perf: optimize multibasis for sparse differentiation

Author: gdalle

DifferentiationInterface/Project.toml

@@ -1,7 +1,7 @@
 name = "DifferentiationInterface"
 uuid = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
 authors = ["Guillaume Dalle", "Adrian Hill"]
-version = "0.6.51"
+version = "0.6.52"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"

DifferentiationInterface/src/utils/basis.jl

@@ -61,12 +61,15 @@ end
     multibasis(a::AbstractArray, inds)
 
 Construct the sum of the `i`-th standard basis arrays in the vector space of `a` for all `i ∈ inds`.
+
+!!! warning
+    Does not work on GPU, since this is intended for sparse autodiff and SparseMatrixColorings.jl doesn't work on GPUs either.
 """
 function multibasis(a::AbstractArray{T}, inds) where {T}
     b = similar(a)
     fill!(b, zero(T))
     for i in inds
-        b .+= OneElement(i, one(T), a)
+        b[i] = one(T)
     end
     return ismutable_array(a) ? b : map(+, zero(a), b)
 end