Error when differentiating a linear problem with Enzyme.jl #766
Description
Describe the bug 🐞
I get an error when differentiating a linear problem with Enzyme.jl. I can fix the error using the set_runtime_activity option, but I'm wondering why this is happening and if this can be fixed.
I don't know whether to put this issue here or in Enzyme.jl. Tell me if the other case is better.
Expected behavior
A correct computation of the gradient.
Minimal Reproducible Example 👇
using LinearAlgebra
using SparseArrays
using LinearSolve
using Zygote
using Enzyme
using BenchmarkTools
# %%
const N = 100
const A = sprand(N, N, 1/N)
const B = sprand(N, N, 1/N)
const x = rand(N)
function test(p)
C = p[1] * A' * A + p[2] * B' * B + I
prob = LinearProblem(C, x)
sol = solve(prob, KrylovJL_GMRES())
return sum(abs2, sol.u .- x)
end
# %%
test([1.0, 2.2])
# %%
Zygote.gradient(test, [1.0, 2.2]) # Works
# %%
Enzyme.gradient(Reverse, test, [1.0, 2.2]) # Doesn't workError & Stacktrace
ERROR: Constant memory is stored (or returned) to a differentiable variable.
As a result, Enzyme cannot provably ensure correctness and throws this error.
This might be due to the use of a constant variable as temporary storage for active memory (https://enzyme.mit.edu/julia/stable/faq/#Runtime-Activity).
If Enzyme should be able to prove this use non-differentable, open an issue!
To work around this issue, either:
a) rewrite this variable to not be conditionally active (fastest, but requires a code change), or
b) set the Enzyme mode to turn on runtime activity (e.g. autodiff(set_runtime_activity(Reverse), ...) ). This will maintain correctness, but may slightly reduce performance.
Mismatched activity for: store {} addrspace(10)* addrspacecast ({}* inttoptr (i64 4521255888 to {}*) to {} addrspace(10)*), {} addrspace(10)** %.fca.1.gep, align 8, !dbg !1206, !noalias !1212 const val: {} addrspace(10)* addrspacecast ({}* inttoptr (i64 4521255888 to {}*) to {} addrspace(10)*)
...Environment (please complete the following information):
- Output of
using Pkg; Pkg.status()
Status `~/GitHub/Research/Undef/Autodiff QuantumToolbox/Project.toml`
[6e4b80f9] BenchmarkTools v1.6.0
[a0c0ee7d] DifferentiationInterface v0.7.7
[7da242da] Enzyme v0.13.72
[26cc04aa] FiniteDifferences v0.12.32
[f6369f11] ForwardDiff v1.1.0
[b27dd330] GTPSA v1.4.7
[7ed4a6bd] LinearSolve v3.38.0
[1dea7af3] OrdinaryDiffEq v6.102.0
[6c2fb7c5] QuantumToolbox v0.34.1
[c0aeaf25] SciMLOperators v1.7.1
[1ed8b502] SciMLSensitivity v7.89.0
[e88e6eb3] Zygote v0.7.10- Output of
using Pkg; Pkg.status(; mode = PKGMODE_MANIFEST)
[47edcb42] ADTypes v1.17.0
[621f4979] AbstractFFTs v1.5.0
[7d9f7c33] Accessors v0.1.42
[79e6a3ab] Adapt v4.3.0
[66dad0bd] AliasTables v1.1.3
[ec485272] ArnoldiMethod v0.4.0
[4fba245c] ArrayInterface v7.20.0
[4c555306] ArrayLayouts v1.11.2
[a9b6321e] Atomix v1.1.2
[6e4b80f9] BenchmarkTools v1.6.0
