Files
tinygrad/tinygrad/engine/fuse.py
T

111 lines
5.8 KiB
Python

from collections import defaultdict, deque
from typing import Tuple, List, Dict, DefaultDict
from tinygrad.ops import GroupOp, MetaOps, ReduceOps, UOp, UnaryOps
from tinygrad.helpers import FUSE_CONV_BW, FUSE_ARANGE, dedup, merge_dicts
from tinygrad.shape.shapetracker import ShapeTracker
from tinygrad.engine.lazy import LazyBuffer
def _recursive_group(tr:LazyBuffer, st:ShapeTracker, r:LazyBuffer, children:DefaultDict[LazyBuffer, Dict[LazyBuffer, None]],
realizes:Dict[LazyBuffer, None], reduce_for_op:Dict[LazyBuffer, LazyBuffer], group:Dict[LazyBuffer, None],
cache:Dict[Tuple[LazyBuffer, ShapeTracker], None]) -> None:
"""recursively search the LazyBuffer for groupable children, realize the LazyBuffer if a child can't group"""
if (tr, st) in cache: return
cache.setdefault((tr, st))
if tr in realizes and tr is not r:
# can only fuse contiguous
# max one reduceop per kernel
if not st.contiguous or st.size != r.st.size or tr in reduce_for_op: group.setdefault(r)
return group.setdefault(tr)
for tr_next in children[tr]:
# max one reduceop per kernel
if tr_next.op in GroupOp.Reduce: return group.setdefault(r)
# can only fuse contiguous
if len(st_childs:=dedup(s for s in tr_next.srcs if s.base == tr)) > 1: return group.setdefault(r)
_recursive_group(tr_next, st+st_childs[0].st, r, children, realizes, reduce_for_op, group, cache)
def _get_isolated_children(r:LazyBuffer, reduce_for_op:Dict[LazyBuffer, LazyBuffer], children:DefaultDict[LazyBuffer, Dict[LazyBuffer, None]],\
realizes:Dict[LazyBuffer, None], group:Dict[LazyBuffer, None]) -> Dict[LazyBuffer, None]:
rc_parents, cache = deque(group), set()
while rc_parents:
if (p:=rc_parents.pop()) in cache: continue
cache.add(p)
# max one reduceop per kernel
if p.op in GroupOp.Reduce: return {}
rc_parents.extend(x.base for x in p.srcs if x.base.realized is None and x.base is not r)
# search descendants of the reduceop that can cleanly group
descendants: Dict[LazyBuffer, None] = {}
for tr in group: _recursive_group(tr, tr.st, tr, children, realizes, reduce_for_op, descendants, cache={})
return merge_dicts([group, {} if any(tr in group for tr in descendants) else descendants])
def get_realizes(children:DefaultDict[LazyBuffer, Dict[LazyBuffer, None]], allbufs:Dict[LazyBuffer, None],
double_reduces:Dict[LazyBuffer, None], ubuf_realizes:Dict[UOp, UOp], ctx) -> List[List[UOp]]:
"""search the graph for all the LazyBuffers that need to realize"""
# get all the realizes from big graph
realizes: Dict[LazyBuffer, None] = {}
for r in allbufs:
if ctx.buf_uops[r.buffer] in ubuf_realizes: realizes[r] = None
# find all reduces, and pair them to a elementwise op. if they can't be cleanly paired, force realize the reduce (or a contig child)
reduce_for_op: Dict[LazyBuffer, LazyBuffer] = {}
reduce_of_const: List[LazyBuffer] = []
for r in allbufs:
if r in realizes or r.op not in GroupOp.Reduce: continue
group: Dict[LazyBuffer, None] = {}
_recursive_group(r, r.st, r, children, realizes, reduce_for_op, group, cache={})
# max one reduceop per kernel
can_chase = all(tr not in reduce_for_op for tr in group)
# TODO: forced_realize exists because the scheduler is incapable of checking for self-contained DAGs
forced_realize = r in group
if not forced_realize and len(group) > 1:
group = _get_isolated_children(r, reduce_for_op, children, realizes, group)
# can only fuse assign if no other assign_target is used in the kernel
if not forced_realize and any(x.op is MetaOps.ASSIGN for x in group):
parents = deque((r, *group))
while parents and not forced_realize:
if (p:=parents.pop().base).is_realized() or p in realizes:
if p.is_realized() and p.buffer in ctx.assigns and not any(x.buffer is p.buffer for x in group): forced_realize, can_chase = True, False
continue
parents.extend(p.srcs)
if forced_realize or not group:
tr = r
if can_chase:
# can chase this down to contiguous children
st = tr.st
while len(children[tr]) == 1:
tr_next = next(iter(children[tr]))
st_childs = dedup(s for s in tr_next.srcs if s.base is tr)
if len(st_childs) > 1: break
if st.size != st_childs[0].st.size: break
st = st + st_childs[0].st
if not st.contiguous or tr_next.op in GroupOp.Reduce: break
tr = tr_next
# don't cast to higher size before store (tr cannot be realized if forced_realize)
if tr.op is UnaryOps.CAST and tr.arg.itemsize > tr.srcs[0].dtype.itemsize:
tr = tr.srcs[0].base
reduce_for_op[tr] = r
realizes[tr] = None
else: reduce_for_op.update((tr, r) for tr in group)
if FUSE_ARANGE and r.op is ReduceOps.SUM and r.srcs[0].base.op is MetaOps.CONST: reduce_of_const.append(r)
# fuse double reduces with no other child
if FUSE_CONV_BW:
for reduceop in double_reduces:
top_reduce = reduceop.base.srcs[0].base
if len(children[top_reduce]) == 1:
del realizes[top_reduce]
if (ubuf:=ctx.buf_uops[top_reduce.buffer]) in ubuf_realizes: del ubuf_realizes[ubuf]
for r in reduce_of_const:
group = {tr:None for tr,rop in reduce_for_op.items() if rop is r}
if any(tr.forced_realize for tr in group): continue
kernel_children = {c for tr in group for c in children[tr] if c.op not in {MetaOps.COPY, MetaOps.BUFFER_VIEW}}
if len(kernel_children) == 0: continue
for tr in group:
del realizes[tr]
if (ubuf:=ctx.buf_uops[tr.buffer]) in ubuf_realizes: del ubuf_realizes[ubuf]
output_groups: DefaultDict[LazyBuffer, List[UOp]] = defaultdict(list)
for buf in realizes:
output_groups[reduce_for_op.get(buf, buf)].append(ubuf:=ctx.buf_uops[buf.buffer])
ubuf_realizes[ubuf] = ubuf
return list(output_groups.values())