[qt/clang/llvm]: Summary of bulk changes made

Git repository change summary for qt/clang/llvm
Pushed by mirror-service into branch 'upstream/users/skatrak/omp-func-filter-03-declare-target'.
Changed from 0000000000000000000000000000000000000000 to f1a52c01a4b602e42204fb1e5683a6492f62fd7d
Acknowledgement was received that this change introduces only existing code that has been pushed to another public open source repository.

This change contains the following new commits:

Git commit bf7b2c660260b2d77430051ad9b35681a35d05b0 by Sergio Afonso on 05/08/2026 at 10:21..
[Flang][MLIR][OpenMP] Move function filtering to the omp dialect

The `FunctionFilteringPass`, which removes host-only functions when
compiling for an OpenMP target device, is currently defined only for
Flang. However, it implements logic that would generally be useful for
other frontends that can generate OpenMP offloading code. This patch
makes that transition by implementing the following changes:
- It rewrites the `FunctionFilteringPass` to work on lower level non-FIR
  MLIR modules.
- It splits off preexisting logic to check for not-yet-implemented target
  device features during function filtering to its own pass and it improves
  context detection to properly diagnostic only device code.
- It delays function filtering to run at the end of the pipeline, as well
  as the `MarkDeclareTargetPass`. This will enable the latter to run
  only once in the pipeline after the `UnimplementedDeviceCheckPass`
  becomes no longer necessary.

One side effect of these changes is that delaying the filtering will
cause all following passes to process host functions that are eventually
deleted. On the other hand, it minimizes divergence between host and
device MLIR modules making passes such as the `DeleteUnreachableTargets`
no longer necessary, as well as allowing passes to introduce new host
functions without causing problems on the device.
https://invent.kde.org/qt/clang/llvm/-/commit/bf7b2c660260b2d77430051ad9b35681a35d05b0

Git commit f03725767c7cbacdb1e2d07308a193e55c363924 by Sergio Afonso on 05/08/2026 at 10:23..
[Flang][OpenMP] Remove the DeleteUnreachableTargets pass

The `DeleteUnreachableTargets` pass was initially added to work around
a problem caused by the interaction between the function filtering and
host op filtering passes and generic MLIR optimizations.

Specifically, by running function and host op filtering before these
optimizations, we would lose the ability to detect unreachable
`omp.target` operations when compiling for the device. This would cause
GPU kernels being created for them, for which no host counterpart
existed.

By now having moved both passes towards the end of the compilation
pipeline, after FIR to LLVM lowering, removal of unreachable host and
device code is no longer impacted by them. This makes the
`DeleteUnreachableTargets` pass redundant.
https://invent.kde.org/qt/clang/llvm/-/commit/f03725767c7cbacdb1e2d07308a193e55c363924

Git commit ecb488cc91fbab7df281347f2c37c2aa887a1f34 by Sergio Afonso on 05/08/2026 at 10:24..
[Flang][OpenMP] Improve implicit declare_target propagation

After starting to run the `MarkDeclareTarget` pass later in the
pipeline, some limitations of its original implementation started to be
hit; specifically, some calls being missed could result in an overly
restrictive marking that would cause the `HostOpFiltering` pass to
remove reachable device code.

This patch aims to address these problems by making the following
changes:
- It makes sure to mark functions in every `RecipeInterface` op pointed
to by OpenMP operations.
- It recursively propagates and combines declare_target information from
target regions and explicitly set declare_target functions to unmarked
functions, but it never modifies explicitly marked functions.
- External and public functions can now only be marked with
`device_type(any)`. Before, marking them as `nohost` or `host` was
possible, but without the ability to see all users we can't give such
guarantees.
- There was a bug in the handling of declare_target on interface
subprograms that improvements to the pass made visible. Instead of
adding the attribute to the MLIR function associated to the interface
subprogram, it wasn't added at all, making it susceptible to being
modified by the pass according to uses. This is fixed.

Fixes #213367.
https://invent.kde.org/qt/clang/llvm/-/commit/ecb488cc91fbab7df281347f2c37c2aa887a1f34

Git commit f1a52c01a4b602e42204fb1e5683a6492f62fd7d by Sergio Afonso on 05/08/2026 at 11:06..
update cir test
https://invent.kde.org/qt/clang/llvm/-/commit/f1a52c01a4b602e42204fb1e5683a6492f62fd7d