|
@@ -1,324 +0,0 @@
|
|
|
-from dataclasses import dataclass, field
|
|
|
-from typing import Dict, Optional, Union
|
|
|
-
|
|
|
-import mlx.core as mx
|
|
|
-import mlx.nn as nn
|
|
|
-
|
|
|
-from exo.inference.shard import Shard
|
|
|
-from mlx_lm.models.base import BaseModelArgs, KVCache, create_additive_causal_mask
|
|
|
-
|
|
|
-
|
|
|
-@dataclass
|
|
|
-class NormalModelArgs(BaseModelArgs):
|
|
|
- model_type: str
|
|
|
- hidden_size: int
|
|
|
- num_hidden_layers: int
|
|
|
- intermediate_size: int
|
|
|
- num_attention_heads: int
|
|
|
- rms_norm_eps: float
|
|
|
- vocab_size: int
|
|
|
- head_dim: Optional[int] = None
|
|
|
- max_position_embeddings: Optional[int] = None
|
|
|
- num_key_value_heads: Optional[int] = None
|
|
|
- attention_bias: bool = False
|
|
|
- mlp_bias: bool = False
|
|
|
- rope_theta: float = 10000
|
|
|
- rope_traditional: bool = False
|
|
|
- rope_scaling: Optional[Dict[str, Union[float, str]]] = None
|
|
|
- tie_word_embeddings: bool = True
|
|
|
-
|
|
|
- def __post_init__(self):
|
|
|
- if self.num_key_value_heads is None:
|
|
|
- self.num_key_value_heads = self.num_attention_heads
|
|
|
-
|
|
|
- if self.rope_scaling:
|
|
|
- if "factor" not in self.rope_scaling:
|
|
|
- raise ValueError("rope_scaling must contain 'factor'")
|
|
|
- rope_type = self.rope_scaling.get("type") or self.rope_scaling.get("rope_type")
|
|
|
- if rope_type is None:
|
|
|
- raise ValueError("rope_scaling must contain either 'type' or 'rope_type'")
|
|
|
- if rope_type not in ["linear", "dynamic", "llama3"]:
|
|
|
- raise ValueError("rope_scaling 'type' currently only supports 'linear', 'dynamic' or 'llama3'")
|
|
|
-
|
|
|
-
|
|
|
-@dataclass
|
|
|
-class ModelArgs(NormalModelArgs):
|
|
|
- shard: Shard = field(default_factory=lambda: Shard("", 0, 0, 0))
|
|
|
-
|
|
|
- def __post_init__(self):
|
|
|
- super().__post_init__() # Ensure parent initializations are respected
|
|
|
-
|
|
|
- if isinstance(self.shard, Shard):
|
|
|
- return
|
|
|
- if not isinstance(self.shard, dict):
|
|
|
- raise TypeError(f"Expected shard to be a Shard instance or a dict, got {type(self.shard)} instead")
|
|
|
-
|
|
|
- self.shard = Shard(**self.shard)
|
|
|
-
|
|
|
-
|
|
|
-class DynamicNTKScalingRoPE(nn.Module):
|
|
|
- """Implements the rotary positional encoding with Dynamic NTK scaling and Llama 3 RoPE."""
