Files
tinygrad/tinygrad/shape/view.py
chenyu 45083ccb43 canonicalize 0 in shape in View.create (#4815)
set strides to 0, offset to 0, mask to None, and contiguous to True with size 0 view.
2024-06-03 13:37:37 -04:00

299 lines
17 KiB
Python

from __future__ import annotations
import functools, operator, itertools, math
from dataclasses import dataclass
from typing import Tuple, List, Optional, Dict, Set, cast
from tinygrad.helpers import prod, all_int, argsort
from tinygrad.shape.symbolic import Node, NumNode, Variable, sint
@functools.lru_cache(maxsize=None)
def canonicalize_strides(shape:Tuple[sint, ...], strides:Tuple[sint, ...]) -> Tuple[sint, ...]:
return tuple(0 if s == 1 else st for s, st in zip(shape, strides))
@functools.lru_cache(maxsize=None)
def strides_for_shape(shape:Tuple[sint, ...]) -> Tuple[sint, ...]:
if not shape: return ()
strides = tuple(itertools.accumulate(reversed(shape[1:]), operator.mul, initial=1))
return canonicalize_strides(shape, strides[::-1])
@functools.lru_cache(maxsize=None)
def _merge_dims(shape:Tuple[int, ...], strides:Tuple[int, ...], mask:Optional[Tuple[Tuple[int, int], ...]]=None) -> Tuple[Tuple[int, int, int], ...]:
# merge contiguous subparts or zero strided dims. ret = List[(merged_dims, stride, merged dims w/o zero stride), ...]
if not shape: return tuple()
assert len(shape) == len(strides)
ret = [(shape[0], strides[0], shape[0] if strides[0] else 0)]
# wrt merging zero strided dimensions
merging = strides[0] == 0 and (mask[0][1] - mask[0][0] == 1 if mask else shape[0] == 1)
for i, (sh, st) in enumerate(zip(shape[1:], strides[1:]), start=1):
if sh == 1: continue
if merging or ret[-1][1] == sh * st: # mergeable
ret[-1] = (ret[-1][0] * sh, st, (sh if merging else ret[-1][2] * sh) if st else 0)
else: ret.append((sh, st, sh if st else 0)) # begin new
# merging ends with either non-zero strided dim or zero strided dim with mask range > 1
merging = st == 0 and (mask[i][1] - mask[i][0] == 1 if mask else sh == 1)
return tuple(ret)
@functools.lru_cache(maxsize=None)
def _reshape_mask(view: View, new_shape:Tuple[sint, ...]) -> Tuple[Optional[Tuple[Tuple[sint, sint], ...]], bool]:
if view.mask is None: return view.mask, False
if any(not isinstance(m[0], int) or not isinstance(m[1], int) for m in view.mask): return view.mask, True
new_mask: List[Tuple[int, int]] = []
r_masks, r_shape, r_new_shape = reversed(view.mask), reversed(view.shape), reversed(new_shape)
curr_stride, old_dim, new_dim, mask = 1, next(r_shape, 1), next(r_new_shape, 1), next(r_masks, (0,1))
if mask[1] - mask[0] < 1: return ((0, 0),) * len(new_shape), False # invalid mask
while len(new_mask) < len(new_shape):
(l, r), next_stride = mask, new_dim * curr_stride
if old_dim >= next_stride: # need to split mask.
if old_dim == next_stride: # simply copy the mask and get next batch for merging
new_mask.append((l // curr_stride, (r - 1) // curr_stride + 1))
curr_stride, old_dim, new_dim, mask = 1, next(r_shape, 1), next(r_new_shape, 1), next(r_masks, (0,1))
if mask[1] - mask[0] < 1: return ((0, 0),) * len(new_shape), False # invalid mask
else: # mask can only be splitted if reshape doesn't cut across the mask.
if (((l % next_stride != 0 or r % next_stride != 0) and l // next_stride != (r - 1) // next_stride)
or old_dim % next_stride != 0): return view.mask, True
new_mask.append((l % next_stride // curr_stride, (r - 1) % next_stride // curr_stride + 1))
curr_stride, new_dim = next_stride, next(r_new_shape, 1) # need to get mask for next dimension
else:
next_mask = next(r_masks, (0, 1))
# combine if the mask can unfold continuously
if mask != (0, old_dim) and next_mask[1] - next_mask[0] != 1: return view.mask, True
mask, old_dim = (next_mask[0] * old_dim + l, (next_mask[1] - 1) * old_dim + r), old_dim * next(r_shape, 1)
for mask in r_masks: # if the old shape has leading 1s, need to make sure their mask is (0,1)
if mask != (0, 1): return ((0, 0),) * len(new_shape), False # invalid mask
return tuple(reversed(new_mask)), False
def un1d(shape:Tuple[sint, ...], offs:sint) -> List[sint]:
strides = strides_for_shape(shape)
result = []
for stride in strides:
here = offs // stride if stride else 0
result.append(here)
offs -= here * stride
return result
@dataclass(frozen=True)
class View:
shape:Tuple[sint, ...]
