AMD Rusticl OpenCL won't compile with llvm22 (upstream issue)

[segeeslice]

(Original title: Unable to enable OpenCL in CachyOS, despite being installed)

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

I'm on CachyOS, using Darktable 5.6.0

I have an AMD GPU (9070 XT) that is clearly recognized by my OS & used in other programs. I thought it was working in Darktable at some point, but I noticed a performance hit recently. This prompted me to check the settings, inside which the “GPU Acceleration” section is grayed out, showing it's “not available”

Running darktable -d opencl from the command line shows a compiler error (shown in the logfile section). Per the documentation, this appears to fall under a "generic compiler error", and I was directed here.

The OpenCL installation came with the OS distro (chatting in a different forum separately just in case it's an OS issue). I have not modified OpenCL on my machine from the stock version that comes with CachyOS.

How can I enable GPU acceleration on my machine? It's noticeably slower without it.

Steps to reproduce

1. Launch Darktable 5.6.0
2. Open preferences
3. Go to the "processing" tab
4. Under "OpenCL GPU acceleration", attempt to check the box by "activate OpenCL support"

Expected behavior

Darktable should recognize my existing OpenCL installation and allow enabling GPU acceleration

Logfile | Screenshot | Screencast

❯ darktable -d opencl
darktable 5.6.0
Copyright (C) 2012-2026 Johannes Hanika and other contributors.

Compile options:
  Bit depth              -> 64 bit
  Exiv2                  -> 0.28.8
  Lensfun                -> 0.3.4
  Debug                  -> DISABLED
  SSE2 optimizations     -> ENABLED
  OpenMP                 -> ENABLED
  OpenCL                 -> ENABLED
  Lua                    -> ENABLED  - API version 9.7.0
  Colord                 -> ENABLED
  gPhoto2                -> ENABLED  - Camera tethering is available
  OSMGpsMap              -> ENABLED  - Map view is available
  GMIC                   -> ENABLED  - Compressed LUTs are supported
  GraphicsMagick         -> ENABLED
  ImageMagick            -> DISABLED
  libavif                -> ENABLED
  libheif                -> ENABLED
  libjxl                 -> ENABLED
  LibRaw                 -> ENABLED  - Version 0.22.0-Release
  OpenJPEG               -> ENABLED
  OpenEXR                -> ENABLED
  WebP                   -> ENABLED
  AI                     -> ENABLED

See https://www.darktable.org/resources/ for detailed documentation.
See https://github.com/darktable-org/darktable/issues/new/choose to report bugs.

[dt starting] as : darktable -d opencl
Gtk-Message: 19:09:15.814: Failed to load module "appmenu-gtk-module"
[opencl_init] opencl disabled via darktable preferences
[opencl_init] opencl library 'libOpenCL' found on your system and loaded, preference 'default path'
[opencl_init] found 1 platform
[opencl_init] found 1 device

   DEVICE:                   0: 'AMD Radeon RX 9070 XT (radeonsi, gfx1201, ACO, DRM 3.64, 7.1.4-1-cachyos)'
   CONF KEY:                 cldevice_v6_rusticlamdradeonrx9070xt
   PLATFORM, VENDOR & ID:    rusticl, Mesa:Mesa/X.org, ID=4098
   CANONICAL NAME:           rusticlamdradeonrx9070xt
   DRIVER VERSION:           26.1.5-arch3.1
   DEVICE VERSION:           OpenCL 3.0  API=300
   DEVICE_TYPE:              GPU, dedicated mem
   GLOBAL MEM SIZE:          16384 MB
   MAX IMAGE ALLOC:          2048 MB
   MAX IMAGE SIZE:           65536 x 65536
   MAX CONSTANT BUFFER:      65536 KB
   LOCAL MEM SIZE:           64 KB
   ADDRESS ALIGN:            512 B
   COMPUTE UNITS:            64
   MAX WORK GROUP SIZE:      1024 (64)
   MAX WORK ITEM DIMENSIONS: 3 [ 1024 1024 1024 ]
   ASYNC PIXELPIPE:          NO
   PINNED MEMORY TILING:     NO
   SUPPORTED ATOMICS:        INT32 
   EVENTS HANDLED:           YES
   OPENCL FAST MODE:         NO
   TILING ADVANTAGE:         0.000
   DEFAULT DEVICE:           NO
   KERNEL BUILD DIRECTORY:   /usr/share/darktable/kernels
   KERNEL DIRECTORY:         /home/seg/.cache/darktable/cached_v6_kernels_for_rusticlAMDRadeonRX9070XT_2615arch31
   CL COMPILER COMMAND:      -w  -DAMD=1 -I"/usr/share/darktable/kernels"
[opencl_build_program] could not build program: CL_BUILD_PROGRAM_FAILURE
[dt_opencl_device_init] failed to compile program `basic.cl'
[opencl_init] no suitable devices found.
[opencl_init] FINALLY: opencl PREFERENCE=NO is NOT AVAILABLE and NOT ENABLED

Commit

No response

Where did you obtain darktable from?

darktable.org / GitHub release

darktable version

5.6.0

What OS are you using?

