CUDA: extend MOE fusion to specdec, earlier MOE glu fusion and topk-router fusion were restricted to 1 token (#27621)

* CUDA: extend MOE fusion to specdec, earlier MOE glu fusion and topk-router fusion were resticted to 1 token

Signed-off-by: ynankani <ynankani@nvidia.com>

* Address review comments

Signed-off-by: ynankani <ynankani@nvidia.com>

* Add SWIGLU_CLAMP case to multi-token moe fusion

Signed-off-by: ynankani <ynankani@nvidia.com>

---------

Signed-off-by: ynankani <ynankani@nvidia.com>

ggml/src/ggml-cuda/ggml-cuda.cu

@@ -1807,7 +1807,7 @@ static bool ggml_cuda_should_fuse_mul_mat_vec_q(const ggml_tensor * tensor) {
         return false;
     }
 
-    if (tensor->op == GGML_OP_MUL_MAT_ID && dst->ne[2] != 1) {
+    if (tensor->op == GGML_OP_MUL_MAT_ID && dst->ne[2] > get_mmvq_mmid_max_batch(src0->type, cc)) {
         return false;
     }
 
@@ -2983,9 +2983,10 @@ static bool ggml_cuda_check_fusion_memory_ranges(const ggml_cgraph * cgraph,
     };
 
     bool is_ok = true;
-    // exception for topk-moe, as each row is read entirely before writing
-    if (ggml_nrows(cgraph->nodes[node_idx]) == 1 && is_topk_moe) {
-        return true;
+    // one block reads all logits before it writes, so logits may alias the out nodes
+    const ggml_tensor * logits_may_alias = nullptr;
+    if (is_topk_moe && ggml_nrows(cgraph->nodes[node_idx]) <= TOPK_MOE_ROWS_PER_BLOCK) {
+        logits_may_alias = cgraph->nodes[node_idx]->src[0];
     }
 
     for (int i = 0; i < out_count; ++i) {
@@ -2999,7 +3000,7 @@ static bool ggml_cuda_check_fusion_memory_ranges(const ggml_cgraph * cgraph,
             for (int src_idx = 0; src_idx < GGML_MAX_SRC; ++src_idx) {
                 const ggml_tensor * src = cgraph->nodes[j]->src[src_idx];
 
-                if (!src || src->op == GGML_OP_NONE) {
+                if (!src || src->op == GGML_OP_NONE || src == logits_may_alias) {
                     continue;
                 }