strides:Tuple[sint, ...]
offset:sint
mask:Optional[Tuple[Tuple[sint, sint], ...]]
contiguous:bool
@functools.lru_cache(maxsize=None) # pylint: disable=method-cache-max-size-none
def size(self) -> int:
# NOTE: Variable and the Node derived from it in symbolic shapes can only have int as max.
ret = prod([x.max if isinstance(x, Node) else x for x in self.shape])
assert isinstance(ret, int), f"{ret=} is not int"
return ret
@staticmethod
@functools.lru_cache(maxsize=None)
def create(shape:Tuple[sint, ...], strides:Optional[Tuple[sint, ...]]=None, offset:sint=0, mask:Optional[Tuple[Tuple[sint, sint], ...]]=None):
strides = canonicalize_strides(shape, strides) if strides else strides_for_shape(shape)
# canonicalize 0 in shape
if 0 in shape: return View(shape, (0,) * len(shape), offset=0, mask=None, contiguous=True)
# canonicalize empty mask
if mask is not None and all(m == (0,s) for m,s in zip(mask, shape)): mask = None
# if any dimension has size >1, but is masked such that only one index in the dimension is unmasked
# then its stride can also be set to 0, albeit with a corresponding adjustment required to the offset
# TODO: assert comparison with LtNode to avoid mis-using symbolic
if mask and any(elim := [not (b+1 < e) for b,e in mask]):
if any(not (b < e) for b,e in mask):
strides, offset, mask = (0,) * len(shape), 0, ((0,0),) * len(shape)
offset += sum((strides[i] * mask[i][0]) if e else 0 for i, e in enumerate(elim))
strides = tuple(0 if e else st for st,e in zip(strides, elim))
contiguous = offset == 0 and mask is None and strides == strides_for_shape(shape)
return View(shape, strides, offset, mask, contiguous)
@functools.lru_cache(None) # pylint: disable=method-cache-max-size-none
def vars(self) -> Set[Variable]:
flatten_mask = tuple(x for m in self.mask for x in m) if self.mask is not None else tuple()
return functools.reduce(operator.or_, [x.vars() for x in self.shape+self.strides+(self.offset,)+flatten_mask if isinstance(x, Node)], set())
@functools.lru_cache(None) # pylint: disable=method-cache-max-size-none
def unbind(self) -> Tuple[View, Dict[Variable, int]]:
var_unboundvar_val = [(v, v.unbind()) for v in self.vars() if v.val is not None]
unbound_vars = {v:uv for v,(uv,_) in var_unboundvar_val}
new_shape = tuple([s if isinstance(s, int) else s.substitute(unbound_vars) for s in self.shape])
new_strides = tuple([s if isinstance(s, int) else s.substitute(unbound_vars) for s in self.strides])
new_offset = self.offset if isinstance(self.offset, int) else self.offset.substitute(unbound_vars)
new_mask = tuple((a if isinstance(a, int) else a.substitute(unbound_vars),
b if isinstance(b, int) else b.substitute(unbound_vars)) for (a, b) in self.mask) if self.mask is not None else None
return View.create(new_shape, new_strides, new_offset, new_mask), dict(x[1] for x in var_unboundvar_val)
@functools.lru_cache(maxsize=None) # pylint: disable=method-cache-max-size-none
def __add__(self, vm1:View) -> Optional[View]:
vm2 = self
if vm2.contiguous: return vm1
if vm1.contiguous and vm1.shape == vm2.shape: return vm2
if vm1.contiguous and vm1.size() == vm2.size() and (ret := vm2.reshape(vm1.shape)) is not None: return ret
if vm1.mask:
for b,e in vm1.mask:
if not (b < e): return View.create(vm1.shape, (0,) * len(vm1.shape), 0, ((0,0),) * len(vm1.shape))
return (merged := vm2 + vm1.shrink(vm1.mask)) and merged.pad(tuple((b,s-e) for (b,e),s in zip(vm1.mask, vm1.shape)))
# Project vm1's offset and strides on to vm2.
origin = un1d(vm2.shape, vm1.offset)
terms: List[List[Tuple[int, sint]]] = [[] for _ in origin]
strides: List[sint] = [0] * len(vm1.shape)
for d1, st in enumerate(vm1.strides):
if st == 0: continue
for d2, (o, s1) in enumerate(zip(origin, un1d(vm2.shape, vm1.offset + st))):
if (s1 := s1 - o) == 0: continue
terms[d2].append((d1, s1))
strides[d1] += s1 * vm2.strides[d2]
