Gemma 4 MTP: bring in the upstream MTP lineage (qwen35 post-norm + gemma4) on TurboQuant+

common/arg.cpp

@@ -540,7 +540,11 @@ static bool common_params_parse_ex(int argc, char ** argv, common_params_context
                 throw std::invalid_argument(string_format("error: invalid argument: %s", arg.c_str()));
             }
             if (!seen_args.insert(arg).second) {
-                LOG_WRN("DEPRECATED: argument '%s' specified multiple times, use comma-separated values instead (only last value will be used)\n", arg.c_str());
+                const bool skip = (arg == "--spec-type");
+
+                if (!skip) {
+                    LOG_WRN("DEPRECATED: argument '%s' specified multiple times, use comma-separated values instead (only last value will be used)\n", arg.c_str());
+                }
             }
             auto & tmp = arg_to_options[arg];
             auto opt = *tmp.first;
@@ -903,7 +907,11 @@ bool common_params_to_map(int argc, char ** argv, llama_example ex, std::map<com
             throw std::invalid_argument(string_format("error: invalid argument: %s", arg.c_str()));
         }
         if (!seen_args.insert(arg).second) {
-            LOG_WRN("DEPRECATED: argument '%s' specified multiple times, use comma-separated values instead (only last value will be used)\n", arg.c_str());
+            const bool skip = (arg == "--spec-type");
+
+            if (!skip) {
+                LOG_WRN("DEPRECATED: argument '%s' specified multiple times, use comma-separated values instead (only last value will be used)\n", arg.c_str());
+            }
         }
         auto opt = *arg_to_options[arg];
         std::string val;
@@ -1037,11 +1045,9 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
     // we define here to make sure it's included in llama-gen-docs
     if (ex == LLAMA_EXAMPLE_COMPLETION) {
         params.use_jinja = false;   // disable jinja by default
-
     } else if (ex == LLAMA_EXAMPLE_MTMD) {
         params.use_jinja = false;   // disable jinja by default
         params.sampling.temp = 0.2; // lower temp by default for better quality
-
     } else if (ex == LLAMA_EXAMPLE_SERVER) {
         params.n_parallel = -1;     // auto by default
     }
@@ -1062,7 +1068,6 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
         sampler_type_names.pop_back(); // remove last semicolon
     }
 
-
     /**
      * filter options by example
      * rules:
@@ -1076,7 +1081,6 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
         }
     };
 
-
     add_opt(common_arg(
         {"-h", "--help", "--usage"},
         "print usage and exit",
@@ -3606,6 +3610,15 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
             params.speculative.draft.p_min = std::stof(value);
         }
     ).set_spec().set_examples({LLAMA_EXAMPLE_SPECULATIVE, LLAMA_EXAMPLE_SERVER, LLAMA_EXAMPLE_CLI}).set_env("LLAMA_ARG_SPEC_DRAFT_P_MIN"));
+    add_opt(common_arg(
+        {"--spec-draft-backend-sampling"},
+        {"--no-spec-draft-backend-sampling"},
+        string_format("offload draft sampling to the backend (default: %s)",
+                      params.speculative.draft.backend_sampling ? "enabled" : "disabled"),
+        [](common_params & params, bool value) {
+            params.speculative.draft.backend_sampling = value;
+        }
+    ).set_spec().set_examples({LLAMA_EXAMPLE_SPECULATIVE, LLAMA_EXAMPLE_SERVER, LLAMA_EXAMPLE_CLI}).set_env("LLAMA_ARG_SPEC_DRAFT_BACKEND_SAMPLING"));
     add_opt(common_arg(
         {"--spec-draft-device", "-devd", "--device-draft"}, "<dev1,dev2,..>",
         "comma-separated list of devices to use for offloading the draft model (none = don't offload)\n"
@@ -4141,6 +4154,12 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
             params.speculative.ngram_mod.n_match = 24;
             params.speculative.ngram_mod.n_min = 48;
             params.speculative.ngram_mod.n_max = 64;
+
+            // TODO: not sure if this is a good config - explore more settings and potentially enable it
+            //params.speculative.types.push_back(COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K4V);
+            //params.speculative.ngram_map_k4v.size_n = 8;
+            //params.speculative.ngram_map_k4v.size_m = 24;
+            //params.speculative.ngram_map_k4v.min_hits = 2;
         }
     ).set_examples({LLAMA_EXAMPLE_SERVER, LLAMA_EXAMPLE_CLI}));
 

common/common.cpp

@@ -1258,29 +1258,6 @@ common_init_result::common_init_result(common_params & params) :
         cparams.n_samplers = pimpl->samplers_seq_config.size();
     }
 
