Deferred codegen

[vchuravy]

using Enzyme

import Enzyme: Compiler
import .Compiler.GPUCompiler: deferred_codegen_jobs
@generated function deferred_codegen(::Val{f}, ::Val{tt}) where {f,tt}
    primal, adjoint = Compiler.fspec(f, tt)
    target = Compiler.EnzymeTarget()
    params = Compiler.EnzymeCompilerParams(adjoint, false)
    job    = Compiler.CompilerJob(target, primal, params)

    push!(deferred_codegen_jobs, job)
    id = length(deferred_codegen_jobs)

    quote
        # TODO: add an edge to this method instance to support method redefinitions
        ccall("extern deferred_codegen", llvmcall, Ptr{Cvoid}, (Int,), $id)
    end
end

f(x) = x^3

function test(x)
    ptr = deferred_codegen(Val(f), Val(Tuple{Active{Float64}}))
    ccall(ptr, Float64, (Float64, Float64), x, 1.0)
end

[vchuravy]

using Enzyme

f(x) = x*x^3

function first_order(x)
    x′, = autodiff(f, Active(x))
    x′
end

function second_order(x)
    x′, = autodiff(first_order, Active(x))
    x′
end

@show first_order(1.0)
@show autodiff(first_order, Active(1.0))
@show second_order(1.0)
@show autodiff(second_order, Active(1.0))

@info "Testing GPUs"
using CUDA
A = CUDA.zeros(2)

function kernel(A,x)
    A[1] = first_order(x)
    A[2] = second_order(x)
    nothing
end

@show A

[vchuravy]

Should use https://github.com/JuliaGPU/GPUCompiler.jl/blob/3aa87d65852aea91cb0d942b1110008961966ca7/src/irgen.jl#L296-L327 to implement the ABI

[vchuravy]

I think that one never landed in Enzyme proper so we should remove

[vchuravy]

Can we move the adapt rules from the test case into this Enzyme.jl

[giordano]

Leftover?

[giordano]

What is ObjectFile used for? readmeta is used:
https://github.com/wsmoses/Enzyme.jl/blob/acc040083067b2a5c6eb9caeb81376a203940c83/src/compiler/validation.jl#L202