Files
tinygrad/tinygrad/tensor.py
George Hotz b132de677d tinygrad.nn (#367)
* tinygrad.nn

* flake8

* working on pylint

* more pylint

* more pylint

* pylint passes

* networkx

* mypy can't infer that type

* junk
2022-08-18 07:41:00 -07:00

331 lines
14 KiB
Python

# inspired by https://github.com/karpathy/micrograd/blob/master/micrograd/engine.py
from __future__ import annotations
import inspect, functools, importlib
import numpy as np
from tinygrad.helpers import prod
from typing import List, Tuple, Callable, Optional
from tinygrad.ops import Device
from tinygrad.ops import LazyBuffer
# **** start with two base classes, Tensor and Function ****
class Tensor:
training, no_grad = False, False
def __init__(self, data, device=Device.DEFAULT, requires_grad=True):
if isinstance(data, list):
data = np.array(data, dtype=np.float32)
elif isinstance(data, LazyBuffer) and data.device != device:
# TODO: this has to realize, it shouldn't have to
data = data.realize().toCPU()
if isinstance(data, np.ndarray):
if data.shape == tuple(): data = data.reshape((1,))
self.lazydata = LazyBuffer.fromCPU(data.astype(np.float32), device)
elif isinstance(data, LazyBuffer): self.lazydata = data
else: raise Exception(f"can't create Tensor from {data}")
# tensors have gradients, buffers do not
self.grad : Optional[Tensor] = None
self.requires_grad = requires_grad
# internal variables used for autograd graph construction
self._ctx : Optional[Function] = None
def __repr__(self):
return f"<Tensor {self.lazydata if self.lazydata.realized is None else self.lazydata.realized!r} with grad {(self.grad.lazydata if self.grad else None)!r}>"
@property
def shape(self): return self.lazydata.shape
# dtype handling was very broken. it's always float32 now
@property
def dtype(self): return np.float32
@property
def device(self): return self.lazydata.device
# ***** data handlers ****
def realize(self):
self.lazydata.realize()
return self
def assign(self, x):
if not isinstance(x, Tensor): x = Tensor(x)
assert self.shape == x.shape
self.lazydata = x.lazydata
return x
def detach(self): return Tensor(self.lazydata, device=self.device, requires_grad=False)
def numpy(self): return np.array(self.lazydata.toCPU())
# TOOD: this keeps the legacy behavior working, remove it after refactor
@property
def data(self): return self.numpy()
# TODO: if things are realized this won't work
def to_(self, device:str):
assert self.lazydata.realized is None
self.lazydata.device = device
if self.grad: self.grad.lazydata.device = device
def to(self, device:str):
ret = Tensor(self.lazydata, device)
if self.grad: ret.grad = self.grad.to(device)
return ret
# ***** creation helper functions *****
# TODO: remove use of numpy here
@classmethod
def zeros(cls, *shape, **kwargs): return cls(np.zeros(shape, dtype=np.float32), **kwargs)
@classmethod
def ones(cls, *shape, **kwargs): return cls(np.ones(shape, dtype=np.float32), **kwargs)
@classmethod
def randn(cls, *shape, **kwargs): return cls(np.random.randn(*shape).astype(np.float32), **kwargs)
@classmethod
def arange(cls, stop, start=0, **kwargs): return cls(np.arange(start=start, stop=stop).astype(np.float32), **kwargs)
@classmethod
def uniform(cls, *shape, **kwargs): return cls((np.random.uniform(-1., 1., size=shape)/np.sqrt(prod(shape))).astype(np.float32), **kwargs)
@classmethod
def eye(cls, dim, **kwargs): return cls(np.eye(dim).astype(np.float32), **kwargs)
