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

Git repository change summary for qt/clang/llvm
Pushed by mirror-service into branch 'upstream/users/kosarev/asmparser-identify-ambiguities'.
Changed from 91af5fb72ccb171a2c6a1dc0de8cffff5928208d to 4532e3157cf7d14054f0e501a5f5b963c87e1a3a
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 4b6a8d81da1a9eb1cee48c318b156ef2f2645c94 by GitHub (on behalf of Matt Arsenault) on 03/08/2026 at 05:24..
AMDGPU: Migrate most llvm-objdump tests to use subarch triple (#213589)
https://invent.kde.org/qt/clang/llvm/-/commit/4b6a8d81da1a9eb1cee48c318b156ef2f2645c94

Git commit 04ea62bc5e2c5596866de7ee6a9c3a8b6aa54d35 by GitHub (on behalf of Arseniy Obolenskiy) on 03/08/2026 at 05:25..
[AMDGPU] Fix miscompile trimming sparse DMask on image stores (#213586)

Dropping a channel from a sparse DMask removes that write entirely

It does not zero-fill like a contiguous trim does

Only simplify stores when DMask is a contiguous prefix
https://invent.kde.org/qt/clang/llvm/-/commit/04ea62bc5e2c5596866de7ee6a9c3a8b6aa54d35

Git commit 4f607e3cd911ccc3d1aab73129aacea97d864663 by GitHub (on behalf of Matt Arsenault) on 03/08/2026 at 05:42..
AMDGPU: Migrate misc. tests to subarch triples (#213593)
https://invent.kde.org/qt/clang/llvm/-/commit/4f607e3cd911ccc3d1aab73129aacea97d864663

Git commit 278b9af90c6fd32776ad3f4f4b5eab87f52587e2 by GitHub (on behalf of Sam Elliott) on 03/08/2026 at 06:02..
[RISCV][MC] Emit Better Token Diagnostics (#209700)

This implements an old FIXME in the AsmMatcherEmitter, which can now
emit a token-specific match error diagnostic id, and potentially a
token-specific error message to go along with the diagnostic id.

For RISC-V, the overall effect is to have fewer "invalid operand for
instruction" diagnostics and have more "expected '<TOKEN>'" diagnostics,
which, with multiple near miss support, gives the user the location that
token was expected (but not found).

The rejig to the order of checks in `validateOperandClass` do not
prevent backends from having custom operand kinds which can accept
tokens, as was available before.

The TableGen parts have been implemented in an opt-in way.

---

This was implemented with the assistance of AI.
https://invent.kde.org/qt/clang/llvm/-/commit/278b9af90c6fd32776ad3f4f4b5eab87f52587e2

Git commit 187c39ba03cfed96c8aab9d0c951d0bea6f27b82 by GitHub (on behalf of Abhinav Gaba) on 03/08/2026 at 06:07..
[OpenMP] Propagate ALWAYS/DELETE/CLOSE map-type modifiers to mapper entries (#210210)

Per OpenMP, when a map/motion clause uses a mapper, any
map-type-modifying modifier on that clause applies to each map the
declared mapper specifies.

This change propagates the `ALWAYS`, `DELETE`, and `CLOSE` bits from the
outer clause's map type into every entry emitted by
emitUserDefinedMapper, except `ATTACH` entries (`ATTACH`|`ALWAYS` is
reserved for `attach(always)`, and the other bits have no meaning for an
`ATTACH` entry).

`PRESENT` is intentionally NOT propagated here: it requires
distinguishing pointee entries from the struct's own storage and is
handled in a follow-up.

Co-authored-by: Claude Opus 4.8 <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/187c39ba03cfed96c8aab9d0c951d0bea6f27b82

Git commit e2c8f57f00971712c1732b137a9afc539e38ff37 by GitHub (on behalf of Robert Imschweiler) on 03/08/2026 at 06:28..
[OpenMPOpt] Null generic-mode wrappers for SPMDized kernels (#207611)

If a kernel gets SPMDized, it doesn't need the wrapper function that is
passed to __kmpc_parallel_60. Keeping the dead wrapper function can lead
to lots of misleading "local memory global used by non-kernel function"
AMDGPU backend warnings.
Let OpenMPOpt null the wrapper argument such that DCE can then remove
the corresponding dead functions.

