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RMS/Layer norm backward would generated 2 kind of reductions:
- the reduction computing dx which reduce across the hidden dimension (in the context of transformer)
- the reduction computing dw/db which reduce across the BxT (batch size , sequence length) dimension.
These 2 set of reductions have common input buffers but inductor can not fuse them because of different loop orders.
There are multiple sources of custom kernels that implement fused version of such kernel (Liger-Kernel, quack, Paul Zhang's internal post). This PR enable Inductor to generate such kernels automatically.
The generated kernel is very similar to 33924d20b6/src/liger_kernel/ops/rms_norm.py (L114) .
To make the implementation simple and performing, we enable such fusion only if the inner reduction (computing dx) is a persistent reduction. This should be true for representative inputs. Persistent reduction is critical for the perf here to make sure a loaded tensor does not need to be reload.
To make sure the inner reduction (computing dx) and outer reductions (computing dw/db) being fusible, the PR does the following:
1. convert the outer reductions to pointwise by replacing 'reduction' & 'store_reduction' node with a new type of node 'parital_accumulate'. The new node will collect the reduction type, buffer name, input of reduction etc, which is essential for proper codegening.
2. do loop reordering (rely on the earlier loop ordering after fusion work) to reorder the loops of the converted pointwise so it can be fused with the inner reduction
3. there can be epilogues that need to be added in the end. E.g. the outer reduction may be followed by a division for mean , or followed by a down cast if dw/db is in low precision (fp16/bf16).
Some early benchmarking on H100 shows about 2X speedup for both RMSNorm and LayerNorm backward for shape (1152 * 500, 384 ) used in some internal model. Note that, I manually disable split reduction in this benchmarking since otherwise the fusion will be skipped right now. The next PR will make the mix-order-reduction compose better with split reduction
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165370
Approved by: https://github.com/jansel
ghstack dependencies: #166204
1170 lines
35 KiB
Python
1170 lines
35 KiB
Python
# mypy: allow-untyped-defs
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from __future__ import annotations
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import inspect
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import itertools
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import re
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import warnings
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from io import StringIO
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from typing import Any, Callable, Generic, Literal, NamedTuple, Optional, TypeVar, Union
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from unittest.mock import patch
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import sympy
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import torch
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import torch.utils._pytree as pytree
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from ..utils._ordered_set import OrderedSet
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from .utils import IndentedBuffer, reduction_num_outputs, sympy_index_symbol, sympy_str
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T = TypeVar("T")
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StoreMode = Optional[Literal["atomic_add", "tma"]]
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ReductionType = Literal[
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"argmax",
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"argmin",
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"welford_reduce",
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"welford_combine",
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"any",
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"max",
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"min",
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"prod",
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"sum",
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"dot",
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"xor_sum",
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"online_softmax_reduce",
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]
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def _arg_str(a: object) -> str:
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if isinstance(a, sympy.Expr):
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return sympy_str(a)
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return str(a)
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# See OpDecompositions for superclass that desugars operations like reciprocal/square.
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class OpsHandler(Generic[T]):
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"""
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Protocol describing the set of valid operations on ``torch._inductor.virtualized.ops``,
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as well as the contract for op handlers. The type T signifies the domain
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of the abstract analysis AKA what all the functions return / take as arguments
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anywhere compute occurs.
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While these operators are typically dtype polymorphic (e.g., you can use mul
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on both integers and floats), they do NOT do promotion and usually return the
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same dtype as the input. You are expected to have handled type promotion
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during ATen decompositions. Most operators correspond exactly to pointwise
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operations as defined by torch, so when in doubt about semantics, check the
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corresponding torch documentation. These are all scalar operations (so they
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are defined to operate on a single element at a time.)
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For convenience, many operators take a src_dtype which indicates what the dtype
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of the input argument is. Although in principle this can be derived by an
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analysis, providing this for ops where it is useful helps avoid having to repeatedly
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recompute dtype in code generation.
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Note that this often describes a class of static methods, for stateless
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ops handlers.
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Handlers are often defined using metaprogramming (e.g. _initialize_pointwise_overrides),
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which means you will not get type errors for those methods. We have tests in
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test/inductor/test_op_completeness.py which check that all operators are implemented after
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all the metaprogramming has run.
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"""
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def constant(self, value: Union[bool, float, int], dtype: torch.dtype) -> T:
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"""Produces a scalar constant of type dtype."""
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raise NotImplementedError
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def load_seed(self, name: str, offset: T) -> T:
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"""Computes inductor_prims.lookup_seed."""
