Start implementation of kernels compatible with in-place problems

[utkarsh530]

MWE:

using DiffEqGPU, DiffEqBase, StaticArrays

function lorenz!(du,u,p,t)
 du[1] = 10.0(u[2]-u[1])
 du[2] = u[1]*(28.0-u[3]) - u[2]
 du[3] = u[1]*u[2] - (8/3)*u[3]
end
u0 = @MArray [1.0;0.0;0.0]
tspan = (0.0,100.0)
prob = ODEProblem(lorenz!,u0,tspan)

ensembleProb = EnsembleProblem(prob)

using CUDA

sol = solve(ensembleProb, GPUTsit5(), EnsembleGPUKernel(CUDABackend()), dt = 0.01, adaptive = false, trajectories = 2)

Current issue:

Tries to dynamically allocate. Hence, it fails for high number of trajectories. Similar to #219

[ChrisRackauckas-Claude]

Status Check - PR #291

This PR has been reviewed as part of automated dependency monitoring.

Current State

• Created: July 7, 2023
• Status: Draft (Work in Progress)
• Last Updated: July 7, 2023 (over 2 years ago)
• CI Status: No CI checks have run on this PR

Implementation Review

The PR implements initial support for in-place (IIP) kernels with the following changes:

Completed:

1. Added step! method for GPUT5I{true, S, T} in src/perform_step/gpu_tsit5_perform_step.jl (lines 1-80)
2. Modified kernel in src/solve.jl to convert MArray u0/p for in-place problems (lines 223-229)
3. Added handle_iip_prob helper function in src/DiffEqGPU.jl (lines 886-894)
4. Removed IIP assertion from integrator type constructors
5. Added type conversions in integrator_utils.jl and solve.jl

Incomplete/Issues:

1. Line 939 in src/DiffEqGPU.jl: handle_iip_prob call is commented out
2. Cannot verify functionality - test suite has dependency conflicts (CUDA 4.1.0 compatibility issue with current Julia/GPUCompiler versions, unrelated to this PR)
3. No tests added for the new IIP functionality
4. Implementation appears abandoned mid-development

Recommendation

This PR needs significant work to be mergeable:

1. Complete the implementation - Uncomment or remove the handle_iip_prob function and its commented usage
2. Add tests - Create tests specifically for in-place GPU kernels with MArrays
3. Update dependencies - The test suite needs CUDA version bounds updated to work with modern Julia versions
4. Rebase on master - PR is 2+ years old and may have conflicts

Given the age and incomplete state, consider:

• Closing this PR and opening a fresh one with a complete implementation
• OR reviving this PR with the necessary fixes and tests

cc @ChrisRackauckas - This PR has been dormant since July 2023. Should it be closed or revived?