Claude assisted with this patch.
https://invent.kde.org/qt/clang/llvm/-/commit/e2c8f57f00971712c1732b137a9afc539e38ff37

Git commit 7f161cde5751ab5ab38a5e52119f9fe867844758 by GitHub (on behalf of Kareem Ergawy) on 03/08/2026 at 06:40..
[flang-rt] enable IsNamelistNameOrSlash lookahead for scalar namelist items (#211224)

Resolves https://github.com/llvm/llvm-project/issues/211747

Problem
-------
An empty NAMELIST assignment on a scalar item — e.g. `l =` in

    &nml l= i_count=7 r_value=2.72/

— aborted at runtime with

fatal Fortran runtime error: Bad character 'i' in LOGICAL input field

Every EditIntegerInput / EditRealInput / EditLogicalInput /
EditCharacterInput function starts its list-directed arm with

    if (IsNamelistNameOrSlash(io)) return false;   // no value

which peeks ahead (via SavedPosition, no stream consumption) for a
`<name>=` / `<name>%` / `<name>(` shape or one of the terminators `/`
`&` `$`, letting the reader bail cleanly for empty values and
short-array ends. That helper's first line is

    if (!listInput || !listInput->namelistGroup()) return false;

InputNamelist however called ResetForNextNamelistItem with
`useDescriptor->rank() > 0 ? &group : nullptr`, so `namelistGroup_`
stayed null for scalars. The peek was silently disabled and the value
reader consumed the next namelist item's name as a bare token, producing
the abort above. Legacy nvfortran / gfortran accept empty scalar
assignments as "keep current value".

Solution
--------
Pass `&group` unconditionally to `ResetForNextNamelistItem`. Today
`IsNamelistNameOrSlash` uses `namelistGroup_` only as a boolean gate
(never as a lookup table), so widening it is a no-op for arrays and
enables the same empty-value / next-name detection for scalars.
NamelistTests.NanInputAmbiguity (which motivated the original pointer
form) still passes; three new tests cover the empty-scalar case, the
empty-array case, and an empty scalar surrounded by arrays.

Co-authored-by: Claude Opus 4.7 <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/7f161cde5751ab5ab38a5e52119f9fe867844758

Git commit f7213d839614c3103f4be28a1459e7f12c44dc77 by GitHub (on behalf of Antonio Frighetto) on 03/08/2026 at 06:57..
[MemorySSA] Clarify `getClobberingMemoryAccess(MA, Loc)` overload does not accept MemoryUse (NFC) (#212512)

Outdated comment has been updated to match the implementation, which
asserts on MemoryUse.
https://invent.kde.org/qt/clang/llvm/-/commit/f7213d839614c3103f4be28a1459e7f12c44dc77

Git commit f901de33ab614a7f13caa66ed966d3cd6bcb6eab by GitHub (on behalf of Antonio Frighetto) on 03/08/2026 at 06:58..
[GVNHoist] Use MemorySSA, drop MemoryDependenceAnalysis (NFCI) (#212773)

Finalize MemorySSA usage in GVNHoist, while transitioning away from
MemoryDependenceAnalysis.
https://invent.kde.org/qt/clang/llvm/-/commit/f901de33ab614a7f13caa66ed966d3cd6bcb6eab

Git commit 738029a68bd265cb4e65e03f63d84c027692adaa by GitHub (on behalf of Madhur Amilkanthwar) on 03/08/2026 at 06:58..
Enforce single-operand form for llvm.loop.vectorize metadata (#210932)

This patch implements Phase 2 of the RFC "Enforce Single-Operand Format
for All .enable Metadata Nodes". Please refer to RFC:

https://discourse.llvm.org/t/rfc-enforce-single-operand-format-for-all-enable-metadata-nodes/90571/

The two-operand boolean form !{!"llvm.loop.vectorize.enable", i1 0/1} is
replaced by a single-operand enable/disable pair:

