blob: 95a48281977c87002e9ee486ae80e0b58b706d33 [file] [log] [blame]
# mypy: allow-untyped-defs
import abc
import dataclasses
import itertools
import logging
import re
import typing
from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Union
from unittest.mock import patch
import sympy
import torch
from torch.fx.experimental.symbolic_shapes import free_unbacked_symbols
from torch.utils._ordered_set import OrderedSet
from .codegen.common import index_prevent_reordering
from .utils import (
get_dtype_size,
reduction_num_outputs,
sympy_index_symbol,
sympy_str,
sympy_subs,
VarRanges,
)
from .virtualized import OpsHandler, ReductionType, V
log = logging.getLogger(__name__)
is_indirect = re.compile(r"indirect|tmp").search
class Dep(abc.ABC):
name: str
index: sympy.Expr
@abc.abstractmethod
def rename(self, renames: Dict[str, str]) -> "Dep":
pass
@abc.abstractmethod
def get_numel(self) -> sympy.Expr:
pass
@abc.abstractmethod
def numbytes_hint(self):
pass
@abc.abstractmethod
def has_unbacked_symbols(self) -> bool:
pass
@abc.abstractmethod
def is_contiguous(self) -> bool:
pass
def normalize_with_stride_order(self, prefix="t"):
return self
@dataclasses.dataclass(frozen=True)
class MemoryDep(Dep):
name: str
index: sympy.Expr
var_names: Tuple[sympy.Symbol, ...]
size: Tuple[sympy.Expr, ...]
mode: Optional[str] = None
def __repr__(self) -> str:
return f"MemoryDep({self.name!r}, {self.index}, {self.ranges}, {self.mode})"
@property
def num_vars(self):
return len(self.var_names)
def decide_loop_order_to_match(self, other):
"""
Can return None if not able to decide loop orders.
"""
assert self.num_vars == other.num_vars
# ignore broadcast for now since broadcast causes extra 0 strides
# which makes it hard to decide the correct loop orders.
if self.num_vars != len(self.index.free_symbols):
return None
if other.num_vars != len(other.index.free_symbols):
return None
# bail out if any size is 0 or 1
# For size == 0, it's an empty tensor, any strides for that dimension
# are equivalent. Skip for simplicity and it may not matter that much.
#
# For size == 1, it cause cause tie for strides of different dimensions.
# Also when we first time create LoopBody in ComputedBuffer.simplify_and_reorder
# we can dependencies.index_vars_squeeze which should already sqeeuze
# the size == 1 dimensions.
if any(s == 0 or s == 1 for s in itertools.chain(self.size, other.size)):
return None
# Extract strides for both expression
self_strides = V.graph.sizevars.stride_hints(self.index, self.var_names)
other_strides = V.graph.sizevars.stride_hints(other.index, other.var_names)
# Even if the shape contains no 0/1, some complex index expression may
# still have duplicate stride values. Here is an example:
# https://gist.github.com/shunting314/511a7e1ec88aa2e1a8ec85d8445ab129
# We don't reorder the loop for these cases for now, but in theory
# we could improve the algorithm to detect the correct loop orders.
if len(set(self_strides)) != len(self_strides) or len(
set(other_strides)
) != len(other_strides):
log.debug(
"unable to decide loop order. self_dep=%s v.s. other_dep=%s, self_strides=%s v.s. other_strides=%s",
self,
other,
self_strides,
other_strides,
)
return None
# May hanppen if self and other are as follows
# MemoryDep('addmm_6', 393216*d0 + 768*d1 + d2, {d0: 16, d1: 512, d2: 768}, None)
# MemoryDep('addmm_6', 98304*d0 + d1 + 768*d2, {d0: 64, d1: 768, d2: 128}, None)
if set(self_strides) != set(other_strides):
return None
stride_to_index = {s: i for i, s in enumerate(self_strides)}
order = []
for s in other_strides:
order.append(stride_to_index[s])
assert set(order) == set(range(0, self.num_vars))
return order
def get_offset(self):
"""
Return the offset by setting every variable to be 0.
