Add gpt2 architecture integration

convert-hf-to-gguf.py

@@ -182,6 +182,8 @@ def from_model_architecture(model_architecture):
             return QwenModel
         if model_architecture == "MixtralForCausalLM":
             return MixtralModel
+        if model_architecture == "GPT2LMHeadModel":
+            return GPT2Model
         if model_architecture == "PhiForCausalLM":
             return Phi2Model
         return Model
@@ -223,6 +225,8 @@ def _get_model_architecture(self) -> gguf.MODEL_ARCH:
             return gguf.MODEL_ARCH.QWEN
         if arch == "MixtralForCausalLM":
             return gguf.MODEL_ARCH.LLAMA
+        if arch == "GPT2LMHeadModel":
+            return gguf.MODEL_ARCH.GPT2
         if arch == "PhiForCausalLM":
             return gguf.MODEL_ARCH.PHI2
 
@@ -984,6 +988,66 @@ def write_tensors(self):
             print(f"{new_name}, n_dims = {n_dims}, {old_dtype} --> {data.dtype}")
             self.gguf_writer.add_tensor(new_name, data)
 
+class GPT2Model(Model):
+    def set_gguf_parameters(self):
+        self.gguf_writer.add_name(self.dir_model.name)
+        self.gguf_writer.add_block_count(self.hparams["n_layer"])
+        self.gguf_writer.add_context_length(self.hparams["n_ctx"])
+        self.gguf_writer.add_embedding_length(self.hparams["n_embd"])
+        self.gguf_writer.add_feed_forward_length(4 * self.hparams["n_embd"])
+        self.gguf_writer.add_head_count(self.hparams["n_head"])
+        self.gguf_writer.add_layer_norm_eps(self.hparams["layer_norm_epsilon"])
+        self.gguf_writer.add_file_type(self.ftype)
+
+    def write_tensors(self):
+        block_count = self.hparams.get("n_layers", self.hparams.get("num_hidden_layers", self.hparams.get("n_layer")))
+        tensor_map = gguf.get_tensor_name_map(self.model_arch, block_count)
+        # import pdb; pdb.set_trace()
+        for name, data_torch in self.get_tensors():
+            # we don't need these
+            if name.endswith((".attention.masked_bias", ".attention.bias", ".attention.rotary_emb.inv_freq", ".attn.bias")):
+                continue
+
+            if name.endswith((".c_attn.weight", ".c_proj.weight", ".c_fc.weight", ".c_proj.weight")):
+                data_torch = data_torch.transpose(1, 0)
+
+            old_dtype = data_torch.dtype
+
+            # convert any unsupported data types to float32
+            if data_torch.dtype not in (torch.float16, torch.float32):
+                data_torch = data_torch.to(torch.float32)
+
+            data = data_torch.squeeze().numpy()
+
+            # map tensor names
+            new_name = tensor_map.get_name(name, try_suffixes=(".weight", ".bias"))
+            if new_name is None:
+                print(f"Can not map tensor {name!r}")
+                sys.exit()
+
+            n_dims = len(data.shape)
+            data_dtype = data.dtype
+
+            # if f32 desired, convert any float16 to float32
+            if self.ftype == 0 and data_dtype == np.float16:
+                data = data.astype(np.float32)
+
+            # TODO: Why cant we use these float16 as-is? There should be not reason to store float16 as float32
+            if self.ftype == 1 and data_dtype == np.float16 and n_dims == 1:
+                data = data.astype(np.float32)
+
+            # if f16 desired, convert any float32 2-dim weight tensors to float16
+            if self.ftype == 1 and data_dtype == np.float32 and name.endswith(".weight") and n_dims == 2:
+                data = data.astype(np.float16)
+
+            print(f"{new_name}, n_dims = {n_dims}, {old_dtype} --> {data.dtype}")
+
+            self.gguf_writer.add_tensor(new_name, data)
+
+            # note: GPT2 output is tied to (same as) wte in original model
+            if new_name == "token_embd.weight":
+                print(f"output.weight, n_dims = {n_dims}, {old_dtype} --> {data.dtype}")
+                self.gguf_writer.add_tensor("output.weight", data)
 
 class Phi2Model(Model):
     def set_gguf_parameters(self):