  !{!"llvm.loop.vectorize.enable"}    ; force vectorization
  !{!"llvm.loop.vectorize.disable"}   ; suppress vectorization

The Verifier rejects the two-operand form, AutoUpgrade rewrites old
bitcode (including the legacy llvm.vectorizer.enable tag), and the
readers and producers across LLVM, Clang, MLIR and Polly are updated.
https://invent.kde.org/qt/clang/llvm/-/commit/738029a68bd265cb4e65e03f63d84c027692adaa

Git commit a7cc9516751d6c5afe35da0628083879cb52f1c0 by GitHub (on behalf of Wenju He) on 03/08/2026 at 06:58..
[llvm-calc-occupancy] Fix title underline length (#213599)

Fix error: invalid header length in
'CommandGuide/llvm-calc-occupancy.rst' (does not match length of title)
in our downstream Sphinx doc build.
https://invent.kde.org/qt/clang/llvm/-/commit/a7cc9516751d6c5afe35da0628083879cb52f1c0

Git commit 748828c3dbeae182d50de46b8fb7cb9c1076aaa0 by GitHub (on behalf of dmaclach) on 03/08/2026 at 07:22..
[clang][ast][objc] Implement getNameForDiagnostic for ObjC{Method,Property}Decl (#213030)

This overrides `getNameForDiagnostic` to provide a qualified name
representation for Objective-C methods and properties in diagnostics.
When qualified is true, it formats them using the standard Objective-C
syntax, such as `-[Class selector]` or `+[Class property]`. Previously
these would be `Class::selector` or `Class::property`. If qualified is
false, it falls back to printName.

Note that I avoided modifying `NamedDecl::getQualifiedNameAsString()` or
`printQualifiedName()` which will continue to (unfortunately) return
`Class::method`, but this is intentional to attempt to avoid any
breakage downstream due to output changing.
https://invent.kde.org/qt/clang/llvm/-/commit/748828c3dbeae182d50de46b8fb7cb9c1076aaa0

Git commit 3be1dff0910dc71df932380c9091a10a54ca9fe0 by GitHub (on behalf of Med Ismail Bennani) on 03/08/2026 at 07:22..
[lldb] Skip flaky test_circular_dependency_evaluate_expression_in_get_frame (#213610)

This provider's identity-forwarding pattern intermittently hits a known
frame-identity-aliasing bug in ScriptedFrameProvider::GetFrameAtIndex,
tracked in https://github.com/llvm/llvm-project/pull/208992.
https://invent.kde.org/qt/clang/llvm/-/commit/3be1dff0910dc71df932380c9091a10a54ca9fe0

Git commit 7dae1728fbedee21bd206b7639600b268c0f1a76 by GitHub (on behalf of dsiroky) on 03/08/2026 at 07:24..
[clang-tidy] ignore uninitialized std::array in member init (#98134)

cppcoreguidelines-pro-type-member-init check has an option IgnoreArrays
for ignoring uninitialized C arrays. This patch adds support for C++
std::array as well.

Co-authored-by: David Siroky <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/7dae1728fbedee21bd206b7639600b268c0f1a76

Git commit 00312bb11db4b0d267309e031e3059e504a7f0bd by GitHub (on behalf of LiqinWeng) on 03/08/2026 at 07:34..
[RISCV][SMT] Add SpacemiT-x100 vector sched info (#210597)
https://invent.kde.org/qt/clang/llvm/-/commit/00312bb11db4b0d267309e031e3059e504a7f0bd

Git commit faee1de64358ad02661da6b469dab6c3dade475e by GitHub (on behalf of Balázs Kéri) on 03/08/2026 at 07:57..
[clang][analyzer] Improved message of CallAndMessageChecker at calls with uninitialized argument (#211038)
https://invent.kde.org/qt/clang/llvm/-/commit/faee1de64358ad02661da6b469dab6c3dade475e

Git commit 2354dce21ab107d0350cea741923bcffbeb14d91 by GitHub (on behalf of Ashutosh Nema) on 03/08/2026 at 08:02..
[Transforms][Utils] Add LoopSplitUtils for iteration-space loop splitting (#205995)

Introduce LoopSplitUtils, a utility that splits a counted loop into a
chain of per-partition sub-loops covering contiguous slices of the
original iteration space. Given a loop and a list of partition ranges,
it clones the body per partition, guards each with an entry check that
skips empty partitions, clamps each latch to its slice, and rebuilds SSA
for loop-carried and live-out values so the result is
behaviour-preserving.