"""
return sympy_subs(self.index, dict.fromkeys(self.var_names, 0))
def normalize(self) -> "MemoryDep":
"""
Normalize by merging loops. The different to normalize_with_stride_order is,
this method does not reorder loops while normalize_with_stride_order reorder
loops based on stride order.
"""
return MemoryDep(
self.name,
*_RecordLoadStoreInner._normalize(self.index, self.ranges), # type: ignore[arg-type]
self.mode,
)
def normalize_with_stride_order(self, prefix="t"):
r"""
Used to decide if two MemoryDep does not equal due to different loop orders.
More specifically, when dep1 and dep2 are not equal, we can normalize
both and check if they are equal after that. If yes, then the mismatch is
caused by different loop orders.
"""
# import here to avoid circular import
from torch._inductor import ir
strides = V.graph.sizevars.stride_hints(self.index, self.var_names)
# pick a loop order with stride ordered decreasingly
order = sorted(range(len(strides)), key=strides.__getitem__, reverse=True)
stride_reorder = ir.same_reorder(order)
sizes = self.size
var_names = self.var_names
new_reordered_sizes = stride_reorder(sizes)
new_reordered_var_names = stride_reorder(var_names)
new_simplified_sizes, reindex, prune = V.graph.sizevars._simplify_loops(
new_reordered_var_names,
new_reordered_sizes,
index_prevent_reordering(
[self.index], new_reordered_var_names, new_reordered_sizes
),
)
# now let's create new symbols with the passed in prefix
var_ranges, add_var = var_builder(prefix)
replacement = dict(
zip(
new_reordered_var_names,
reindex([add_var(x) for x in new_simplified_sizes]),
)
)
new_index = sympy_subs(sympy.expand(self.index), replacement) # type: ignore[arg-type] # next PR
out = MemoryDep(self.name, new_index, tuple(var_ranges.keys()), tuple(var_ranges.values())) # type: ignore[arg-type]
return out
@property
def ranges(self) -> Dict[sympy.Symbol, sympy.Expr]:
"""{c0: 128, c1: 512, ...}"""
return dict(zip(self.var_names, self.size))
def get_numel(self) -> sympy.Expr:
if self.is_indirect():
numel = V.graph.get_numel(self.name)
else:
vars: OrderedSet[sympy.Basic] = OrderedSet(self.index.free_symbols)
numel = sympy.Integer(1)
for var, size in zip(self.var_names, self.size):
if var in vars:
numel = numel * size
return numel # type: ignore[return-value]
def rename(self, renames: Dict[str, str]) -> "MemoryDep":
if self.name in renames:
return MemoryDep(
renames[self.name],
self.index,
var_names=self.var_names,
size=self.size,
mode=self.mode,
)
return self
def numbytes_hint(self):
return V.graph.sizevars.size_hint(self.get_numel()) * get_dtype_size(
V.graph.get_dtype(self.name)
)
def has_unbacked_symbols(self):
return len(free_unbacked_symbols(self.get_numel())) > 0
def is_contiguous(self) -> bool:
return isinstance(self.index, sympy.Symbol) and self.index in self.var_names
def stride1_for_last_dim(self, result_for_complex_expression=True) -> bool:
"""
Whether the stride for the last dimension is 1.
"""
# python test/inductor/test_torchinductor_opinfo.py -k test_comprehensive_masked_scatter_cuda_float16
# will exercise thru this corner case.
if len(self.var_names) == 0:
return True
terms = self.index.args if isinstance(self.index, sympy.Add) else [self.index]
last_sym = self.var_names[-1]
for term in terms:
if term is last_sym:
