gpt4all/gpt4all-backend/scripts/convert_gptj_to_gguf.py
Jared Van Bortel 26acdebafa
convert: replace GPTJConfig with AutoConfig (#1866)
Signed-off-by: Jared Van Bortel <jared@nomic.ai>
2024-01-22 12:14:55 -05:00

166 lines
4.7 KiB
Python
Executable File

#!/usr/bin/env python3
# Convert GPT-J-6B h5 transformer model to ggml format
#
# Load the model using GPTJForCausalLM.
# Iterate over all variables and write them to a binary file.
#
# For each variable, write the following:
# - Number of dimensions (int)
# - Name length (int)
# - Dimensions (int[n_dims])
# - Name (char[name_length])
# - Data (float[n_dims])
#
# By default, the bigger matrices are converted to 16-bit floats.
# This can be disabled by adding the "ftype" CLI argument.
#
# At the start of the ggml file we write the model parameters
# and vocabulary.
#
from __future__ import annotations
import sys
import struct
import json
from pathlib import Path
import gguf
import numpy as np
from transformers import AutoConfig, AutoTokenizer, GPTJForCausalLM
from transformers.models.gpt2 import tokenization_gpt2
if not 2 <= len(sys.argv) < 4:
print("Usage: python {} dir-model [ftype]\n".format(Path(__file__).name))
print(" ftype == 0 -> float32")
print(" ftype == 1 -> float16")
sys.exit(1)
# output in the same directory as the model
dir_model = Path(sys.argv[1])
fname_out = dir_model / "ggml-model.gguf"
# possible data types
# ftype == 0 -> float32
# ftype == 1 -> float16
#
# map from ftype to string
ftype_str = ["f32", "f16"]
ftype = 1
if len(sys.argv) > 2:
ftype = int(sys.argv[2])
if ftype < 0 or ftype > 1:
print("Invalid ftype: " + str(ftype))
sys.exit(1)
fname_out = dir_model / ("ggml-model-" + ftype_str[ftype] + ".gguf")
ARCH = gguf.MODEL_ARCH.GPTJ
gguf_writer = gguf.GGUFWriter(fname_out, gguf.MODEL_ARCH_NAMES[ARCH])
print("gguf: get model metadata")
config = AutoConfig.from_pretrained(dir_model)
block_count = config.n_layer
gguf_writer.add_name("GPT-J")
gguf_writer.add_context_length(config.n_positions)
gguf_writer.add_embedding_length(config.n_embd)
gguf_writer.add_block_count(block_count)
gguf_writer.add_feed_forward_length(4 * config.n_embd)
gguf_writer.add_head_count(config.n_head)
gguf_writer.add_rope_dimension_count(config.rotary_dim)
gguf_writer.add_layer_norm_eps(config.layer_norm_epsilon)
gguf_writer.add_file_type(ftype)
print("gguf: get gpt2 tokenizer vocab")
tokenizer = AutoTokenizer.from_pretrained(dir_model)
reverse_vocab = {id: encoded_tok for encoded_tok, id in tokenizer.vocab.items()}
byte_encoder = tokenization_gpt2.bytes_to_unicode()
byte_decoder = {v: k for k, v in byte_encoder.items()}
tokens: list[bytearray] = []
for i in range(config.vocab_size):
if i in reverse_vocab:
try:
text = bytearray([byte_decoder[c] for c in reverse_vocab[i]])
except KeyError:
text = bytearray()
for c in reverse_vocab[i]:
if ord(c) < 256: # single byte character
text.append(byte_decoder[c])
else: # multibyte special token character
text.extend(c.encode('utf-8'))
else:
print(f"Key {i} not in tokenizer vocabulary. Padding with an arbitrary token.")
pad_token = f"[PAD{i}]".encode("utf8")
text = bytearray(pad_token)
tokens.append(text)
gguf_writer.add_tokenizer_model("gpt2")
gguf_writer.add_token_list(tokens)
special_vocab = gguf.SpecialVocab(dir_model, load_merges=True)
special_vocab.add_to_gguf(gguf_writer)
print("gguf: get tensor metadata")
model = GPTJForCausalLM.from_pretrained(dir_model, config=config, low_cpu_mem_usage=True)
#print (model)
tensor_map = gguf.get_tensor_name_map(ARCH, block_count)
list_vars = model.state_dict()
#print (list_vars)
for name in list_vars.keys():
data = list_vars[name].squeeze().numpy()
print("Processing variable:", name, "with shape:", data.shape)
# we don't need these
if name.endswith("attn.masked_bias") or name.endswith(".attn.bias"):
print(" Skipping variable:", name)
continue
n_dims = len(data.shape)
# ftype == 0 -> float32, ftype == 1 -> float16
ftype_cur = 0
if ftype == 1 and name[-7:] == ".weight" and n_dims == 2:
print(" Converting to float16")
data = data.astype(np.float16)
ftype_cur = 1
elif ftype == 1 or data.dtype != np.float32:
print(" Converting to float32")
data = data.astype(np.float32)
ftype_cur = 0
# map tensor names
new_name = tensor_map.get_name(name, try_suffixes=(".weight", ".bias"))
if new_name is None:
print("Can not map tensor '" + name + "'")
sys.exit()
gguf_writer.add_tensor(new_name, data)
print("gguf: write header")
gguf_writer.write_header_to_file()
print("gguf: write metadata")
gguf_writer.write_kv_data_to_file()
print("gguf: write tensors")
gguf_writer.write_tensors_to_file()
gguf_writer.close()
print(f"gguf: model successfully exported to '{fname_out}'")
print()