Key properties:
- Supports ascending (+1) and descending (-1) unit-step inductions, in
both signed and unsigned iteration orderings, with direction-aware
guard/latch predicates and end clamps.
- Reuses the original loop for partition 0 and clones the rest, exposing
per-partition value maps via getPartitionValue()/getPartitionValueMap().
- Lets callers drop the entry guard for a partition proven non-empty via
avoidPartitionGuard(); provably-empty partitions are always skipped.
- Patches the dominator tree and LoopInfo incrementally rather than
rebuilding them.

How to use:

  LoopSplitUtils LSU(L, LI, SE, DT);
if (!LSU.isLegal()) // counted, bottom-tested, LCSSA, unit step
    return false;
  // Tile the iteration space in order; e.g. split [Start, End] at K:
  LSU.addPartition(Start, K - 1);   // partition 0: [Start, K-1]
  LSU.addPartition(K, End);         // partition 1: [K, End]
  LSU.split();
  // After split(), query a cloned value in a given partition:
  Value *V1 = LSU.getPartitionValue(Orig, /*PartitionIndex=*/1);

A new test pass, loop-split-test (opt -passes=loop-split-test with
-loop-split-points=...), drives the utility for testing. Adds lit tests
covering basic/multiple/four-partition splits, descending loops,
reductions, empty-leading partitions, optional guards, and the
per-partition value map.
https://invent.kde.org/qt/clang/llvm/-/commit/2354dce21ab107d0350cea741923bcffbeb14d91

Git commit dda7cb5354cad9507bedbfd44d3fdc4c3e956d63 by GitHub (on behalf of Brad Smith) on 03/08/2026 at 08:17..
[Driver][Hurd] Remove llvm_unreachable (#171077)

Remove the llvm_unreachable from getDynamicLinker(). The code path is
reachable. In the case of an unsupported architecture we're not worrying
about trying to actually determine the dynamic linker, and I don't think
it makes sense for the Driver to crash.

Pointed out by bug report #64194

---------

Co-authored-by: Shivam Gupta <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/dda7cb5354cad9507bedbfd44d3fdc4c3e956d63

Git commit a9ebf2cdff376a74bfb05ecc58386f7c54a4c532 by GitHub (on behalf of Ramkumar Ramachandra) on 03/08/2026 at 08:17..
[LV] Add iv_outside_user ptr-ind variant test (#213263)

There was previously a doubt about whether the integer variant of the
test should use wrap-flags on the latch exit value, which motivates us
to add coverage for the ptr variant.
https://invent.kde.org/qt/clang/llvm/-/commit/a9ebf2cdff376a74bfb05ecc58386f7c54a4c532

Git commit c99e6752b9f9e1867af88c07ee44f837bc6e4311 by GitHub (on behalf of Ties Stuij) on 03/08/2026 at 08:35..
[ARM][MVE] Match canonical saturating negation patterns (#213085)

InstCombine pull request
https://github.com/llvm/llvm-project/pull/194519 canonicalized the
saturating negation idiom to
an llvm.ssub.sat operation. For the ARM backend we only recognized the
original
select and subtract pattern, causing vector absolute values to expand to
VQSUB
plus a compare and select instead of VQABS.

