equihash192_7.cl's decompress/decompress2 used double + sqrt behind
cl_khr_fp64, so the kernel failed to build on OpenCL stacks without fp64
(notably rusticl/Mesa) — those workers died with 'use of type double requires
cl_khr_fp64'. Replace round(sqrt(2*x+1)) with an exact integer square root
(single-precision estimate corrected to the integer floor, then rounded; inputs
are triangular indices < ~2^26). No fp64, no behavior change on ROCm (verified
bit-identical: 77 solutions/40 nonces, same as before), and rusticl devices now
build and solve correctly.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
AMD GPU backend:
- Add the GCN-tuned equihash192_7.cl kernel (clearCounter/blake/round1..7/
combine pipeline) and its host driver src/gpu_amd.rs. GpuSolver now dispatches
AMD-vendor OpenCL devices to it and other devices to the existing kernel
(force with ZCL_OPENCL_KERNEL=amd|legacy). Validated on an RX 9060 XT: GPU
solutions match the CPU reference 1/1.
- Expose BatchHasher::midstate() for the kernel's ulong8 hashState arg.
Runtime-loaded GPU drivers (minimum host deps):
- dlopen libcuda / libnvidia-ml via libloading instead of linking them
(src/dylib.rs macro; cuda.rs, nvml.rs, gpu_probe.rs). The binary now builds
and starts on hosts without an NVIDIA driver and reports no CUDA devices
gracefully; remove build.rs (its only job was linking those libs).
- Add Dockerfile.portable + build-portable.sh: build against Debian bullseye's
glibc 2.31 for a binary that runs on older distros and drives both AMD
(OpenCL) and NVIDIA (CUDA) cards. Document the build matrix in the README.
Mixed backend (default):
- Add --backend mixed (now the default): each card on its native backend
(NVIDIA->CUDA, AMD/Intel->OpenCL), deduped so no card is mined twice.
--devices indexes the unified list shown by --list-devices.
Misc:
- Stale-work timeout (--job-timeout) default 300s -> 600s (10 minutes).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
jackpotincorporated