initial release

ggml/examples/gpt-2/convert-ckpt-to-ggml.py

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+# Convert a model checkpoint to a ggml compatible file
+#
+# Load the model using TensorFlow.
+# 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 "use-f32" CLI argument.
+#
+# At the start of the ggml file we write the model parameters
+# and vocabulary.
+#
+
+import sys
+import json
+import struct
+import numpy as np
+import tensorflow as tf
+
+# ref: https://github.com/openai/gpt-2/blob/master/src/encoder.py
+def bytes_to_unicode():
+    """
+    Returns list of utf-8 byte and a corresponding list of unicode strings.
+    The reversible bpe codes work on unicode strings.
+    This means you need a large # of unicode characters in your vocab if you want to avoid UNKs.
+    When you're at something like a 10B token dataset you end up needing around 5K for decent coverage.
+    This is a signficant percentage of your normal, say, 32K bpe vocab.
+    To avoid that, we want lookup tables between utf-8 bytes and unicode strings.
+    And avoids mapping to whitespace/control characters the bpe code barfs on.
+    """
+    bs = list(range(ord("!"), ord("~")+1))+list(range(ord("¡"), ord("¬")+1))+list(range(ord("®"), ord("ÿ")+1))
+    cs = bs[:]
+    n = 0
+    for b in range(2**8):
+        if b not in bs:
+            bs.append(b)
+            cs.append(2**8+n)
+            n += 1
+    cs = [chr(n) for n in cs]
+    return dict(zip(bs, cs))
+
+# helper method to convert a numpy array to different float types
+def convert_to_ftype(data, ftype):
+    # fp16
+    if ftype == 1:
+        return data.astype(np.float16)
+
+    assert False, "Invalid ftype: " + str(ftype)
+
+if len(sys.argv) < 3:
+    print("Usage: convert-ckpt-to-ggml.py dir-model ftype\n")
+    print("  ftype == 0 -> float32")
+    print("  ftype == 1 -> float16")
+    sys.exit(1)
+
+# output in the same directory as the model
+dir_model = sys.argv[1]
+fname_out = sys.argv[1] + "/ggml-model.bin"
+
+with open(dir_model + "/encoder.json", "r", encoding="utf-8") as f:
+    encoder = json.load(f)
+
+with open(dir_model + "/hparams.json", "r", encoding="utf-8") as f:
+    hparams = json.load(f)
+
+# 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 = sys.argv[1] + "/ggml-model-" + ftype_str[ftype] + ".bin"
+
+list_vars = tf.train.list_variables(dir_model)
+
+fout = open(fname_out, "wb")
+
+fout.write(struct.pack("i", 0x67676d6c)) # magic: ggml in hex
+fout.write(struct.pack("i", hparams["n_vocab"]))
+fout.write(struct.pack("i", hparams["n_ctx"]))
+fout.write(struct.pack("i", hparams["n_embd"]))
+fout.write(struct.pack("i", hparams["n_head"]))
+fout.write(struct.pack("i", hparams["n_layer"]))
+fout.write(struct.pack("i", ftype))
+
+byte_encoder = bytes_to_unicode()
+byte_decoder = {v:k for k, v in byte_encoder.items()}
+
+fout.write(struct.pack("i", len(encoder)))
+
+for key in encoder:
+    text = bytearray([byte_decoder[c] for c in key])
+    fout.write(struct.pack("i", len(text)))
+    fout.write(text)
+
+for name, shape in list_vars:
+    print("Processing variable: " + name + " with shape: ", shape)
+
+    data = tf.train.load_variable(dir_model, name).squeeze()
+    n_dims = len(data.shape);
+
+    # for efficiency - transpose the projection matrices
+    # "model/h.*/attn/c_attn/w"
+    # "model/h.*/attn/c_proj/w"
+    # "model/h.*/mlp/c_fc/w"
+    # "model/h.*/mlp/c_proj/w"
+    if name[-14:] == "/attn/c_attn/w" or \
+       name[-14:] == "/attn/c_proj/w" or \
+       name[-11:] == "/mlp/c_fc/w" or \
+       name[-13:] == "/mlp/c_proj/w":
+        print("  Transposing")
+        data = data.transpose()
+
+    dshape = data.shape
+
+    ftype_cur = 0
+    if ftype != 0:
+        # match name:
+        #  "model/wte"
+        #  "model/h.*/attn/c_attn/w"
+        #  "model/h.*/attn/c_proj/w"
+        #  "model/h.*/mlp/c_fc/w"
+        #  "model/h.*/mlp/c_proj/w"
+        if name == "model/wte" or name[-2:] == "/w":
+            print("  Converting to " + ftype_str[ftype])
+            data = convert_to_ftype(data, ftype)
+            ftype_cur = ftype
+        else:
+            print("  Converting to float32")
+            data = data.astype(np.float32)
+            ftype_cur = 0
+
+    # header
+    str = name.encode('utf-8')
+    fout.write(struct.pack("iii", n_dims, len(str), ftype_cur))
+    for i in range(n_dims):
+        fout.write(struct.pack("i", dshape[n_dims - 1 - i]))
+    fout.write(str);
+
+    # data
+    data.tofile(fout)
+
+fout.close()
+
+print("Done. Output file: " + fname_out)
+print("")