In this patch we teach the VQABS and VQNEG patterns to recognize this
ssub.sat
form.
https://invent.kde.org/qt/clang/llvm/-/commit/c99e6752b9f9e1867af88c07ee44f837bc6e4311

Git commit 58862f1adfc9690ddcda8cded008bc0ecda54859 by GitHub (on behalf of Berke Ates) on 03/08/2026 at 08:36..
[MLIR][Arith] Fix BitcastOp fold crashing on unhandled constant attributes (#212483)

`BitcastOp::fold` assumed any non-poison scalar operand attribute is a
`FloatAttr` or `IntegerAttr` and hard-casted it.
Constant attributes from other dialects, e.g. the `LLVM::UndefAttr`
produced by `llvm.mlir.undef`'s fold, hit the cast assertion.
This crashed SCCP on IR where `llvm.mlir.undef` feeds `arith.bitcast`.
Bail out on attributes and result types the fold does not handle.
https://invent.kde.org/qt/clang/llvm/-/commit/58862f1adfc9690ddcda8cded008bc0ecda54859

Git commit b5d93cd7773b203e3523f36cf1b63c16f23c921b by GitHub (on behalf of Pierre van Houtryve) on 03/08/2026 at 08:38..
[clang][AMDGPU] Clean-up handling of named barrier type (#207687)

- Allow the type in struct/classes in very limited circumstances. The
goal is to enable creating trivial wrappers around the named barrier
variable, but ensure we can't get into situations where things would get
awkward. Currently this means we only allow the named barrier in
RecordDecls with exactly 1 field, that have no base class, and are not
inherited.
- Use a `amdgpu_barrier` LangAS for this type that currently maps to the
local AS. This allows easy switching to the barrier AS in a future
patch.
https://invent.kde.org/qt/clang/llvm/-/commit/b5d93cd7773b203e3523f36cf1b63c16f23c921b

Git commit ba1c26cf9f4826c9e82d43859c91fab9facf689f by GitHub (on behalf of Akshat Dalal) on 03/08/2026 at 08:44..
[X86] Fix missing CFI after the Swift async context push (#202570)

The Swift async prologue pushes the context slot (pushq %r14 / $0) but
doesn't touch the CFA until the later .cfi_def_cfa_register %rbp. So the
CFA still describes the stack from before the push and stays stale all
the way through the leaq and the subq. If something unwinds in that
window (debugger, profiler, signal) it reads the wrong slot. Normal
execution is fine.

FIX: account for the push with .cfi_adjust_cfa_offset 8, then switch to
an %rbp-relative CFA (.cfi_def_cfa %rbp, 16) right after the leaq and
before the subq, so the rule is correct before rsp moves again.

Adds swift-async-cfi-prologue.ll (directives + .eh_frame rows, plus a
locals case for the subq) and updates swift-async.ll.
https://invent.kde.org/qt/clang/llvm/-/commit/ba1c26cf9f4826c9e82d43859c91fab9facf689f

Git commit 095ff52bd7281046925bf7146c17d0cae68fb6ed by GitHub (on behalf of Med Ismail Bennani) on 03/08/2026 at 09:06..
[lldb] Fix test_case_insensitivity's register value for canonical/PAC constraints (#213605)

This addresses a test failure introduced in
4f6cf2c2072ccf5780ac30bf69ebf99b788dbd52.

`0x1122334455667788` is a non-canonical address on x86_64 (fails to
write to rsp) and gets its non-addressing bits masked off on read for
pc/lr/sp/fp on Darwin AArch64, so it doesn't round-trip on either. Zero
the top 20 bits to stay clear of both.
https://invent.kde.org/qt/clang/llvm/-/commit/095ff52bd7281046925bf7146c17d0cae68fb6ed

Git commit bd7433bd275cacc7493892e5bfbdb76de0f18cd4 by GitHub (on behalf of Gábor Horváth) on 03/08/2026 at 09:07..
[clang][LifetimeSafety] Fix unnamed TimeTraceScope in computePersistentOrigins (#213521)

The TimeTraceScope was constructed as a temporary and destroyed
immediately, so the prepass was reported as taking ~0. It actually
accounts for ~14% of LoanPropagation in some cases.

