simplify the control logic for using shared experts fusion (#5504)

python/sglang/srt/server_args.py

@@ -183,7 +183,6 @@ class ServerArgs:
     warmups: Optional[str] = None
     moe_dense_tp_size: Optional[int] = None
     n_share_experts_fusion: int = 0
-    disable_shared_experts_fusion: bool = False
     disable_chunked_prefix_cache: bool = False
     disable_fast_image_processor: bool = False
 
@@ -229,9 +228,6 @@ class ServerArgs:
             # GPU memory is not known yet or no GPU is available.
             gpu_mem = None
 
-        if is_hip():
-            self.disable_shared_experts_fusion = True
-
         # Set mem fraction static, which depends on the tensor parallelism size
         if self.mem_fraction_static is None:
             if self.tp_size >= 16:
@@ -1126,13 +1122,8 @@ class ServerArgs:
             "--n-share-experts-fusion",
             type=int,
             default=0,
-            help="The number of shared_experts need to be replica to fuse with normal experts in deepseek v3/r1 "
-            "we use tp_size by default.",
-        )
-        parser.add_argument(
-            "--disable-shared-experts-fusion",
-            action="store_true",
-            help="Disable shared experts fusion by setting n_share_experts_fusion to 0.",
+            help="The number of shared_experts need to be replicated to fuse with normal experts in deepseek v3/r1, "
+            "set it to tp_size can get best optimized performace.",
         )
         parser.add_argument(
             "--disable-chunked-prefix-cache",