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

Git repository change summary for qt/clang/llvm
Pushed by mirror-service into branch 'upstream/release/23.x'.
Changed from 63a847a41d0bbd4ab05f980ca895fbc7ab5c863b to 2a0942d3e93c15e8923054797fe93704dd35c92b
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 18f4b593ef0ef8d44879fa52496e2327689ff0d4 by Tobias Hieta (on behalf of Florian Hahn) on 24/07/2026 at 06:06..
[LV] Add test showing incorrect trip count materialization (NFC) (#209460)

Add test case showing mis-compile for
https://github.com/llvm/llvm-project/issues/209159.
https://invent.kde.org/qt/clang/llvm/-/commit/18f4b593ef0ef8d44879fa52496e2327689ff0d4

Git commit 09b884a41dab18f4bb933e999d7923970698aed1 by Tobias Hieta (on behalf of Florian Hahn) on 24/07/2026 at 06:06..
[VPlan] Use VPlan::hasTailFolded in materializeConstantVectorTC. (#209502)

The current checks in materializeConstantVectorTripCount miss
tail-folded cases when vectorizing loops with fmax without fast-math
flags. Use recently added hasTailFolded helper to ensure we always bail
out on tail-folded loops.

Fixes https://github.com/llvm/llvm-project/issues/209159.
https://invent.kde.org/qt/clang/llvm/-/commit/09b884a41dab18f4bb933e999d7923970698aed1

Git commit 060d53f28f9692cb29c4900774adb6d47c00d482 by Tobias Hieta (on behalf of Jonas Devlieghere) on 24/07/2026 at 06:32..
[DebugInfo] Don't assert on missing template parameter names (#211412)

The DWARF verifier reconstructs simplified template names through
DWARFTypePrinter to compare them against the original DW_AT_name. On
malformed input, a template parameter can have no recoverable name,
which tripped assert(RawName) and aborted instead of letting the
verifier report the problem.

Assisted-by: Claude

rdar://182715403
(cherry picked from commit bdddd134c1af6b0c5196ea944edf4c5c76019306)
https://invent.kde.org/qt/clang/llvm/-/commit/060d53f28f9692cb29c4900774adb6d47c00d482

Git commit e39f33c9efdb1b3e2712e60659b0ecd646df85bd by Tobias Hieta (on behalf of Phoebe Wang) on 24/07/2026 at 06:33..
[X86][CCMP] Fix invalid CCMP emission (#211161)

This patch ports AArch64's negation-aware conjunction algorithm to fix
invalid CCMP emission when OR nested inside an AND.

Example: https://godbolt.org/z/ave7f61hK

Before the change, the above case returns 5 rather the 9 when CCMP
enabled.

Assisted-by: Claude Opus 4.8
(cherry picked from commit 45b30651cf94ddb32676550cca7ddd3f6a5e66e0)
https://invent.kde.org/qt/clang/llvm/-/commit/e39f33c9efdb1b3e2712e60659b0ecd646df85bd

Git commit 5e7b435ebd6f5ade85e33d139ae47ad4f4685ba7 by Tobias Hieta (on behalf of Charles Zablit) on 24/07/2026 at 06:33..
[lldb][Windows] ignore loader breakpoints in system modules (#208233)

Currently, when debugging a program with `lldb-dap` on Windows and using
the `integratedTerminal` option, lldb-dap immediatly stops with an
`0x80000003` Exception. This is because `ntdll` executes an `int3`
breakpoint during process initialization when a debugger is attached.

This patch makes `lldb` and `lldb-server` skip the first `int3` after
launch when it originates from a system module (the loader's debugger
notification). Only that first loader breakpoint is skipped. Any later
int3, including `__debugbreak()`, `__builtin_debugtrap()` in the
debuggee's own code, still stops the debugger.

Fixes https://github.com/llvm/llvm-project/issues/198763

(cherry picked from commit 83530ce356dd55fdc981b5325ca1f5117b4a58f8)
https://invent.kde.org/qt/clang/llvm/-/commit/5e7b435ebd6f5ade85e33d139ae47ad4f4685ba7

Git commit 1bbf4454fcc4635aececb5c25963dab2f18fe92a by Tobias Hieta (on behalf of David Green) on 24/07/2026 at 06:35..
[AArch64] Reuse NeoverseN1 and N2 scheduling models for A76/A77/A78. (#211209)

We do not have native scheduling models for some of the Cortex-A
generations of CPUs, so they were still using the old Cortex-A57 model.
Whilst not perfectly accurate, the NeoverseN1 and NoeverseN2 scheduling
models should be a better fit for these CPUs. I mostly just tried to
make sure the number of pipelines matches between the neoverse core and
the cortex core. If we need something more accurate then we can start
adding new models for the CPUs.

