fix sliding window mask

This commit is contained in:
Awni Hannun 2025-03-13 07:46:16 -07:00
parent 0cff3b781b
commit f124c1e373

View File

@ -1,3 +1,5 @@
# Copyright © 2025 Apple Inc.
from dataclasses import dataclass
from typing import Any, Optional
@ -27,7 +29,6 @@ class ModelArgs(BaseModelArgs):
sliding_window_pattern: int = 6
class Attention(nn.Module):
def __init__(self, args: ModelArgs, layer_idx: int):
super().__init__()
@ -85,10 +86,8 @@ class Attention(nn.Module):
keys = self.rope(keys)
# Sliding window
if self.is_sliding and mask is not None:
key_len = keys.shape[-2]
if mask.shape[-1] != key_len:
mask = mask[..., -key_len:]
if mask is not None and mask.shape[-1] != keys.shape[-2]:
mask = mask[..., -keys.shape[-2] :]
output = mx.fast.scaled_dot_product_attention(
queries, keys, values, scale=self.scale, mask=mask
@ -169,16 +168,27 @@ class Gemma3Model(nn.Module):
):
h = self.embed_tokens(inputs)
h *= self.args.hidden_size**0.5 # persistent precision issue in scaling
h *= mx.array(self.args.hidden_size**0.5, mx.bfloat16).astype(h.dtype)
if cache is None:
cache = [None] * len(self.layers)
if mask is None:
j = self.args.sliding_window_pattern
mask = create_attention_mask(h, cache[j - 1 : j])
full_mask = create_attention_mask(h, cache[j - 1 : j])
sliding_window_mask = create_attention_mask(h, cache)
for i, (layer, c) in enumerate(zip(self.layers, cache)):
is_sliding = (
i % self.args.sliding_window_pattern
== self.args.sliding_window_pattern - 1
)
if mask is None and is_sliding:
mask = sliding_window_mask
elif mask is None:
mask = full_mask
for layer, c in zip(self.layers, cache):
h = layer(h, mask, c)
return self.norm(h)
@ -213,7 +223,6 @@ class Model(nn.Module):
def layers(self):
return self.model.layers
def make_cache(self):
caches = []
for i in range(self.args.num_hidden_layers):