feat: Add llama_model_is_hybrid API call

Also, split llama_model_is_recurrent into llm_arch_is_recurrent in
llama-arch with llama_model_is_recurrent delegating to
llm_arch_is_recurrent. The same split is done for hybird. This is needed
because there are places where the llama_model has not yet been initialized
but we need to check if the model is recurrent (specifically for the
per-layer recurrent check array in hparams).

Branch: GraniteFour

Signed-off-by: Gabe Goodhart <ghart@us.ibm.com>

Author: gabe-l-hart

include/llama.h

@@ -557,6 +557,9 @@ extern "C" {
     // Returns true if the model is recurrent (like Mamba, RWKV, etc.)
     LLAMA_API bool llama_model_is_recurrent(const struct llama_model * model);
 
+    // Returns true if the model is hybrid-recurrent (like Jamba, Bamba, etc.)
+    LLAMA_API bool llama_model_is_hybrid(const struct llama_model * model);
+
     // Returns 0 on success
     LLAMA_API uint32_t llama_model_quantize(
             const char * fname_inp,

src/llama-arch.cpp

@@ -1747,3 +1747,25 @@ llm_arch llm_arch_from_string(const std::string & name) {
 const llm_tensor_info & llm_tensor_info_for(llm_tensor tensor) {
     return LLM_TENSOR_INFOS.at(tensor);
 }
+
+bool llm_arch_is_recurrent(const llm_arch & arch) {
+    switch (arch) {
+        case LLM_ARCH_MAMBA:
+        case LLM_ARCH_RWKV6:
+        case LLM_ARCH_RWKV6QWEN2:
+        case LLM_ARCH_RWKV7:
+        case LLM_ARCH_ARWKV7:
+            return true;
+        default:
+            return false;
+    }
+}
+
+bool llm_arch_is_hybrid(const llm_arch & arch) {
+    // TODO: There are currently no hybrid models! Once there are, this will be
+    //  the place to identify them
+    switch (arch) {
+        default:
+            return false;
+    }
+}

src/llama-arch.h

@@ -437,3 +437,6 @@ const char * llm_arch_name(llm_arch arch);
 llm_arch llm_arch_from_string(const std::string & name);
 
 const llm_tensor_info & llm_tensor_info_for(llm_tensor tensor);
+
+bool llm_arch_is_recurrent(const llm_arch& arch);
+bool llm_arch_is_hybrid(const llm_arch& arch);

src/llama-model.cpp

@@ -13804,14 +13804,11 @@ llama_token llama_model_decoder_start_token(const llama_model * model) {
 }
 
 bool llama_model_is_recurrent(const llama_model * model) {
-    switch (model->arch) {
-        case     LLM_ARCH_MAMBA:      return true;
-        case     LLM_ARCH_RWKV6:      return true;
-        case     LLM_ARCH_RWKV6QWEN2: return true;
-        case     LLM_ARCH_RWKV7:      return true;
-        case     LLM_ARCH_ARWKV7:     return true;
-        default: return false;
-    }
+    return llm_arch_is_recurrent(model->arch);
+}
+
+bool llama_model_is_hybrid(const llama_model * model) {
+    return llm_arch_is_hybrid(model->arch);
 }
 
 const std::vector<std::pair<std::string, ggml_tensor *>> & llama_internal_get_tensor_map(const llama_model * model) {