Files
tinygrad/test/unit/test_llm_moe.py
George Hotz a9b6cfece0 refactor llm into files (#15780)
* refactor llm into files

* chat.html

* tokenizer cleanup

* cleanup

* tests
2026-04-17 12:33:11 +08:00

101 lines
4.8 KiB
Python

import unittest
import numpy as np
from dataclasses import replace
from tinygrad import Tensor
from tinygrad.llm.model import TransformerBlock, TransformerConfig
def _moe_config(dim=8, hidden=16, n_heads=2, num_experts=4, num_experts_per_tok=2):
return TransformerConfig(
num_blocks=1, dim=dim, hidden_dim=hidden, n_heads=n_heads, n_kv_heads=n_heads,
norm_eps=1e-5, vocab_size=100, head_dim=dim//n_heads, rope_theta=10000,
rope_dim=dim//n_heads, v_head_dim=dim//n_heads, max_context=16,
num_experts=num_experts, num_experts_per_tok=num_experts_per_tok)
class TestMoEFeedForward(unittest.TestCase):
def test_moe_feed_forward(self):
dim, hidden, n_heads = 8, 16, 2
num_experts, k = 4, 2
block = TransformerBlock(_moe_config(dim, hidden, n_heads, num_experts, k))
# set up weights: gate scales by (expert_id+1), up/down are identity-ish, router picks experts 0,2
block.ffn_gate_exps.weight = Tensor.stack(*[Tensor.eye(hidden, dim) * (i + 1) for i in range(num_experts)])
block.ffn_up_exps.weight = Tensor.stack(*[Tensor.eye(hidden, dim) for _ in range(num_experts)])
block.ffn_down_exps.weight = Tensor.stack(*[Tensor.eye(dim, hidden) for _ in range(num_experts)])
block.ffn_gate_inp.weight = Tensor([[1, 0, 1, 0]] * dim).T # router strongly prefers experts 0 and 2
block.ffn_norm.weight = Tensor.ones(dim) # identity norm
# input of ones -> after norm still ~ones -> experts 0,2 selected -> weighted sum of silu outputs
h = Tensor.ones(1, 1, dim)
out = block._feed_forward(block.ffn_norm(h))
# expected moe_output ≈ avg(silu(1), silu(3))
expected = (Tensor([1.0]).silu().item() + Tensor([3.0]).silu().item()) / 2
np.testing.assert_allclose(out.numpy()[0, 0, 0], expected, rtol=1e-2)
def test_moe_feed_forward_batched(self):
dim, hidden, n_heads = 8, 16, 2
num_experts, k = 4, 2
block = TransformerBlock(_moe_config(dim, hidden, n_heads, num_experts, k))
# same setup as BS=1 test
block.ffn_gate_exps.weight = Tensor.stack(*[Tensor.eye(hidden, dim) * (i + 1) for i in range(num_experts)])
block.ffn_up_exps.weight = Tensor.stack(*[Tensor.eye(hidden, dim) for _ in range(num_experts)])
block.ffn_down_exps.weight = Tensor.stack(*[Tensor.eye(dim, hidden) for _ in range(num_experts)])
block.ffn_gate_inp.weight = Tensor([[1, 0, 1, 0]] * dim).T
block.ffn_norm.weight = Tensor.ones(dim)
# test with BS=2, T=3
h = Tensor.ones(2, 3, dim)
out = block._feed_forward(block.ffn_norm(h))
# all outputs should match the BS=1 expected value
expected = (Tensor([1.0]).silu().item() + Tensor([3.0]).silu().item()) / 2
np.testing.assert_allclose(out.numpy(), expected, rtol=1e-2)
def test_moe_feed_forward_norm_topk_prob(self):
dim, hidden, n_heads = 8, 16, 2
num_experts, k = 4, 2
block = TransformerBlock(replace(_moe_config(dim, hidden, n_heads, num_experts, k), norm_topk_prob=True))
block.ffn_gate_exps.weight = Tensor.stack(*[Tensor.eye(hidden, dim) * (i + 1) for i in range(num_experts)])
block.ffn_up_exps.weight = Tensor.stack(*[Tensor.eye(hidden, dim) for _ in range(num_experts)])
block.ffn_down_exps.weight = Tensor.stack(*[Tensor.eye(dim, hidden) for _ in range(num_experts)])
block.ffn_gate_inp.weight = Tensor([[0.1, 0, 0.1, 0]] * dim).T # equal top-2 experts, but only ~69% mass before renorm
block.ffn_norm.weight = Tensor.ones(dim)
h = Tensor.ones(1, 1, dim)
out = block._feed_forward(block.ffn_norm(h))
expected = (Tensor([1.0]).silu().item() + Tensor([3.0]).silu().item()) / 2
np.testing.assert_allclose(out.numpy()[0, 0, 0], expected, rtol=1e-2)
def test_moe_feed_forward_shared_expert(self):
dim, hidden, n_heads = 8, 16, 2
num_experts, k = 4, 2
block = TransformerBlock(replace(_moe_config(dim, hidden, n_heads, num_experts, k), shared_expert_dim=dim))
block.ffn_gate_exps.weight = Tensor.stack(*[Tensor.eye(hidden, dim) * (i + 1) for i in range(num_experts)])
block.ffn_up_exps.weight = Tensor.stack(*[Tensor.eye(hidden, dim) for _ in range(num_experts)])
block.ffn_down_exps.weight = Tensor.stack(*[Tensor.eye(dim, hidden) for _ in range(num_experts)])
block.ffn_gate_inp.weight = Tensor([[1, 0, 1, 0]] * dim).T
block.ffn_gate_shexp.weight = Tensor.eye(dim) * 2
block.ffn_up_shexp.weight = Tensor.eye(dim)
block.ffn_down_shexp.weight = Tensor.eye(dim)
block.ffn_gate_inp_shexp["weight"] = Tensor.zeros(dim)
block.ffn_norm.weight = Tensor.ones(dim)
h = Tensor.ones(1, 1, dim)
out = block._feed_forward(block.ffn_norm(h))
moe_expected = (Tensor([1.0]).silu().item() + Tensor([3.0]).silu().item()) / 2
shared_expected = Tensor([2.0]).silu().item() * 0.5
expected = moe_expected + shared_expected
np.testing.assert_allclose(out.numpy(), expected, rtol=1e-2)
if __name__ == '__main__':
unittest.main()