# ***** toposort and backward pass *****
def deepwalk(self):
def _deepwalk(node, visited, nodes):
visited.add(node)
if node._ctx:
[_deepwalk(i, visited, nodes) for i in node._ctx.parents if i not in visited]
nodes.append(node)
return nodes
return _deepwalk(self, set(), [])
def backward(self):
assert self.shape == (1,)
# fill in the first grad with one
# this is "implicit gradient creation"
self.grad = Tensor.ones(*self.shape, device=self.device, requires_grad=False)
for t0 in reversed(self.deepwalk()):
if not any(x.requires_grad for x in t0._ctx.parents): continue
assert (t0.grad is not None)
grads = t0._ctx.backward(t0.grad.lazydata)
grads = [Tensor(g, device=self.device, requires_grad=False) if g is not None else None
for g in ([grads] if len(t0._ctx.parents) == 1 else grads)]
for t, g in zip(t0._ctx.parents, grads):
if g is not None and t.requires_grad:
assert g.shape == t.shape, f"grad shape must match tensor shape in {self._ctx!r}, {g.shape!r} != {t.shape!r}"
t.grad = g if t.grad is None else (t.grad + g)
# ***** non first class ops (hlops) *****
def __getitem__(self, val):
arg = []
for i, s in enumerate(val if isinstance(val, (list, tuple)) else [val]) if val is not None else []:
if isinstance(s, int): s = slice(s, s+1, None)
arg.append((s.start if s.start is not None else 0,
(s.stop if s.stop >=0 else self.shape[i]+s.stop) if s.stop is not None else self.shape[i]))
assert s.step is None or s.step == 1
return self.slice(arg = arg + [(0,self.shape[i]) for i in range(len(arg), len(self.shape))])
# TODO: there has to be a cleaner way to write this
def cat(self, *args, dim=0):
dim = (dim + len(self.shape)) if dim < 0 else dim
for y in args: assert len(self.shape) == len(y.shape)
args = [self] + list(args)
s = [[] for _ in range(len(args))]
for i in range(len(self.shape)):
if i != dim:
for y in args: assert self.shape[i] == y.shape[i]
for j in range(len(args)):
s[j].append((0, self.shape[i]))
else:
shape_sum = 0
for y in args: shape_sum += y.shape[i]
k = 0
for j,y in enumerate(args):
s[j].append((-k, shape_sum-k))
k += y.shape[i]
ret = self.slice(arg=s[0])
for ts,y in zip(s[1:], args[1:]):
ret += y.slice(arg=ts)
return ret
def matmul(self:Tensor, w:Tensor):
# NOTE: we use a 1x1 conv2d to do the matmul. mxk @ kxn = (1,k,m,1).conv2d(n,k,1,1)
bs, groups = prod(self.shape[0:-2]), prod(w.shape[0:-2])
cin, cout = w.shape[-2], w.shape[-1]
out_shape_t = tuple(list(self.shape[0:-2])+[cout,-1])
if len(self.shape) > 1: order = tuple(list(range(len(self.shape)-2))+[len(self.shape)-1, len(self.shape)-2])
else: order, out_shape_t = (0,), (cout, )
worder = tuple(list(range(len(w.shape)-2))+[len(w.shape)-1, len(w.shape)-2])
# NOTE: with NHWC we can remove the transposes
# bs x groups*cin x H x W
cx = self.transpose(order=order).reshape(shape=(bs//groups, groups*cin, -1, 1))
# groups*cout x cin x H, W
cw = w.transpose(order=worder).reshape(shape=(groups*cout, cin, 1, 1))
return cx.conv2d(cw, groups=groups).reshape(shape=out_shape_t).transpose(order=order)
# TODO: what's the difference between dot and matmul?
dot = matmul
# (padding_left, padding_right, padding_top, padding_bottom)
def pad2d(self, padding:Tuple[int, ...]): return self[:, :, -padding[2]:self.shape[2]+padding[3], -padding[0]:self.shape[3]+padding[1]]
def transpose(self, order=(1,0)): return self.permute(order=order)
def flatten(self, start_dim=0): return self.reshape(shape=tuple(list(self.shape[0:start_dim]) + [-1]))
