# Problem of binarycrossentropy with GPU?

**URL:** https://discourse.julialang.org/t/problem-of-binarycrossentropy-with-gpu/31026
**Category:** Machine Learning
**Tags:** cuda, flux
**Created:** [November 13, 2019, 2:26am UTC](https://discourse.julialang.org/t/problem-of-binarycrossentropy-with-gpu/31026 "2019-11-13T02:26:12Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![taot](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/taot/32/11257_2.png) [@taot](https://discourse.julialang.org/u/taot)
#### Post date: [November 13, 2019, 2:26am UTC](https://discourse.julialang.org/t/problem-of-binarycrossentropy-with-gpu/31026/1 "2019-11-13T02:26:12Z")

</div>

Hi,

I am trying to create a model in Flux, with binarycrossentropy in loss function, but encountered a problem invoking binarycrossentropy on GPU. I reproduced the error with this simple case:

```julia
# just copy from document in Flux/src/layers/stateless.jl
binarycrossentropy.(σ.([-1.1491, 0.8619, 0.3127]), [0.9, 0.9, 0.1])

```

which works find and output:

```julia
3-element Array{Float64,1}:
 1.309487097347566  
 0.43850664672364076
 0.8304003662235442 

```

But when I moved the inputs to GPU, and run binarycrossentropy:

```julia
a1 = gpu([-1.1491, 0.8619, 0.3127])
a2 = gpu([1, 1, 0.])
binarycrossentropy.(σ.(a1), a2)

