Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Accumulate NamedTuple + Tangent #88

Merged
merged 3 commits into from
Sep 4, 2022
Merged

Accumulate NamedTuple + Tangent #88

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
b548b4e
accumulate NamedTuple + Tangent
mcabbott Aug 31, 2022
d50f6e8
fixup
mcabbott Aug 31, 2022
c9f2a90
don't test on 1.8
mcabbott Sep 4, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions src/extra_rules.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -266,3 +266,6 @@ end
function ChainRulesCore.rrule(::DiffractorRuleConfig, ::Type{InplaceableThunk}, add!!, val)
val, Δ->(NoTangent(), NoTangent(), Δ)
end

Base.real(z::ZeroTangent) = z # TODO should be in CRC
Base.real(z::NoTangent) = z
Comment on lines +270 to +271
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is JuliaDiff/ChainRulesCore.jl#581 now

20 changes: 17 additions & 3 deletions src/runtime.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,11 +5,25 @@ struct DiffractorRuleConfig <: RuleConfig{Union{HasReverseMode,HasForwardsMode}}
@Base.constprop :aggressive accum(a::Tuple, b::Tuple) = map(accum, a, b)
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I get some errors from this adding tuples of mis-matched lengths, which I haven't tracked down. Not touched in this PR.

What I don't know here is whether accum is only ever called on a single tangent, or also on a tuple of a function's arguments. IIRC there is no distinction in Zygote, but in CR the former can be Array or Tangent or NoTangent, but the latter can only ever be a Tuple (of the right length).

@Base.constprop :aggressive @generated function accum(x::NamedTuple, y::NamedTuple)
fnames = union(fieldnames(x), fieldnames(y))
isempty(fnames) && return :((;)) # code below makes () instead
gradx(f) = f in fieldnames(x) ? :(getfield(x, $(quot(f)))) : :(ZeroTangent())
grady(f) = f in fieldnames(y) ? :(getfield(y, $(quot(f)))) : :(ZeroTangent())
Expr(:tuple, [:($f=accum($(gradx(f)), $(grady(f)))) for f in fnames]...)
end
@Base.constprop :aggressive accum(a, b, c, args...) = accum(accum(a, b), c, args...)
@Base.constprop :aggressive accum(a::NoTangent, b) = b
@Base.constprop :aggressive accum(a, b::NoTangent) = a
@Base.constprop :aggressive accum(a::NoTangent, b::NoTangent) = NoTangent()
@Base.constprop :aggressive accum(a::AbstractZero, b) = b
@Base.constprop :aggressive accum(a, b::AbstractZero) = a
@Base.constprop :aggressive accum(a::AbstractZero, b::AbstractZero) = NoTangent()

using ChainRulesCore: Tangent, backing

function accum(x::Tangent{T}, y::NamedTuple) where T
# @warn "gradient is both a Tangent and a NamedTuple" x y
_tangent(T, accum(backing(x), y))
end
accum(x::NamedTuple, y::Tangent) = accum(y, x)
# This solves an ambiguity, but also avoids Tangent{ZeroTangent}() which + does not:
accum(x::Tangent{T}, y::Tangent) where T = _tangent(T, accum(backing(x), backing(y)))

_tangent(::Type{T}, z) where T = Tangent{T,typeof(z)}(z)
_tangent(::Type, ::NamedTuple{()}) = NoTangent()
10 changes: 1 addition & 9 deletions test/runtests.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -162,15 +162,7 @@ end
# Make sure that there's no infinite recursion in kwarg calls
g_kw(;x=1.0) = sin(x)
f_kw(x) = g_kw(;x)
@test bwd(f_kw)(1.0) == bwd(sin)(1.0) broken=true
#=
MethodError: no method matching +(::Tangent{var"#g_kw#47"{var"#g_kw#11#48"}, NamedTuple{(Symbol("#g_kw#11"),), Tuple{ZeroTangent}}}, ::Tangent{Diffractor.KwFunc{var"#g_kw#47"{var"#g_kw#11#48"}, var"#g_kw#47##kw"}, NamedTuple{(:kwf,), Tuple{ZeroTangent}}})
...
[2] elementwise_add(a::NamedTuple{(:contents,), Tuple{Tangent{var"#g_kw#47"{var"#g_kw#11#48"}, NamedTuple{(Symbol("#g_kw#11"),), Tuple{ZeroTangent}}}}}, b::NamedTuple{(:contents,), Tuple{Tangent{Diffractor.KwFunc{var"#g_kw#47"{var"#g_kw#11#48"}, var"#g_kw#47##kw"}, NamedTuple{(:kwf,), Tuple{ZeroTangent}}}}})
@ ChainRulesCore ~/.julia/packages/ChainRulesCore/ctmSK/src/tangent_types/tangent.jl:287
[3] +(a::Tangent{Core.Box, NamedTuple{(:contents,), Tuple{Tangent{var"#g_kw#47"{var"#g_kw#11#48"}, NamedTuple{(Symbol("#g_kw#11"),), Tuple{ZeroTangent}}}}}}, b::Tangent{Core.Box, NamedTuple{(:contents,), Tuple{Tangent{Diffractor.KwFunc{var"#g_kw#47"{var"#g_kw#11#48"}, var"#g_kw#47##kw"}, NamedTuple{(:kwf,), Tuple{ZeroTangent}}}}}})
@ ChainRulesCore ~/.julia/packages/ChainRulesCore/ctmSK/src/tangent_arithmetic.jl:130
=#
@test bwd(f_kw)(1.0) == bwd(sin)(1.0)

function f_crit_edge(a, b, c, x)
# A function with two critical edges. This used to trigger an issue where
Expand Down