This reapplies 272d1b44 (from #85756),
which was reverted in
40793703.

In the previous attempt, empty CMAKE_INSTALL_PREFIX was handled by
quoting them, in d209d134. That made the
calls to cmake_path(ABSOLUTE_PATH) succeed, but the output paths of that
weren't actually absolute, which was required by file(RELATIVE_PATH).

Avoid this issue by constructing a non-empty base directory variable
to use for calculating the relative path.

(cherry picked from commit 50801f10)

We use the VSCBIQ/VSBIQ/VSBCBIQ family of instructions to implement
USUBO/USUBO_CARRY for the i128 data type. However, these instructions
use an inverted sense of the borrow indication flag (a value of 1
indicates *no* borrow, while a value of 0 indicated borrow). This does
not match the semantics of the boolean "overflow" flag of the
USUBO/USUBO_CARRY ISD nodes.

Fix this by generating code to explicitly invert the flag. These cancel
out of the result of USUBO feeds into an USUBO_CARRY.

To avoid unnecessary zero-extend operations, also improve the DAGCombine
handling of ZERO_EXTEND to optimize (zext (xor (trunc))) sequences where
appropriate.

Fixes: https://github.com/llvm/llvm-project/issues/83268

The existing implementation didn't handle when the input text section
was some offset from the output section.

This resulted in an assert in relaxGot() with an lld built with asserts
for some large binaries, or even worse, a silently broken binary with an
lld without asserts.

(cherry picked from commit 48048051)

Using range.size() "as is" means we accumulate 'size_t' values into
'int32_t' variable. This may produce narrowing conversion warnings
(particularly, on MSVC). The surrounding code seems to cast <x>.size()
to 'int32_t' so following this practice seems safe enough.

Co-authored-by: Ovidiu Pintican <ovidiu.pintican@intel.com>
(cherry picked from commit bce17034)

Fix #61881

(cherry picked from commit 5d7fd6a0)

Add sign extension "SEB/SEH" before compare.

Fix #61881

(cherry picked from commit 755b4396)

Delete the code that skips the CFI for the condition register on ELF32.
The code checked !MustSaveCR, which happened only when
Subtarget.is32BitELFABI(), where spillCalleeSavedRegisters is spilling
cr in a different way. The spill was missing CFI. After deleting this
code, a spill of cr2 to cr4 gets CFI in the same way as a spill of r14
to r31.

Fixes #83094

(cherry picked from commit 6b70c5d7)

(cherry picked from commit 3196005f)

This ports the change from TSan
(https://github.com/llvm/llvm-project/commit/0784b1eefa36d4acbb0dacd2d18796e26313b6c5).

Testing notes: run 'sudo sysctl vm.mmap_rnd_bits=32; ninja check-msan'
before and after this patch.

N.B. aggressive ASLR may also cause the app to overlap with the
allocator region; for MSan, this was fixed in
https://github.com/llvm/llvm-project/commit/af2bf86a372cacf5f536bae06e2f2d3886eefb7b

(cherry picked from commit 58f72518)

MSan divides the virtual address space into APP, INVALID, SHADOW and
ORIGIN memory. The allocator usually just steals a bit of the APP
address space: typically the bottom portion of the PIE binaries section,
which works because the Linux kernel maps from the top of the PIE
binaries section. However, if ASLR is very aggressive, the binary may
end up mapped in the same location where the allocator wants to live;
this results in a segfault.

This patch adds in a MappingDesc::ALLOCATOR type and enforces that the
memory range for the allocator is not occupied by anything else.

Since the allocator range information is not readily available in
msan.h, we duplicate the information from msan_allocator.cpp.

Note: aggressive ASLR can also lead to a different type of failure,
where the PIE binaries/libraries are mapped entirely outside of the
APP/ALLOCATOR sections; that will be addressed in a separate patch
(https://github.com/llvm/llvm-project/pull/85142).

(cherry picked from commit af2bf86a)

When emitting the storage (or memory copy operations) for constant
initializers, the decision whether to split a constant structure or
array store into a sequence of field stores or to use `memcpy` is
based upon the optimization level and the size of the initializer.
In afe8b93f, we extended this by
allowing constants to be split when the array (or struct) type does
not match the type of data the address to the object (constant) is
expected to contain. This may happen when `emitStoresForConstant` is
called by `EmitAutoVarInit`, as the element type of the address gets
shrunk. When this occurs, let the initializer be split into a bunch
of stores only under `-ftrivial-auto-var-init=pattern`.

Fixes: https://github.com/llvm/llvm-project/issues/84178.

This PR indicates that `addrspacecasts` are always no-ops on LoongArch.

Fixes #82330

(cherry picked from commit dd3e0a46)

Change-Id: Ic77f87290905addadd5819dff2d0c62f031022ab
(cherry picked from commit 1e828f83)

PR #75527 fixed ARMFrameLowering to set the IsRestored flag for LR based
on all of the return instructions in the function, not just one.
However, there is also code in ARMLoadStoreOptimizer which changes
return instructions, but it set IsRestored based on the one instruction
it changed, not the whole function.