|
|
|
-
|
|
|
- def __init__(
|
|
|
- self,
|
|
|
- dims: int,
|
|
|
- max_position_embeddings: int = 2048,
|
|
|
- traditional: bool = False,
|
|
|
- base: float = 10000,
|
|
|
- scale: float = 1.0,
|
|
|
- rope_type: str = "default",
|
|
|
- rope_scaling: dict = None,
|
|
|
- ):
|
|
|
- super().__init__()
|
|
|
- self.dims = dims
|
|
|
- self.max_position_embeddings = max_position_embeddings
|
|
|
- self.traditional = traditional
|
|
|
- self.original_base = base
|
|
|
- self.scale = scale
|
|
|
- self.rope_type = rope_type
|
|
|
- self.rope_scaling = rope_scaling
|
|
|
- self.base = self.compute_base_freq()
|
|
|
-
|
|
|
- def compute_base_freq(self):
|
|
|
- if self.rope_type == "llama3":
|
|
|
- return self.compute_llama3_base_freq()
|
|
|
- return self.original_base
|
|
|
-
|
|
|
- # source: https://github.com/huggingface/transformers/blob/d5a99dfcee6e94065cb7c83cc8ab6fc5daa0cc4e/src/transformers/modeling_rope_utils.py#L318
|
|
|
- def compute_llama3_base_freq(self):
|
|
|
- factor = self.rope_scaling["factor"]
|
|
|
- low_freq_factor = self.rope_scaling.get("low_freq_factor", 1.0)
|
|
|
- high_freq_factor = self.rope_scaling.get("high_freq_factor", 4.0)
|
|
|
- old_context_len = self.rope_scaling.get(
|
|
|
- "original_max_position_embeddings",
|
|
|
- 8192,
|
|
|
- )
|
|
|
-
|
|
|
- low_freq_wavelen = old_context_len / low_freq_factor
|
|
|
- high_freq_wavelen = old_context_len / high_freq_factor
|
|
|
-
|
|
|
- freqs = self.original_base ** (mx.arange(0, self.dims, 2) / self.dims)
|
|
|
- wavelens = 2 * mx.pi * freqs
|
|
|
- new_base_freqs = []
|
|
|
-
|
|
|
- smooths = (wavelens - high_freq_wavelen) / (low_freq_wavelen - high_freq_wavelen)
|
|
|
- new_base_freqs = freqs * (1 - smooths) * factor + smooths
|
|
|
- new_base_freqs = mx.where(wavelens < high_freq_wavelen, freqs, new_base_freqs)
|
|
|
- new_base_freqs = mx.where(wavelens > low_freq_wavelen, freqs * factor, new_base_freqs)
|
|
|
- return new_base_freqs.mean().item()
|
|
|
-
|
|
|
- def extra_repr(self):
|
|
|
- return f"{self.dims}, traditional={self.traditional}, " f"max_position_embeddings={self.max_position_embeddings}, " f"scaling_factor={self.scale}, rope_type={self.rope_type}"
|
|
|
-
|
|
|
- def __call__(self, x, offset: int = 0):
|
|
|
- seq_len = x.shape[1] + offset
|
|
|
- base = self.base
|
|
|
- if self.max_position_embeddings and seq_len > self.max_position_embeddings:
|
|
|
- base *= ((self.scale * seq_len / self.max_position_embeddings) - (self.scale - 1)) ** (self.dims / (self.dims - 2))
|
|
|
-
|
|
|
- return mx.fast.rope(
|
|
|
- x,
|
|
|
- self.dims,
|
|
|
- traditional=self.traditional,
|
|
|
- base=base,
|
|
|
- scale=self.scale,
|
|
|
- offset=offset,
|
|
|
- )
|
|
|
-
|
|
|
-
|
|
|
-def initialize_rope(args: ModelArgs):
|
|
|
- head_dim = args.head_dim or args.hidden_size // args.num_attention_heads
|
|
|
-
|
|
|
- rope_scaling = args.rope_scaling
|
|
|
- rope_type = "default"
|
|
|
- rope_scale = 1.0
|
|
|
-
|
|
|
- if rope_scaling is not None:
|
|
|
- rope_type = rope_scaling.get("type") or rope_scaling.get("rope_type") or "default"
|
|
|
- if rope_type == "linear":
|
|
|
- rope_scale = 1 / rope_scaling["factor"]
|
|
|
- elif rope_type == "llama3":
