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

Git repository change summary for qt/clang/llvm-project
Pushed by mirror-service into branch 'upstream/users/arsenm/amdgpu/fix-extended-image-insts-feature-map'.
Changed from 0000000000000000000000000000000000000000 to 8e1b018e70a79d547db8268d7528c418e0d2f2e8
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 776971a11fdce76b243bd94b1fe7d2b1957da969 by GitHub (on behalf of Pengcheng Wang) on 28/07/2026 at 05:25..
Revert "[RISCV] Add TuneNoDefaultUnroll to generic CPUs (#135318)" (#212400)

This reverts commit 9c5858eb699390c2cac5f7f032279be275fa6aef which
causes some regressions.
https://invent.kde.org/qt/clang/llvm-project/-/commit/776971a11fdce76b243bd94b1fe7d2b1957da969

Git commit 2f6ec89938aa12ba5190477032b974524c956b54 by GitHub (on behalf of Corentin Jabot) on 28/07/2026 at 05:46..
[Clang] Implement P3658R1 (#212131)

As a DR in all C++ language modes.
Because we already supported the feature this is only modifying the
extensions warnings.
https://invent.kde.org/qt/clang/llvm-project/-/commit/2f6ec89938aa12ba5190477032b974524c956b54

Git commit 0a30b0c8909dca8764d994a748bd7d53c68d94f7 by GitHub (on behalf of Matt Arsenault) on 28/07/2026 at 06:03..
AMDGPU: Declare FeatureDPP with AMDGPUSubtargetFeature (#212408)

All other features were defined using the AMDGPUSubtargetFeature
subclass of SubtargetFeature, so fix the odd one out.
https://invent.kde.org/qt/clang/llvm-project/-/commit/0a30b0c8909dca8764d994a748bd7d53c68d94f7

Git commit de962dda125154abb64446c198b5349cf05311cb by GitHub (on behalf of Hui) on 28/07/2026 at 06:15..
[libc++] Implement P0528R3 `std::atomic` CAS for types with padding (#76180)

Fixes #99984

Implement P0528R3 The Curious Case of Padding Bits, Featuring Atomic
Compare-and-Exchange


The unit test padding.pass.cpp is assisted by Cursor. However, all tests
have been modified to test what I wanted to test

---------

Co-authored-by: Louis Dionne <[email protected]>
https://invent.kde.org/qt/clang/llvm-project/-/commit/de962dda125154abb64446c198b5349cf05311cb

Git commit ed4090047fb6c40d8d014559da16cee934f124c0 by GitHub (on behalf of Kazu Hirata) on 28/07/2026 at 06:17..
[SampleProfile] Fix symbol partitioning in Eytzinger name table (#211906)

This patch fixes the symbol partitioning between context-sensitive
and flat profiles in writeEytzingerNameTableSection.

In split-layout profiles, top-level symbols in the Eytzinger name
table are partitioned into two bins -- context-sensitive and flat keys
-- so that they form parallel arrays with function offsets.

Without this patch, writeEytzingerNameTableSection uses:

  if (Ctx.hasContext())

to decide which bin to use even though splitProfileMapToTwo uses:

  if (!I.second.getCallsiteSamples().empty())

to partition the profile.  This difference causes certain symbols to
be classified into FlatKeys in the name table but into
ContextProfileMap in the LBR profile.

The patch fixes the problem by using the same condition to partition
keys.

This misclassification happens to top-level symbols (like main or
un-inlined root callers) that lack context delimiters in their
function names (hasContext() == false) but still contain inlined
callees in their profile hierarchies.

RFC:
https://discourse.llvm.org/t/rfc-faster-sample-profile-loading/90957/8

Assisted-by: Antigravity
https://invent.kde.org/qt/clang/llvm-project/-/commit/ed4090047fb6c40d8d014559da16cee934f124c0

Git commit d1ce5f95fb661999bcc99a3a816cc72c1220a36d by GitHub (on behalf of Alexis Engelke) on 28/07/2026 at 06:18..
[ASan] Instrument ptrtoaddr as pointer difference (#211988)

We want to emit ptrtoaddr instead of ptrtoint for pointer differences to
not expose the provenance. Adjust ASan instrumentation to handle this
case as well.
https://invent.kde.org/qt/clang/llvm-project/-/commit/d1ce5f95fb661999bcc99a3a816cc72c1220a36d

Git commit f2c7e2bcd57ef2a9db23e5071618d3e02ee9c33d by GitHub (on behalf of Pavel Labath) on 28/07/2026 at 06:20..
[libc] Fix atexit_test in hermetic mode (#210656)

We never unlocked the ThreadAtExit mutex, which meant the second call to
exit deadlocked. This was detected in the unit tests as they were
calling __cxa_thread_atexit from the system C library.
https://invent.kde.org/qt/clang/llvm-project/-/commit/f2c7e2bcd57ef2a9db23e5071618d3e02ee9c33d

Git commit 8e1b018e70a79d547db8268d7528c418e0d2f2e8 by Matt Arsenault on 28/07/2026 at 07:02..
AMDGPU: Fix missing extended-image-insts missing from feature map

Unsurprisingly, this manually maintained table is buggy.
fillAMDGCNFeatureMap never set extended-image-insts, so clang's builtin
feature check rejected every case. The tests were working around this with
manually specified -target-features flags.

Co-authored-by: Claude (Claude-Opus-4.8)
https://invent.kde.org/qt/clang/llvm-project/-/commit/8e1b018e70a79d547db8268d7528c418e0d2f2e8