def _reduce(self, fxn, axis=None, keepdim=False):
if axis is None: axis = range(len(self.shape))
if isinstance(axis, int): axis = [axis]
axis = tuple([x if x >= 0 else x+len(self.shape) for x in axis])
shape = [self.shape[i] for i in range(len(self.shape)) if i not in axis]
ret = fxn(axis=axis)
return ret if keepdim else ret.reshape(shape=[1] if shape == [] else shape)
def sum(self, axis=None, keepdim=False): return self._reduce(self._sum, axis, keepdim)
def max(self, axis=None, keepdim=False): return self._reduce(self._max, axis, keepdim)
def mean(self, axis=None, keepdim=False):
out = self.sum(axis=axis, keepdim=keepdim)
return out * (prod(out.shape)/prod(self.shape))
def _softmax(self):
m = self - self.max(axis=len(self.shape)-1, keepdim=True)
e = m.exp()
return m, e, e.sum(axis=len(self.shape)-1, keepdim=True)
def softmax(self):
_, e, ss = self._softmax()
return e.div(ss)
def logsoftmax(self):
m, _, ss = self._softmax()
return m - ss.log()
def dropout(self, p=0.5):
if not Tensor.training: return self
_mask = np.asarray(np.random.binomial(1, 1.0-p, size=self.shape), dtype=self.dtype)
return self * Tensor(_mask, requires_grad=False, device=self.device) * (1/(1.0 - p))
# TODO: support arbitrary strides
def _pool2d(self, py, px):
xup = self[:, :, :self.shape[2]-self.shape[2]%py, :self.shape[3]-self.shape[3]%px] if (self.shape[2]%py != 0) or (self.shape[3]%px != 0) else self
return xup.reshape(shape=(xup.shape[0], xup.shape[1], xup.shape[2]//py, py, xup.shape[3]//px, px))
def avg_pool2d(self, kernel_size=(2,2)): return self._pool2d(*kernel_size).mean(axis=(3,5))
def max_pool2d(self, kernel_size=(2,2)): return self._pool2d(*kernel_size).max(axis=(3,5))
def conv2d(self, weight, bias=None, **kwargs):
ret = self._conv2d(weight, **kwargs)
return ret if bias is None else ret.add(bias.reshape(shape=[1, -1, 1, 1]))
# ***** math functions (unary) *****
def __neg__(self): return 0.0-self
def sqrt(self): return self.pow(0.5)
def clip(self, min_, max_): return ((self-min_).relu()+min_) - (self-max_).relu()
def abs(self): return self.relu() + (-self).relu()
def sign(self): return self / (self.abs() + 1e-10)
# ***** activation functions (unary) *****
def sigmoid(self): return (1.0 + (-self).exp()) ** -1.0
# TODO: implement generic constant folding
def elu(self, alpha=1.0): return self.relu() - alpha*(1-self.exp()).relu()
def swish(self): return self * self.sigmoid()
def relu6(self): return self.relu() - (self-6).relu()
def hardswish(self): return self * (self+3).relu6() * (1/6)
def tanh(self): return 2.0 * ((2.0 * self).sigmoid()) - 1.0
def gelu(self): return 0.5 * self * (1 + (self * 0.7978845608 * (1 + 0.044715 * self * self)).tanh())
def leakyrelu(self, neg_slope=0.01): return self.relu() - (-neg_slope*self).relu()
def mish(self): return self * self.softplus().tanh()
def softplus(self, limit=20, beta=1): return (1/beta) * (1 + (self*beta).exp()).log()
# ***** broadcasted binary ops *****
@staticmethod
def broadcasted(fxn, x, y):
tt = [arg for arg in [x,y] if isinstance(arg, Tensor)][0] # this is the prototype tensor
x,y = [Tensor([t], device=tt.device, requires_grad=False) if not isinstance(t, Tensor) else t for t in [x,y]]
x,y = [t.reshape(list(t.shape) + [1]*(max(len(x.shape), len(y.shape))-len(t.shape))) for t in [x,y]]
shape_ret = tuple(max(sx, sy) for sx,sy in zip(x.shape, y.shape))