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raise NotImplementedError
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def rand(self, seed: T, offset: T) -> T:
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"""Computes inductor_prims.random with mode="rand". offset has dtype int32."""
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raise NotImplementedError
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def randn(self, seed: T, offset: T) -> T:
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"""Computes inductor_prims.random with mode="randn". offset has dtype int32."""
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raise NotImplementedError
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def randint64(self, seed: T, offset: T, low: T, high: T) -> T:
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"""Computes inductor_prims.randint. offset has dtype int32."""
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raise NotImplementedError
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def masked(self, mask: T, body: Callable[[], T], other: T) -> T:
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"""
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Computes body, but only perform loads/stores if the boolean mask
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evaluates to true. For example, you would use this if you needed to
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perform an indirect load that may not be valid on some elements;
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without masking, invalid accesses can cause IMAs. When mask is true,
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the result is the result of body; otherwise it is other. Here, `other`
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needs to be a constant.
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Contrast this with ops.where, which can multiplex between two values
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that have been unconditionally computed.
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"""
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raise NotImplementedError
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def where(self, condition: T, input: T, other: T) -> T:
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"""
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Computes torch.where: when condition is true, return input; otherwise return other.
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"""
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raise NotImplementedError
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def index_expr(self, expr: sympy.Expr, dtype: torch.dtype) -> T:
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"""
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Converts a sympy expression into a scalar of type dtype. expr is typically
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an indexing expression, thus the name; however, it can also be used in
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non-indexing situations.
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"""
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raise NotImplementedError
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def to_dtype(
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self,
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x: T,
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dtype: torch.dtype,
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src_dtype: Optional[torch.dtype] = None,
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use_compute_types: bool = True,
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) -> T:
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"""
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Convert x to dtype. src_dtype can be optionally set to specify what the original
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dtype of x was, which can improve code generation (used by torch to(dtype=dtype)).
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"""
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raise NotImplementedError
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def trunc_to_int(self, x: T, dtype: torch.dtype) -> T:
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"""
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Convert x to dtype with truncation semantics (similar to how the int
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constructor works in Python). In Inductor codegen, this just decays
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to trunc and then to_dtype, but this composite operation helps
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roundtrips for Sympy evaluation.
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dtype is taken as an explicit parameter because the desired output
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dtype is typically the index dtype, which may vary between int32 and
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int64 depending on if we've shown that all the indexing operations can
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be done in int32.
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"""
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raise NotImplementedError
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def ceil_to_int(self, x: T, dtype: torch.dtype) -> T:
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"""
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Convert x to dtype with ceiling semantics. See also trunc_to_int.
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"""
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raise NotImplementedError
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def floor_to_int(self, x: T, dtype: torch.dtype) -> T:
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"""
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Convert x to dtype with ceiling semantics. See also trunc_to_int.
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"""
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raise NotImplementedError
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def round_to_int(self, x: T, dtype: torch.dtype) -> T:
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"""
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Convert x to dtype with round-to-even semantics. See also trunc_to_int.
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"""
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raise NotImplementedError
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def to_dtype_bitcast(self, x: T, dtype: torch.dtype, src_dtype: torch.dtype) -> T:
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"""
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Reinterpret cast x to dtype (reinterpreting the bits in memory as another dtype.)
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src_dtype must be the original type of x.
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"""
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raise NotImplementedError
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def identity(self, x: T) -> T:
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"""
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Returns x as is. This is used to trigger CSE.
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"""
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raise NotImplementedError
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# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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# These operations are only available in a "kernel" context. Check
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# torch._inductor.codegen.common.CSEProxy for their typical implementation
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# in op handler (routing to their respective implementations in the kernel
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# handler)
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#
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# Importantly, inside a kernel, indexing and mask variables are available
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# in scope, which are typically used by sympy.Expr indexing.
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def indirect_indexing(
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self, x: T, size: sympy.Expr, check: bool = True, wrap_neg=True
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) -> sympy.Expr:
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"""
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Convert an integral x into a sympy.Expr that can be subsequently used in
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indexing computation. 'size' represents an upper bound on what valid
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indexes can be; when 'check' is True, we check that the x is in bounds.
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NB: This is typically mandatory to implement for any analysis, because you
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MUST return a valid sympy.Expr of some sort (even if it's a meaningless symbol).
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"""
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raise NotImplementedError
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def load(self, name: str, index: sympy.Expr) -> T:
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"""
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Load from the memory location 'name', offset by some indexing expression 'index'.
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"""
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raise NotImplementedError
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def store(
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self,
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name: str,
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index: sympy.Expr,
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value: T,
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mode: StoreMode = None,
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) -> None:
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"""
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Store 'value' to the memory location 'name' offset by 'expr'. If
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specified, 'mode' can require the store to be an atomic addition.
