diff --git a/llms/mlx_lm/models/phimoe.py b/llms/mlx_lm/models/phimoe.py new file mode 100644 index 000000000..db6bd4b55 --- /dev/null +++ b/llms/mlx_lm/models/phimoe.py @@ -0,0 +1,218 @@ +# Copyright © 2024 Apple Inc. +import math +from dataclasses import dataclass +from typing import Dict, List, Optional, Union + +import mlx.core as mx +import mlx.nn as nn + +from .base import BaseModelArgs, create_attention_mask +from .su_rope import SuScaledRotaryEmbedding +from .switch_layers import SwitchGLU + + +@dataclass +class ModelArgs(BaseModelArgs): + model_type: str = "phimoe" + vocab_size: int = 32064 + hidden_size: int = 4096 + intermediate_size: int = 6400 + num_hidden_layers: int = 32 + num_attention_heads: int = 32 + num_key_value_heads: int = 8 + max_position_embeddings: int = 131072 + original_max_position_embeddings: int = 4096 + rms_norm_eps: float = 1e-6 + rope_scaling: Dict[str, Union[float, List[float]]] = None + num_local_experts: int = 16 + num_experts_per_tok: int = 2 + rope_theta: float = 10000.0 + + +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 + + head_dim = args.hidden_size // n_heads + self.scale = head_dim**-0.5 + + self.q_proj = nn.Linear(dim, n_heads * head_dim, bias=True) + self.k_proj = nn.Linear(dim, n_kv_heads * head_dim, bias=True) + self.v_proj = nn.Linear(dim, n_kv_heads * head_dim, bias=True) + self.o_proj = nn.Linear(n_heads * head_dim, dim, bias=True) + + self.rope = SuScaledRotaryEmbedding( + head_dim, + base=args.rope_theta, + max_position_embeddings=args.max_position_embeddings, + original_max_position_embeddings=args.original_max_position_embeddings, + short_factor=args.rope_scaling["short_factor"], + long_factor=args.rope_scaling["long_factor"], + short_mscale=args.rope_scaling["short_mscale"], + long_mscale=args.rope_scaling["long_mscale"], + ) + + def __call__( + self, + x: mx.array, + mask: Optional[mx.array] = None, + cache=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 PhiMoESparseMoeBlock(nn.Module): + def __init__(self, args: ModelArgs): + super().__init__() + self.hidden_dim = args.hidden_size + self.ffn_dim = args.intermediate_size + self.num_experts = args.num_local_experts + self.top_k = args.num_experts_per_tok + + self.gate = nn.Linear(self.hidden_dim, self.num_experts, bias=False) + self.switch_mlp = SwitchGLU(self.hidden_dim, self.ffn_dim, self.num_experts) + + def __call__(self, x: mx.array) -> mx.array: + gates = self.gate(x) + + k = self.top_k + inds = mx.stop_gradient(mx.argpartition(-gates, kth=k - 1, axis=-1)[..., :k]) + scores = mx.take_along_axis(gates, inds, axis=-1) + scores = mx.softmax(scores, axis=-1, precise=True) + + y = self.switch_mlp(x, inds) + y = (y * scores[..., None]).sum(axis=-2) + + return y + + +class PhiMoEDecoderLayer(nn.Module): + def __init__(self, args: ModelArgs): + super().__init__() + self.hidden_size = args.hidden_size + + self.self_attn = Attention(args) + self.block_sparse_moe = PhiMoESparseMoeBlock(args) + self.input_layernorm = nn.LayerNorm(args.hidden_size, eps=args.rms_norm_eps) + self.post_attention_layernorm = nn.LayerNorm( + args.hidden_size, eps=args.rms_norm_eps + ) + + def __call__( + self, + x: mx.array, + mask: Optional[mx.array] = None, + cache=None, + ) -> mx.array: + residual = x + hidden_states = self.input_layernorm(x) + hidden_states = self.self_attn(hidden_states, mask=mask, cache=cache) + hidden_states = residual + hidden_states + + residual = hidden_states + hidden_states = self.post_attention_layernorm(hidden_states) + hidden_states = self.block_sparse_moe(hidden_states) + hidden_states = residual + hidden_states + + return hidden_states + + +class PhiMoEModel(nn.Module): + def __init__(self, args: ModelArgs): + super().