(cherry picked from commit 54a0f730d9f8df4e7f5e4bfd4c03acbc182eb3cf)
https://invent.kde.org/qt/clang/llvm/-/commit/1bbf4454fcc4635aececb5c25963dab2f18fe92a

Git commit 5bb1351e692fad3e6f824fce2a755e3db0b9a9e5 by Tobias Hieta (on behalf of Jonas Devlieghere) on 24/07/2026 at 06:36..
[DWARFLinker] Fix placement lost-update crash in parallel marking (#211009)

(cherry picked from commit acb8fbe83ff12711317118b8c9831905d301b56a)
https://invent.kde.org/qt/clang/llvm/-/commit/5bb1351e692fad3e6f824fce2a755e3db0b9a9e5

Git commit 2284dea038d8354c17f95df136d32e73b8b8bb60 by Tobias Hieta (on behalf of Eli Friedman) on 24/07/2026 at 06:39..
[LoopInfo] Fix makeLoopInvariant to strip UB-implying attributes. (#211413)

isSafeToSpeculativelyExecute gained an argument to check for UB-implying
attributes in 830cf36bd4c49, but the default is to ignore them. Update
this code to account for that.

Fixes #210137

(cherry picked from commit fcff12829ecee44d715d9f901c0195fb1f30a881)
https://invent.kde.org/qt/clang/llvm/-/commit/2284dea038d8354c17f95df136d32e73b8b8bb60

Git commit 4977a9adab25df32ba965b8f594ebe544576eaf3 by Tobias Hieta (on behalf of Jonas Devlieghere) on 24/07/2026 at 06:40..
[DWARFLinker] Treat DW_AT_LLVM_alloc_type as a type reference (#211655)

The parallel linker's getODRAttributes() did not list
`DW_AT_LLVM_alloc_type`, so the dependency tracker treated it as a live
reference rather than a type reference. A type reachable only through
DW_AT_LLVM_alloc_type was therefore never kept: the enclosing subprogram
is marked live, and its type-table-candidate children are skipped during
live marking on the assumption they are retained through the type path.

The attribute then resolved to offset 0, landing on the compile unit
header, which got correctly caught by the DWARF verifier.

The classic linker already lists `DW_AT_LLVM_alloc_type` in
isODRAttribute(), so this PR restores parity between the two.

Assisted-by: Claude

rdar://182715403
(cherry picked from commit bb17e718bc419b46bb2596c2f25c9cc0f76a2d5a)
https://invent.kde.org/qt/clang/llvm/-/commit/4977a9adab25df32ba965b8f594ebe544576eaf3

Git commit 77b12913a0e3a2769dbc93569944c7187c934ae8 by Tobias Hieta (on behalf of Hubert Tong) on 24/07/2026 at 06:41..
[libunwind][test][AIX] Add C API test for unwinding from AIX VAPI (non-signal-handler case) (#209306)

Test detection, during stepping, of the backchain mutation introduced by
a VAPI call (see https://github.com/llvm/llvm-project/pull/209280).
Further, test resumption of contexts using cursors obtained while a VAPI
is active on the thread.

Testing is done via FileCheck inspection of trace output enabled by
`LIBUNWIND_PRINT_UNWINDING=1`. When Live Library Update is not enabled,
synthetic trace output is generated by the test program itself.

---------

Assisted-by: IBM Bob
(cherry picked from commit 861efe03d96d93cd7e475d15bbc676f6d521f4fd)
https://invent.kde.org/qt/clang/llvm/-/commit/77b12913a0e3a2769dbc93569944c7187c934ae8

Git commit 2a0942d3e93c15e8923054797fe93704dd35c92b by Tobias Hieta (on behalf of Hubert Tong) on 24/07/2026 at 06:43..
[libunwind][test][AIX] Add C API test for unwinding from AIX VAPI (as signal handler) (#209662)

Further to https://github.com/llvm/llvm-project/pull/209306, test a case
where a signal handler is a Virtual API function triggered synchronously
while the VAPI is not active. Resuming an ancestor context of the signal
frame should call the VAPI return glue.

---------

Assisted-by: IBM Bob
(cherry picked from commit dbaabbc920fcd60aeed5109c3c6353830e7605c5)
https://invent.kde.org/qt/clang/llvm/-/commit/2a0942d3e93c15e8923054797fe93704dd35c92b