[62783981] BitTwiddlingConvenienceFunctions v0.1.6
[70df07ce] BracketingNonlinearSolve v1.3.0
[fa961155] CEnum v0.5.0
[2a0fbf3d] CPUSummary v0.2.7
[7057c7e9] Cassette v0.3.14
[082447d4] ChainRules v1.72.5
[d360d2e6] ChainRulesCore v1.26.0
[fb6a15b2] CloseOpenIntervals v0.1.13
[38540f10] CommonSolve v0.2.4
[bbf7d656] CommonSubexpressions v0.3.1
[f70d9fcc] CommonWorldInvalidations v1.0.0
[34da2185] Compat v4.18.0
[a33af91c] CompositionsBase v0.1.2
[2569d6c7] ConcreteStructs v0.2.3
[187b0558] ConstructionBase v1.6.0
[adafc99b] CpuId v0.3.1
[a8cc5b0e] Crayons v4.1.1
[9a962f9c] DataAPI v1.16.0
⌅ [864edb3b] DataStructures v0.18.22
[e2d170a0] DataValueInterfaces v1.0.0
[2b5f629d] DiffEqBase v6.186.0
[459566f4] DiffEqCallbacks v4.9.0
[77a26b50] DiffEqNoiseProcess v5.24.1
[163ba53b] DiffResults v1.1.0
[b552c78f] DiffRules v1.15.1
[a0c0ee7d] DifferentiationInterface v0.7.7
[b4f34e82] Distances v0.10.12
[31c24e10] Distributions v0.25.120
[ffbed154] DocStringExtensions v0.9.5
[4e289a0a] EnumX v1.0.5
[7da242da] Enzyme v0.13.72
[f151be2c] EnzymeCore v0.8.12
[7d51a73a] ExplicitImports v1.13.2
[d4d017d3] ExponentialUtilities v1.27.0
[e2ba6199] ExprTools v0.1.10
[55351af7] ExproniconLite v0.10.14
[7a1cc6ca] FFTW v1.9.0
[7034ab61] FastBroadcast v0.3.5
[9aa1b823] FastClosures v0.3.2
[442a2c76] FastGaussQuadrature v1.0.2
[a4df4552] FastPower v1.1.3
[1a297f60] FillArrays v1.13.0
[6a86dc24] FiniteDiff v2.28.1
[26cc04aa] FiniteDifferences v0.12.32
[f6369f11] ForwardDiff v1.1.0
[f62d2435] FunctionProperties v0.1.2
[069b7b12] FunctionWrappers v1.1.3
[77dc65aa] FunctionWrappersWrappers v0.1.3
[d9f16b24] Functors v0.5.2
[46192b85] GPUArraysCore v0.2.0
[61eb1bfa] GPUCompiler v1.6.1
[b27dd330] GTPSA v1.4.7
[c145ed77] GenericSchur v0.5.5
[86223c79] Graphs v1.13.1
[076d061b] HashArrayMappedTries v0.2.0
[34004b35] HypergeometricFunctions v0.3.28
[7869d1d1] IRTools v0.4.15
[615f187c] IfElse v0.1.1
[40713840] IncompleteLU v0.2.1
[d25df0c9] Inflate v0.1.5
[3587e190] InverseFunctions v0.1.17
[92d709cd] IrrationalConstants v0.2.4
[82899510] IteratorInterfaceExtensions v1.0.0
[692b3bcd] JLLWrappers v1.7.1
[682c06a0] JSON v0.21.4
[ae98c720] Jieko v0.2.1
[ccbc3e58] JumpProcesses v9.17.0
[63c18a36] KernelAbstractions v0.9.38
[ba0b0d4f] Krylov v0.10.1
[929cbde3] LLVM v9.4.2
[b964fa9f] LaTeXStrings v1.4.0
[10f19ff3] LayoutPointers v0.1.17
[5078a376] LazyArrays v2.6.2
[2d8b4e74] LevyArea v1.0.0
[87fe0de2] LineSearch v0.1.4
[d3d80556] LineSearches v7.4.0
[7ed4a6bd] LinearSolve v3.38.0
[2ab3a3ac] LogExpFunctions v0.3.29
[1914dd2f] MacroTools v0.5.16
[d125e4d3] ManualMemory v0.1.8
[bb5d69b7] MaybeInplace v0.1.4
[e1d29d7a] Missings v1.2.0
[2e0e35c7] Moshi v0.3.7
[46d2c3a1] MuladdMacro v0.2.4
[d41bc354] NLSolversBase v7.10.0
[2774e3e8] NLsolve v4.5.1
[872c559c] NNlib v0.9.31
[77ba4419] NaNMath v1.1.3
[8913a72c] NonlinearSolve v4.10.0
[be0214bd] NonlinearSolveBase v1.14.0
