tinygrad: A Python repository from uffxoje

For something in between a pytorch and a karpathy/micrograd

This may not be the best deep learning framework, but it is a deep learning framework.

Due to its extreme simplicity, it aims to be the easiest framework to add new accelerators to, with support for both inference and training. Support the simple basic ops, and you get SOTA vision extra/efficientnet.py and language extra/transformer.py models. We are working on support for the Apple Neural Engine.

Eventually, we will build custom hardware for tinygrad, and it will be blindingly fast. Now, it is slow.

Installation

pip3 install git+https://github.com/geohot/tinygrad.git --upgrade

Example

from tinygrad.tensor import Tensor

x = Tensor.eye(3)
y = Tensor([[2.0,0,-2.0]])
z = y.matmul(x).sum()
z.backward()

print(x.grad)  # dz/dx
print(y.grad)  # dz/dy

Same example in torch

import torch

x = torch.eye(3, requires_grad=True)
y = torch.tensor([[2.0,0,-2.0]], requires_grad=True)
z = y.matmul(x).sum()
z.backward()

print(x.grad)  # dz/dx
print(y.grad)  # dz/dy

Neural networks?

It turns out, a decent autograd tensor library is 90% of what you need for neural networks. Add an optimizer (SGD, RMSprop, and Adam implemented) from tinygrad.optim, write some boilerplate minibatching code, and you have all you need.

Neural network example (from test/test_mnist.py)

from tinygrad.tensor import Tensor
import tinygrad.optim as optim

class TinyBobNet:
  def __init__(self):
    self.l1 = Tensor.uniform(784, 128)
    self.l2 = Tensor.uniform(128, 10)

  def forward(self, x):
    return x.dot(self.l1).relu().dot(self.l2).logsoftmax()

model = TinyBobNet()
optim = optim.SGD([model.l1, model.l2], lr=0.001)

# ... and complete like pytorch, with (x,y) data

out = model.forward(x)
loss = out.mul(y).mean()
optim.zero_grad()
loss.backward()
optim.step()

GPU and Accelerator Support

tinygrad supports GPUs through PyOpenCL.

from tinygrad.tensor import Tensor
(Tensor.ones(4,4).gpu() + Tensor.ones(4,4).gpu()).cpu()

ANE Support?!

If all you want to do is ReLU, you are in luck! You can do very fast ReLU (at least 30 MEGAReLUs/sec confirmed)

Requires your Python to be signed with ane/lib/sign_python.sh to add the com.apple.ane.iokit-user-access entitlement, which also requires amfi_get_out_of_my_way=0x1 in your boot-args. Build the library with ane/lib/build.sh

from tinygrad.tensor import Tensor

a = Tensor([-2,-1,0,1,2]).ane()
b = a.relu()
print(b.cpu())

Warning: do not rely on the ANE port. It segfaults sometimes. So if you were doing something important with tinygrad and wanted to use the ANE, you might have a bad time.

Adding an accelerator

You need to support 14 first class ops:

Relu, Log, Exp                  # unary ops
Sum, Max                        # reduce ops (with axis argument)
Add, Sub, Mul, Pow              # binary ops (with broadcasting)
Reshape, Transpose, Slice       # movement ops
Matmul, Conv2D                  # processing ops

While more ops may be added, I think this base is stable.

ImageNet inference

Despite being tiny, tinygrad supports the full EfficientNet. Pass in a picture to discover what it is.

ipython3 examples/efficientnet.py https://upload.wikimedia.org/wikipedia/commons/4/41/Chicken.jpg

Or, if you have a webcam and cv2 installed

ipython3 examples/efficientnet.py webcam

PROTIP: Set "GPU=1" environment variable if you want this to go faster.

PROPROTIP: Set "DEBUG=1" environment variable if you want to see why it's slow.

tinygrad also supports GANs

See examples/mnist_gan.py

The promise of small

tinygrad will always be below 1000 lines. If it isn't, we will revert commits until tinygrad becomes smaller.

Running tests

python3 -m pytest

TODO (updated)

PYTHONPATH="." DEBUG=1 CHERRY=1 python3 examples/efficientnet.py https://upload.wikimedia.org/wikipedia/commons/4/41/Chicken.jpg

~~Add reduce ops to CHERRY, and fully support forward pass. See extra/ops_risk.py and extra/risk.py~~
Switch convolution backward pass to CHERRY instead of the numpy placeholder
Confirm EfficientNet backward pass fully uses CHERRY instructions
Benchmark that and transformers

uffxoje/tinygrad