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+## This file is adapted from the original file from the Lightning-AI lit-gpt repository: https://github.com/Lightning-AI/lit-gpt
+
+import sys
+import time
+from pathlib import Path
+from typing import Any, Literal, Optional
+
+import lightning as L
+import torch
+import torch._dynamo.config
+import torch._inductor.config
+from lightning.fabric.plugins import BitsandbytesPrecision
+from lightning.fabric.strategies import FSDPStrategy
+
+# support running without installing as a package
+wd = Path(__file__).parent.parent.resolve()
+sys.path.append(str(wd))
+
+from lit_gpt import GPT, Config, Tokenizer
+from lit_gpt.model import Block
+from lit_gpt.utils import (
+    check_valid_checkpoint_dir,
+    get_default_supported_precision,
+    gptq_quantization,
+    load_checkpoint,
+)
+
+
+def multinomial_num_samples_1(probs: torch.Tensor) -> torch.Tensor:
+    if torch._dynamo.is_compiling():
+        # Faster alternative to `torch.multinomial(probs, num_samples=1)` that is also CUDAGraph friendly
+        distribution = torch.empty_like(probs).exponential_(1)
+        return torch.argmax(probs / distribution, dim=-1, keepdim=True)
+    return torch.multinomial(probs, num_samples=1)
+
+
+def sample(logits: torch.Tensor, temperature: float = 1.0, top_k: Optional[int] = None) -> torch.Tensor:
+    logits = logits[0, -1]
+    # optionally crop the logits to only the top k options
+    if top_k is not None:
+        v, i = torch.topk(logits, min(top_k, logits.size(-1)))
+        # do not use `torch.where` as in nanogpt because it will repeat top-k collisions
+        logits = torch.full_like(logits, float("-inf")).scatter_(-1, i, v)
+    # optionally scale the logits and sample from a probability distribution
+    if temperature > 0.0:
+        probs = torch.nn.functional.softmax(logits / temperature, dim=-1)
+        return multinomial_num_samples_1(probs)
+    return torch.argmax(logits, dim=-1, keepdim=True)
+
+
+def next_token(model: GPT, input_pos: torch.Tensor, x: torch.Tensor, **kwargs: Any) -> torch.Tensor:
+    logits = model(x, input_pos)
+    next = sample(logits, **kwargs)
+    return next.type_as(x)
+
+
+@torch.inference_mode()
+def generate(
+    model: GPT,
+    prompt: torch.Tensor,
+    max_returned_tokens: int,
+    *,
+    temperature: float = 1.0,
+    top_k: Optional[int] = None,
+    eos_id: Optional[int] = None,
+) -> torch.Tensor:
+    """Takes a conditioning sequence (prompt) as input and continues to generate as many tokens as requested.
+
+    The implementation of this function is modified from A. Karpathy's nanoGPT.
+
+    Args:
+        model: The model to use.
+        prompt: Tensor of shape (T) with indices of the prompt sequence.
+        max_returned_tokens: The maximum number of tokens to return (given plus generated).
+        temperature: Scales the predicted logits by 1 / temperature.
+        top_k: If specified, only sample among the tokens with the k highest probabilities.
+        eos_id: If specified, stop generating any more token once the <eos> token is triggered.
+    """
+    T = prompt.size(0)
+    assert max_returned_tokens > T
+    if model.max_seq_length < max_returned_tokens - 1:
+        # rolling the kv cache based on the `input_pos` value would be necessary. However, doing so would introduce a
+        # data dependency on the `input_pos` tensor and impact model compilation. Since this setting is uncommon, we do
+        # not support it to avoid negatively impacting the overall speed
+        raise NotImplementedError(f"max_seq_length {model.max_seq_length} needs to be >= {max_returned_tokens - 1}")
+
+    device = prompt.device
+    tokens = [prompt]
+    input_pos = torch.tensor([T], device=device)
+    token = next_token(
+        model, torch.arange(0, T, device=device), prompt.view(1, -1), temperature=temperature, top_k=top_k
+    ).clone()
+    tokens.append(token)
+    for _ in range(2, max_returned_tokens - T + 1):
+        token = next_token(model, input_pos, token.view(1, -1), temperature=temperature, top_k=top_k).clone()
+        tokens.append(token)
+        if token == eos_id:
+            break
+        input_pos = input_pos.add_(1)
+    return torch.cat(tokens)
+
+
+def main(
+    prompt: str = "What food do llamas eat?",
+    *,
+    num_samples: int = 1,
+    max_new_tokens: int = 50,
+    top_k: Optional[int] = 200,
+    temperature: float = 0.8,
+    checkpoint_dir: Path = Path("checkpoints/stabilityai/stablelm-base-alpha-3b"),
+    quantize: Optional[Literal["bnb.nf4", "bnb.nf4-dq", "bnb.fp4", "bnb.fp4-dq", "bnb.int8", "gptq.int4"]] = None,
+    strategy: str = "auto",
+    devices: int = 1,
+    precision: Optional[str] = None,
+    compile: bool = False,
+) -> None:
+    """Generates text samples based on a pre-trained model and tokenizer.
