Add LLaDA 8b Diffusion model (#14771)

* Add support for Llada-8b: diffusion model

* Add README

* Fix README and convert_hf_to_gguf

* convert_hf_to_gguf.py: address review comments

* Make everything in a single example

* Remove model-specific sampling

* Remove unused argmax

* Remove braced initializers, improve README.md a bit

* Add diffusion specific gguf params in set_vocab, remove setting rope_theta and rms_norm_eps

* Remove adding the mask token

* Move add_add_bos_token to set_vocab

* use add_bool in gguf_writer.py

Author: am17an

common/arg.cpp

@@ -3438,34 +3438,51 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
         }
     ).set_examples({LLAMA_EXAMPLE_SERVER}));
 
-    // diffusion parameters
     add_opt(common_arg(
         { "--diffusion-steps" }, "N",
         string_format("number of diffusion steps (default: %d)", params.diffusion.steps),
         [](common_params & params, int value) { params.diffusion.steps = value; }
     ).set_examples({ LLAMA_EXAMPLE_DIFFUSION }));
+    add_opt(common_arg(
+        { "--diffusion-visual" },
+        string_format("enable visual diffusion mode (show progressive generation) (default: %s)",
+                      params.diffusion.visual_mode ? "true" : "false"),
+        [](common_params & params) { params.diffusion.visual_mode = true; }
+    ).set_examples({ LLAMA_EXAMPLE_DIFFUSION }));
+
     add_opt(common_arg(
         { "--diffusion-eps" }, "F",
         string_format("epsilon for timesteps (default: %.6f)", (double) params.diffusion.eps),
         [](common_params & params, const std::string & value) { params.diffusion.eps = std::stof(value); }
     ).set_examples({ LLAMA_EXAMPLE_DIFFUSION }));
     add_opt(common_arg(
         { "--diffusion-algorithm" }, "N",
-        string_format("diffusion algorithm: 0=ORIGIN, 1=MASKGIT_PLUS, 2=TOPK_MARGIN, 3=ENTROPY (default: %d)",
+        string_format("diffusion algorithm: 0=ORIGIN, 1=ENTROPY_BASED, 2=MARGIN_BASED, 3=RANDOM, 4=LOW_CONFIDENCE (default: %d)",
                       params.diffusion.algorithm),
         [](common_params & params, int value) { params.diffusion.algorithm = value; }
     ).set_examples({ LLAMA_EXAMPLE_DIFFUSION }));
     add_opt(common_arg(
         { "--diffusion-alg-temp" }, "F",
-        string_format("algorithm temperature (default: %.3f)", (double) params.diffusion.alg_temp),
+        string_format("dream algorithm temperature (default: %.3f)", (double) params.diffusion.alg_temp),
         [](common_params & params, const std::string & value) { params.diffusion.alg_temp = std::stof(value); }
     ).set_examples({ LLAMA_EXAMPLE_DIFFUSION }));
+
     add_opt(common_arg(
-        { "--diffusion-visual" },
-        string_format("enable visual diffusion mode (show progressive generation) (default: %s)",
-                      params.diffusion.visual_mode ? "true" : "false"),
-        [](common_params & params) { params.diffusion.visual_mode = true; }
+        { "--diffusion-block-length" }, "N",
+        string_format("llada block length for generation (default: %d)", params.diffusion.block_length),
+        [](common_params & params, int value) { params.diffusion.block_length = value; }
+    ).set_examples({ LLAMA_EXAMPLE_DIFFUSION }));
+    add_opt(common_arg(
+        { "--diffusion-cfg-scale" }, "F",
+        string_format("llada classifier-free guidance scale (default: %.3f)", (double) params.diffusion.cfg_scale),
+        [](common_params & params, const std::string & value) { params.diffusion.cfg_scale = std::stof(value); }
+    ).set_examples({ LLAMA_EXAMPLE_DIFFUSION }));
+    add_opt(common_arg(
+        { "--diffusion-add-gumbel-noise" }, "F",
+        string_format("add gumbel noise to the logits if temp > 0.0 (default: %s)", params.diffusion.add_gumbel_noise ? "true" : "false"),
+        [](common_params & params, const std::string & value) { params.diffusion.add_gumbel_noise = std::stof(value); }
     ).set_examples({ LLAMA_EXAMPLE_DIFFUSION }));
 
+
     return ctx_arg;
 }

common/common.h

@@ -220,11 +220,17 @@ struct common_params_vocoder {
 };
 
 struct common_params_diffusion {
-    int32_t steps       = 64;     // number of diffusion steps
-    float   eps         = 1e-3f;  // epsilon for timesteps
-    int32_t algorithm   = 0;      // diffusion algorithm (0=ORIGIN, 1=MASKGIT_PLUS, 2=TOPK_MARGIN, 3=ENTROPY)
-    float   alg_temp    = 0.0f;   // algorithm temperature
-    bool    visual_mode = false;  // show progressive diffusion on screen
+    int32_t steps         = 128;
+    bool    visual_mode   = false;
+
+    float   eps           = 0;        // epsilon for timesteps
+    int32_t block_length  = 32;       // block length for generation
+
+    int32_t algorithm     = 4;        // default algorithm: low-confidence
+    float   alg_temp      = 0.0f;     // algorithm temperature
+
+    float   cfg_scale     = 0;        // classifier-free guidance scale
+    bool    add_gumbel_noise = false; // add gumbel noise to the logits if temp > 0.0
 };
 
 enum common_reasoning_format {

convert_hf_to_gguf.py

@@ -2904,6 +2904,107 @@ def modify_tensors(self, data_torch: Tensor, name: str, bid: int | None) -> Iter
         yield from super().modify_tensors(data_torch, name, bid)
 