[5959db7a] NonlinearSolveFirstOrder v1.7.0
[9a2c21bd] NonlinearSolveQuasiNewton v1.8.0
[26075421] NonlinearSolveSpectralMethods v1.3.0
[d8793406] ObjectFile v0.5.0
[429524aa] Optim v1.13.2
[3bd65402] Optimisers v0.4.6
[bac558e1] OrderedCollections v1.8.1
[1dea7af3] OrdinaryDiffEq v6.102.0
[89bda076] OrdinaryDiffEqAdamsBashforthMoulton v1.5.0
[6ad6398a] OrdinaryDiffEqBDF v1.10.1
[bbf590c4] OrdinaryDiffEqCore v1.30.0
[50262376] OrdinaryDiffEqDefault v1.8.0
[4302a76b] OrdinaryDiffEqDifferentiation v1.14.0
[9286f039] OrdinaryDiffEqExplicitRK v1.4.0
[e0540318] OrdinaryDiffEqExponentialRK v1.8.0
[becaefa8] OrdinaryDiffEqExtrapolation v1.8.0
[5960d6e9] OrdinaryDiffEqFIRK v1.16.0
[101fe9f7] OrdinaryDiffEqFeagin v1.4.0
[d3585ca7] OrdinaryDiffEqFunctionMap v1.5.0
[d28bc4f8] OrdinaryDiffEqHighOrderRK v1.5.0
[9f002381] OrdinaryDiffEqIMEXMultistep v1.7.0
[521117fe] OrdinaryDiffEqLinear v1.6.0
[1344f307] OrdinaryDiffEqLowOrderRK v1.6.0
[b0944070] OrdinaryDiffEqLowStorageRK v1.6.0
[127b3ac7] OrdinaryDiffEqNonlinearSolve v1.14.1
[c9986a66] OrdinaryDiffEqNordsieck v1.4.0
[5dd0a6cf] OrdinaryDiffEqPDIRK v1.6.0
[5b33eab2] OrdinaryDiffEqPRK v1.4.0
[04162be5] OrdinaryDiffEqQPRK v1.4.0
[af6ede74] OrdinaryDiffEqRKN v1.5.0
[43230ef6] OrdinaryDiffEqRosenbrock v1.17.0
[2d112036] OrdinaryDiffEqSDIRK v1.7.0
[669c94d9] OrdinaryDiffEqSSPRK v1.6.0
[e3e12d00] OrdinaryDiffEqStabilizedIRK v1.6.0
[358294b1] OrdinaryDiffEqStabilizedRK v1.4.0
[fa646aed] OrdinaryDiffEqSymplecticRK v1.7.0
[b1df2697] OrdinaryDiffEqTsit5 v1.5.0
[79d7bb75] OrdinaryDiffEqVerner v1.6.0
[90014a1f] PDMats v0.11.35
[d96e819e] Parameters v0.12.3
[69de0a69] Parsers v2.8.3
[e409e4f3] PoissonRandom v0.4.6
[f517fe37] Polyester v0.7.18
[1d0040c9] PolyesterWeave v0.2.2
[85a6dd25] PositiveFactorizations v0.2.4
[d236fae5] PreallocationTools v0.4.33
⌅ [aea7be01] PrecompileTools v1.2.1
[21216c6a] Preferences v1.5.0
⌅ [08abe8d2] PrettyTables v2.4.0
[43287f4e] PtrArrays v1.3.0
[1fd47b50] QuadGK v2.11.2
[6c2fb7c5] QuantumToolbox v0.34.1
[74087812] Random123 v1.7.1
[e6cf234a] RandomNumbers v1.6.0
[c1ae055f] RealDot v0.1.0
[3cdcf5f2] RecipesBase v1.3.4
[731186ca] RecursiveArrayTools v3.37.1
[189a3867] Reexport v1.2.2
[ae029012] Requires v1.3.1
[ae5879a3] ResettableStacks v1.1.1
[37e2e3b7] ReverseDiff v1.16.1
[708f8203] Richardson v1.4.2
[79098fc4] Rmath v0.8.0
[7e49a35a] RuntimeGeneratedFunctions v0.5.15
[94e857df] SIMDTypes v0.1.0
[0bca4576] SciMLBase v2.115.0
[19f34311] SciMLJacobianOperators v0.1.8
[c0aeaf25] SciMLOperators v1.7.1
[1ed8b502] SciMLSensitivity v7.89.0
[53ae85a6] SciMLStructures v1.7.0
[7e506255] ScopedValues v1.5.0
[6c6a2e73] Scratch v1.3.0
[efcf1570] Setfield v1.1.2
[727e6d20] SimpleNonlinearSolve v2.7.0
[699a6c99] SimpleTraits v0.9.5
[ce78b400] SimpleUnPack v1.1.0
[a2af1166] SortingAlgorithms v1.2.2
[dc90abb0] SparseInverseSubset v0.1.2
[0a514795] SparseMatrixColorings v0.4.21
[276daf66] SpecialFunctions v2.5.1
