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

Git repository change summary for qt/clang/llvm
Pushed by mirror-service into branch 'upstream/main'.
Changed from ae0f00de4ce82fb933c326980464c8cefb4e0029 to f3b31871e9b8e0fe07c92c91854861365ea189a4
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 bab258ae1eaa56cbdc86b19f8063be612e1e4795 by GitHub (on behalf of Tom Stellard) on 26/07/2026 at 05:14..
workflows/relase-tasks: Fix variable name typo (#211732)
https://invent.kde.org/qt/clang/llvm/-/commit/bab258ae1eaa56cbdc86b19f8063be612e1e4795

Git commit 2ad69983d8b72d8a665a2552aac15517fe0cb351 by GitHub (on behalf of Tom Stellard) on 26/07/2026 at 05:25..
workflows/libclang-abi-tests: Fix missing environment variable (#211959)

This was accidentally removed in
f6af6cedfd2fa731bf323608116d373379838b9a.
https://invent.kde.org/qt/clang/llvm/-/commit/2ad69983d8b72d8a665a2552aac15517fe0cb351

Git commit 6cdc7bd8c97b633f7095a5df32fb8003ee1b49b9 by GitHub (on behalf of Andrew Savonichev) on 26/07/2026 at 05:57..
[AArch64] Add CAS instructions to NeoverseN2 schedule model (#211195)

CAS instructions (B, H, W, X variants) are not described in the ARM
Neoverse N2 Software Optimization Guide. There used to be no schedule
model for them, so `llvm-mca` was unable to analyze code containing
these instructions:

    llvm-mca  -mtriple=aarch64 -mcpu=cortex-a78 -mattr=+lse casb.s

    error: found an unsupported instruction in the input assembly
    sequence, use -skip-unsupported-instructions=lack-sched to ignore
    these on the input.

    note: instruction: 	casb	w0, w1, [sp]

The patch adds a basic schedule model of 14 cycles (as measured on
Cortex-A78 with llvm-exegesis) and L/S utilized pipelines (this is a
guess, the reality is likely more complicated).
https://invent.kde.org/qt/clang/llvm/-/commit/6cdc7bd8c97b633f7095a5df32fb8003ee1b49b9

Git commit 3fd07e32350c4f15a9377466ab4cffb042a1ecb7 by GitHub (on behalf of Timm Baeder) on 26/07/2026 at 06:14..
[clang][bytecode] Only override constant-context state if we have an EvalEmitter (#211475)

This does not make sense when emitting bytecode, as the bytecode would
just contain a `PushCC`/`PopCC` pair with nothing in between.
https://invent.kde.org/qt/clang/llvm/-/commit/3fd07e32350c4f15a9377466ab4cffb042a1ecb7

Git commit 4eeff3e309da3a5d827aadc6fb6915b968b23ad5 by GitHub (on behalf of Lucas Mellone) on 26/07/2026 at 06:30..
[libc++][math] Add `constexpr` to `std::fpclassify` (#210993)

Adds `constexpr` to `std::fpclassify` as required by
[P0533R9](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p0533r9.pdf).

Towards https://github.com/llvm/llvm-project/issues/105174. Follows-up
8889a3d3b5154d7d5bd4e58ab10d3df503544742.
https://invent.kde.org/qt/clang/llvm/-/commit/4eeff3e309da3a5d827aadc6fb6915b968b23ad5

Git commit 545f9fab9ed84d55a97b3f08d306c0da70b625a6 by GitHub (on behalf of Timm Baeder) on 26/07/2026 at 06:53..
[clang][bytecode] Don't check global variable init size (#212092)

The current interpreter doesn't do this either. If we do, the clang
build fails because AMDGPUGenGlobalISel.inc: contains a global constexpr
array called MatchTable0 with 1'926'005 elements.
https://invent.kde.org/qt/clang/llvm/-/commit/545f9fab9ed84d55a97b3f08d306c0da70b625a6

Git commit 5d582e4003b1cab59900d16fa3db9c3a9d16b462 by GitHub (on behalf of Fangrui Song) on 26/07/2026 at 07:15..
[LoopInfo] Identify loops with a single-pass DFS algorithm. NFC (#212000)

analyze() numbers the dominator tree, scans it in reverse preorder for
header candidates, floods backward through the CFG from each header's
latches, then walks the CFG again to order the blocks.

Do all of it in one forward DFS, with the algorithm of Wei et al.,
"A New Algorithm for Identifying Loops in Decompilation", which
GenericCycleInfo already implements.

On an irreducible CFG that algorithm may return an irreducible superset
of the natural loop subset `discoverAndMapSubloop` would return.
(Depending on the successor visiting order, the algorithm may report a
reducible loop nested in an irreducible loop, where the reducible one
exactly matches `discoverAndMapSubloop`.)

To satisfy verifyLoop and LoopSimplify, reduce each such ireducible loop
to the natural loop of its header's backedges instead: the latches the
header dominates, and the blocks reaching them without passing the
header.

A function whose loops are all reducible needs no dominance query.

1000x require<loops> on sqlite3.bc: instructions -24%, cycles -14%.

