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

Use lispy tuples in cat (fixes #21673) #39314

Merged
merged 2 commits into from
Jan 20, 2021
Merged

Use lispy tuples in cat (fixes #21673) #39314

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
3b2407a
Use lispy tuples in cat (fixes #21673)
timholy Jan 19, 2021
4be707f
reduce specialization cost (?)
timholy Jan 19, 2021
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
43 changes: 22 additions & 21 deletions base/abstractarray.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1639,28 +1639,29 @@ _cat(dims, X...) = cat_t(promote_eltypeof(X...), X...; dims=dims)
return __cat(A, shape, catdims, X...)
end

function __cat(A, shape::NTuple{M}, catdims, X...) where M
N = M::Int
offsets = zeros(Int, N)
inds = Vector{UnitRange{Int}}(undef, N)
concat = copyto!(zeros(Bool, N), catdims)
for x in X
for i = 1:N
if concat[i]
inds[i] = offsets[i] .+ cat_indices(x, i)
offsets[i] += cat_size(x, i)
else
inds[i] = 1:shape[i]
end
end
I::NTuple{N, UnitRange{Int}} = (inds...,)
if x isa AbstractArray
A[I...] = x
else
fill!(view(A, I...), x)
end
# Why isn't this called `__cat!`?
__cat(A, shape, catdims, X...) = __cat_offset!(A, shape, catdims, ntuple(zero, length(shape)), X...)

function __cat_offset!(A, shape, catdims, offsets, x, X...)
# splitting the "work" on x from X... may reduce latency (fewer costly specializations)
Copy link
Member

Choose a reason for hiding this comment

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

Clever!

newoffsets = __cat_offset1!(A, shape, catdims, offsets, x)
return __cat_offset!(A, shape, catdims, newoffsets, X...)
end
__cat_offset!(A, shape, catdims, offsets) = A

function __cat_offset1!(A, shape, catdims, offsets, x)
inds = ntuple(length(offsets)) do i
(i <= length(catdims) && catdims[i]) ? offsets[i] .+ cat_indices(x, i) : 1:shape[i]
end
if x isa AbstractArray
A[inds...] = x
else
fill!(view(A, inds...), x)
end
newoffsets = ntuple(length(offsets)) do i
(i <= length(catdims) && catdims[i]) ? offsets[i] + cat_size(x, i) : offsets[i]
end
return A
return newoffsets
end

"""
Expand Down