Co-authored-by: Gabor Horvath <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/bd7433bd275cacc7493892e5bfbdb76de0f18cd4

Git commit 1fe8f95f24adbf26943e48f8c2e8419d4010e599 by GitHub (on behalf of David Spickett) on 03/08/2026 at 09:10..
Revert "Disable this test on Darwin to give the author a chance to fix it." (#213624)

Reverts llvm/llvm-project#213388

#213605 fixes the test.
https://invent.kde.org/qt/clang/llvm/-/commit/1fe8f95f24adbf26943e48f8c2e8419d4010e599

Git commit 667bc9df31a8f5cc833b3e9bee4dbdc0463fc4b1 by GitHub (on behalf of Arseniy Obolenskiy) on 03/08/2026 at 09:23..
[mlir][SPIR-V] Restrict GroupNonUniform ops to Subgroup scope (#213087)

spirv-val now limits execution scope for GroupNonUniform* ops to
Subgroup, except OpGroupNonUniformRotateKHR which still allows Workgroup
(see https://github.com/KhronosGroup/SPIRV-Tools/pull/6811). Tighten the
ODS trait accordingly and stop lowering GPU non-uniform reductions to a
Workgroup scope op

Follow-up to #212928
https://invent.kde.org/qt/clang/llvm/-/commit/667bc9df31a8f5cc833b3e9bee4dbdc0463fc4b1

Git commit 66173168efff1085a785b9908296be8146a4399c by GitHub (on behalf of Matt Arsenault) on 03/08/2026 at 09:27..
X86: Defend against regression from SimplifyDemandedVectorElts load support (#213611)

It doesn't appear possible to test this independently.

Co-authored-by: Claude (Opus 4.8) <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/66173168efff1085a785b9908296be8146a4399c

Git commit 536acc23e473855f900e0ef65fd1a3fc254264b0 by GitHub (on behalf of Lang Hames) on 03/08/2026 at 09:31..
[ORC] Fix COFFAutoImportGeneratorTest on Darwin. (#213616)

Add linker-level mangling prefix for lookups on Darwin.

These should fix the build failures associated with PR203914 on Darwin,
e.g. https://lab.llvm.org/buildbot/#/builders/23/builds/21523
https://invent.kde.org/qt/clang/llvm/-/commit/536acc23e473855f900e0ef65fd1a3fc254264b0

Git commit 9baf14f77a632e6863c599228213620e0362c321 by GitHub (on behalf of Ömer Sinan Ağacan) on 03/08/2026 at 09:32..
[TLI] Update `getWCharSize` documentation (NFC) (#213622)

`return 0` part of `getWCharSize` was added in cc603ee3d563 but then
removed in 5a88dffc40d2. Update the documentation as it no longer
returns 0 when the size is unknown (instead returns the default).
https://invent.kde.org/qt/clang/llvm/-/commit/9baf14f77a632e6863c599228213620e0362c321

Git commit 2fe9fc90780d65935e075fecbffd3d5103c83838 by GitHub (on behalf of Krish Gupta) on 03/08/2026 at 09:38..
[mlir][bufferization] Handle arith.select-based deallocs in static memory planner (#209106)

The static memory planner currently skips any allocation that doesn't
have a direct `memref.dealloc` user. This is overly conservative, after
running `ownership-based-buffer-deallocation`, it's common to see
patterns like:

  `%2 = arith.select %c, %0, %1 : memref<1024xf32>`
  `memref.dealloc %2 : memref<1024xf32>`

where both `%0` and `%1` get skipped with `++numSkipNoDealloc` even
though their lifetimes are well-defined.

This patch teaches `collectCandidates` to follow `arith.select` chains
when looking for potential deallocs. We traverse the use-def graph
forward from each alloc, collecting any `memref.dealloc` ops reachable
through select results.

Since a single select-based dealloc can conditionally free one of
several allocs, we enforce a group constraint: all allocs that share a
dealloc via a select must either all go into the arena or all be
skipped. Without this, we could end up with a `memref.view` (an arena
slice) and a raw alloc being fed into the same select, making the
resulting dealloc invalid.

The group constraint is computed with a simple fixpoint iteration , if
any member of a group is ineligible, the whole group is dropped.

The lifetime indices (`timeStart`/`timeEnd`) in `buildAllocInfos` are
also fixed: the old code did one block scan per candidate (O(n×m)). This
replaces it with a single pass upfront using a `DenseMap`, and sets
`timeEnd` conservatively to the latest dealloc index across all
potential deallocs for an alloc.