 
+@ModelBase.register("LLaDAModelLM")
+class LLaDAModel(TextModel):
+    model_arch = gguf.MODEL_ARCH.LLADA
+    undo_permute = True
+
+    def get_vocab_base(self) -> tuple[list[str], list[int], str]:
+        tokens: list[str] = []
+        toktypes: list[int] = []
+
+        from transformers import AutoTokenizer
+        tokenizer = AutoTokenizer.from_pretrained(self.dir_model, trust_remote_code=True)
+
+        vocab_dict = tokenizer.get_vocab()
+        vocab_size = self.hparams.get("vocab_size", len(vocab_dict))
+        assert max(vocab_dict.values()) < vocab_size
+
+        tokpre = self.get_vocab_base_pre(tokenizer)
+
+        reverse_vocab = {id_: encoded_tok for encoded_tok, id_ in vocab_dict.items()}
+        added_vocab = tokenizer.get_added_vocab()
+
+        for i in range(vocab_size):
+            if i not in reverse_vocab:
+                tokens.append(f"[PAD{i}]")
+                toktypes.append(gguf.TokenType.UNUSED)
+            elif reverse_vocab[i] in added_vocab:
+                tokens.append(reverse_vocab[i])
+                # Check if it's a special token - treat special tokens as CONTROL tokens
+                if hasattr(tokenizer, 'added_tokens_decoder') and i in tokenizer.added_tokens_decoder:
+                    if tokenizer.added_tokens_decoder[i].special:
+                        toktypes.append(gguf.TokenType.CONTROL)
+                    else:
+                        toktypes.append(gguf.TokenType.USER_DEFINED)
+                else:
+                    # Fallback: treat all added vocab as control tokens for special tokens like <|im_start|>
+                    toktypes.append(gguf.TokenType.CONTROL)
+            else:
+                tokens.append(reverse_vocab[i])
+                toktypes.append(gguf.TokenType.NORMAL)
+
+        return tokens, toktypes, tokpre
+
+    def set_vocab(self):
+        self._set_vocab_gpt2()
+
+        # LLaDA specific parameters
+        self.gguf_writer.add_add_bos_token(True)
+
+    def set_gguf_parameters(self):
+        super().set_gguf_parameters()
+        self._try_set_pooling_type()
+
+        # Add parameters similar to LlamaModel
+        hparams = self.hparams
+        self.gguf_writer.add_vocab_size(hparams["vocab_size"])
+
+        if (rope_dim := hparams.get("head_dim")) is None:
+            n_heads = hparams.get("num_attention_heads", hparams.get("n_heads"))
+            rope_dim = hparams.get("hidden_size", hparams.get("d_model")) // n_heads
+        self.gguf_writer.add_rope_dimension_count(rope_dim)
+
+        # Set context length for LLaDA
+        context_length = self.hparams.get("max_sequence_length", 4096)
+        self.gguf_writer.add_context_length(context_length)
+
+        # Set embedding length (dimension size)
+        embedding_length = self.hparams.get("d_model", 4096)
+        self.gguf_writer.add_embedding_length(embedding_length)
+
+        # Set feed forward length (MLP hidden size)
+        feed_forward_length = self.hparams.get("mlp_hidden_size", 12288)
+        self.gguf_writer.add_feed_forward_length(feed_forward_length)
+
+        # LLaDA models use non-causal attention for diffusion, similar to Dream
+        self.gguf_writer.add_causal_attention(False)
+
+        # LLaDA models don't shift their logits
+        self.gguf_writer.add_diffusion_shift_logits(False)
+
+    @staticmethod
+    def permute(weights: Tensor, n_head: int, n_head_kv: int | None):
+        if n_head_kv is not None and n_head != n_head_kv:
+            n_head = n_head_kv
+        return (weights.reshape(n_head, 2, weights.shape[0] // n_head // 2, *weights.shape[1:])
+                .swapaxes(1, 2)
+                .reshape(weights.shape))
+
+    def modify_tensors(self, data_torch: Tensor, name: str, bid: int | None) -> Iterable[tuple[str, Tensor]]:
+        n_head = self.hparams.get("num_attention_heads", self.hparams.get("n_heads"))
+        n_kv_head = self.hparams.get("num_key_value_heads", self.hparams.get("n_kv_heads"))
+
+        if self.undo_permute:
+            if name.endswith(("q_proj.weight", "q_proj.bias")):
+                data_torch = LLaDAModel.permute(data_torch, n_head, n_head)
+            if name.endswith(("k_proj.weight", "k_proj.bias")):
+                data_torch = LLaDAModel.permute(data_torch, n_head, n_kv_head)
+
+        # LLaDA model tensors should be mapped directly since it's the base model
+        yield from super().modify_tensors(data_torch, name, bid)
+
+
 @ModelBase.register("Ernie4_5_ForCausalLM")
 class Ernie4_5Model(TextModel):
     model_arch = gguf.MODEL_ARCH.ERNIE4_5

examples/diffusion/README.md

@@ -0,0 +1,13 @@
+# Diffusion Text Generation
+
+This directory contains implementations for Diffusion LLMs (DLLMs)
+
+More Info:
+- https://github.com/ggml-org/llama.cpp/pull/14644
+- https://github.com/ggml-org/llama.cpp/pull/14771
+
+
+Example of using Dream architechture: `llama-diffusion-cli -m dream7b.gguf -p "write code to train MNIST in pytorch" -ub 512 --diffusion-eps 0.001 --diffusion-algorithm 3 --diffusion-steps 256 --diffusion-visual`
+
+Example of using LLaDA architechture: `llama-diffusion-cli -m llada-8b.gguf -p "write code to train MNIST in pytorch" -ub 512 --diffusion-block-length 32 --diffusion-steps 256 --diffusion-visual`
+