Indexing with a CuArrays causes a 'scalar indexing disallowed' error from checkbounds

[tanhevg]

I have stumbled upon this when playing around with FluxML/Flux.jl#1006

MWE:

using CuArrays
CuArrays.allowscalar(false)
x = cu(rand(10));
ind = cu(rand(1:10, 20));
x[ind]

This gives an error, because checkbounds in base goes through the index array one by one:

ERROR: scalar getindex is disallowed
Stacktrace:
 [1] error(::String) at ./error.jl:33
 [2] assertscalar(::String) at /data/.julia/packages/GPUArrays/QDGmr/src/host/indexing.jl:41
 [3] getindex(::CuArray{Int64,1,Nothing}, ::Int64) at /data/.julia/packages/GPUArrays/QDGmr/src/host/indexing.jl:86
 [4] iterate at ./abstractarray.jl:914 [inlined]
 [5] iterate at ./abstractarray.jl:912 [inlined]
 [6] checkindex at ./abstractarray.jl:572 [inlined]
 [7] checkbounds at ./abstractarray.jl:488 [inlined]
 [8] checkbounds at ./abstractarray.jl:503 [inlined]
 [9] _getindex at ./multidimensional.jl:669 [inlined]
 [10] getindex(::CuArray{Float32,1,Nothing}, ::CuArray{Int64,1,Nothing}) at ./abstractarray.jl:981
 [11] top-level scope at REPL[5]:1

Now, disable checkindex:

import Base.checkindex

checkindex(::Type{Bool}, inds::AbstractUnitRange, I::CuArray) = true
checkindex (generic function with 12 methods)

x[ind]
# prints the expected output

I presume, checkindex needs overriding to something meaningful for GPUArrays?

[maleadt]

JuliaGPU/GPUArrays.jl#309