Aided by Claude Opus 5
https://invent.kde.org/qt/clang/llvm/-/commit/5d582e4003b1cab59900d16fa3db9c3a9d16b462

Git commit 5bafce4a37c7702f2ecb857eb18df6c211fc19bf by GitHub (on behalf of forking-google-bazel-bot[bot]) on 26/07/2026 at 07:20..
[Bazel] Fixes abd6e74 (#212081)

This fixes abd6e745e22e83af7986cdca4c1ba2d798e00156 (#196613).

Buildkite error link:
https://buildkite.com/llvm-project/upstream-bazel/builds?commit=abd6e745e22e83af7986cdca4c1ba2d798e00156

Co-authored-by: Google Bazel Bot <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/5bafce4a37c7702f2ecb857eb18df6c211fc19bf

Git commit 653e7b05bbd7fbcaab3721ebfb2b3c2304f15ee4 by GitHub (on behalf of Jeff Bailey) on 26/07/2026 at 07:47..
[libc][test][NFC] Fix pthread_setschedparam_test flakiness (#212067)

Synchronised child thread execution in pthread_setschedparam_test using
a mutex lock. This prevents race conditions where the child thread
exited before scheduling parameter assertions ran on multi-core
platforms such as aarch64.

Added missing pthread target dependencies to CMakeLists.txt.

Assisted-by: Automated tooling, human reviewed.
https://invent.kde.org/qt/clang/llvm/-/commit/653e7b05bbd7fbcaab3721ebfb2b3c2304f15ee4

Git commit 75dff4f8527fe9a52d5f60b4c089162845f72080 by GitHub (on behalf of David Green) on 26/07/2026 at 07:56..
[AArch64] Replace some used of SDValue.getNode()-> with direct accesses. NFC (#212099)
https://invent.kde.org/qt/clang/llvm/-/commit/75dff4f8527fe9a52d5f60b4c089162845f72080

Git commit 2b660e0f1b6dce0484a2f83c02395a919a063ab2 by GitHub (on behalf of Martin Storsjö) on 26/07/2026 at 09:28..
[clang] [test] Fix a new test on mingw (#212064)

This fixes running a new test that was added in
4b66bacd1fdf02803509b744034f3ab09945157c, in mingw environments.

The quirks that warranted adding the `!defined(_WIN32)` condition in the
test aren't actually specific to Windows in general, but specific to
MSVC environments - mingw environments behave just like other platforms.

Ideally we'd use `!defined(_MSC_VER)`, however in -cc1 mode, Clang
doesn't automatically define `_MSC_VER`; defining it requires setting a
command line option that the driver normally passes in MSVC mode.
Therefore, qualify the condition as `!defined(_MSC_VER) ||
defined(__MINGW32__)`.
https://invent.kde.org/qt/clang/llvm/-/commit/2b660e0f1b6dce0484a2f83c02395a919a063ab2

Git commit 40daec88f9e2719c5c2caa05d6003c9effde18d3 by GitHub (on behalf of Martin Storsjö) on 26/07/2026 at 09:28..
[docs] Remove release notes for backported changes (#212069)

Commit 68f703f3e58a52c41b39dfc654a675560b6c5614 added these release
notes, but this commit was backported to the 23.x release branch in
47e2df730a099583f16fc6fe64f0d2ffc5b7a16a (included in the 23.1.0 RC 1
tag).

Therefore, remove these release notes from the main branch (where they
would have been included in the 24.x release notes).
https://invent.kde.org/qt/clang/llvm/-/commit/40daec88f9e2719c5c2caa05d6003c9effde18d3

Git commit f5652b9800c997f3c76f84ea81de1175561ed59c by GitHub (on behalf of Florian Hahn) on 26/07/2026 at 09:47..
[SCEV] Store type of expression inline, compute up front (NFC). (#211891)

Add SCEV::Type to store the expressions immutable type. This slightly
increases object size for most sub-types, but avoids more expensive
recomputing of the type repeatedly.

Improves compile time slightly overall, more in SCEV-heavy workloads.

 * stage1-O3: -0.08%
 * stage1-ReleaseThinLTO: -0.07%
 * stage1-ReleaseLTO-g: -0.07%
 * stage1-aarch64-O3: -0.07%
 * stage2-O3: -0.08%


https://llvm-compile-time-tracker.com/compare.php?from=f9b12955f891bb086d12309d89656821d776e858&to=0e8df1e93422960640d0efd460212a463700a64a&stat=instructions:u

It looks like there's no notable increase in max-rss
https://llvm-compile-time-tracker.com/compare.php?from=f9b12955f891bb086d12309d89656821d776e858&to=0e8df1e93422960640d0efd460212a463700a64a&stat=max-rss

PR: https://github.com/llvm/llvm-project/pull/211891
https://invent.kde.org/qt/clang/llvm/-/commit/f5652b9800c997f3c76f84ea81de1175561ed59c

Git commit f3b31871e9b8e0fe07c92c91854861365ea189a4 by GitHub (on behalf of Balázs Benics) on 26/07/2026 at 10:34..
[clang][CFG] Fix lambda capture evaluation order (#211877)

Previously, the captures were emitted in their spelling order - but in
the CFG that gets translared in a reversed order.
Because of this, we need to emit them in reversed order to get them
appear in their natural order.

Fixes rdar://183140177
https://invent.kde.org/qt/clang/llvm/-/commit/f3b31871e9b8e0fe07c92c91854861365ea189a4