return True
# Having a >1 stride for the last dimension is bad for perf
# return False.
if (
isinstance(term, sympy.Mul)
and len(term.args) == 2
and term.args[1] is last_sym
and isinstance(term.args[0], (int, sympy.Integer))
and term.args[0] > 1
):
return False
return result_for_complex_expression
def is_scalar(self) -> bool:
if isinstance(self.index, sympy.Symbol):
return self.index not in self.var_names and not self.is_indirect()
return isinstance(self.index, (int, sympy.Integer))
def is_indirect(self) -> bool:
return any(is_indirect(v.name) for v in self.index.free_symbols) # type: ignore[attr-defined]
@dataclasses.dataclass(frozen=True)
class StarDep(Dep):
name: str
mode: Optional[str] = None
# depends on the entire buffer
@property
def index(self):
raise NotImplementedError("StarDep does not have an index")
def get_numel(self) -> sympy.Expr:
return V.graph.get_numel(self.name) # type: ignore[return-value]
def rename(self, renames: Dict[str, str]) -> "StarDep":
if self.name in renames:
return StarDep(renames[self.name], self.mode)
return self
def numbytes_hint(self):
return V.graph.sizevars.size_hint(self.get_numel()) * get_dtype_size(
V.graph.get_dtype(self.name)
)
def has_unbacked_symbols(self):
return len(free_unbacked_symbols(self.get_numel())) > 0
def is_contiguous(self) -> bool:
return False
def is_scalar(self) -> bool:
return False
def is_indirect(self) -> bool:
return False
# Used for tracking mutation ordering
# if A reads a buffer and B mutates it
# B must be ordered after A
#
# This is useful for a variety of reasons.
# For example, if A's read is never actually used, we can eliminate it.
# Another case is if A's buffer ends up being fused away, we never need to
# materialize that buffer
@dataclasses.dataclass(frozen=True)
class WeakDep(Dep):
# Fake dependency on unused buffer
name: str
# Buffer that is doing the mutation
mutating_buf: str
@property
def index(self):
raise NotImplementedError("WeakDep does not have an index")
def get_numel(self) -> sympy.Expr:
return sympy.Integer(1)
def rename(self, renames: Dict[str, str]) -> "WeakDep":
if self.name in renames:
return WeakDep(renames[self.name], self.mutating_buf)
return self
def numbytes_hint(self):
return 1 # Purely inserted for ordering, not an actual dep
def has_unbacked_symbols(self):
return False
def is_contiguous(self) -> bool:
return False
@dataclasses.dataclass(frozen=True)
class IndexExprDep:
index: sympy.Expr # type: ignore[assignment]
var_names: Tuple[sympy.Symbol, ...]
size: Tuple[sympy.Expr, ...]
@dataclasses.dataclass
class ReadWrites:
reads: OrderedSet[Dep]
writes: OrderedSet[Dep]
index_exprs: OrderedSet[IndexExprDep]
range_vars: Optional[List[sympy.Expr]] = None
var_ranges: Optional[VarRanges] = None
def rename(self, renames: typing.Dict[str, str]) -> "ReadWrites":
return ReadWrites(
OrderedSet(dep.rename(renames) for dep in self.reads),
OrderedSet(dep.rename(renames) for dep in self.writes),
self.index_exprs,
self.range_vars,
self.var_ranges,
)
def with_read(self, dep: Union[Dep, Set[Dep]]) -> "ReadWrites":
assert isinstance(dep, (WeakDep, StarDep, set))
if not isinstance(dep, set):
dep = {dep}
return ReadWrites(
OrderedSet.union(self.reads, dep),
self.writes,
self.index_exprs,
self.range_vars,
self.var_ranges,
)
def merge(self, other: "ReadWrites"):
reads = OrderedSet.union(self.reads, other.reads)
writes = OrderedSet.union(self.writes, other.writes)
index_exprs = OrderedSet.union(self.index_exprs, other.index_exprs)
return ReadWrites(reads - writes, writes, index_exprs)
@staticmethod
def merge_list(read_writes: List["ReadWrites"]):
all_writes = OrderedSet.union(*[rw.writes for rw in read_writes])
all_reads = OrderedSet.union(*[rw.reads for rw in read_writes]) - all_writes
all_index_exprs = OrderedSet.union(*[rw.index_exprs for rw in read_writes])
return ReadWrites(all_reads, all_writes, all_index_exprs)
def remove_reads(self, rem_reads):
return ReadWrites(
self.reads - rem_reads,
self.writes,
self.index_exprs,
self.range_vars,
self.var_ranges,
)
def reads_and_writes(self):
return itertools.chain(self.reads, self.writes)
def buffer_names(self, ignore_integer_index=True):
"""
Integer index is used for load_seed.