Tests added for:
- Single alloc freed via a self-select dealloc
- Two allocs sharing one select-based dealloc (group constraint active)
- The two-select two-dealloc pattern from the design discussion
https://invent.kde.org/qt/clang/llvm/-/commit/2fe9fc90780d65935e075fecbffd3d5103c83838

Git commit 80df471b75d0736a8bc5d30f6e483bb0de302c7e by GitHub (on behalf of Pengcheng Wang) on 03/08/2026 at 09:49..
Reland [MachineLICM] Use `RegisterClassInfo::getRegPressureSetLimit` (#213584)

This relands #211715 which was reverted because of some failures
in experimental targets and one AMDGPU test `diverged-entry-basic.ll`.

Below is the original commit message.

----

This recommits #119826, which taught `MachineLICM` to use
`RegisterClassInfo` when computing register pressure limits so
reserved registers are accounted for (#118787).

The original change was reverted by eeac0ff because it increased
compile time by causing repeated `RegisterClassInfo` computations.

This PR is based on #210826, in which `MachineRegisterClassInfo`
analysis pass was added. `MachineRegisterClassInfo` is required
by `MachineLICM` now, but the intervening machine passes that do
not affect `RegisterClassInfo` now preserve it, so the analysis
is reused instead of recomputed.

Assisted-by: TRAE CLI (GPT-5.5)
https://invent.kde.org/qt/clang/llvm/-/commit/80df471b75d0736a8bc5d30f6e483bb0de302c7e

Git commit fb77712fd1dd911330bd432d1fd9313081b40c59 by GitHub (on behalf of Arseniy Obolenskiy) on 03/08/2026 at 09:50..
[clang][AMDGPU] Widen ballot for read_exec_lo/hi to wavefront size (#212813)

GlobalISel cannot select a ballot narrower than the wavefront width,
since it can't represent one bit per lane

Widen the ballot to the wave size and narrow the result afterwards

This is a prerequisite for relanding
https://github.com/llvm/llvm-project/pull/211493 (reverted in
https://github.com/llvm/llvm-project/pull/212628 to unblock buildbot) to
prevent device libs side failures

---------

Co-authored-by: Matt Arsenault <[email protected]>
https://invent.kde.org/qt/clang/llvm/-/commit/fb77712fd1dd911330bd432d1fd9313081b40c59

Git commit 5daadaa0264a350c3faa4dd0759fec7ef5fe8a75 by GitHub (on behalf of Timur Golubovich) on 03/08/2026 at 09:59..
[X86] Add PSEUDO_FMIN/PSEUDO_FMAX to canCombineAsMaskOperation (#213475)

Add FP min/max opcodes to the list of operations that can be folded into
write-masked instructions. This allows commuteSelect to recognize these
operations and invert the setcc condition to enable ISel to match fused
vminps/vmaxps {%k} patterns.
https://invent.kde.org/qt/clang/llvm/-/commit/5daadaa0264a350c3faa4dd0759fec7ef5fe8a75

Git commit 8f1efc26e47f6a3c7b2c623b5de44b99529e3a02 by GitHub (on behalf of Ashutosh Nema) on 03/08/2026 at 10:25..
[Transforms][Utils] Preserve branch weights in LoopSplitUtils (#213626)

Carry the original latch's branch weights onto the clamped latch, and
mark the newly created partition-guard branches as having unknown
weights so profile-tracking passes are not misled.
https://invent.kde.org/qt/clang/llvm/-/commit/8f1efc26e47f6a3c7b2c623b5de44b99529e3a02

Git commit 4532e3157cf7d14054f0e501a5f5b963c87e1a3a by Ivan Kosarev on 03/08/2026 at 10:41..
Merge remote-tracking branch 'origin/main' into users/kosarev/asmparser-identify-ambiguities
https://invent.kde.org/qt/clang/llvm/-/commit/4532e3157cf7d14054f0e501a5f5b963c87e1a3a