+
+    Args:
+        prompt: The prompt string to use for generating the samples.
+        num_samples: The number of text samples to generate.
+        max_new_tokens: The number of generation steps to take.
+        top_k: The number of top most probable tokens to consider in the sampling process.
+        temperature: A value controlling the randomness of the sampling process. Higher values result in more random
+            samples.
+        checkpoint_dir: The checkpoint directory to load.
+        quantize: Whether to quantize the model and using which method:
+            - bnb.nf4, bnb.nf4-dq, bnb.fp4, bnb.fp4-dq: 4-bit quantization from bitsandbytes
+            - bnb.int8: 8-bit quantization from bitsandbytes
+            - gptq.int4: 4-bit quantization from GPTQ
+            for more details, see https://github.com/Lightning-AI/lit-gpt/blob/main/tutorials/quantize.md
+        strategy: Indicates the Fabric strategy setting to use.
+        devices: How many devices to use.
+        precision: Indicates the Fabric precision setting to use.
+        compile: Whether to compile the model.
+    """
+    precision = precision or get_default_supported_precision(training=False)
+
+    plugins = None
+    if quantize is not None:
+        if devices > 1:
+            raise NotImplementedError(
+                "Quantization is currently not supported for multi-GPU training. Please set devices=1 when using the"
+                " --quantize flag."
+            )
+        if quantize.startswith("bnb."):
+            if "mixed" in precision:
+                raise ValueError("Quantization and mixed precision is not supported.")
+            dtype = {"16-true": torch.float16, "bf16-true": torch.bfloat16, "32-true": torch.float32}[precision]
+            plugins = BitsandbytesPrecision(quantize[4:], dtype)
+            precision = None
+
+    if strategy == "fsdp":
+        strategy = FSDPStrategy(auto_wrap_policy={Block}, cpu_offload=False)
+
+    fabric = L.Fabric(devices=devices, precision=precision, strategy=strategy, plugins=plugins)
+    fabric.launch()
+
+    check_valid_checkpoint_dir(checkpoint_dir)
+
+    config = Config.from_json(checkpoint_dir / "lit_config.json")
+
+    if quantize == "gptq.int4":
+        model_file = "lit_model_gptq.4bit.pth"
+        if not (checkpoint_dir / model_file).is_file():
+            raise ValueError("Please run `python quantize/gptq.py` first")
+    else:
+        model_file = "lit_model.pth"
+    checkpoint_path = checkpoint_dir / model_file
+
+    tokenizer = Tokenizer(checkpoint_dir)
+    encoded = tokenizer.encode(prompt, device=fabric.device)
+    prompt_length = encoded.size(0)
+    max_returned_tokens = prompt_length + max_new_tokens
+
+    fabric.print(f"Loading model {str(checkpoint_path)!r} with {config.__dict__}", file=sys.stderr)
+    t0 = time.perf_counter()
+    with fabric.init_module(empty_init=True), gptq_quantization(quantize == "gptq.int4"):
+        model = GPT(config)
+    fabric.print(f"Time to instantiate model: {time.perf_counter() - t0:.02f} seconds.", file=sys.stderr)
+    with fabric.init_tensor():
+        # set the max_seq_length to limit the memory usage to what we need
+        model.max_seq_length = max_returned_tokens
+        # enable the kv cache
+        model.set_kv_cache(batch_size=1)
+    model.eval()
+
+    if compile:
+        torch._dynamo.config.automatic_dynamic_shapes = True
+        torch._inductor.config.triton.unique_kernel_names = True
+        torch._inductor.config.coordinate_descent_tuning = True
+        global next_token
+        next_token = torch.compile(next_token, mode="reduce-overhead")
+
+    model = fabric.setup_module(model)
+
+    t0 = time.perf_counter()
+    load_checkpoint(fabric, model, checkpoint_path)
+    fabric.print(f"Time to load the model weights: {time.perf_counter() - t0:.02f} seconds.", file=sys.stderr)
+
+    L.seed_everything(1234)
+    for i in range(num_samples):
+        t0 = time.perf_counter()
+        y = generate(model, encoded, max_returned_tokens, temperature=temperature, top_k=top_k)
+        t = time.perf_counter() - t0
+        for block in model.transformer.h:
+            block.attn.kv_cache.reset_parameters()
+        fabric.print(tokenizer.decode(y))
+        tokens_generated = y.size(0) - prompt_length
+        fabric.print(
+            f"Time for inference {i + 1}: {t:.02f} sec total, {tokens_generated / t:.02f} tokens/sec", file=sys.stderr
+        )
+    if fabric.device.type == "cuda":
+        fabric.print(f"Memory used: {torch.cuda.max_memory_allocated() / 1e9:.02f} GB", file=sys.stderr)
+
+
+if __name__ == "__main__":
+    from jsonargparse import CLI
+
+    torch.set_float32_matmul_precision("high")
+    CLI(main)