gguf-py/gguf/constants.py

@@ -350,7 +350,16 @@ class MODEL_TENSOR(IntEnum):
         MODEL_TENSOR.FFN_UP,
     ],
     MODEL_ARCH.GPT2: [
-        # TODO
+        MODEL_TENSOR.TOKEN_EMBD,
+        MODEL_TENSOR.POS_EMBD,
+        MODEL_TENSOR.OUTPUT_NORM,
+        MODEL_TENSOR.OUTPUT,
+        MODEL_TENSOR.ATTN_NORM,
+        MODEL_TENSOR.ATTN_QKV,
+        MODEL_TENSOR.ATTN_OUT,
+        MODEL_TENSOR.FFN_NORM,
+        MODEL_TENSOR.FFN_DOWN,
+        MODEL_TENSOR.FFN_UP,
     ],
     MODEL_ARCH.PHI2: [
         MODEL_TENSOR.TOKEN_EMBD,

gguf-py/gguf/tensor_mapping.py

@@ -17,6 +17,7 @@ class TensorNameMap:
             "tok_embeddings",                            # llama-pth
             "embeddings.word_embeddings",                # bert
             "language_model.embedding.word_embeddings",  # persimmon
+            "wte",                                       # gpt2
             "transformer.embd.wte",                      # phi2
         ),
 
@@ -34,6 +35,7 @@ class TensorNameMap:
         MODEL_TENSOR.POS_EMBD: (
             "transformer.wpe",                 # gpt2
             "embeddings.position_embeddings",  # bert
+            "wpe",                             # gpt2
         ),
 
         # Output
@@ -53,7 +55,7 @@ class TensorNameMap:
             "norm",                                    # llama-pth
             "embeddings.LayerNorm",                    # bert
             "transformer.norm_f",                      # mpt
-            "ln_f",                                    # refact bloom qwen
+            "ln_f",                                    # refact bloom qwen gpt2
             "language_model.encoder.final_layernorm",  # persimmon
             "lm_head.ln",                              # phi2
         ),
@@ -78,6 +80,7 @@ class TensorNameMap:
             "encoder.layer.{bid}.attention.output.LayerNorm",       # bert
             "language_model.encoder.layers.{bid}.input_layernorm",  # persimmon
             "model.layers.{bid}.ln1",                               # yi
+            "h.{bid}.ln_1",                                         # gpt2
             "transformer.h.{bid}.ln",                               # phi2
         ),
 
@@ -94,6 +97,7 @@ class TensorNameMap:
             "transformer.h.{bid}.self_attention.query_key_value",                  # falcon
             "h.{bid}.self_attention.query_key_value",                              # bloom
             "language_model.encoder.layers.{bid}.self_attention.query_key_value",  # persimmon
+            "h.{bid}.attn.c_attn",                                                 # gpt2
             "transformer.h.{bid}.mixer.Wqkv",                                      # phi2
         ),
 
@@ -133,6 +137,7 @@ class TensorNameMap:
             "encoder.layer.{bid}.attention.output.dense",                # bert
             "transformer.h.{bid}.attn.out_proj",                         # gpt-j
             "language_model.encoder.layers.{bid}.self_attention.dense",  # persimmon
+            "h.{bid}.attn.c_proj",                                       # gpt2
             "transformer.h.{bid}.mixer.out_proj",                        # phi2
         ),
 
@@ -153,6 +158,7 @@ class TensorNameMap:
             "encoder.layer.{bid}.output.LayerNorm",                          # bert
             "language_model.encoder.layers.{bid}.post_attention_layernorm",  # persimmon
             "model.layers.{bid}.ln2",                                        # yi
+            "h.{bid}.ln_2",                                                  # gpt2
         ),
 
         MODEL_TENSOR.FFN_GATE_INP: (
@@ -173,6 +179,7 @@ class TensorNameMap:
             "transformer.h.{bid}.mlp.fc_in",                          # gpt-j
             "language_model.encoder.layers.{bid}.mlp.dense_h_to_4h",  # persimmon
             "transformer.h.{bid}.mlp.w1",                             # qwen
+            "h.{bid}.mlp.c_fc",                                       # gpt2
             "transformer.h.{bid}.mlp.fc1",                            # phi2
         ),
 
@@ -205,6 +212,7 @@ class TensorNameMap:
             "encoder.layer.{bid}.output.dense",                       # bert
             "transformer.h.{bid}.mlp.fc_out",                         # gpt-j
             "language_model.encoder.layers.{bid}.mlp.dense_4h_to_h",  # persimmon
+            "h.{bid}.mlp.c_proj",                                     # gpt2
             "transformer.h.{bid}.mlp.fc2",                            # phi2
         ),