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"""
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raise NotImplementedError
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# TODO: Better explain how the "collective" semantics of these ops;
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# remember that the input value is a scalar, you can't reduce on it in the
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# traditional sense!
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def reduction(
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self,
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dtype: torch.dtype,
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src_dtype: torch.dtype,
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reduction_type: ReductionType,
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value: T,
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) -> Union[T, tuple[T, ...]]:
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"""
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Perform a 'reduction_type' reduction on 'value' of dtype 'src_dtype',
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using 'dtype' as the accumulation dtype for the reduction. The result
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is an intermediate computation which should be stored to the final
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location using 'ops.store_reduction'.
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Valid reduction types are . For Welford reduction types, this
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function returns multiple outputs; consult reduction_num_outputs to
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determine the amount in metaprogramming applications.
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"""
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raise NotImplementedError
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# TODO: in practice, this seems to actually return None, but not returning
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# a T makes common __getattr__ idioms not type correctly. Figure out if
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# this should be returning something.
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def store_reduction(self, name: str, index: sympy.Expr, value: T) -> None:
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"""
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Store the fully accumulated result of 'reduction' to the memory
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location 'name' offset by 'expr'.
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"""
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raise NotImplementedError
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def scan(
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self,
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dtypes: tuple[torch.dtype, ...],
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combine_fn: Callable[[tuple[T, ...], tuple[T, ...]], tuple[T, ...]],
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values: tuple[T, ...],
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) -> tuple[T, ...]:
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"""
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Perform an associative scan on 'value'.
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"""
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# TODO: Improve the description with some pseudocode
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raise NotImplementedError
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def sort(
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self,
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dtypes: tuple[torch.dtype, ...],
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values: tuple[T, ...],
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stable: bool,
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descending: bool,
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) -> tuple[T, ...]:
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"""
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Sort values along the reduction dimension.
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"""
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raise NotImplementedError
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def bucketize(
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self,
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values: T,
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boundaries: tuple[str, sympy.Expr, sympy.Expr, sympy.Expr],
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boundary_indices: T,
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indexing_dtype: torch.dtype,
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right: bool,
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sorter: Optional[tuple[str, sympy.Expr]] = None,
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sorter_indices: Optional[T] = None,
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) -> T:
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# See [Note: Inductor bucketize op]
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raise NotImplementedError
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def partial_accumulate(
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self,
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name: str,
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reduction_type: ReductionType,
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value: T,
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) -> None:
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raise NotImplementedError
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# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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# The following ops have semantics that correspond exactly to the torch
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# operation with the same corresponding name.
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def abs(self, x0: T) -> T:
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raise NotImplementedError
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def exp(self, x0: T) -> T:
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raise NotImplementedError
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def exp2(self, x0: T) -> T:
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raise NotImplementedError
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def expm1(self, x0: T) -> T:
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raise NotImplementedError
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def sqrt(self, x0: T) -> T:
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raise NotImplementedError
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def relu(self, x0: T) -> T:
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raise NotImplementedError
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def minimum(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def maximum(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def cos(self, x0: T) -> T:
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raise NotImplementedError
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def sin(self, x0: T) -> T:
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raise NotImplementedError
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def lgamma(self, x0: T) -> T:
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raise NotImplementedError
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def erf(self, x0: T) -> T:
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raise NotImplementedError
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def cosh(self, x0: T) -> T:
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raise NotImplementedError
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def sinh(self, x0: T) -> T:
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raise NotImplementedError
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def acos(self, x0: T) -> T:
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raise NotImplementedError
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def acosh(self, x0: T) -> T:
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raise NotImplementedError
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def asin(self, x0: T) -> T:
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raise NotImplementedError
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def asinh(self, x0: T) -> T:
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raise NotImplementedError
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def atan2(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def atan(self, x0: T) -> T:
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raise NotImplementedError
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def atanh(self, x0: T) -> T:
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raise NotImplementedError
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def copysign(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def erfc(self, x0: T) -> T:
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raise NotImplementedError