Linux

What is the version of your OS?

CachyOS

Describe your system

Arch Linux via CachyOS with AMD GPU - a 9070 XT. Wholly up-to-date as of the time this ticket is being posted.

❯ fastfetch
           .-------------------------:                    seg@lilith
          .+=========================.                    ----------
         :++===++==================-       :++-           OS: CachyOS x86_64
        :*++====+++++=============-        .==:           Host: X570 AORUS ELITE WIFI (-CF)
       -*+++=====+***++==========:                        Kernel: Linux 7.1.4-1-cachyos
      =*++++========------------:                         Uptime: 3 hours, 15 mins
     =*+++++=====-                     ...                Packages: 1522 (pacman)
   .+*+++++=-===:                    .=+++=:              Shell: fish 4.8.1
  :++++=====-==:                     -*****+              Display (Sceptre Y27): 2560x1440 @ 1.15x in 27", 165 Hz [External] *
 :++========-=.                      .=+**+.              Display (Sceptre Y27): 2560x1440 @ 1.15x in 27", 165 Hz [External]
.+==========-.                          .                 DE: KDE Plasma 6.7.3
 :+++++++====-                                .--==-.     WM: KWin (Wayland)
  :++==========.                             :+++++++:    WM Theme: Layan
   .-===========.                            =*****+*+    Theme: Breeze (Layan) [Qt], Breeze-Dark [GTK2], Breeze [GTK3]
    .-===========:                           .+*****+:    Icons: Tela [Qt], Tela [GTK2/3/4]
      -=======++++:::::::::::::::::::::::::-:  .---:      Font: Noto Sans (10pt) [Qt], Noto Sans (10pt) [GTK2/3/4]
       :======++++====+++******************=.             Cursor: Layan-white (24px)
        :=====+++==========++++++++++++++*-               Terminal: konsole 26.4.3
         .====++==============++++++++++*-                CPU: AMD Ryzen 7 5800X (16) @ 4.85 GHz
          .===+==================+++++++:                 GPU: AMD Radeon RX 9070 XT [Discrete]
           .-=======================+++:                  Memory: 6.16 GiB / 31.26 GiB (20%)
             ..........................                   Swap: 6.45 MiB / 31.26 GiB (0%)
                                                          Disk (/): 593.05 GiB / 929.51 GiB (64%) - btrfs
                                                          Local IP (enp5s0): 131.241.136.160/24
                                                          Locale: en_US.UTF-8

Are you using OpenCL GPU in darktable?

None

If yes, what is the GPU card and driver?

No response

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

No response

[gi-man]

This looks like a driver issue. You are in 26.1.5, which is fairly recent. We might need to ping Karol.

[Jedek-Selera]

Hi, I also have a 9070 XT and run Slackware64-current. After upgrading to Mesa 26.1.5, OpenCL (Rusticl) stopped working in darktable 5.6.0. I also tried mesa-26.2.0_rc2, but darktable still doesn't detect OpenCL. Additionally, I tested kernels 6.18.40 and 7.1.5, but it makes no difference. When I downgrade back to 26.1.4, Rusticl works fine again. Curiously, running clinfo on all of these Mesa versions shows that OpenCL is present and available.

[karolherbst]

Huh, so 26.1.5 regressed things?

[karolherbst]

What libclc version is installed? Because the llvm-22 one is broken

[Jedek-Selera]

libclc-22.1.8

[karolherbst]

libclc-22.1.8

yeah, that's broken, needs llvm/llvm-project#207264, which upstream won't merge, because llvm-22 is EoL, so every distribution has to patch now.

Or download the binaries from https://gitlab.freedesktop.org/karolherbst/mesa-libclc/-/releases And use them instead. There is no override, so would have to overwrite the package files.

[Jedek-Selera]

Thanks, Karol. I will forward this to Patrick Volkerding so he can merge the patch into -current.

[gi-man]

I think we should change the title of this issue to: AMD Rusticl OpenCL won't compile with llvm22 (upstream issue) or some similar wording.

[karolherbst]

Fyi, Arch picked the patch. Not sure if that also will fix cachyos tho. But Arch should be fine. I've also pinged Fedora maintainers to backport it.

[segeeslice]

@karolherbst to clarify: there is something the CachyOS maintainers need to do here to get this working, not something that is fixed in the Darktable code?

Do they need to upgrade to llvm23, for OpenCL to work?

[karolherbst]

@karolherbst to clarify: there is something the CachyOS maintainers need to do here to get this working, not something that is fixed in the Darktable code?

Do they need to upgrade to llvm23, for OpenCL to work?

please don't update to llvm23

For this to be fixed, this PR needs to be added to the libclc build: llvm/llvm-project#207264

[gi-man]

It issue is at the llvm22 code and it will need to be patched there and not on dt. llvm23 is not released yet.