return fxn(x.expand(shape_ret), y.expand(shape_ret))
# TODO: are these the only ones that can take number arguments?
def add(self, x): return Tensor.broadcasted(Tensor._add, self, x)
def sub(self, x): return Tensor.broadcasted(Tensor._sub, self, x)
def mul(self, x): return Tensor.broadcasted(Tensor._mul, self, x)
def pow(self, x): return Tensor.broadcasted(Tensor._pow, self, x)
# TODO: should be broadcasted binary op
def div(self, y): return self * (y ** -1.0)
__truediv__ = div
# ***** functional nn ops *****
# TODO: fix the kwargs problem, then remove these
# NOTE: perhaps don't, since they create NOOPs if the shape already matches
def reshape(self, shape): return self._reshape(shape=shape) if tuple(self.shape) != tuple(shape) else self
def expand(self, shape): return self._expand(shape=shape) if tuple(self.shape) != tuple(shape) else self
def linear(self, weight:Tensor, bias:Tensor):
shp = [1] * (len(self.shape)-1) + [-1]
return (self.mul(weight.reshape(shape=shp)) if len(weight.shape) == 1 else self.dot(weight)).add(bias.reshape(shape=shp))
def sequential(self, ll:List[Callable[[Tensor], Tensor]]): return functools.reduce(lambda x,f: f(x), ll, self)
def layernorm(self, eps=1e-5):
y = (self - self.mean(axis=-1, keepdim=True))
return y.div((y*y).mean(axis=-1, keepdim=True).add(eps).sqrt())
# An instantiation of the Function is the Context
class Function:
def __init__(self, device:str, *tensors:Tensor):
self.device, self.parents = device, tensors
self.needs_input_grad = [t.requires_grad for t in self.parents]
self.requires_grad = any(self.needs_input_grad)
self.saved_tensors : List[Tensor] = []
def forward(self, *args, **kwargs): raise NotImplementedError(f"forward not implemented for {type(self)}")
def backward(self, *args, **kwargs): raise NotImplementedError(f"backward not implemented for {type(self)}")
# NOTE: it doesn't hurt to save this since the ctx will be freed fast without grad
def save_for_backward(self, *x): self.saved_tensors.extend(x)
@classmethod
def apply(cls, *x:Tensor, **kwargs):
ctx = cls(x[0].device, *x)
ret = Tensor(ctx.forward(*[t.lazydata for t in x], **kwargs), device=ctx.device, requires_grad=ctx.requires_grad)
if ctx.requires_grad and not Tensor.no_grad: ret._ctx = ctx # used by autograd engine
return ret
# register functions to move between devices
for device in [device for device in Device.__dict__.keys() if device[0] != "_"]:
setattr(Tensor, f"{device.lower()}", functools.partialmethod(Tensor.to, Device.__dict__[device]))
setattr(Tensor, f"{device.lower()}_", functools.partialmethod(Tensor.to_, Device.__dict__[device]))
# register all the mlops "math" operations
def register(name:str, fxn:Function):
def dispatch(*x, **kwargs): return fxn.apply(*x, **kwargs) # TODO: there's probably a very pythonic thing to replace this with
setattr(Tensor, "_"+name if (getattr(Tensor, name, None) is not None) else name, dispatch)
for name, cls in inspect.getmembers(importlib.import_module('tinygrad.mlops'), inspect.isclass):
if name[0] != "_" and name != "Function" and not name.endswith("Ops"): register(name.lower(), cls)
# register the operators
# TODO: add div
def register_op(name, fxn):
setattr(Tensor, f"__{name}__", fxn)
setattr(Tensor, f"__i{name}__", lambda self,x: self.assign(fxn(self,x)))
setattr(Tensor, f"__r{name}__", lambda self,x: fxn(x,self))
for name in ['add', 'sub', 'mul', 'pow', 'matmul']: register_op(name, getattr(Tensor, name))