mlecauchois / micrograd-cuda

micrograd CUDA

Teaching myself basic CUDA by building GPU-accelerated tensor-based autodiff from the ground up, inspired by Andrej's micrograd.

No dependencies other than Python's standard library and CUDA.

Compiling

To compile the CUDA kernels:

nvcc -shared -o liboperations.so micrograd_cuda/operations.cu -Xcompiler -fPIC

Usage

import random
import time

from micrograd_cuda.mlp import MLP
from micrograd_cuda.tensor import Tensor
from micrograd_cuda.operations import Operations

# Model
model = MLP(100, [100, 100, 1])
epochs = 20
device = "cpu"

# Data
xs_batch = Tensor([[random.choice([-1, 1]) for _ in range(100)] for _ in range(10)]).T
ys_batch = Tensor([[random.choice([-1, 1])] for _ in range(10)]).T

# Move to device
model.to(device)
xs_batch.to(device)
ys_batch.to(device)

start = time.time()

for k in range(epochs):

    # Forward pass
    ypred = model(xs_batch)
    diff = ypred - ys_batch
    loss = (diff**2).sum()

    # Backward pass
    for p in model.parameters():
        p.zero_grad()
        
    loss.backward()
    
    # Update
    for p in model.parameters():
        p.data = (-0.1 * p.grad + p).data_copy()

print(f"Elapsed: {time.time() - start:.2f} sec")
    
loss.to("cpu")
print(loss.data)

Speedup

Roadmap

The codebase is still WIP with some rough spots, especially around CUDA Tensor data manipulation and copying.

• Micrograd extension with basic 2D tensors and naïve matrix multiplication for MLP
• Batching
• CUDA kernel for matrix multiplication
• Less verbose code
• Error handling
• CUDA optimizations
• >2D tensors
• Rust

Running tests

python -m pytest

License

MIT