"""
names: OrderedSet[str] = OrderedSet()
for dep in self.reads_and_writes():
if not isinstance(dep, MemoryDep):
continue
if not ignore_integer_index or not isinstance(
dep.index, (int, sympy.Integer)
):
names.add(dep.name)
return names
class _RecordLoadStoreInner(V.MockHandler): # type: ignore[name-defined]
def __init__(self, var_ranges: VarRanges, normalize: bool) -> None:
super().__init__()
self._reads: OrderedSet[Dep] = OrderedSet()
self._writes: OrderedSet[MemoryDep] = OrderedSet()
self._index_exprs: OrderedSet[IndexExprDep] = OrderedSet()
self._var_ranges: VarRanges = var_ranges
self._should_normalize: bool = normalize
@staticmethod
def drop_unused_symbols(index, var_names, sizes):
"""
Reduction has last (reduced) dim in its sizes, but
downstream users won't. Normalize this away.
"""
if not isinstance(index, sympy.Expr):
# index can be an int
return
free_symbols = index.free_symbols
while var_names and var_names[-1] not in free_symbols:
var_names.pop()
sizes.pop()
@classmethod
def _normalize(
cls, index: sympy.Expr, var_ranges: VarRanges
) -> Tuple[sympy.Expr, Tuple[sympy.Symbol, ...], Tuple[sympy.Expr, ...]]:
# Try to further simplify the indexes even if simplify_loops didn't
# convert it to the simplest form because of the interference from
# different indexing formulas.
index_vars = [*var_ranges.keys()]
sizes = tuple(var_ranges.values()) # type: ignore[assignment]
new_sizes, reindex, prune = V.graph.sizevars._simplify_loops(
index_vars,
sizes,
index_prevent_reordering([index], index_vars, sizes),
)
# assign new variables each dimension to deal with numbering mismatches
# d0, d1, d2 could become d0, d2 -- which won't match d0, d1
new_vars, add_var = var_builder(canonicalization_prefix())
replacement = dict(zip(index_vars, reindex([add_var(x) for x in new_sizes])))
index = sympy_subs(sympy.expand(index), replacement)
new_vars = [*new_vars.keys()]
new_sizes = [*new_sizes]
cls.drop_unused_symbols(index, new_vars, new_sizes)
return index, tuple(new_vars), tuple(new_sizes) # type: ignore[arg-type]
def canonicalize(
self, index: sympy.Expr
) -> Tuple[sympy.Expr, Tuple[sympy.Symbol, ...], Tuple[sympy.Expr, ...]]:
if not self._should_normalize:
sizes = [V.graph.sizevars.simplify(x) for x in self._var_ranges.values()]
var_names = [k for k, v in zip(self._var_ranges.keys(), sizes) if v != 1]
sizes = [v for v in sizes if v != 1]
self.drop_unused_symbols(index, var_names, sizes)
return index, tuple(var_names), tuple(sizes) # type: ignore[return-value, arg-type]
var_ranges = {
k: V.graph.sizevars.simplify(v)
for k, v in self._var_ranges.items()
# TODO(jansel): explore this further normalization
# if k in free_symbols
}
return self._normalize(index, var_ranges)
def load(self, name: str, index: sympy.Expr) -> str:
self._reads.add(MemoryDep(name, *self.canonicalize(index)))
return f"load({name}, {sympy_str(index)})"
def load_seed(self, name: str, index: int):
assert isinstance(index, int)
return self.load(name, sympy.Integer(index))
def store(self, name: str, index: sympy.Expr, value: str, mode=None) -> str:
self._writes.add(MemoryDep(name, *self.canonicalize(index), mode=mode))
return f"store({name}, {sympy_str(index)}, {value}, {mode})"
def store_reduction(self, name: str, index, value) -> str:
return self.store(name, index, f"store_reduction({value})")
def index_expr(self, index: sympy.Expr, dtype) -> str:
self._index_exprs.add(IndexExprDep(*self.canonicalize(index)))
return f"index_expr({sympy_str(index)}, {dtype})"
def bucketize(
self,
values,
offsets_name: str,
offsets_size: sympy.Expr,
indexing_dtype: torch.dtype,
right: bool,
):