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def erfinv(self, x0: T) -> T:
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raise NotImplementedError
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def frexp(self, x0: T):
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raise NotImplementedError
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def hypot(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def log10(self, x0: T) -> T:
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raise NotImplementedError
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def log2(self, x0: T) -> T:
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raise NotImplementedError
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def nextafter(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def logical_and(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def logical_not(self, x0: T) -> T:
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raise NotImplementedError
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def logical_or(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def logical_xor(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def bitwise_and(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def bitwise_not(self, x0: T) -> T:
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raise NotImplementedError
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def bitwise_or(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def bitwise_xor(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def bitwise_left_shift(self, x0: T, x1: T) -> T:
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raise NotImplementedError
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def bitwise_right_shift(self, x0: T, x1: T) -> T:
|
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raise NotImplementedError
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|
|
def rsqrt(self, x0: T) -> T:
|
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raise NotImplementedError
|
|
|
|
def log1p(self, x0: T) -> T:
|
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raise NotImplementedError
|
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|
|
def tan(self, x0: T) -> T:
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raise NotImplementedError
|
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|
|
def tanh(self, x0: T) -> T:
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raise NotImplementedError
|
|
|
|
def sigmoid(self, x0: T) -> T:
|
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raise NotImplementedError
|
|
|
|
def signbit(self, x0: T) -> T:
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raise NotImplementedError
|
|
|
|
def fmod(self, x0: T, x1: T) -> T:
|
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raise NotImplementedError
|
|
|
|
def log(self, x0: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def isinf(self, x0: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def isnan(self, x0: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
# NB: this returns a float, like the torch operation
|
|
# This rounds half to even to break ties
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|
def round(self, x0: T) -> T:
|
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raise NotImplementedError
|
|
|
|
# NB: this returns a float, like the torch operation
|
|
def floor(self, x0: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def sign(self, x0: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
# NB: this returns a float, like the torch operation
|
|
def trunc(self, x0: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
# NB: this returns a float, like the torch operation
|
|
def ceil(self, x0: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def neg(self, x0: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def reciprocal(self, x0: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def eq(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def ne(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def lt(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def gt(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def le(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def ge(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def add(self, x0: T, x1: T) -> T:
|
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raise NotImplementedError
|
|
|
|
def sub(self, x0: T, x1: T) -> T:
|
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raise NotImplementedError
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|
|
def mul(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
# NB: this returns a float, like the torch operation
|
|
def pow(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def and_(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def or_(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def xor(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
# These are metaprogrammed by MockHandler._init_cls
|
|
def lshift(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def rshift(self, x0: T, x1: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
# These are "special" operators. These only exist if the target
|
|
# language actually supports the operator. Keep this in sync with
|
|
# pointwise_overrides_data.
|
|
|
|
def airy_ai(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def bessel_j0(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def bessel_j1(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def bessel_y0(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def bessel_y1(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def digamma(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def erfcx(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def fma(self, x: T, y: T, z: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def igamma(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def igammac(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def gammainc(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def gammaincc(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def i0(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def i0e(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def i1(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def i1e(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def log_ndtr(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def modified_bessel_i0(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def modified_bessel_i1(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def modified_bessel_k0(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def modified_bessel_k1(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def ndtr(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def ndtri(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def polygamma(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def scaled_modified_bessel_k0(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def scaled_modified_bessel_k1(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def spherical_bessel_j0(self, x: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def zeta(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def chebyshev_polynomial_t(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def chebyshev_polynomial_u(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def chebyshev_polynomial_v(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def chebyshev_polynomial_w(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def legendre_polynomial_p(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def shifted_chebyshev_polynomial_t(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def shifted_chebyshev_polynomial_u(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def shifted_chebyshev_polynomial_v(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def shifted_chebyshev_polynomial_w(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def hermite_polynomial_h(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def hermite_polynomial_he(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def laguerre_polynomial_l(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
# These operators are a bit special, because they are conventionally
|
|
# natively supported in both Python and C, but the semantics differ so
|
|
# care must be taken
|
|
|
|
def truncdiv(self, x0: T, x1: T) -> T:
|
|
"""C-style trunc division between integers only. Computes the true
|
|
division of two numbers and rounds the result to zero.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def floordiv(self, x0: T, x1: T) -> T:
|
|
"""Python-style floor division between integers only. Computes the
|
|
true division of two numbers and floors the result. If you want
|
|
floor division for floats, do regular truediv and floor the result.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def truediv(self, x0: T, x1: T) -> T:
|
|
"""True division between floats. Integer inputs are NOT valid. To
|
|
do Python-style (int, int) -> float division, use int_truediv"""
|
|
raise NotImplementedError
|
|
|
|
def int_truediv(self, x0: T, x1: T) -> T:
|
|
"""True division between integers. This is NOT the same as promoting
|
|
to float and doing integer division, there is a bespoke algorithm for
|
|
doing the division in higher precision than the above.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def mod(self, x0: T, x1: T) -> T:
|
|
"""C-style modulus, take sign from LHS (x0)."""
