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

Git repository change summary for qt/clang/llvm
Pushed by mirror-service into branch 'upstream/users/arsenm/clang/amdgpu-migrate-tests-bare-triple'.
Changed from 0000000000000000000000000000000000000000 to 1c7cd7f0633fa277eaec066c0db0b7cc43e54547
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 026a34b3ff5e6a53313ae81853278d55926785d1 by GitHub (on behalf of Yingwei Zheng) on 25/07/2026 at 17:14..
[SimplifyCFG] Fix DomTree update in `simplifySwitchDefaultBranch` (#212030)

When there is no edge to the original default destination BB, also
remove the edge in DT.

This issue cannot be reproduced via
-simplifycfg-require-and-preserve-domtree=1. I just found it by checking
DT in requestResimplify (will be added after fixing all existing
issues). The following test covers this case:

https://github.com/llvm/llvm-project/blob/5bc304c65494702d9d4928ff6cb369e6e6496e53/llvm/test/Transforms/SimplifyCFG/switch-simplify-default.ll#L172-L214
https://invent.kde.org/qt/clang/llvm/-/commit/026a34b3ff5e6a53313ae81853278d55926785d1

Git commit b071e92ca3d3db20711daffce6cf5b813cc5da49 by GitHub (on behalf of Alexis Engelke) on 25/07/2026 at 17:29..
[DomTree] Remove support for unnumbered graphs (#212026)

After VPlan, all our in-tree users of the dominator tree have numbered
nodes. Remove the support for unnumbered graphs.

Also slightly simplify the numbering for pre-dominator trees to avoid an
extra +1 on every node number.
https://invent.kde.org/qt/clang/llvm/-/commit/b071e92ca3d3db20711daffce6cf5b813cc5da49

Git commit 191c60fe7cee5587ad7f7a6fd7b5bbf7b0042bec by GitHub (on behalf of Benjamin Kramer) on 25/07/2026 at 18:03..
[ThreadSafety] Fix C++20 build (#212042)

In C++20 (P1008R1 https://wg21.link/p1008r1), aggregates are prohibited
from having any user-declared constructors, even if they are = delete or
= default.
https://invent.kde.org/qt/clang/llvm/-/commit/191c60fe7cee5587ad7f7a6fd7b5bbf7b0042bec

Git commit 197cf54ac854f475b7ab2e1d23f02dff16ded5ca by GitHub (on behalf of Matt Arsenault) on 25/07/2026 at 18:24..
clang/AMDGPU: Migrate cc1 tests to subarch triples (10) (#211955)

Rewrite the first half of CodeGenOpenCL cc1 test RUN lines to the new
subarch triple form, dropping the redundant -target-cpu.

Co-authored-by: Claude (Opus 4.8) <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/197cf54ac854f475b7ab2e1d23f02dff16ded5ca

Git commit d1af60ff088ba003ec0830cf8f4fd579646d736e by GitHub (on behalf of Matt Arsenault) on 25/07/2026 at 18:39..
DAG: Stop legalizing poison to undef (#211890)

Previously all targets would expand poison to undef, which was a
shortcut taken when poison was introduced.

Introduces a new dedicated poison matcher in tablegen; this avoids
multiple opcode changes, and avoids some problematic contexts that
couldn't deal with PatFrags.

This probably should be legal by default for all legal types.

Co-authored-by: Claude (Claude-Opus-4.8)
https://invent.kde.org/qt/clang/llvm/-/commit/d1af60ff088ba003ec0830cf8f4fd579646d736e

Git commit 890d1331a35c6961191db07447df2623619afb7e by GitHub (on behalf of Alexis Engelke) on 25/07/2026 at 19:07..
[Clang] Don't build static analyzer if disabled (#212024)

Even if the static analyzer is disabled, it still gets built into the
dylib. Unit tests and tools already get disables, so also stop building
the library. This reduces the time needed to build a dylib clang by
8-9%.
https://invent.kde.org/qt/clang/llvm/-/commit/890d1331a35c6961191db07447df2623619afb7e

Git commit 6b0a46958c56d91e3b2fd5ffecfe163dde1fac3a by GitHub (on behalf of Piotr Kubaj) on 25/07/2026 at 19:11..
[libunwind][PPC64] Fix unw_getcontext corrupting callee-saved VSX registers on LE (#198371)

This is the first of two independent fixes for libunwind on ppc64le
(ELFv2 ABI, little-endian), where two separate bugs together cause
SIGSEGV during backtracing. This commit addresses the VSX register
corruption; the TOC-restore fault is handled in a follow-up. Both
were discovered while debugging lang/rust build failures with
RUST_BACKTRACE=1 on FreeBSD/powerpc64le (IBM POWER9).