# Merge dimensions in vm2 if required.
# NB: Merging too many dimensions can make it difficult to project vm2's mask, hence only combining when required.
idxs: List[Node] = [Variable(f"idx{i}", 0, s-1) for i,s in enumerate(vm1.shape)]
merged_size, merged_term = 1, NumNode(0)
extents: List[Tuple[sint, Node]] = []
for term, s, o in zip(reversed(terms), reversed(vm2.shape), reversed(origin)):
merged_term += Variable.sum([idxs[d1] * (s1 * merged_size) for d1, s1 in term]) + o * merged_size
merged_size *= s
if not (merged_term >= merged_size) and not (merged_term < 0):
extents.append((merged_size, merged_term))
merged_size, merged_term = 1, NumNode(0)
if merged_term: return None
if (vm2_shape := tuple(s for s,_ in reversed(extents))) != vm2.shape:
return (reshaped_vm2 := vm2.reshape(vm2_shape)) and reshaped_vm2 + vm1
if vm2.mask:
# Try to project vm2's mask on to vm1.
newb, newe, bad = [0] * len(vm1.shape), list(vm1.shape), False
for d2, ((b, e), o, (_, t)) in enumerate(zip(vm2.mask, origin, reversed(extents))):
if not (t.min < b or t.max >= e): continue
if not isinstance(o, int) or not isinstance(b, int) or not isinstance(e, int):
bad = True
continue
term = terms[d2]
if len(term) != 1:
if not term and newe: newe[0] = 0
else: bad = True
continue
d1, s1 = term[0]
if not isinstance(s1, int) or not isinstance(newe[d1], int):
bad = True
continue
newb[d1] = max(newb[d1], math.ceil((b - o if s1 > 0 else e - o - 1) / s1))
newe[d1] = min(newe[d1], (b - o if s1 < 0 else e - o - 1) // s1 + 1)
# If any of vm1 was masked off, try again with that mask in place.
for b, e, s in zip(newb, newe, vm1.shape):
if b != 0 or e != s:
return vm2 + View.create(vm1.shape, vm1.strides, vm1.offset, tuple(zip(newb, newe)))
# Otherwise if vm2's mask was violated, then cannot merge.
if bad: return None
return View.create(vm1.shape, tuple(strides), sum(o * s for o, s in zip(origin, vm2.strides)) + vm2.offset)
@functools.lru_cache(maxsize=None) # pylint: disable=method-cache-max-size-none
def invert(self, out_shape:Tuple[sint, ...]) -> Optional[View]:
ret = View.create(self.shape)
if self.mask: ret = ret.shrink(self.mask)
ret = ret.stride(tuple(-1 if x < 0 else 1 for x in self.strides)).permute(argsort(tuple(-x if x > 0 else x for x in self.strides)))
return ret if prod(ret.shape) == prod(out_shape) else None # don't support shrink, expand, or stride != (-1, 1)
@functools.lru_cache(maxsize=None) # pylint: disable=method-cache-max-size-none
def minify(self):
min_shape = tuple(x[0] for x in _merge_dims(self.shape, self.strides, self.mask))
return nv if (nv := self.reshape(min_shape)) else self
def __unsafe_resize(self, arg: Tuple[Tuple[sint, sint], ...], mask=None) -> View:
offset = sum([s * x[0] for s, x in zip(self.strides,arg)])
if self.mask:
# move the old mask
nmask = tuple([(max(0, min(mx-ax,ay-ax)), max(0, min(my-ax,ay-ax))) for (mx,my),(ax,ay) in zip(self.mask, arg)])
# merge the masks if we have two
mask = tuple([(max(mx1, mx2), min(my1, my2)) for (mx1, my1), (mx2, my2) in zip(nmask, mask)]) if mask is not None else nmask
shape = [y-x for x,y in arg]
if mask is not None and all(m[0] == 0 and m[1] == s for m,s in zip(mask, shape)): mask = None
return View.create(tuple(s.b if isinstance(s, NumNode) else s for s in shape), self.strides, self.offset+offset, mask)
@functools.lru_cache(maxsize=None) # pylint: disable=method-cache-max-size-none
def pad(self, arg: Tuple[Tuple[sint, sint], ...]) -> View:
assert all((b>=0 and e>=0) for b,e in arg) and len(arg) == len(self.shape), f"{self.shape=}, {arg=}"
if any(b or e for b, e in arg):
zvarg = tuple([(-b,s+e) for s,(b,e) in zip(self.shape, arg)])
mask = tuple([(b,s+b) for s,(b,_) in zip(self.shape, arg)])
return self.__unsafe_resize(zvarg, mask=mask)
return self
@functools.lru_cache(maxsize=None) # pylint: disable=method-cache-max-size-none
def shrink(self, arg: Tuple[Tuple[sint, sint], ...]) -> View:
assert all((0<=b<=e<=s) for s,(b,e) in zip(self.shape,arg)) and len(arg) == len(self.shape), f"invalid shrink {arg} for {self.shape}"
return self.__unsafe_resize(arg)
@functools.lru_cache(maxsize=None) # pylint: disable=method-cache-max-size-none
def expand(self, new_shape: Tuple[sint, ...]) -> View:
if len(new_shape) != len(self.shape): raise ValueError(f"expand arg {new_shape=} must have same number of dimensions as shape {self.shape=}")
if 0 in self.shape:
assert all((s == x == 0) or (s > 0 and (x % s) == 0) for s,x in zip(self.shape, new_shape)), f"can't expand {self.shape} into {new_shape}"
return View.create(new_shape)
assert all((s == x or (s == 1 and st == 0)) for s,x,st in zip(self.shape, new_shape, self.strides)), f"can't expand {self.shape} into {new_shape}"