|
|
raise NotImplementedError
|
|
|
|
def remainder(self, x0: T, x1: T) -> T:
|
|
"""Python-style modulus, take sign from RHS (x1)."""
|
|
raise NotImplementedError
|
|
|
|
def square(self, x0: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
def check_bounds(
|
|
self, expr: sympy.Expr, size: sympy.Expr, lower: bool, upper: bool
|
|
) -> None:
|
|
raise NotImplementedError
|
|
|
|
# halide-only
|
|
def halide_clamp(self, value: T, size: sympy.Expr, check: bool) -> T:
|
|
raise NotImplementedError
|
|
|
|
# triton-only
|
|
def dot(self, x: T, y: T) -> T:
|
|
raise NotImplementedError
|
|
|
|
# triton-only
|
|
def inline_asm_elementwise(
|
|
self,
|
|
*inputs: T,
|
|
asm: str,
|
|
constraints: Optional[str] = None,
|
|
dtype: torch.dtype = torch.float32,
|
|
is_pure: bool = True,
|
|
pack: int = 1,
|
|
) -> T:
|
|
raise NotImplementedError
|
|
|
|
def output(self, *args: T) -> None:
|
|
"""This is a fake op used in analysis but not codegen"""
|
|
raise NotImplementedError
|
|
|
|
def placeholder(self, index: int) -> T:
|
|
"""This is a fake op used in analysis but not codegen"""
|
|
raise NotImplementedError
|
|
|
|
def device_assert_async(self, cond: T, msg: str) -> T:
|
|
raise NotImplementedError
|
|
|
|
|
|
_ignore_op_re = re.compile(r"_.*|paren").fullmatch
|
|
|
|
|
|
def list_ops(cls: type[Any]):
|
|
return OrderedSet([x for x in dir(cls) if not _ignore_op_re(x)])
|
|
|
|
|
|
OP_NAMES = list_ops(OpsHandler)
|
|
|
|
|
|
class DefaultHandler(OpsHandler[Any]):
|
|
def _default(self, name: str, args: tuple[Any, ...], kwargs: dict[str, Any]) -> Any:
|
|
"""
|
|
Default implementation for all ops. Override in a subclass to
|
|
provide generic op behavior.
|
|
|
|
Args:
|
|
name: name of the op, see OpHandler.{name}
|
|
args: positional args passed to the op
|
|
kwargs: keyword args passed to the op
|
|
|
|
Returns:
|
|
return value of the op
|
|
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def __getattr__(self, name: str) -> Any:
|
|
def fallback(*args: Any, **kwargs: Any) -> Any:
|
|
return self._default(name, args, kwargs)
|
|
|
|
# would like to remove this function entirely, but it's used in MTIA backend
|
|
warnings.warn(f"undefined OpHandler.{name}, please add missing op schema")
|
|
return fallback
|
|
|
|
@staticmethod
|
|
def _call_default(target: str):
|
|
def call_default(self, *args, **kwargs):
|
|
return self._default(target, args, kwargs)
|
|
|
|
call_default.__name__ = target
|
|
return call_default
|
|
|
|
@classmethod
|
|
def _init_cls(cls):
|
|
"""
|
|
Here we codegen many functions of the form:
|
|
|
|
def add(self, a, b):
|
|
return self._default('add', (a, b), {})
|
|
|
|
and install them in cls. This is the same as _call_default above,
|
|
but is about 1.2x faster since CPython varargs parsing is slow.
