.is_linear_fp8_enabled()
+        use_aiter_fused_se = rocm_aiter_ops.is_fusion_moe_shared_experts_enabled()
 
         if compilation_config.cudagraph_mode.has_full_cudagraphs():
             # decode context parallel does not support full cudagraphs
@@ -458,6 +460,22 @@ class RocmPlatform(Platform):
         if use_aiter_fp8_linear and "-quant_fp8" not in compilation_config.custom_ops:
             compilation_config.custom_ops.append("+quant_fp8")
 
+        if use_aiter_fused_se and "-grouped_topk" in compilation_config.custom_ops:
+            logger.warning_once(
+                "VLLM_ROCM_USE_AITER_FUSION_SHARED_EXPERTS is enabled, which "
+                "requires the 'grouped_topk' custom op. Overriding the "
+                "user-provided '-grouped_topk'."
+            )
+            compilation_config.custom_ops.remove("-grouped_topk")
+        # Ensure grouped_topk is always enabled when using AITER if
+        # its not disabled by user
+        if (
+            use_aiter_fused_moe
+            and "+grouped_topk" not in compilation_config.custom_ops
+            and "-grouped_topk" not in compilation_config.custom_ops
+        ):
+            compilation_config.custom_ops.append("+grouped_topk")
+
     @classmethod
     def verify_model_arch(cls, model_arch: str) -> None:
         if model_arch in _ROCM_UNSUPPORTED_MODELS: