[IanButterworth]

A PackageCompiler sysimage that includes KernelAbstractions 0.10 builds, but doesn't load:

ERROR: could not load library "ka.so"
ka.so: undefined symbol: julia.gpu.state_getter

The POCL device runtime (kernel_state, claim_output, signal_exception, the RNG helpers, ...) was defined as ordinary methods whose bodies reach llvmcalls that declare device intrinsics. Sysimage builds compile such methods for the host:

• Julia 1.12 and later compile every method with a compileable signature.
• Julia 1.11 keeps native code instances, e.g. those left by inferring initialize_rng_state with Core.Compiler.return_type in finish_module!.

A sysimage is loaded with RTLD_NOW, so the undefined symbols stop it from loading. Package images load lazily, except on Windows, where lld links them eagerly: that is why src/precompile.jl didn't launch a kernel on Julia 1.11 on Windows. This is the same class of leak as JuliaGPU/GPUCompiler.jl#611.

pocl: Define the device runtime as overlays so sysimages load

• The device-only runtime functions are @device_functions: a host method that throws, with the real body in the overlay table.
• malloc and report_oom use no intrinsics and stay host methods.
• initialize_rng_state returns nothing. It's looked up through the job's method tables and called as a void function, instead of inferring its return type with the native interpreter.
• A test checks GPUToolbox.Overlays.host_leaks(KernelAbstractions) is empty. It emulates the sysimage compile-all on typed IR and reports methods that reach device symbols.

Precompile a kernel launch on Julia 1.11 on Windows again

With the runtime fixed, and GPUCompiler 2.19 (JuliaGPU/GPUCompiler.jl#1067) making its boxing functions linkable on the host, the Windows 1.11 gate on the precompile workload goes.

Requires GPUToolbox 3.5 (host_leaks, registered), SPIRVIntrinsics 1.6 (JuliaGPU/OpenCL.jl#598, whose @device_function defines the body as a plain rather than a consistent overlay, so inference can't fold calls into the host error) and GPUCompiler 2.19 (being registered).

Reproducer:

# precompile.jl
using KernelAbstractions
@kernel function fill_index!(a)
    i = @index(Global)
    a[i] = i
end
a = zeros(Float32, 16)
fill_index!(CPU())(a; ndrange = length(a))
KernelAbstractions.synchronize(CPU())

# build.jl
using PackageCompiler
create_sysimage([:KernelAbstractions]; sysimage_path = "ka.so", precompile_execution_file = "precompile.jl")

Then julia -J ka.so -e 'println("loaded")'. On v0.10.3 this fails on Julia 1.11.9, 1.12.7 and 1.13.3; with this PR it loads on all three. On Windows, Julia 1.11 precompiles with the launch, loads, runs kernels and reports device exceptions.

The other back ends get the same treatment in separate PRs.

[codecov]

Codecov Report

❌ Patch coverage is 94.44444% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 83.13%. Comparing base (5dd8a01) to head (de05727).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
src/pocl/device/random.jl	83.33%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #930   +/-   ##
=======================================
  Coverage   83.13%   83.13%           
=======================================
  Files          31       31           
  Lines        2568     2568           
=======================================
  Hits         2135     2135           
  Misses        433      433           

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[maleadt]

Rebased and reworked.

• The device functions now use GPUToolbox 3.5's shared definitions, via SPIRVIntrinsics 1.6.
• kernel_state is a @device_function directly, since that handles @generated now.
• seed!(::Philox2x32, ::Nothing) is back to a plain method: there's no host method for it to be consistent with.
• The test is now GPUToolbox.Overlays.host_leaks, which emulates the sysimage compile-all.
• I added a commit that re-enables the precompiled launch on Windows 1.11, now that GPUCompiler 2.19 fixes the box tags.

The other back ends get the same fix in separate PRs.