1 files changed, 134 insertions, 0 deletions
diff --git a/gguf-py/scripts/gguf_convert_endian.py b/gguf-py/scripts/gguf_convert_endian.py
new file mode 100755
index 00000000..b698af0f
--- /dev/null
+++ b/gguf-py/scripts/gguf_convert_endian.py
@@ -0,0 +1,134 @@
+#!/usr/bin/env python3
+from __future__ import annotations
+
+import logging
+import argparse
+import os
+import sys
+from tqdm import tqdm
+from pathlib import Path
+
+import numpy as np
+
+# Necessary to load the local gguf package
+if "NO_LOCAL_GGUF" not in os.environ and (Path(__file__).parent.parent.parent / 'gguf-py').exists():
+    sys.path.insert(0, str(Path(__file__).parent.parent))
+
+import gguf
+
+logger = logging.getLogger("gguf-convert-endian")
+
+
+def convert_byteorder(reader: gguf.GGUFReader, args: argparse.Namespace) -> None:
+    if np.uint32(1) == np.uint32(1).newbyteorder("<"):
+        # Host is little endian
+        host_endian = "little"
+        swapped_endian = "big"
+    else:
+        # Sorry PDP or other weird systems that don't use BE or LE.
+        host_endian = "big"
+        swapped_endian = "little"
+    if reader.byte_order == "S":
+        file_endian = swapped_endian
+    else:
+        file_endian = host_endian
+    order = host_endian if args.order == "native" else args.order
+    logger.info(f"* Host is {host_endian.upper()} endian, GGUF file seems to be {file_endian.upper()} endian")
+    if file_endian == order:
+        logger.info(f"* File is already {order.upper()} endian. Nothing to do.")
+        sys.exit(0)
+    logger.info("* Checking tensors for conversion compatibility")
+    for tensor in reader.tensors:
+        if tensor.tensor_type not in (
+            gguf.GGMLQuantizationType.F32,
+            gguf.GGMLQuantizationType.F16,
+            gguf.GGMLQuantizationType.Q8_0,
+        ):
+            raise ValueError(f"Cannot handle type {tensor.tensor_type.name} for tensor {repr(tensor.name)}")
+    logger.info(f"* Preparing to convert from {file_endian.upper()} to {order.upper()}")
+    if args.dry_run:
+        return
+    logger.warning("*** Warning *** Warning *** Warning **")
+    logger.warning("* This conversion process may damage the file. Ensure you have a backup.")
+    if order != host_endian:
+        logger.warning("* Requested endian differs from host, you will not be able to load the model on this machine.")
+    logger.warning("* The file will be modified immediately, so if conversion fails or is interrupted")
+    logger.warning("* the file will be corrupted. Enter exactly YES if you are positive you want to proceed:")
+    response = input("YES, I am sure> ")
+    if response != "YES":
+        logger.warning("You didn't enter YES. Okay then, see ya!")
+        sys.exit(0)
+    logger.info(f"* Converting fields ({len(reader.fields)})")
+    for idx, field in enumerate(reader.fields.values()):
+        logger.info(f"- {idx:4}: Converting field {repr(field.name)}, part count: {len(field.parts)}")
+        for part in field.parts:
+            part.byteswap(inplace=True)
+    logger.info(f"* Converting tensors ({len(reader.tensors)})")
+
+    for idx, tensor in enumerate(pbar := tqdm(reader.tensors, desc="Converting tensor")):
+        log_message = (
+            f"Converting tensor {repr(tensor.name)}, "
+            f"type={tensor.tensor_type.name}, "
+            f"elements={tensor.n_elements} "
+        )
+
+        # Byte-swap each part of the tensor's field
+        for part in tensor.field.parts:
+            part.byteswap(inplace=True)
+
+        # Byte-swap tensor data if necessary
+        if tensor.tensor_type == gguf.GGMLQuantizationType.Q8_0:
+            # Handle Q8_0 tensor blocks (block_q8_0)
+            # Specific handling of block_q8_0 is required.
+            # Each block_q8_0 consists of an f16 delta (scaling factor) followed by 32 int8 quantizations.
+
+            block_size = 34 # 34 bytes = <f16 delta scaling factor> + 32 * <int8 quant>
+
+            n_blocks = len(tensor.data) // block_size
+            for block_num in (inner_pbar := tqdm(range(n_blocks), desc="Byte-swapping Blocks", leave=False)):
+                block_offs = block_num * block_size
+
+                # Byte-Swap f16 sized delta field
+                delta = tensor.data[block_offs:block_offs + 2].view(dtype=np.uint16)
+                delta.byteswap(inplace=True)
+
+                # Byte-Swap Q8 weights
+                if block_num % 100000 == 0:
+                    inner_pbar.set_description(f"Byte-swapping Blocks [{(n_blocks - block_num) // n_blocks}]")
+
+        else:
+            # Handle other tensor types
+            tensor.data.byteswap(inplace=True)
+
+        pbar.set_description(log_message)
+
+    logger.info("* Completion")
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description="Convert GGUF file byte order")
+    parser.add_argument(
+        "model", type=str,
+        help="GGUF format model filename",
+    )
+    parser.add_argument(
+        "order", type=str, choices=['big', 'little', 'native'],
+        help="Requested byte order",
+    )
+    parser.add_argument(
+        "--dry-run", action="store_true",
+        help="Don't actually change anything",
+    )
+    parser.add_argument("--verbose", action="store_true", help="increase output verbosity")
+
+    args = parser.parse_args(None if len(sys.argv) > 1 else ["--help"])
+
+    logging.basicConfig(level=logging.DEBUG if args.verbose else logging.INFO)
+
+    logger.info(f'* Loading: {args.model}')
+    reader = gguf.GGUFReader(args.model, 'r' if args.dry_run else 'r+')
+    convert_byteorder(reader, args)
+
+
+if __name__ == "__main__":
+    main()