|
|
"""
|
|
code = StringIO()
|
|
for target in OP_NAMES:
|
|
sig = inspect.signature(getattr(OpsHandler, target))
|
|
if all(
|
|
p.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD
|
|
and p.default is inspect.Parameter.empty
|
|
for p in sig.parameters.values()
|
|
):
|
|
self_arg, *args = sig.parameters.keys()
|
|
assert self_arg == "self"
|
|
code.write(
|
|
f"""
|
|
def {target}(self, {", ".join(args)}):
|
|
return self._default({target!r}, ({", ".join(args)}, ), {{}})
|
|
""".strip()
|
|
)
|
|
code.write("\n\n")
|
|
else:
|
|
# slower fallback for ops with default or variadic arguments
|
|
setattr(cls, target, cls._call_default(target))
|
|
|
|
ctx: dict[str, Any] = {}
|
|
exec(code.getvalue(), ctx)
|
|
for target, impl in ctx.items():
|
|
if target in OP_NAMES:
|
|
setattr(cls, target, impl)
|
|
|
|
|
|
DefaultHandler._init_cls()
|
|
|
|
|
|
class NoopHandler(DefaultHandler):
|
|
name = "NoopHandler"
|
|
|
|
def _default(self, name: str, args: tuple[Any, ...], kwargs: dict[str, Any]) -> Any:
|
|
return None
|
|
|
|
@staticmethod
|
|
def masked(mask, body, other) -> None:
|
|
return None
|
|
|
|
@staticmethod
|
|
def frexp(x) -> tuple[None, None]:
|
|
return (None, None)
|
|
|
|
@staticmethod
|
|
def scan(dtypes, combine_fn, values) -> tuple[None, ...]:
|
|
return (None,) * len(values)
|
|
|
|
@staticmethod
|
|
def sort(dtypes, values, stable, descending) -> tuple[None, ...]:
|
|
return (None,) * len(values)
|
|
|
|
@staticmethod
|
|
def indirect_indexing(index_var, size, check=True, wrap_neg=True) -> sympy.Symbol:
|
|
return sympy.S.Zero
|
|
|
|
|
|
class BasicMathOpsMixin:
|
|
@staticmethod
|
|
def add(a, b):
|
|
return f"{a} + {b}"
|
|
|
|
@staticmethod
|
|
def sub(a, b):
|
|
return f"{a} - {b}"
|
|
|
|
@staticmethod
|
|
def mul(a, b):
|
|
return f"{a} * {b}"
|
|
|
|
@staticmethod
|
|
def floordiv(a, b):
|
|
return f"{a} // {b}"
|
|
|
|
@staticmethod
|
|
def truediv(a, b):
|
|
return f"{a} / {b}"
|
|
|
|
@staticmethod
|
|
def mod(a, b):
|
|
# careful, depending on target semantics varies
|
|
return f"{a} % {b}"
|
|
|
|
@staticmethod
|
|
def pow(a, b):
|
|
return f"{a} ** {b}"
|
|
|
|
@staticmethod
|
|
def lshift(a, b):
|
|
return f"{a} << {b}"
|
|
|
|
@staticmethod
|
|
def rshift(a, b):
|
|
return f"{a} >> {b}"
|
|
|
|
@staticmethod
|
|
def and_(a, b):
|
|
return f"{a} & {b}"
|
|
|
|
@staticmethod
|
|
def or_(a, b):
|
|
return f"{a} | {b}"
|
|
|
|
@staticmethod
|
|
def xor(a, b):
|
|
return f"{a} ^ {b}"
|
|
|
|
@staticmethod
|
|
def eq(a, b):
|
|
return f"{a} == {b}"
|
|
|
|
@staticmethod
|
|
def ne(a, b):
|
|
return f"{a} != {b}"
|
|
|
|
@staticmethod
|
|
def lt(a, b):
|
|
return f"{a} < {b}"
|
|
|
|
@staticmethod
|
|
def gt(a, b):
|
|
return f"{a} > {b}"
|
|
|
|
@staticmethod
|
|
def le(a, b):
|
|
return f"{a} <= {b}"
|
|
|
|
@staticmethod
|
|
def ge(a, b):
|
|
return f"{a} >= {b}"
|
|
|
|
@staticmethod
|
|
def neg(a):
|
|
return f"-{a}"
|
|
|
|
|
|
class MockHandler(BasicMathOpsMixin, DefaultHandler):
|
|
name = "MockHandler"
|
|
|
|
def _default(self, name: str, args: tuple[Any, ...], kwargs: dict[str, Any]) -> Any:
|
|
fargs = [*map(_arg_str, args)]
|
|
for k, v in kwargs.items():
|
|
fargs.append(f"{k}={_arg_str(v)}")
|
|
return f"ops.{name}({', '.join(fargs)})"
|
|
|
|
@staticmethod
|
|
def masked(mask, body, other) -> str:
|
|
return f"ops.masked({mask}, {body()}, {other})"
|
|
|
|
@staticmethod
|
|
def frexp(x):
|
|
return (f"ops.frexp({x})[0]", f"ops.frexp({x})[1]")
|
|
|
|
@staticmethod
|
|
def scan(dtypes, combine_fn, values):
|
|
return tuple(
|
|
f"ops.scan({dtypes}, {combine_fn}, {values})[{i}]"
|
|
for i in range(len(values))
|
|
)
|
|
|
|
@staticmethod
|
|
def sort(dtypes, values, stable, descending):
|
|
return tuple(
|
|
f"ops.sort({dtypes}, {values}, stable={stable}, descending={descending})[{i}]"
|
|
for i in range(len(values))
|
|
)
|
|
|