-    // [TAG_RS_STATE_ROLLBACK_SUPPORT]
-    // TODO: ngram speculative methods require checkpointing in addition to partial RS rollback
-    //       currently this is not supported. so we disable the partial rollback
-    if (cparams.n_rs_seq > 0 && (llama_model_is_recurrent(model) || llama_model_is_hybrid(model))) {
-        auto & types = params.speculative.types;
-
-        for (int i = 0; i < (int) types.size(); i++) {
-            if (types[i] == COMMON_SPECULATIVE_TYPE_NONE) {
-                continue;
-            }
-            if (types[i] == COMMON_SPECULATIVE_TYPE_DRAFT_MTP) {
-                continue;
-            }
-
-            cparams.n_rs_seq = 0;
-
-            LOG_WRN("%s: recurrent state rollback is not compatible with '%s' - disabling rollback support\n", __func__,
-                    common_speculative_type_to_str(types[i]).c_str());
-
-            break;
-        }
-    }
-
     llama_context * lctx = llama_init_from_model(model, cparams);
     if (lctx == NULL) {
         LOG_ERR("%s: failed to create context with model '%s'\n", __func__, params.model.path.c_str());
@@ -1562,6 +1539,7 @@ struct llama_context_params common_context_params_to_llama(const common_params &
 
     cparams.n_ctx             = params.n_ctx;
     cparams.n_seq_max         = params.n_parallel;
+    cparams.n_outputs_max     = params.n_outputs_max;
     cparams.n_rs_seq          = params.speculative.need_n_rs_seq();
     cparams.n_batch           = params.n_batch;
     cparams.n_ubatch          = params.n_ubatch;

common/common.h

@@ -299,11 +299,13 @@ struct common_params_model {
 
 // draft-model-based speculative decoding parameters
 struct common_params_speculative_draft {
-    int32_t n_max = 16; // maximum number of tokens to draft during speculative decoding
-    int32_t n_min = 0;  // minimum number of draft tokens to use for speculative decoding
+    int32_t n_max = 3; // maximum number of tokens to draft during speculative decoding
+    int32_t n_min = 0; // minimum number of draft tokens to use for speculative decoding
 
-    float p_split = 0.1f;  // speculative decoding split probability
-    float p_min   = 0.75f; // minimum speculative decoding probability (greedy) // TODO: change default to 0.0f
+    float p_split = 0.1f; // speculative decoding split probability
+    float p_min   = 0.0f; // minimum speculative decoding probability (greedy)
+
+    bool backend_sampling = true; // offload draft sampling to the backend (default: on)
 
     common_params_model mparams;
 
@@ -428,6 +430,7 @@ struct common_params {
     int32_t n_keep                =     0; // number of tokens to keep from initial prompt
     int32_t n_chunks              =    -1; // max number of chunks to process (-1 = unlimited)
     int32_t n_parallel            =     1; // number of parallel sequences to decode
+    int32_t n_outputs_max         =     0; // max outputs supported by the context (0 = derive)
     int32_t n_sequences           =     1; // number of sequences to decode
     int32_t grp_attn_n            =     1; // group-attention factor
     int32_t grp_attn_w            =   512; // group-attention width

common/ngram-map.cpp

@@ -500,7 +500,7 @@ void common_ngram_map_draft(common_ngram_map & map,
         draft.push_back(inp[match_pos + n + i]);
     }
 
-    LOG_INF("%s: key_offset = %zu, slot_max = %d, key_num = %d, draft.size = %zu\n", __func__,
+    LOG_DBG("%s: key_offset = %zu, slot_max = %d, key_num = %d, draft.size = %zu\n", __func__,
             key_offset, slot_max,
             curr_key.key_num, draft.size());