__init__() + self.args = args + self.vocab_size = args.vocab_size + + self.embed_tokens = nn.Embedding(args.vocab_size, args.hidden_size) + self.layers = [PhiMoEDecoderLayer(args) for _ in range(args.num_hidden_layers)] + self.norm = nn.LayerNorm(args.hidden_size, eps=args.rms_norm_eps) + + def __call__( + self, + inputs: mx.array, + cache=None, + ) -> mx.array: + h = self.embed_tokens(inputs) + + mask = create_attention_mask(h, cache) + + if cache is None: + cache = [None] * len(self.layers) + + for layer, c in zip(self.layers, cache): + h = layer(h, mask, c) + + return self.norm(h) + + +class Model(nn.Module): + def __init__(self, args: ModelArgs): + super().__init__() + self.args = args + self.model = PhiMoEModel(args) + self.lm_head = nn.Linear(args.hidden_size, args.vocab_size, bias=True) + + def __call__( + self, + inputs: mx.array, + cache=None, + ): + out = self.model(inputs, cache) + return self.lm_head(out) + + def sanitize(self, weights): + if "model.layers.0.block_sparse_moe.experts.0.w1.weight" not in weights: + return weights + for l in range(self.args.num_hidden_layers): + prefix = f"model.layers.{l}" + for n, m in [("w1", "gate_proj"), ("w2", "down_proj"), ("w3", "up_proj")]: + for k in ["weight", "scales", "biases"]: + if f"{prefix}.block_sparse_moe.experts.0.{n}.{k}" in weights: + to_join = [ + weights.pop( + f"{prefix}.block_sparse_moe.experts.{e}.{n}.{k}" + ) + for e in range(self.args.num_local_experts) + ] + weights[f"{prefix}.block_sparse_moe.switch_mlp.{m}.{k}"] = ( + mx.stack(to_join) + ) + + return weights + + @property + def layers(self): + return self.model.layers + + @property + def head_dim(self): + return self.args.hidden_size // self.args.num_attention_heads + + @property + def n_kv_heads(self): + return self.args.num_key_value_heads diff --git a/llms/mlx_lm/models/su_rope.py b/llms/mlx_lm/models/su_rope.py index f96b99574..9c414afda 100644 --- a/llms/mlx_lm/models/su_rope.py +++ b/llms/mlx_lm/models/su_rope.py @@ -16,6 +16,8 @@ def __init__( original_max_position_embeddings: int = 4096, short_factor: Union[List[float], float] = 1.0, long_factor: Union[List[float], float] = 1.0, + short_mscale: float = None, + long_mscale: float = None, ): """ Phi3Su Scaled Rotary Embedding layer for Phi-3 models. @@ -37,12 +39,14 @@ def __init__( long_factor (float or list[float], optional): List of scaling factors for sequences of length greater than ``original_max_position_embeddings``. Default: ``1.0``. + short_mscale (float, optional): Scale the input prior to embedding. + long_mscale (float, optional): Scale the input prior to embedding. """ super().__init__() freqs = base ** (mx.arange(0, dims, 2, dtype=mx.float32) / dims) self._freqs = mx.array(long_factor, dtype=mx.float32) * freqs self.original_max_position_embeddings = original_max_position_embeddings - self.scale = math.sqrt( + self.scale = long_mscale or math.sqrt( 1 + math.log(max_position_embeddings / original_max_position_embeddings) / math.log(original_max_position_embeddings) diff --git a/llms/mlx_lm/tuner/utils.py b/llms/mlx_lm/tuner/utils.py index 9f18c2c0d..1a54a9254 100644 --- a/llms/mlx_lm/tuner/utils.py +++ b/llms/mlx_lm/tuner/utils.py @@ -96,6 +96,7 @@ def to_lora(layer): "stablelm", "qwen2", "qwen2_moe", + "phimoe", "gemma", "gemma2", "starcoder2", @@ -104,7 +105,7 @@ def to_lora(layer): "deepseek", ]: keys = set(["self_attn.q_proj", "self_attn.v_proj"]) - if model.model_type == "mixtral": + if model.model_type in ["mixtral", "phimoe"]: keys.add("block_sparse_moe.gate") if model.model_type == "qwen2_moe": keys.add("mlp.gate")