|
@staticmethod
|
|
def indirect_indexing(index_var, size, check=True, wrap_neg=True) -> sympy.Symbol:
|
|
return sympy_index_symbol(str(index_var))
|
|
|
|
|
|
class KernelFormatterHandler(DefaultHandler):
|
|
def __init__(self, parent_handler: OpsHandler[Any]):
|
|
self.parent_handler = parent_handler
|
|
self._output = IndentedBuffer(1)
|
|
self.var_counter = itertools.count()
|
|
|
|
@staticmethod
|
|
def ir_to_string(ir_fn, index, rindex=None) -> str:
|
|
from .ir import FlexibleLayout
|
|
from .virtualized import V
|
|
|
|
args = [index, rindex] if rindex is not None else [index]
|
|
names = ["index", "rindex"] if rindex is not None else ["index"]
|
|
formatter = KernelFormatterHandler(MockHandler())
|
|
|
|
with formatter._output.indent(-1):
|
|
formatter._output.writeline(f"def inner_fn({', '.join(names)}):")
|
|
for name, arg in zip(names, args):
|
|
if arg:
|
|
lhs = ", ".join(
|
|
[
|
|
str("_" if isinstance(v, (int, sympy.Integer)) else v)
|
|
for v in arg
|
|
]
|
|
)
|
|
formatter._output.writeline(f"{lhs} = {name}")
|
|
|
|
with (
|
|
V.set_ops_handler(formatter),
|
|
patch.object(FlexibleLayout, "allow_indexing", True),
|
|
):
|
|
result = ir_fn(*args)
|
|
return formatter.getvalue(result)
|
|
|
|
def indirect_indexing(self, *args, **kwargs) -> sympy.Symbol:
|
|
return self.parent_handler.indirect_indexing(*args, **kwargs)
|
|
|
|
def _write(self, line):
|
|
# replace line with a new variable name
|
|
varname = f"tmp{next(self.var_counter)}"
|
|
self._output.writeline(f"{varname} = {line}")
|
|
return varname
|
|
|
|
def _default(self, name: str, args: tuple[Any, ...], kwargs: dict[str, Any]) -> Any:
|
|
return pytree.tree_map(
|
|
self._write, getattr(self.parent_handler, name)(*args, **kwargs)
|
|
)
|
|
|
|
def reduction(
|
|
self,
|
|
dtype: torch.dtype,
|
|
src_dtype: torch.dtype,
|
|
reduction_type: ReductionType,
|
|
value: Union[str, tuple[str, ...]],
|
|
) -> Union[str, tuple[str, ...]]:
|
|
line = self.parent_handler.reduction(dtype, src_dtype, reduction_type, value)
|
|
num_values = reduction_num_outputs(reduction_type)
|
|
varnames = [f"tmp{next(self.var_counter)}" for _ in range(num_values)]
|
|
self._output.writeline(f"{','.join(varnames)} = {line}")
|
|
return tuple(varnames) if num_values > 1 else varnames[0]
|
|
|
|
def getvalue(self, result):
|
|
self._output.writeline(f"return {result}")
|
|
return self._output.getvalue()
|
|
|
|
|
|
class WrapperHandler(DefaultHandler):
|
|
def __init__(self, inner: OpsHandler[Any]):
|
|
self._inner = inner
|
|
|
|
def _default(self, name: str, args: tuple[Any, ...], kwargs: dict[str, Any]) -> Any:
|
|
return getattr(self._inner, name)(*args, **kwargs)
|
|
|
|
|
|
class AddParenHandler(WrapperHandler):
|
|
def _default(self, name: str, args: tuple[Any, ...], kwargs: dict[str, Any]) -> Any:
|
|
val = getattr(self._inner, name)(*args, **kwargs)
|
|
if not val or isinstance(val, (sympy.Expr, tuple, list)):
|
|
return val
|
|
return f"({val})"
|
|
|
|
|
|
class OpCountResult(NamedTuple):
|
|
num_ops: int
|
|
used_ops: OrderedSet[str]
|
|
read_buffers: list[str]
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nontrivial_read_count: int
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|
|
|
|
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class OpCounterCSE(DefaultHandler):
|
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"""Shim to count how many ops are used"""
|
|
|
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def __init__(self, inner: OpsHandler[Any]):
|
|
super().__init__()
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self.parent_handler = inner
|
|
self.op_count = 0
|
|
self.var_names: dict[str, str] = {}
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self._used_ops: OrderedSet[str] = OrderedSet()
|
|
self._read_names: list[str] = []
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|