self._reads.add(StarDep(offsets_name))
return f"bucketize({values}, {offsets_name}, {sympy_str(offsets_size)}, {indexing_dtype}, {right})"
class RecordLoadStore(V.KernelFormatterHandler): # type: ignore[name-defined]
def __init__(self, var_ranges: VarRanges, normalize: bool) -> None:
parent_handler = _RecordLoadStoreInner(
var_ranges=var_ranges, normalize=normalize
)
super().__init__(parent_handler=parent_handler)
# TODO: check call sites
def var_builder(prefix: str) -> Tuple[VarRanges, Callable[[sympy.Expr], sympy.Symbol]]:
cnt = itertools.count()
var_ranges: VarRanges = {}
def add_var(length: sympy.Expr) -> sympy.Symbol:
v = sympy_index_symbol(f"{prefix}{next(cnt)}")
var_ranges[v] = length
return v
return var_ranges, add_var
def index_vars_no_squeeze(*argsizes: Tuple[sympy.Expr, ...], prefix: str):
var_ranges, add_var = var_builder(prefix)
args: List[List[sympy.Symbol]] = []
for size in argsizes:
args.append(list(map(add_var, size)))
return args, var_ranges
def index_vars_squeeze(*argsizes: Tuple[sympy.Expr, ...], prefix: str = "d"):
from .ir import SqueezeView
var_ranges, add_var = var_builder(prefix)
args: List[List[sympy.Expr]] = []
new_sizes: List[List[sympy.Expr]] = []
for size in argsizes:
new_size, reindex = SqueezeView.squeezer(size)
new_sizes.append(new_size)
args.append(reindex(list(map(add_var, new_size))))
return args, var_ranges
def extract_read_writes(
fn: Callable[..., Any],
*argsizes: Tuple[sympy.Expr, ...],
normalize: bool = False,
prefix: str = "d",
hidden_args=(),
):
args, var_ranges = index_vars_squeeze(*argsizes, prefix=prefix)
from .loop_body import LoopBody, MemoryUsageType
if isinstance(fn, LoopBody):
# Fast path to avoid tracing when we already have a LoopBody
inner = _RecordLoadStoreInner(var_ranges=var_ranges, normalize=normalize)
name_to_index = fn.indexing_from_args([*args, *hidden_args])
if fn.indirect_vars:
# mimic the `tmpX` naming tracing gives us
repl = {v: sympy.Symbol(f"tmp{i}") for i, v in enumerate(fn.indirect_vars)}
name_to_index = {k: sympy_subs(v, repl) for k, v in name_to_index.items()}
for entry in fn.memory_usage[MemoryUsageType.LOAD]:
inner.load(entry.buffer_name, name_to_index[entry.index_name])
for entry in fn.memory_usage[MemoryUsageType.LOAD_SEED]:
inner.load_seed(entry.buffer_name, int(name_to_index[entry.index_name]))
for entry in fn.memory_usage[MemoryUsageType.STORE]:
inner.store(
entry.buffer_name, name_to_index[entry.index_name], None, entry.mode
)
for entry in fn.memory_usage[MemoryUsageType.STORE_REDUCTION]:
inner.store_reduction(
entry.buffer_name, name_to_index[entry.index_name], None
)
for entry in fn.memory_usage[MemoryUsageType.INDEX_EXPR]:
inner.index_expr(name_to_index[entry.index_name], None)
for entry in fn.memory_usage[MemoryUsageType.BUCKETIZE]:
inner.bucketize(
None, entry.buffer_name, name_to_index[entry.index_name], None, None
)
# fn.memory_usage[MemoryUsageType.CHECK_BOUNDS] intentionally skipped
else:
# Slow path tracing the function
rw = RecordLoadStore(var_ranges, normalize=normalize)
with V.set_ops_handler(rw):
fn(*args, *hidden_args)
inner = rw.parent_handler
if normalize:
range_vars = [] # Number of vars could differ due to normalization
else:
range_vars = [*itertools.chain.from_iterable(args)]
return ReadWrites(
OrderedSet(inner._reads),
OrderedSet(inner._writes),
inner._index_exprs,
range_vars,
var_ranges,
)
def extract_input_node_reduction_ranges(
input_node: "torch._inductor.ir.TensorBox",
) -> Tuple[Optional[List[sympy.Expr]], Optional[List[sympy.Expr]]]:
"""
Returns the size and reduction size of all inputs, if the sizes and reduction_sizes (if exist) are all the same.