# NOTE: can the mask ever be (0,0)?
mask = tuple([(((0,0) if m != (0,1) else (0,ns)) if s != ns else m) for m,s,ns in zip(self.mask, self.shape, new_shape)]) if self.mask else None
return View.create(new_shape, self.strides, self.offset, mask)
@functools.lru_cache(maxsize=None) # pylint: disable=method-cache-max-size-none
def permute(self, axis: Tuple[int, ...]) -> View:
assert all(isinstance(x, int) and x >= 0 and x < len(self.shape) for x in axis), f"invalid permute {axis} for {self.shape}"
assert len(set(axis)) == len(axis) and len(axis) == len(self.shape), f"can't permute {self.shape} with {axis}"
return View.create(tuple(self.shape[a] for a in axis), tuple(self.strides[a] for a in axis), self.offset,
tuple(self.mask[a] for a in axis) if self.mask is not None else None)
@functools.lru_cache(maxsize=None) # pylint: disable=method-cache-max-size-none
def stride(self, mul: Tuple[int, ...]) -> View:
# except for the negative case, you can build this from the others. invertible in the negative case
assert all(isinstance(x, int) and x != 0 for x in mul), f"invalid stride {mul} for {self.shape}"
strides = tuple([z*m for z,m in zip(self.strides, mul)])
new_shape = tuple([(s+(abs(m)-1))//abs(m) for s,m in zip(self.shape, mul)])
offset = sum([(s-1)*z for s,z,m in zip(self.shape, self.strides, mul) if m < 0])
mask = tuple([(((mx if m > 0 else s-my)+(abs(m)-1))//abs(m), ((my if m > 0 else s-mx)+(abs(m)-1))//abs(m)) \
for (mx,my),s,m in zip(self.mask, self.shape, mul)]) if self.mask is not None else None
return View.create(new_shape, strides, self.offset + offset, mask)
@functools.lru_cache(maxsize=None) # pylint: disable=method-cache-max-size-none
def reshape(self, new_shape: Tuple[sint, ...]) -> Optional[View]:
if self.shape == new_shape: return self
assert all(x >= 0 for x in new_shape), f"shape can't contain negative numbers {new_shape}"
if 0 in self.shape:
assert 0 in new_shape, f"cannot reshape 0 size to {new_shape}"
return View.create(new_shape)
# check for the same size
if all_int(self.shape):
assert all(isinstance(s, (int, Variable)) for s in new_shape), f"{self.shape=} -> {new_shape=} contains non (int, Variable) dim"
if prod(self.shape) != prod([s if isinstance(s, int) else cast(Variable,s).val for s in new_shape]):
raise ValueError(f"size mismatched, can't reshape {self.shape=} -> {new_shape=}")
if new_shape == () and self.mask and any(mx==my for (mx,my) in self.mask): return None
# after the asserts, it's okay to check contiguous
if self.contiguous: return View.create(new_shape)
strides, r_new_shape = [], reversed(new_shape)
for merged_dim, new_stride, real_dim in reversed(_merge_dims(self.shape, self.strides, self.mask)):
acc = 1
# TODO: this <= and != is for symbolic!?
while acc <= merged_dim and acc != merged_dim and (new_dim := next(r_new_shape, None)):
strides.append(new_stride)
if new_dim != 1: new_stride *= (new_dim if (acc := acc * new_dim) < real_dim else 0)
if acc != merged_dim: break
else:
strides += [0,] * (len(new_shape) - len(strides))
new_mask, extra = _reshape_mask(self, new_shape)
if not extra:
new_strides = canonicalize_strides(tuple(e-b for b,e in new_mask) if new_mask else new_shape, tuple(reversed(strides)))
extra_offset = (sum(m[0] * s for m,s in zip(self.mask, self.strides)) if self.mask else 0) - \
(sum(m[0] * s for m,s in zip(new_mask, new_strides)) if new_mask else 0)
return View.create(new_shape, new_strides, self.offset + extra_offset, new_mask)
return None