[aedffcd0] Static v1.2.0
[0d7ed370] StaticArrayInterface v1.8.0
[90137ffa] StaticArrays v1.9.15
[1e83bf80] StaticArraysCore v1.4.3
[10745b16] Statistics v1.11.1
[82ae8749] StatsAPI v1.7.1
[2913bbd2] StatsBase v0.34.6
[4c63d2b9] StatsFuns v1.5.0
[789caeaf] StochasticDiffEq v6.81.0
[7792a7ef] StrideArraysCore v0.5.8
[892a3eda] StringManipulation v0.4.1
[09ab397b] StructArrays v0.7.1
[53d494c1] StructIO v0.3.1
[2efcf032] SymbolicIndexingInterface v0.3.43
[3783bdb8] TableTraits v1.0.1
[bd369af6] Tables v1.12.1
[8290d209] ThreadingUtilities v0.5.5
[a759f4b9] TimerOutputs v0.5.29
[9f7883ad] Tracker v0.2.38
[e689c965] Tracy v0.1.5
[781d530d] TruncatedStacktraces v1.4.0
[3a884ed6] UnPack v1.0.2
[013be700] UnsafeAtomics v0.3.0
[e88e6eb3] Zygote v0.7.10
[700de1a5] ZygoteRules v0.2.7
[7cc45869] Enzyme_jll v0.0.195+0
[f5851436] FFTW_jll v3.3.11+0
[a4739e29] GTPSA_jll v1.6.1+0
[1d5cc7b8] IntelOpenMP_jll v2025.2.0+0
[dad2f222] LLVMExtra_jll v0.0.37+2
[ad6e5548] LibTracyClient_jll v0.9.1+6
[856f044c] MKL_jll v2025.2.0+0
[656ef2d0] OpenBLAS32_jll v0.3.29+0
[efe28fd5] OpenSpecFun_jll v0.5.6+0
[f50d1b31] Rmath_jll v0.5.1+0
[1317d2d5] oneTBB_jll v2022.0.0+0
[0dad84c5] ArgTools v1.1.2
[56f22d72] Artifacts v1.11.0
[2a0f44e3] Base64 v1.11.0
[ade2ca70] Dates v1.11.0
[8ba89e20] Distributed v1.11.0
[f43a241f] Downloads v1.6.0
[7b1f6079] FileWatching v1.11.0
[9fa8497b] Future v1.11.0
[b77e0a4c] InteractiveUtils v1.11.0
[4af54fe1] LazyArtifacts v1.11.0
[b27032c2] LibCURL v0.6.4
[76f85450] LibGit2 v1.11.0
[8f399da3] Libdl v1.11.0
[37e2e46d] LinearAlgebra v1.11.0
[56ddb016] Logging v1.11.0
[d6f4376e] Markdown v1.11.0
[a63ad114] Mmap v1.11.0
[ca575930] NetworkOptions v1.2.0
[44cfe95a] Pkg v1.11.0
[de0858da] Printf v1.11.0
[9abbd945] Profile v1.11.0
[9a3f8284] Random v1.11.0
[ea8e919c] SHA v0.7.0
[9e88b42a] Serialization v1.11.0
[1a1011a3] SharedArrays v1.11.0
[6462fe0b] Sockets v1.11.0
[2f01184e] SparseArrays v1.11.0
[4607b0f0] SuiteSparse
[fa267f1f] TOML v1.0.3
[a4e569a6] Tar v1.10.0
[cf7118a7] UUIDs v1.11.0
[4ec0a83e] Unicode v1.11.0
[e66e0078] CompilerSupportLibraries_jll v1.1.1+0
[deac9b47] LibCURL_jll v8.6.0+0
[e37daf67] LibGit2_jll v1.7.2+0
[29816b5a] LibSSH2_jll v1.11.0+1
[c8ffd9c3] MbedTLS_jll v2.28.6+0
[14a3606d] MozillaCACerts_jll v2023.12.12
[4536629a] OpenBLAS_jll v0.3.27+1
[05823500] OpenLibm_jll v0.8.5+0
[bea87d4a] SuiteSparse_jll v7.7.0+0
[83775a58] Zlib_jll v1.2.13+1
[8e850b90] libblastrampoline_jll v5.11.0+0
[8e850ede] nghttp2_jll v1.59.0+0
[3f19e933] p7zip_jll v17.4.0+2- Output of
versioninfo()
Julia Version 1.11.6
Commit 9615af0f269 (2025-07-09 12:58 UTC)
Build Info:
Official https://julialang.org/ release
Platform Info:
OS: macOS (arm64-apple-darwin24.0.0)
CPU: 8 × Apple M3
WORD_SIZE: 64
LLVM: libLLVM-16.0.6 (ORCJIT, apple-m2)
Threads: 4 default, 0 interactive, 2 GC (on 4 virtual cores)
Environment:
JULIA_EDITOR = code
JULIA_VSCODE_REPL = 1