self._nontrivial_read_count = 0
|
|
|
|
def _default(self, name: str, args: tuple[Any, ...], kwargs: dict[str, Any]) -> Any:
|
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self._used_ops.add(name)
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|
return pytree.tree_map(
|
|
self._update_count, getattr(self.parent_handler, name)(*args, **kwargs)
|
|
)
|
|
|
|
def _update_count(self, val):
|
|
varname = self.var_names.get(val)
|
|
if not varname:
|
|
varname = f"tmp{self.op_count}"
|
|
self.op_count += 1
|
|
self.var_names[val] = varname
|
|
return varname
|
|
|
|
def indirect_indexing(self, *args, **kwargs):
|
|
self._used_ops.add("indirect_indexing")
|
|
return self.parent_handler.indirect_indexing(*args, **kwargs)
|
|
|
|
def load(self, name: str, index: sympy.Expr) -> str:
|
|
val = self.parent_handler.load(name, index)
|
|
if val not in self.var_names:
|
|
self._used_ops.add("load")
|
|
self._read_names.append(name)
|
|
if not isinstance(index, (sympy.Integer, int)):
|
|
self._nontrivial_read_count += 1
|
|
return self._update_count(val)
|
|
|
|
def load_seed(self, name: str, offset: T):
|
|
val = self.parent_handler.load_seed(name, offset)
|
|
if val not in self.var_names:
|
|
self._used_ops.add("load_seed")
|
|
self._read_names.append(name)
|
|
return self._update_count(val)
|
|
|
|
def bucketize(
|
|
self,
|
|
values: T,
|
|
boundaries: tuple[str, sympy.Expr, sympy.Expr, sympy.Expr],
|
|
boundary_indices: T,
|
|
indexing_dtype: torch.dtype,
|
|
right: bool,
|
|
sorter: Optional[tuple[str, sympy.Expr]] = None,
|
|
sorter_indices: Optional[T] = None,
|
|
) -> T:
|
|
"""
|
|
See [Note: Inductor bucketize op]
|
|
"""
|
|
val = self.parent_handler.bucketize(
|
|
values,
|
|
boundaries,
|
|
boundary_indices,
|
|
indexing_dtype,
|
|
right,
|
|
sorter,
|
|
sorter_indices,
|
|
)
|
|
if val not in self.var_names:
|
|
self._used_ops.add("bucketize")
|
|
self._read_names.append(boundaries[0])
|
|
if sorter is not None:
|
|
self._read_names.append(sorter[0])
|
|
return self._update_count(val)
|
|
|
|
def getvalue(self):
|
|
return OpCountResult(
|
|
self.op_count, self._used_ops, self._read_names, self._nontrivial_read_count
|
|
)
|
|
|
|
|
|
class ExtractConstantsHandler(NoopHandler):
|
|
def __init__(self, device: Optional[torch.device]):
|
|
self.device = device
|
|
|
|
def constant(self, value: Any, dtype: torch.dtype) -> torch._inductor.ir.Constant:
|
|
from torch._inductor import ir
|
|
|
|
return ir.Constant(
|
|
value=value, dtype=dtype, device=self.device or torch.get_default_device()
|
|
)
|
|
|
|
|
|
class SimpleCSEHandler(WrapperHandler):
|
|
"""Wraps the underlying handler with a CSE pass
|
|
|
|
NOTE: Compared to codegen level CSE this is simplified as it
|
|
doesn't support stores which require load cache invalidation.
|
|
"""
|
|
|
|
def __init__(self, inner: Any):
|
|
super().__init__(inner)
|
|
self.cse_cache: dict[str, Union[Any, tuple[Any, ...]]] = {}
|
|
self.mock = MockHandler()
|
|
|
|
def indirect_indexing(self, *args, **kwargs) -> sympy.Expr:
|
|
return super().indirect_indexing(*args, **kwargs) # type: ignore[misc]
|
|
|
|
def store(self, *args, **kwargs) -> None:
|
|
raise NotImplementedError("store not implemented")
|
|
|
|
def store_reduction(self, *args, **kwargs) -> None:
|
|
raise NotImplementedError("store not implemented")
|
|
|
|
def _default(self, name: str, args: tuple[Any, ...], kwargs: dict[str, Any]) -> Any:
|
|
key = getattr(self.mock, name)(*args, **kwargs)
|
|
val = self.cse_cache.get(key)
|
|
if val is not None:
|
|
return val
|
|
|
|
val = getattr(self._inner, name)(*args, **kwargs)
|
|
self.cse_cache[key] = val
|
|
return val
|
|
|
|
def device_assert_async(self, *args, **kwargs) -> None:
|
|
raise NotImplementedError(
|
|
f"{type(self).__name__}: device_assert_async should be handled by CSEProxy"
|
|
)
|