|
|
|
- rope_scale = 1.0 # The scaling is handled internally for llama3
|
|
|
-
|
|
|
- return DynamicNTKScalingRoPE(
|
|
|
- dims=head_dim,
|
|
|
- max_position_embeddings=args.max_position_embeddings,
|
|
|
- traditional=args.rope_traditional,
|
|
|
- base=args.rope_theta,
|
|
|
- scale=rope_scale,
|
|
|
- rope_type=rope_type,
|
|
|
- rope_scaling=rope_scaling,
|
|
|
- )
|
|
|
-
|
|
|
-
|
|
|
-class Attention(nn.Module):
|
|
|
- def __init__(self, args: ModelArgs):
|
|
|
- super().__init__()
|
|
|
-
|
|
|
- dim = args.hidden_size
|
|
|
- self.n_heads = n_heads = args.num_attention_heads
|
|
|
- self.n_kv_heads = n_kv_heads = args.num_key_value_heads
|
|
|
-
|
|
|
- self.head_dim = head_dim = args.head_dim or args.hidden_size // n_heads
|
|
|
-
|
|
|
- self.scale = head_dim**-0.5
|
|
|
- if hasattr(args, "attention_bias"):
|
|
|
- attention_bias = args.attention_bias
|
|
|
- else:
|
|
|
- attention_bias = False
|
|
|
-
|
|
|
- self.q_proj = nn.Linear(dim, n_heads * head_dim, bias=attention_bias)
|
|
|
- self.k_proj = nn.Linear(dim, n_kv_heads * head_dim, bias=attention_bias)
|
|
|
- self.v_proj = nn.Linear(dim, n_kv_heads * head_dim, bias=attention_bias)
|
|
|
- self.o_proj = nn.Linear(n_heads * head_dim, dim, bias=attention_bias)
|
|
|
-
|
|
|
- self.rope = initialize_rope(args)
|
|
|
-
|
|
|
- def __call__(
|
|
|
- self,
|
|
|
- x: mx.array,
|
|
|
- mask: Optional[mx.array] = None,
|
|
|
- cache: Optional[KVCache] = None,
|
|
|
- ) -> mx.array:
|
|
|
- B, L, _D = x.shape
|
|
|
-
|
|
|
- queries, keys, values = self.q_proj(x), self.k_proj(x), self.v_proj(x)
|
|
|
-
|
|
|
- # Prepare the queries, keys and values for the attention computation
|
|
|
- queries = queries.reshape(B, L, self.n_heads, -1).transpose(0, 2, 1, 3)
|
|
|
- keys = keys.reshape(B, L, self.n_kv_heads, -1).transpose(0, 2, 1, 3)
|
|
|
- values = values.reshape(B, L, self.n_kv_heads, -1).transpose(0, 2, 1, 3)
|
|
|
-
|
|
|
- if cache is not None:
|
|
|
- queries = self.rope(queries, offset=cache.offset)
|
|
|
- keys = self.rope(keys, offset=cache.offset)
|
|
|
- keys, values = cache.update_and_fetch(keys, values)
|
|
|
- else:
|
|
|
- queries = self.rope(queries)
|
|
|
- keys = self.rope(keys)
|
|
|
-
|
|
|
- output = mx.fast.scaled_dot_product_attention(queries, keys, values, scale=self.scale, mask=mask)
|
|
|
- output = output.transpose(0, 2, 1, 3).reshape(B, L, -1)
|
|
|
- return self.o_proj(output)
|
|
|
-
|
|
|
-
|
|
|
-class MLP(nn.Module):
|
|
|
- def __init__(self, args: ModelArgs):
|
|
|
- super().__init__()
|
|
|
-
|
|
|
- dim = args.hidden_size
|
|
|
- hidden_dim = args.intermediate_size
|
|
|
- if hasattr(args, "mlp_bias"):
|
|
|
- mlp_bias = args.mlp_bias
|
|
|
- else:
|
|
|
- mlp_bias = False
|
|
|
-
|
|
|
- self.gate_proj = nn.Linear(dim, hidden_dim, bias=mlp_bias)
|
|
|
- self.down_proj = nn.Linear(hidden_dim, dim, bias=mlp_bias)
|
|
|
- self.up_proj = nn.Linear(dim, hidden_dim, bias=mlp_bias)
|
|
|
-
|
|
|
- def __call__(self, x) -> mx.array:
|
|
|
- return self.down_proj(nn.silu(self.gate_proj(x)) * self.up_proj(x))
|
|
|
-
|
|
|
-
|
|
|
-class TransformerBlock(nn.Module):
|
|
|
- def __init__(self, args: ModelArgs):
|
|
|
- super().__init__()