It's possible that a node has multiple inputs, some are Reduction nodes and others are Pointwise nodes.
In this case, reduction_sizes of the Reduction nodes need to be the same.
Otherwise returns (None, None).
"""
from .ir import ComputedBuffer, Loops
if isinstance(input_node.data, ComputedBuffer):
# Input node has already been realized. Return its size and reduction_size.
size = input_node.get_size()
reduction_size = input_node.get_reduction_size()
if len(reduction_size) > 0:
return (size, reduction_size)
else:
return (None, None)
if not isinstance(input_node.data.data, Loops): # type: ignore[attr-defined]
# Other IRNodes do not have reduction_ranges.
return (None, None)
# There is one issue: what if there are views / permutations between the input node and its dependent realized nodes?
# The current method still uses reduction ranges from the dependent realized node, which is not ideal.
# Is there a way to check whether there are permutations inbetween?
reads = input_node.get_reads()
reduction_size = None
size = None
while reduction_size is None and len(reads) > 0:
seen: OrderedSet[str] = OrderedSet()
new_reads = []
for read in reads:
if not isinstance(read, MemoryDep):
continue
if read.name in seen:
continue
seen.add(read.name)
buffer = V.graph.try_get_buffer(read.name)
if buffer is None:
continue
op = buffer.get_defining_op()
if op is None:
continue
if isinstance(op, ComputedBuffer) and len(op.get_reduction_size()) > 0:
if reduction_size is None:
reduction_size = op.get_reduction_size()
size = op.get_size()
elif reduction_size != op.get_reduction_size() or size != op.get_size():
return (None, None)
else:
new_reads.extend(op.get_reads())
if reads == new_reads:
return (size, reduction_size)
else:
reads = new_reads
return (size, reduction_size)
def canonicalization_prefix():
return "c"
# ops handler which computes all the free unbacked symbols for an IR
class FreeUnbackedSymbolsOpsHandler:
symbols: OrderedSet[sympy.Symbol]
def __init__(self) -> None:
self.symbols = OrderedSet()
def __getattr__(self, name: str) -> Callable[..., Any]:
def inner(*args, **kwargs):
for a in itertools.chain(args, kwargs.values()):
if isinstance(a, (sympy.Expr, sympy.logic.boolalg.Boolean)):
self.symbols |= free_unbacked_symbols(a)
return inner
def indirect_indexing(
self, index_var, size, check=True, wrap_neg=True
) -> sympy.Symbol:
assert not isinstance(index_var, (sympy.Expr, sympy.logic.boolalg.Boolean))
self.symbols |= free_unbacked_symbols(size)
return sympy_index_symbol(f"({str(index_var)})")
def frexp(self, x):
return (None,) * 2
def scan(self, dtypes, combine_fn, values):
return (None,) * len(values)
def sort(self, dtypes, values, stable, descending):
return (None,) * len(values)
def reduction(
self,
dtype: torch.dtype,
src_dtype: torch.dtype,
reduction_type: ReductionType,
value: Union[None, Tuple[None, ...]],
) -> Union[None, Tuple[None, ...]]:
num_values = reduction_num_outputs(reduction_type)
return (None,) * num_values if num_values > 1 else None
def _typecheck_FreeUnbackedSymbolsOpsHandler(
h: FreeUnbackedSymbolsOpsHandler,
) -> OpsHandler[None]:
return h
def extract_free_unbacked_symbols(fn: Callable[..., Any], index, rindex=None):
from .ir import FlexibleLayout
args = [index, rindex] if rindex is not None else [index]
handler = FreeUnbackedSymbolsOpsHandler()
# NB: I cargo culted the allow_indexing patch here, I don't understand why
# people do this all over
with V.set_ops_handler(handler), patch.object(
FlexibleLayout, "allow_indexing", True
):
fn(*args)
return handler.symbols