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| import torch
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| import torch.nn as nn
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| import torch.nn.functional as F
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| import math
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| VOCAB_SIZE = 50257
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| MODEL_DIM = 14336
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| NUM_HEADS = 112
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| NUM_KV_HEADS = 8
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| NUM_LAYERS = 108
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| MAX_SEQ_LEN = 4096
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| FFN_HIDDEN_DIM = 40960
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| HEAD_DIM = MODEL_DIM // NUM_HEADS
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| EPSILON = 1e-5
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| class RMSNorm(nn.Module):
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| def __init__(self, dim, eps=EPSILON):
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| super().__init__()
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| self.eps = eps
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| self.weight = nn.Parameter(torch.ones(dim))
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| def forward(self, x):
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| return (x * torch.rsqrt(x.pow(2).mean(-1, keepdim=True) + self.eps)) * self.weight
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| def precompute_freqs_cis(dim, seq_len, theta=100000.0):
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| freqs = 1.0 / (theta ** (torch.arange(0, dim, 2)[: (dim // 2)].float() / dim))
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| t = torch.arange(seq_len)
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| freqs = torch.outer(t, freqs).float()
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| return torch.polar(torch.ones_like(freqs), freqs)
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| def apply_rotary_emb(xq, xk, freqs_cis):
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| xq_ = torch.view_as_complex(xq.float().reshape(*xq.shape[:-1], -1, 2))
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| xk_ = torch.view_as_complex(xk.float().reshape(*xk.shape[:-1], -1, 2))
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| freqs_cis = freqs_cis.view(1, xq_.size(1), 1, xq_.size(3))
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| xq_out = torch.view_as_real(xq_ * freqs_cis).flatten(3)
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| xk_out = torch.view_as_real(xk_ * freqs_cis).flatten(3)
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| return xq_out.type_as(xq), xk_out.type_as(xk)
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| def repeat_kv(x: torch.Tensor, n_rep: int) -> torch.Tensor:
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| if n_rep == 1: return x
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| bs, slen, n_kv_heads, head_dim = x.shape
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| return x[:, :, :, None, :].expand(bs, slen, n_kv_heads, n_rep, head_dim).reshape(bs, slen, n_kv_heads * n_rep, head_dim)
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| class MultiHeadAttention(nn.Module):
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| def __init__(self):
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| super().__init__()
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| self.n_kv_heads = NUM_KV_HEADS
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| self.n_rep = NUM_HEADS // NUM_KV_HEADS
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| self.wq = nn.Linear(MODEL_DIM, NUM_HEADS * HEAD_DIM, bias=False)
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| self.wk = nn.Linear(MODEL_DIM, NUM_KV_HEADS * HEAD_DIM, bias=False)
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| self.wv = nn.Linear(MODEL_DIM, NUM_KV_HEADS * HEAD_DIM, bias=False)
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| self.wo = nn.Linear(NUM_HEADS * HEAD_DIM, MODEL_DIM, bias=False)
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| def forward(self, x, freqs_cis, past_kv=None):
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| b, t, _ = x.shape
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| q, k, v = self.wq(x), self.wk(x), self.wv(x)
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| q, k = apply_rotary_emb(q.view(b, t, NUM_HEADS, HEAD_DIM), k.view(b, t, self.n_kv_heads, HEAD_DIM), freqs_cis[:t])
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| if past_kv is not None:
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| k = torch.cat([past_kv[0], k], dim=1)
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| v = torch.cat([past_kv[1], v], dim=1)
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| current_kv = (k.detach(), v.detach())
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| k, v = repeat_kv(k, self.n_rep), repeat_kv(v, self.n_rep)
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| out = F.scaled_dot_product_attention(q.transpose(1, 2), k.transpose(1, 2), v.transpose(1, 2), is_causal=True)
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| return self.wo(out.transpose(1, 2).contiguous().view(b, t, MODEL_DIM)), current_kv
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| class JiRackPyTorch(nn.Module):
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| def __init__(self):
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| super().__init__()
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| self.token_emb = nn.Embedding(VOCAB_SIZE, MODEL_DIM)
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| self.blocks = nn.ModuleList([nn.ModuleDict({
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| 'norm1': RMSNorm(MODEL_DIM),
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| 'attn': MultiHeadAttention(),
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| 'norm2': RMSNorm(MODEL_DIM),
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| 'ffn': nn.Sequential(
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| nn.Linear(MODEL_DIM, FFN_HIDDEN_DIM, bias=False),
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| nn.SiLU(),
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| nn.Linear(FFN_HIDDEN_DIM, MODEL_DIM, bias=False)
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| )
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| }) for _ in range(NUM_LAYERS)])
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| self.norm_f = RMSNorm(MODEL_DIM)
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| self.head = nn.Linear(MODEL_DIM, VOCAB_SIZE, bias=False)
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| self.head.weight = self.token_emb.weight
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| self.register_buffer("freqs_cis", precompute_freqs_cis(HEAD_DIM, MAX_SEQ_LEN))
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| def forward(self, idx, targets=None):
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| x = self.token_emb(idx)
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| for block in self.blocks:
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| h, _ = block['attn'](block['norm1'](x), self.freqs_cis)
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| x = x + h
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| x = x + block['ffn'](block['norm2'](x))
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| logits = self.head(self.norm_f(x))
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| if targets is not None:
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| return None, F.cross_entropy(logits.view(-1, VOCAB_SIZE), targets.view(-1)), None
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| return logits, None
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|
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| def get_author_info(self):
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| return "Author: Konstantin Vladimirovich Grabko (CMS Manhattan) 2025 | JiRack 236B Dense" |