```

then I got this error:

```julia
┌ Warning: calls to Base intrinsics might be GPU incompatible
│ exception = (CUDAnative.MethodSubstitutionWarning(log(x::Float32) in Base.Math at special/log.jl:290, log(x::Float32) in CUDAnative at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/device/cuda/math.jl:71), Base.StackTraces.StackFrame[log at log.jl:290, binarycrossentropy at stateless.jl:26, #25 at broadcast.jl:49])
└ @ CUDAnative /home/taot/.julia/packages/CUDAnative/Lr0yj/src/compiler/irgen.jl:116
┌ Warning: calls to Base intrinsics might be GPU incompatible
│ exception = (CUDAnative.MethodSubstitutionWarning(log(x::Float32) in Base.Math at special/log.jl:290, log(x::Float32) in CUDAnative at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/device/cuda/math.jl:71), Base.StackTraces.StackFrame[log at log.jl:290, binarycrossentropy at stateless.jl:26, #25 at broadcast.jl:49])
└ @ CUDAnative /home/taot/.julia/packages/CUDAnative/Lr0yj/src/compiler/irgen.jl:116

InvalidIRError: compiling #25(CuArrays.CuKernelState, CUDAnative.CuDeviceArray{Float32,1,CUDAnative.AS.Global}, Base.Broadcast.Broadcasted{Nothing,Tuple{Base.OneTo{Int64}},typeof(binarycrossentropy),Tuple{Base.Broadcast.Broadcasted{Base.Broadcast.ArrayStyle{CuArrays.CuArray},Nothing,typeof(CuArrays.cuσ),Tuple{Base.Broadcast.Extruded{CUDAnative.CuDeviceArray{Float32,1,CUDAnative.AS.Global},Tuple{Bool},Tuple{Int64}}}},Base.Broadcast.Extruded{CUDAnative.CuDeviceArray{Float32,1,CUDAnative.AS.Global},Tuple{Bool},Tuple{Int64}}}}) resulted in invalid LLVM IR
Reason: unsupported call through a literal pointer (call to jl_alloc_string)
Stacktrace:
 [1] _string_n at strings/string.jl:60
 [2] StringVector at iobuffer.jl:31
 [3] #IOBuffer#318 at iobuffer.jl:114
 [4] multiple call sites at unknown:0
Reason: unsupported call through a literal pointer (call to jl_string_to_array)
Stacktrace:
 [1] unsafe_wrap at strings/string.jl:71
 [2] StringVector at iobuffer.jl:31
 [3] #IOBuffer#318 at iobuffer.jl:114
 [4] multiple call sites at unknown:0
Reason: unsupported call through a literal pointer (call to __memset_avx2_unaligned_erms)
Stacktrace:
 [1] fill! at array.jl:366
 [2] #IOBuffer#318 at iobuffer.jl:121
 [3] multiple call sites at unknown:0
Reason: unsupported dynamic function invocation (call to print)
Stacktrace:
 [1] print_to_string at strings/io.jl:124
 [2] string at strings/io.jl:168
 [3] throw_complex_domainerror at math.jl:31
 [4] log at special/log.jl:321
 [5] #binarycrossentropy#49 at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [6] binarycrossentropy at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [7] _broadcast_getindex_evalf at broadcast.jl:625
 [8] _broadcast_getindex at broadcast.jl:598
 [9] getindex at broadcast.jl:558
 [10] #25 at /home/taot/.julia/packages/GPUArrays/tIMl5/src/broadcast.jl:50
Reason: unsupported dynamic function invocation (call to print)
Stacktrace:
 [1] print_to_string at strings/io.jl:129
 [2] string at strings/io.jl:168
 [3] throw_complex_domainerror at math.jl:31
 [4] log at special/log.jl:321
 [5] #binarycrossentropy#49 at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [6] binarycrossentropy at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [7] _broadcast_getindex_evalf at broadcast.jl:625
 [8] _broadcast_getindex at broadcast.jl:598
 [9] getindex at broadcast.jl:558
 [10] #25 at /home/taot/.julia/packages/GPUArrays/tIMl5/src/broadcast.jl:50
Reason: unsupported call through a literal pointer (call to jl_array_grow_end)
Stacktrace:
 [1] _growend! at array.jl:811
 [2] resize! at array.jl:1003
 [3] print_to_string at strings/io.jl:131
 [4] string at strings/io.jl:168
 [5] throw_complex_domainerror at math.jl:31
 [6] log at special/log.jl:321
 [7] #binarycrossentropy#49 at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [8] binarycrossentropy at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [9] _broadcast_getindex_evalf at broadcast.jl:625
 [10] _broadcast_getindex at broadcast.jl:598
 [11] getindex at broadcast.jl:558
 [12] #25 at /home/taot/.julia/packages/GPUArrays/tIMl5/src/broadcast.jl:50
Reason: unsupported call through a literal pointer (call to jl_array_del_end)
Stacktrace:
 [1] _deleteend! at array.jl:820
 [2] resize! at array.jl:1008
 [3] print_to_string at strings/io.jl:131
 [4] string at strings/io.jl:168
 [5] throw_complex_domainerror at math.jl:31
 [6] log at special/log.jl:321
 [7] #binarycrossentropy#49 at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [8] binarycrossentropy at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [9] _broadcast_getindex_evalf at broadcast.jl:625
 [10] _broadcast_getindex at broadcast.jl:598
 [11] getindex at broadcast.jl:558
 [12] #25 at /home/taot/.julia/packages/GPUArrays/tIMl5/src/broadcast.jl:50
Reason: unsupported call through a literal pointer (call to jl_array_to_string)
Stacktrace:
 [1] Type at strings/string.jl:39
 [2] print_to_string at strings/io.jl:131
 [3] string at strings/io.jl:168
 [4] throw_complex_domainerror at math.jl:31
 [5] log at special/log.jl:321
 [6] #binarycrossentropy#49 at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [7] binarycrossentropy at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [8] _broadcast_getindex_evalf at broadcast.jl:625
 [9] _broadcast_getindex at broadcast.jl:598
 [10] getindex at broadcast.jl:558
 [11] #25 at /home/taot/.julia/packages/GPUArrays/tIMl5/src/broadcast.jl:50
Reason: unsupported call to the Julia runtime (call to jl_type_error)
Stacktrace:
 [1] print_to_string at strings/io.jl:124
 [2] string at strings/io.jl:168
 [3] throw_complex_domainerror at math.jl:31
 [4] log at special/log.jl:321
 [5] #binarycrossentropy#49 at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [6] binarycrossentropy at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [7] _broadcast_getindex_evalf at broadcast.jl:625
