hvncat triggers scalar iteration

[roflmaostc]

gg = CUDA.rand(2,2)

# errors with
[gg;; gg]
Scalar indexing is disallowed.

Invocation of getindex resulted in scalar indexing of a GPU array.

This is typically caused by calling an iterating implementation of a method.

Such implementations *do not* execute on the GPU, but very slowly on the CPU,

and therefore are only permitted from the REPL for prototyping purposes.

If you did intend to index this array, annotate the caller with @allowscalar.

    error(::String)@error.jl:35
    assertscalar(::String)@GPUArraysCore.jl:103
    getindex(::CUDA.CuArray{Float32, 2, CUDA.Mem.DeviceBuffer}, ::Int64)@indexing.jl:9
    _typed_hvncat(::Type{Float32}, ::Val{2}, ::CUDA.CuArray{Float32, 2, CUDA.Mem.DeviceBuffer}, ::CUDA.CuArray{Float32, 2, CUDA.Mem.DeviceBuffer})@abstractarray.jl:2259
    _typed_hvncat(::Type, ::Int64, ::Bool, ::CUDA.CuArray{Float32, 2, CUDA.Mem.DeviceBuffer}, ::Vararg{CUDA.CuArray{Float32, 2, CUDA.Mem.DeviceBuffer}})@abstractarray.jl:2215
    _hvncat@abstractarray.jl:2196[inlined]
    hvncat@abstractarray.jl:2189[inlined]
    top-level scope@[Local: 1](http://localhost:1234/edit?id=77e8e67e-c8bb-11ed-06aa-479b71d48037#)[inlined]


# works
[gg; gg]

CUDA runtime 11.8, artifact installation
CUDA driver 12.0
NVIDIA driver 525.85.5

Libraries:

• CUBLAS: 11.11.3
• CURAND: 10.3.0
• CUFFT: 10.9.0
• CUSOLVER: 11.4.1
• CUSPARSE: 11.7.5
• CUPTI: 18.0.0
• NVML: 12.0.0+525.85.5

Toolchain:

• Julia: 1.8.5
• LLVM: 13.0.1
• PTX ISA support: 3.2, 4.0, 4.1, 4.2, 4.3, 5.0, 6.0, 6.1, 6.3, 6.4, 6.5, 7.0, 7.1, 7.2
• Device capability support: sm_35, sm_37, sm_50, sm_52, sm_53, sm_60, sm_61, sm_62, sm_70, sm_72, sm_75, sm_80, sm_86

1 device:
0: NVIDIA GeForce RTX 3060 (sm_86, 6.252 GiB / 12.000 GiB available)

❔

Julia Version 1.8.5
Commit 17cfb8e65ea (2023-01-08 06:45 UTC)
Platform Info:
OS: Linux (x86_64-linux-gnu)
CPU: 24 × AMD Ryzen 9 5900X 12-Core Processor
WORD_SIZE: 64
LIBM: libopenlibm
LLVM: libLLVM-13.0.1 (ORCJIT, znver3)
Threads: 12 on 24 virtual cores
Environment:
JULIA_NUM_THREADS = 12
JULIA_REVISE_WORKER_ONLY = 1

[maleadt]

;; lowers to Base.hvncat

julia> Meta.@lower [a ;; a]
:($(Expr(:thunk, CodeInfo(
    @ none within `top-level scope`
1 ─ %1 = Base.hvncat(2, a, a)
└──      return %1
))))

This can probably be implemented in GPUArrays.