model : support LiquidAI LFM2 hybrid family (#14620)

**Important**
LFM2 was [merged ](https://github.com/huggingface/transformers/pull/39340)into transformers, but has not yet been released.
To convert into gguf, install transformers from source
```shell
pip install "transformers @ git+https://github.com/huggingface/transformers.git@main"
```

gguf-py/gguf/constants.py

@@ -187,6 +187,9 @@ class Keys:
     class Classifier:
         OUTPUT_LABELS = "{arch}.classifier.output_labels"
 
+    class ShortConv:
+        L_CACHE = "{arch}.shortconv.l_cache"
+
     class Tokenizer:
         MODEL                = "tokenizer.ggml.model"
         PRE                  = "tokenizer.ggml.pre"
@@ -362,6 +365,7 @@ class MODEL_ARCH(IntEnum):
     ERNIE4_5         = auto()
     HUNYUAN_MOE      = auto()
     SMOLLM3          = auto()
+    LFM2             = auto()
 
 
 class VISION_PROJECTOR_TYPE(IntEnum):
@@ -533,6 +537,9 @@ class MODEL_TENSOR(IntEnum):
     POSNET_ATTN_K        = auto()
     POSNET_ATTN_V        = auto()
     POSNET_ATTN_OUT      = auto()
+    SHORTCONV_CONV       = auto()
+    SHORTCONV_INPROJ     = auto()
+    SHORTCONV_OUTPROJ    = auto()
     # vision
     V_MMPROJ             = auto()
     V_MMPROJ_FC          = auto()
@@ -673,6 +680,7 @@ MODEL_ARCH_NAMES: dict[MODEL_ARCH, str] = {
     MODEL_ARCH.FALCON_H1:        "falcon-h1",
     MODEL_ARCH.HUNYUAN_MOE:      "hunyuan-moe",
     MODEL_ARCH.SMOLLM3:          "smollm3",
+    MODEL_ARCH.LFM2:             "lfm2",
 }
 
 VISION_PROJECTOR_TYPE_NAMES: dict[VISION_PROJECTOR_TYPE, str] = {
@@ -844,6 +852,9 @@ TENSOR_NAMES: dict[MODEL_TENSOR, str] = {
     MODEL_TENSOR.POSNET_ATTN_K:             "posnet.{bid}.attn_k",
     MODEL_TENSOR.POSNET_ATTN_V:             "posnet.{bid}.attn_v",
     MODEL_TENSOR.POSNET_ATTN_OUT:           "posnet.{bid}.attn_output",
+    MODEL_TENSOR.SHORTCONV_CONV:            "blk.{bid}.shortconv.conv",
+    MODEL_TENSOR.SHORTCONV_INPROJ:          "blk.{bid}.shortconv.in_proj",
+    MODEL_TENSOR.SHORTCONV_OUTPROJ:         "blk.{bid}.shortconv.out_proj",
     # vision
     MODEL_TENSOR.V_MMPROJ:                  "mm.{bid}",
     MODEL_TENSOR.V_MMPROJ_FC:               "mm.model.fc",
@@ -2356,6 +2367,24 @@ MODEL_TENSORS: dict[MODEL_ARCH, list[MODEL_TENSOR]] = {
         MODEL_TENSOR.FFN_DOWN,
         MODEL_TENSOR.FFN_UP,
     ],
+    MODEL_ARCH.LFM2: [
+        MODEL_TENSOR.TOKEN_EMBD,
+        MODEL_TENSOR.TOKEN_EMBD_NORM,
+        MODEL_TENSOR.SHORTCONV_CONV,
+        MODEL_TENSOR.SHORTCONV_INPROJ,
+        MODEL_TENSOR.SHORTCONV_OUTPROJ,
+        MODEL_TENSOR.FFN_GATE,
+        MODEL_TENSOR.FFN_DOWN,
+        MODEL_TENSOR.FFN_UP,
+        MODEL_TENSOR.FFN_NORM,
+        MODEL_TENSOR.ATTN_NORM, # operator_norm
+        MODEL_TENSOR.ATTN_Q_NORM,
+        MODEL_TENSOR.ATTN_K_NORM,
+        MODEL_TENSOR.ATTN_Q,
+        MODEL_TENSOR.ATTN_K,
+        MODEL_TENSOR.ATTN_V,
+        MODEL_TENSOR.ATTN_OUT,
+    ],
     # TODO
 }
 

gguf-py/gguf/gguf_writer.py

@@ -648,6 +648,9 @@ class GGUFWriter:
     def add_convnext_block_count(self, length: int) -> None:
         self.add_uint32(Keys.ConvNext.BLOCK_COUNT.format(arch=self.arch), length)
 
+    def add_shortconv_l_cache(self, length: int) -> None:
+        self.add_uint32(Keys.ShortConv.L_CACHE.format(arch=self.arch), length)
+
     def add_block_count(self, length: int) -> None:
         self.add_uint32(Keys.LLM.BLOCK_COUNT.format(arch=self.arch), length)
 

gguf-py/gguf/tensor_mapping.py

@@ -50,6 +50,7 @@ class TensorNameMap:
             "model.pre_ln",               # rwkv7
             "model.layers.0.pre_norm",    # rwkv7
             "backbone.norm",              # wavtokenizer
+            "model.embedding_norm",       # lfm2
         ),
 
         # Position embeddings
@@ -136,6 +137,7 @@ class TensorNameMap:
             "model.layers.{bid}.ln1",                               # rwkv7
             "model.layers.{bid}.input_layernorm",                   # llama4
             "transformer_encoder.{bid}.attention_norm",             # neobert
+            "model.layers.{bid}.operator_norm",                     # lfm2
         ),
 
         # Attention norm 2
@@ -220,6 +222,7 @@ class TensorNameMap:
             "transformer.h.{bid}.self_attention.dense",                     # falcon
             "h.{bid}.self_attention.dense",                                 # bloom
             "model.layers.{bid}.self_attn.o_proj",                          # llama-hf nemotron olmoe olmo2 phimoe
+            "model.layers.{bid}.self_attn.out_proj",                        # lfm2
             "model.layers.{bid}.self_attn.linear_attn",                     # deci
             "layers.{bid}.attention.wo",                                    # llama-pth
             "encoder.layer.{bid}.attention.output.dense",                   # bert
@@ -1015,6 +1018,18 @@ class TensorNameMap:
             "backbone.posnet.{bid}.proj_out", # wavtokenizer
         ),
 
+        MODEL_TENSOR.SHORTCONV_CONV: (
+            "model.layers.{bid}.conv.conv",
+        ),
+
+        MODEL_TENSOR.SHORTCONV_INPROJ: (
+            "model.layers.{bid}.conv.in_proj",
+        ),
+
+        MODEL_TENSOR.SHORTCONV_OUTPROJ: (
+            "model.layers.{bid}.conv.out_proj",
+        ),
+
         #############################################################################
         ## Vision encoder