 [8] _broadcast_getindex at broadcast.jl:598
 [9] getindex at broadcast.jl:558
 [10] #25 at /home/taot/.julia/packages/GPUArrays/tIMl5/src/broadcast.jl:50
Reason: unsupported call through a literal pointer (call to jl_alloc_string)
Stacktrace:
 [1] _string_n at strings/string.jl:60
 [2] string at strings/substring.jl:186
 [3] throw_complex_domainerror at math.jl:31
 [4] log at special/log.jl:321
 [5] #binarycrossentropy#49 at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [6] binarycrossentropy at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [7] _broadcast_getindex_evalf at broadcast.jl:625
 [8] _broadcast_getindex at broadcast.jl:598
 [9] getindex at broadcast.jl:558
 [10] #25 at /home/taot/.julia/packages/GPUArrays/tIMl5/src/broadcast.jl:50
Reason: unsupported call through a literal pointer (call to __memcpy_avx_unaligned_erms)
Stacktrace:
 [1] unsafe_copyto! at array.jl:226
 [2] __unsafe_string! at strings/substring.jl:173
 [3] string at strings/substring.jl:189
 [4] throw_complex_domainerror at math.jl:31
 [5] log at special/log.jl:321
 [6] #binarycrossentropy#49 at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [7] binarycrossentropy at /home/taot/.julia/packages/Flux/dkJUV/src/layers/stateless.jl:26
 [8] _broadcast_getindex_evalf at broadcast.jl:625
 [9] _broadcast_getindex at broadcast.jl:598
 [10] getindex at broadcast.jl:558
 [11] #25 at /home/taot/.julia/packages/GPUArrays/tIMl5/src/broadcast.jl:50

Stacktrace:
 [1] check_ir(::CUDAnative.CompilerJob, ::LLVM.Module) at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/compiler/validation.jl:114
 [2] macro expansion at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/compiler/driver.jl:188 [inlined]
 [3] macro expansion at /home/taot/.julia/packages/TimerOutputs/ohPOH/src/TimerOutput.jl:197 [inlined]
 [4] #codegen#136(::Bool, ::Bool, ::Bool, ::Bool, ::Bool, ::typeof(CUDAnative.codegen), ::Symbol, ::CUDAnative.CompilerJob) at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/compiler/driver.jl:186
 [5] #codegen at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/compiler/driver.jl:0 [inlined]
 [6] #compile#135(::Bool, ::Bool, ::Bool, ::Bool, ::Bool, ::typeof(CUDAnative.compile), ::Symbol, ::CUDAnative.CompilerJob) at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/compiler/driver.jl:47
 [7] #compile#134 at ./none:0 [inlined]
 [8] #compile at ./none:0 [inlined] (repeats 2 times)
 [9] macro expansion at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/execution.jl:389 [inlined]
 [10] #cufunction#176(::Nothing, ::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::typeof(CUDAnative.cufunction), ::getfield(GPUArrays, Symbol("##25#26")), ::Type{Tuple{CuArrays.CuKernelState,CUDAnative.CuDeviceArray{Float32,1,CUDAnative.AS.Global},Base.Broadcast.Broadcasted{Nothing,Tuple{Base.OneTo{Int64}},typeof(binarycrossentropy),Tuple{Base.Broadcast.Broadcasted{Base.Broadcast.ArrayStyle{CuArrays.CuArray},Nothing,typeof(CuArrays.cuσ),Tuple{Base.Broadcast.Extruded{CUDAnative.CuDeviceArray{Float32,1,CUDAnative.AS.Global},Tuple{Bool},Tuple{Int64}}}},Base.Broadcast.Extruded{CUDAnative.CuDeviceArray{Float32,1,CUDAnative.AS.Global},Tuple{Bool},Tuple{Int64}}}}}}) at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/execution.jl:357
 [11] cufunction(::Function, ::Type) at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/execution.jl:357
 [12] macro expansion at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/execution.jl:174 [inlined]
 [13] macro expansion at ./gcutils.jl:87 [inlined]
 [14] macro expansion at /home/taot/.julia/packages/CUDAnative/Lr0yj/src/execution.jl:171 [inlined]
 [15] _gpu_call(::CuArrays.CuArrayBackend, ::Function, ::CuArrays.CuArray{Float32,1}, ::Tuple{CuArrays.CuArray{Float32,1},Base.Broadcast.Broadcasted{Nothing,Tuple{Base.OneTo{Int64}},typeof(binarycrossentropy),Tuple{Base.Broadcast.Broadcasted{Base.Broadcast.ArrayStyle{CuArrays.CuArray},Nothing,typeof(CuArrays.cuσ),Tuple{Base.Broadcast.Extruded{CuArrays.CuArray{Float32,1},Tuple{Bool},Tuple{Int64}}}},Base.Broadcast.Extruded{CuArrays.CuArray{Float32,1},Tuple{Bool},Tuple{Int64}}}}}, ::Tuple{Tuple{Int64},Tuple{Int64}}) at /home/taot/.julia/packages/CuArrays/kOUu1/src/gpuarray_interface.jl:60
 [16] gpu_call at /home/taot/.julia/packages/GPUArrays/tIMl5/src/abstract_gpu_interface.jl:151 [inlined]
 [17] gpu_call(::Function, ::CuArrays.CuArray{Float32,1}, ::Tuple{CuArrays.CuArray{Float32,1},Base.Broadcast.Broadcasted{Nothing,Tuple{Base.OneTo{Int64}},typeof(binarycrossentropy),Tuple{Base.Broadcast.Broadcasted{Base.Broadcast.ArrayStyle{CuArrays.CuArray},Nothing,typeof(CuArrays.cuσ),Tuple{Base.Broadcast.Extruded{CuArrays.CuArray{Float32,1},Tuple{Bool},Tuple{Int64}}}},Base.Broadcast.Extruded{CuArrays.CuArray{Float32,1},Tuple{Bool},Tuple{Int64}}}}}) at /home/taot/.julia/packages/GPUArrays/tIMl5/src/abstract_gpu_interface.jl:128
 [18] copyto! at /home/taot/.julia/packages/GPUArrays/tIMl5/src/broadcast.jl:48 [inlined]
 [19] copyto! at ./broadcast.jl:842 [inlined]
 [20] copy(::Base.Broadcast.Broadcasted{Base.Broadcast.ArrayStyle{CuArrays.CuArray},Tuple{Base.OneTo{Int64}},typeof(binarycrossentropy),Tuple{Base.Broadcast.Broadcasted{Base.Broadcast.ArrayStyle{CuArrays.CuArray},Nothing,typeof(CuArrays.cuσ),Tuple{CuArrays.CuArray{Float32,1}}},CuArrays.CuArray{Float32,1}}}) at ./broadcast.jl:818
 [21] materialize(::Base.Broadcast.Broadcasted{Base.Broadcast.ArrayStyle{CuArrays.CuArray},Nothing,typeof(binarycrossentropy),Tuple{Base.Broadcast.Broadcasted{Base.Broadcast.ArrayStyle{CuArrays.CuArray},Nothing,typeof(CuArrays.cuσ),Tuple{CuArrays.CuArray{Float32,1}}},CuArrays.CuArray{Float32,1}}}) at ./broadcast.jl:798
 [22] top-level scope at In[3]:3