On ppc64le, `unw_getcontext` saves each VS register with an in-place
`xxswapd n, n` followed by `stxvd2x`. The swap is needed because
`stxvd2x` stores doublewords in the wrong order on LE. However, the
macro never applies a second `xxswapd` to restore the register after
the store, so all 64 VS registers are permanently corrupted on return
from `unw_getcontext`.

This affects every callee-saved VSX register: f14-f31 (VSR14-VSR31)
and VR20-VR31 (VSR52-VSR63). After `_Unwind_Backtrace` returns, any
code that uses these registers sees wrong values. In practice this
manifests as SIGSEGV inside hashbrown's `reserve_rehash`: VR20-VR31
are corrupted before a SIMD comparison loop runs, producing an
out-of-bounds access.

Fix: add a second `xxswapd n, n` after the `stxvd2x` store. Since
`xxswapd` is its own inverse, the pair is a no-op on the architectural
register while still writing the correctly byte-swapped value to memory.
https://invent.kde.org/qt/clang/llvm/-/commit/6b0a46958c56d91e3b2fd5ffecfe163dde1fac3a

Git commit 56f4b9c4e875477c0fbc73160f96524d4915040c by GitHub (on behalf of Matt Arsenault) on 25/07/2026 at 19:50..
clang/AMDGPU: Migrate cc1 tests to subarch triples (11) (#211956)

Rewrite the second half of CodeGenOpenCL cc1 test RUN lines to the new
subarch triple form, dropping the redundant -target-cpu.

Co-authored-by: Claude (Opus 4.8) <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/56f4b9c4e875477c0fbc73160f96524d4915040c

Git commit 353729bbe4c53086c9acf3a9d1a4a88a61eec997 by GitHub (on behalf of Arseniy Obolenskiy) on 25/07/2026 at 20:31..
[AMDGPU] Avoid quadratic erase in SIInstrWorklist (#211801)
https://invent.kde.org/qt/clang/llvm/-/commit/353729bbe4c53086c9acf3a9d1a4a88a61eec997

Git commit 96a85478fbb2dd0b4fd5d11aeb9eae396499b8b5 by GitHub (on behalf of Florian Hahn) on 25/07/2026 at 20:51..
[VPlan] Add VPRegionBlock::getEntryBranchOnMask helper (NFC) (#212060)

Add an accessor returning the VPBranchOnMaskRecipe guarding a replicate
region, i.e. the sole recipe of the region's entry block.
https://invent.kde.org/qt/clang/llvm/-/commit/96a85478fbb2dd0b4fd5d11aeb9eae396499b8b5

Git commit f704f396072bd0fffc13ce2aae5fb58dfe26bce6 by GitHub (on behalf of Matt Arsenault) on 25/07/2026 at 20:52..
clang/AMDGPU: Migrate OpenMP cc1 tests to amdgpu triples (12) (#212051)

Migrate the OpenMP offload cc1 tests to the new amdgpu triple scheme:

* -fopenmp-targets=amdgcn-amd-amdhsa ->
-fopenmp-targets=amdgpu-amd-amdhsa
    (the offload toolchain triple, the generic amdgpu arch).
  * The device -triple amdgcn-amd-amdhsa -> amdgpu-amd-amdhsa, or to the
specific subarch triple (dropping -target-cpu) where a -target-cpu was
    present.

Autogenerated CHECK lines are regenerated, and the few -Wopenmp-target-
exception diagnostics that embed the triple string are updated. Tests
that
intentionally assert the "target-cpu" function attribute are left
unchanged.

Co-authored-by: Claude (Opus 4.8) <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/f704f396072bd0fffc13ce2aae5fb58dfe26bce6

Git commit 2f3f97fb72606f51ece7d64d6a7a73c9eaad8978 by GitHub (on behalf of Matt Arsenault) on 25/07/2026 at 20:54..
clang/AMDGPU: Migrate -aux-triple amdgcn in cc1 tests to amdgpu (13) (#212052)

Update to the new architecture name.

Co-authored-by: Claude (Opus 4.8) <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/2f3f97fb72606f51ece7d64d6a7a73c9eaad8978

Git commit 1c7cd7f0633fa277eaec066c0db0b7cc43e54547 by Matt Arsenault on 25/07/2026 at 21:19..
clang/AMDGPU: Rename amdgcn triples to amdgpu in cc1 tests (14)

Replace the legacy amdgcn architecture name with amdgpu in various
test triples. This set of updates covers cases that did not have
a set -target-cpu.

Co-authored-by: Claude (Opus 4.8) <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/1c7cd7f0633fa277eaec066c0db0b7cc43e54547