Illegal type analysis error with gemv call

[gaurav-arya]

With a slightly modified version of #1004, where part of the loop body is put into a function, we get an error "Enzyme compilation failed due to illegal type analysis.", on Enzyme.jl master. Note that manually inlining mymul! resolves the error. (Edit: also, using mul! rather than the gemv call directly also resolves the error.) MWE:

using Enzyme, LinearAlgebra

LinearAlgebra.BLAS.set_num_threads(1)
Enzyme.Compiler.bitcode_replacement!(true)

@inline function coupled_springs(K, m, x0, v0, T)
    Ktmp = copy(K)
    xtmp = copy(x0)
    vtmp = copy(v0)
    N = length(m)
    pX = pointer(xtmp)
    pY = pointer(vtmp)
    pA = pointer(Ktmp)
    for j in 1:5000
        mymul!(vtmp, Ktmp, xtmp, pX, pY, pA)
        xtmp .+= vtmp ./ 5000
    end
    return @inbounds xtmp[1]
end

@inline function mymul!(vtmp, Ktmp, xtmp, pX, pY, pA) 
    sX = 1
    sY = 1
    GC.@preserve vtmp Ktmp xtmp ccall((:dgemv_64_, LinearAlgebra.BLAS.libblastrampoline), Cvoid,
    (Ref{UInt8}, Ref{LinearAlgebra.BLAS.BlasInt}, Ref{LinearAlgebra.BLAS.BlasInt}, Ref{Float64},
    Ptr{Float64}, Ref{LinearAlgebra.BLAS.BlasInt}, Ptr{Float64}, Ref{LinearAlgebra.BLAS.BlasInt},
    Ref{Float64}, Ptr{Float64}, Ref{LinearAlgebra.BLAS.BlasInt}, Clong),
    'N', N, N, 1/5000,
    pA, N, pX, sX,
    1.0, pY, sY, 1)
end

function make_args(N)
    K = ones(N, N)#collect(reshape(1:N^2, N, N))
    K[diagind(K)] .= 0
    m = 0.5 .+ 0.5 * rand(N)
    x0 = float.(collect(1:N)) ./ N
    v0 = zeros(N)
    T = 1.0
    return K, m, x0, v0, T
end

function enzyme_inputs(K, m, x0, v0, T)
    dK = zero(K)
    dm = zero(m)
    dx0 = zero(x0)
    dv0 = zero(v0)
    return Duplicated(K, dK), Duplicated(m, dm), Duplicated(x0, dx0), Duplicated(v0, dv0), Const(T)
end

function enzyme_gradient(args...)
    inputs = enzyme_inputs(args...)
    dK = inputs[1].dval
    Enzyme.autodiff(Reverse, Const(coupled_springs), inputs...)
    return dK
end

N = 200
args = make_args(N)
coupled_springs(args...)
enzyme_gradient(args...)

Error:
error.ll.txt

[wsmoses]

I think this should've been fixed by: EnzymeAD/Enzyme#1369

I assume you're using the custom jll here. Can you make sure whatever branch you're based on is rebased on main (past that commit)

cc @ZuseZ4