```

I tried testing crossentropy function in the same way, and didn’t have the same problem.

Is it a bug in any related package? Or am I doing something wrong? I notice the warning in the message, but don’t understand what it means. Could the error relate to this warning?

Thanks!

---

<div class="post-metadata">

### Author: ![merckxiaan](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/merckxiaan/32/4697_2.png) [@merckxiaan](https://discourse.julialang.org/u/merckxiaan)
#### Post date: [November 14, 2019, 9:56am UTC](https://discourse.julialang.org/t/problem-of-binarycrossentropy-with-gpu/31026/2 "2019-11-14T09:56:46Z")

</div>

I’m not sure where the root of this problem lies, but this is a quick fix:

```julia
a1 = gpu([-1.1491, 0.8619, 0.3127])
a2 = gpu([1, 1, 0.])

CuArrays.@cufunc Flux.binarycrossentropy(ŷ, y; ϵ=eps(ŷ)) = -y*log(ŷ + ϵ) - (1 - y)*log(1 - ŷ + ϵ)

Flux.binarycrossentropy.(σ.(a1), a2)

```

This cufunc makes sure all functions get dispatched to their relevant CUDA implementation, in this case I believe only `log` is changed.

---

<div class="post-metadata">

### Author: ![taot](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/taot/32/11257_2.png) [@taot](https://discourse.julialang.org/u/taot)
#### Post date: [November 15, 2019, 9:49am UTC](https://discourse.julialang.org/t/problem-of-binarycrossentropy-with-gpu/31026/3 "2019-11-15T09:49:41Z")

</div>

Hi, merck xiaan

Thank your for the reply! Yes the trick did solve my problem!

Today I just found this issue on Github [https://github.com/FluxML/Flux.jl/issues/889](https://github.com/FluxML/Flux.jl/issues/889), and someone has submitted a fix the same as your trick. I really should have looked at Github first.