Allow non-DeepSeekV3 routing with one group

Signed-off-by: Dimitrios Bariamis <12195802+dbari@users.noreply.github.com>

Author: dbari

csrc/trtllm_fused_moe_kernel_launcher.cu

@@ -765,10 +765,15 @@ class Fp8BlockScaleLauncher : public FusedMoeLauncher {
 
     FusedMoeLauncher::check_routing_common();
 
-    if (args->n_group != 0) {
-      TVM_FFI_ICHECK(static_cast<RoutingMethodType>(routing_method_type) ==
-                     RoutingMethodType::DeepSeekV3)
-          << "Routing kernel with groups implies DeepSeekV3 routing method.";
+    if (static_cast<RoutingMethodType>(routing_method_type) != RoutingMethodType::DeepSeekV3) {
+      TVM_FFI_ICHECK(args->n_group <= 1)
+          << "Current routing kernel (no groups) only supports n_group <= 1";
+      TVM_FFI_ICHECK(args->topk_group <= 1)
+          << "Current routing kernel (no groups) only supports topk_group <= 1";
+    }
+
+    if (static_cast<RoutingMethodType>(routing_method_type) == RoutingMethodType::DeepSeekV3) {
+      TVM_FFI_ICHECK(args->n_group != 0) << "n_group should not be zero for DeepSeekV3 routing";
       TVM_FFI_ICHECK(args->topk_group != 0) << "if n_group is given, topk_group must be given";
       TVM_FFI_ICHECK_EQ(args->num_experts % args->n_group, 0)
           << "num_experts must be divisible by n_group";
@@ -790,6 +795,7 @@ class Fp8BlockScaleLauncher : public FusedMoeLauncher {
       TVM_FFI_ICHECK_EQ(args->top_k, 1)
           << "Current routing kernel (no groups, Llama4) only supports top_k=1.";
     }
+
     TVM_FFI_ICHECK_EQ(args->num_experts % 4, 0)
         << "Routing kernel expects that num_experts must be divisible by 4";
     TVM_FFI_ICHECK_GT(args->num_experts, args->top_k) << "num_experts must be greater than top_k";
@@ -2004,9 +2010,8 @@ Array<Array<int64_t>> trtllm_get_valid_moe_configs(
   }
 
   TVM_FFI_LOG_AND_THROW(NotImplementedError)
-      << "Unsupported data type combination for getValidConfigs: "
-      << "dtype_act=" << static_cast<int>(dtype_act)
-      << ", dtype_weights=" << static_cast<int>(dtype_weights)
+      << "Unsupported data type combination for getValidConfigs: " << "dtype_act="
+      << static_cast<int>(dtype_act) << ", dtype_weights=" << static_cast<int>(dtype_weights)
       << ", useDeepSeekFp8=" << useDeepSeekFp8;
 
   // Unreachable code - added to suppress compiler warning