File size: 5,373 Bytes
198fb2a
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
import argparse
from pathlib import Path
from typing import Iterable, List, Tuple

import numpy as np

from export_weights import SCALE, load_state_dict, quantize_q12
from karpathy_exact_reference import (
    BLOCK_SIZE,
    N_LAYER,
    consume_training_rng_state,
    gpt,
    load_docs,
    sample_names,
    softmax,
)


def load_float_state(weights_path: Path) -> dict[str, np.ndarray]:
    state = load_state_dict(weights_path)
    return {key: np.asarray(value, dtype=np.float64) for key, value in state.items()}


def load_q12_dequant_state(weights_path: Path) -> dict[str, np.ndarray]:
    state = load_float_state(weights_path)
    return {
        key: quantize_q12(value).astype(np.float64) / float(SCALE)
        for key, value in state.items()
    }


def build_vocab(names_path: Path) -> tuple[dict[int, str], int, list[str]]:
    docs = load_docs(names_path)
    uchars = sorted(set("".join(docs)))
    bos_token = len(uchars)
    itos = {idx: ch for idx, ch in enumerate(uchars)}
    return itos, bos_token, docs


def count_params(state: dict[str, np.ndarray]) -> int:
    return sum(int(np.prod(value.shape)) for value in state.values())


def xorshift32(state: int) -> int:
    state &= 0xFFFFFFFF
    state ^= (state << 13) & 0xFFFFFFFF
    state ^= (state >> 17) & 0xFFFFFFFF
    state ^= (state << 5) & 0xFFFFFFFF
    return state & 0xFFFFFFFF


def sample_names_xorshift(
    state: dict[str, np.ndarray],
    itos: dict[int, str],
    bos_token: int,
    count: int,
    temperature: float,
    seed: int,
) -> Iterable[Tuple[int, str, List[int], int]]:
    rng_state = seed & 0xFFFFFFFF
    for sample_idx in range(count):
        keys = [[] for _ in range(N_LAYER)]
        values = [[] for _ in range(N_LAYER)]
        token_id = bos_token
        sample = []
        tokens = []
        for pos_id in range(BLOCK_SIZE):
            logits = gpt(state, token_id, pos_id, keys, values, bos_token)
            probs = softmax([logit / temperature for logit in logits])
            rng_state = xorshift32(rng_state)
            threshold = (rng_state & 0xFFFFFF) / float(1 << 24)
            cdf = 0.0
            token_id = len(probs) - 1
            for idx, prob in enumerate(probs):
                cdf += prob
                if threshold < cdf:
                    token_id = idx
                    break
            tokens.append(token_id)
            if token_id == bos_token:
                break
            sample.append(itos[token_id])
        yield sample_idx + 1, "".join(sample), tokens, rng_state


def collect_python_reference(
    state: dict[str, np.ndarray],
    names_path: Path,
    count: int,
    temperature: float,
) -> list[tuple[int, str, list[int]]]:
    itos, bos_token, docs = build_vocab(names_path)
    consume_training_rng_state(docs, bos_token + 1)
    return list(sample_names(state, itos, bos_token, count, temperature))


def collect_xorshift_reference(
    state: dict[str, np.ndarray],
    names_path: Path,
    count: int,
    temperature: float,
    seed: int,
) -> list[tuple[int, str, list[int], int]]:
    itos, bos_token, _ = build_vocab(names_path)
    return list(sample_names_xorshift(state, itos, bos_token, count, temperature, seed))


def main() -> None:
    parser = argparse.ArgumentParser(
        description="Compare exact Python microGPT outputs against the exported RTL Q4.12 weights."
    )
    parser.add_argument("--weights", default="rtl/microgpt/weights_only.npy")
    parser.add_argument("--names", default="rtl/microgpt/names.txt")
    parser.add_argument("--count", type=int, default=5)
    parser.add_argument("--temperature", type=float, default=0.5)
    parser.add_argument("--xorshift-seed", type=int, default=2)
    args = parser.parse_args()

    root = Path(__file__).resolve().parents[2]
    weights_path = Path(args.weights)
    names_path = Path(args.names)
    if not weights_path.is_absolute():
        weights_path = root / weights_path
    if not names_path.is_absolute():
        names_path = root / names_path

    float_state = load_float_state(weights_path)
    q12_state = load_q12_dequant_state(weights_path)

    print(f"param_count={count_params(float_state)}")

    float_python = collect_python_reference(float_state, names_path, args.count, args.temperature)
    q12_python = collect_python_reference(q12_state, names_path, args.count, args.temperature)
    print("python_rng_float:")
    for idx, text, tokens in float_python:
        print(f"  sample {idx:2d}: {text:<16s} tokens={tokens}")
    print("python_rng_q12_dequant:")
    for idx, text, tokens in q12_python:
        print(f"  sample {idx:2d}: {text:<16s} tokens={tokens}")

    float_xorshift = collect_xorshift_reference(
        float_state, names_path, args.count, args.temperature, args.xorshift_seed
    )
    q12_xorshift = collect_xorshift_reference(
        q12_state, names_path, args.count, args.temperature, args.xorshift_seed
    )
    print(f"xorshift_float_seed={args.xorshift_seed}:")
    for idx, text, tokens, seed_after in float_xorshift:
        print(f"  sample {idx:2d}: {text:<16s} tokens={tokens} rng=0x{seed_after:08X}")
    print(f"xorshift_q12_dequant_seed={args.xorshift_seed}:")
    for idx, text, tokens, seed_after in q12_xorshift:
        print(f"  sample {idx:2d}: {text:<16s} tokens={tokens} rng=0x{seed_after:08X}")


if __name__ == "__main__":
    main()