|
|
|
- self.num_attention_heads = args.num_attention_heads
|
|
|
- self.hidden_size = args.hidden_size
|
|
|
- self.self_attn = Attention(args)
|
|
|
- self.mlp = MLP(args)
|
|
|
- self.input_layernorm = nn.RMSNorm(args.hidden_size, eps=args.rms_norm_eps)
|
|
|
- self.post_attention_layernorm = nn.RMSNorm(args.hidden_size, eps=args.rms_norm_eps)
|
|
|
- self.args = args
|
|
|
-
|
|
|
- def __call__(
|
|
|
- self,
|
|
|
- x: mx.array,
|
|
|
- mask: Optional[mx.array] = None,
|
|
|
- cache: Optional[KVCache] = None,
|
|
|
- ) -> mx.array:
|
|
|
- r = self.self_attn(self.input_layernorm(x), mask, cache)
|
|
|
- h = x + r
|
|
|
- r = self.mlp(self.post_attention_layernorm(h))
|
|
|
- out = h + r
|
|
|
- return out
|
|
|
-
|
|
|
-
|
|
|
-class LlamaModel(nn.Module):
|
|
|
- def __init__(self, args: ModelArgs):
|
|
|
- super().__init__()
|
|
|
- self.args = args
|
|
|
- self.vocab_size = args.vocab_size
|
|
|
- self.num_hidden_layers = args.num_hidden_layers
|
|
|
- assert self.vocab_size > 0
|
|
|
- self.embed_tokens = nn.Embedding(args.vocab_size, args.hidden_size)
|
|
|
- self.layers = [TransformerBlock(args=args) for _ in range(args.shard.end_layer - args.shard.start_layer + 1)]
|
|
|
- self.norm = nn.RMSNorm(args.hidden_size, eps=args.rms_norm_eps)
|
|
|
-
|
|
|
- def __call__(
|
|
|
- self,
|
|
|
- inputs: mx.array,
|
|
|
- cache=None,
|
|
|
- ):
|
|
|
- if self.args.shard.is_first_layer():
|
|
|
- h = self.embed_tokens(inputs)
|
|
|
- else:
|
|
|
- h = inputs
|
|
|
-
|
|
|
- mask = None
|
|
|
- if h.shape[1] > 1:
|
|
|
- mask = create_additive_causal_mask(h.shape[1], cache[0].offset if cache is not None else 0)
|
|
|
- mask = mask.astype(h.dtype)
|
|
|
-
|
|
|
- if cache is None:
|
|
|
- cache = [None] * len(self.layers)
|
|
|
-
|
|
|
- for layer, c in zip(self.layers, cache):
|
|
|
- h = layer(h, mask, cache=c)
|
|
|
-
|
|
|
- if self.args.shard.is_last_layer():
|
|
|
- return self.norm(h)
|
|
|
- else:
|
|
|
- return h
|
|
|
-
|
|
|
-
|
|
|
-class Model(nn.Module):
|
|
|
- def __init__(self, args: ModelArgs):
|
|
|
- super().__init__()
|
|
|
- self.args = args
|
|
|
- self.model_type = args.model_type
|
|
|
- self.model = LlamaModel(args)
|
|
|
- if not args.tie_word_embeddings:
|
|
|
- self.lm_head = nn.Linear(args.hidden_size, args.vocab_size, bias=False)
|
|
|
-
|
|
|
- def __call__(
|
|
|
- self,
|
|
|
- inputs: mx.array,
|
|
|
- cache=None,
|
|
|
- ):
|
|
|
- out = self.model(inputs, cache)
|
|
|
-
|
|
|
- if self.args.shard.is_last_layer():
|
|
|
- if self.args.tie_word_embeddings:
|
|
|
- out = self.model.embed_tokens.as_linear(out)
|
|
|
- else:
|
|
|
- out = self.lm_head(out)
|
|
|
-
|
|
|
- return out
|
|
|
-
|
|
|
- def sanitize(self, weights):
|
|
|
- # Remove unused precomputed rotary freqs
|
|
|
- return {k: v for k, v in weights.items() if "self_attn.rotary_emb.inv_freq" not in k}
|
|
|
-
|
|
|
- @property
|
|
|
- def layers(self):
|
|
|
- return self.model.layers
|
|
|
-
|
|
|
- @property
|
|
|
- def head_dim(self):
|
|
|
- return self.args.head_dim or self.args.hidden_size // self.args.num_attention_heads
|
|
|
-
|
|
|
- @property
|
|
|
- def n_kv_heads(self):
|
|
|
- return self.args.num_key_value_heads
|