The fix is to factor out the code added in #75527, and also call it from
ARMLoadStoreOptimizer if it made a change to return instructions.

Fixes #80287.

(cherry picked from commit 749384c0)

This test shows the bug where LR is used as a general-purpose register
on a code path where it is not spilled to the stack.

(cherry picked from commit 8779cf68)

Previously we disabled to compute ODR hash for declarations from the
global module fragment. However, we missed the case that the functions
lives in the concept requiments (see the attached the test files for
example). And the mismatch causes the potential crashment.

Due to we will set the function body as lazy after we deserialize it and
we will only take its body when needed. However, we don't allow to take
the body during deserializing. So it is actually potentially problematic
if we set the body as lazy first and computing the hash value of the
function, which requires to deserialize its body. So we will meet a
crash here.

This patch tries to solve the issue by not taking the body of the
function from GMF. Note that we can't skip comparing the constraint
expression from the GMF directly since it is an key part of the
function selecting and it may be the reason why we can't return 0
directly for `FunctionDecl::getODRHash()` from the GMF.

This fixes the miscompile reported in #82430 by telling
isSimpleVIDSequence to sign extend to XLen instead of the width of the
indices, since the "sequence" of indices generated by a strided load
will be at XLen.

This was the simplest way I could think of getting isSimpleVIDSequence
to treat the indexes as if they were zero extended to XLenVT.

Another way we could do this is by refactoring out the "get constant
integers" part from isSimpleVIDSequence and handle them as APInts so we
can separately zero extend it.

Fixes #82430

(cherry picked from commit 815644b4)

See https://github.com/llvm/llvm-project/pull/82506#discussion_r1498080785

(cherry picked from commit 11d115d0)

This shows the issue in #82430, but triggers it via the widening SEW combine
rather than a GEP that RISCVGatherScatterLowering doesn't detect.

(cherry picked from commit 2cd59bdc)

atomicrmw xchg also accepts pointer and floating-point values. To handle
those, insert necessary casts to and from integer. This is what we do
for cmpxchg as well.

Fixes https://github.com/llvm/llvm-project/issues/85226.

(cherry picked from commit ff2fb2a1)

LDDRdPtrQ was marked as `earlyclobber`, which doesn't play well with
GreedyRA (which can generate this instruction through `loadRegFromStackSlot()`).

This seems to be the same case as:

https://github.com/llvm/llvm-project/blob/a99b912c9b74f6ef91786b4dfbc25160c27d3b41/llvm/lib/Target/AVR/AVRInstrInfo.td#L1421

Closes https://github.com/llvm/llvm-project/issues/81911.

This reverts commit 9b3edb59.

(cherry picked from commit e5b20c83)

This reverts the changes from 91a38462
for Windows targets. The changes in that commit don't work as expected
for Windows targets (those parts of llvm_add_library don't quite behave
the same for Windows), while the previous status quo (producing a
library named "libLLVM-<major>.dll") is the defacto standard way of
doing versioned library names there, contrary to on Unix.

After that commit, the library always ended up named "libLLVM.dll",
executables linking against it would reference "libLLVM.dll", and
"libLLVM-<major>.dll" was provided as a symlink.

Thus revert this bit back to as it were, so that executables actually
link against a versioned libLLVM, and no separate symlink is needed.

The only thing that might be improved compared to the status quo as it
was before these changes, is that the import library is named
"lib/libLLVM-<major>.dll.a", while the common style would be to name it
plainly "lib/libLLVM.dll.a" (even while it produces references to
"libLLVM-<major>.dll", but none of these had that effect for Windows
targets.

(As a side note, the llvm-shlib library can be built for MinGW, but not
currently in MSVC configurations.)

(cherry picked from commit cb2ca233)

The TARGET_SONAME_FILE_NAME generator expression is not available on dll
target platforms.

(cherry picked from commit f8498057)

This is a partial revert of 10c48a77
with a fix for the symlink target name on MacOS

See #84637

(cherry picked from commit ec2b7522)

This commit changes the default linker in the WebAssembly toolchain for
the `wasm32-wasip2` target. This target is being added to the
WebAssembly/wasi-sdk and WebAssembly/wasi-libc projects to target the
Component Model by default, in contrast with the preexisting
`wasm32-wasi` target (in the process of being renamed to
`wasm32-wasip1`) which outputs a core WebAssembly module by default.

The `wasm-component-ld` project currently lives in my GitHub account at
https://github.com/alexcrichton/wasm-component-ld and isn't necessarily
"official" yet, but it's expected to continue to evolve as the
`wasm32-wasip2` target continues to shape up and evolve.

(cherry picked from commit d66121d7)

The baseline version calculations was assuming the minor release would
always be 0.

(cherry picked from commit d93363a0)

When speculating an instruction in `InstCombinerImpl::FoldOpIntoSelect`,
the call may result in undefined behavior. This patch drops all
UB-implying attrs/metadata to fix this.

Fixes #85536.

(cherry picked from commit 252d0195)

(cherry picked from commit a41bcb39)

Buildbot failure:
https://lab.llvm.org/buildbot/#/builders/5/builds/41530/steps/9/logs/stdio

(cherry picked from commit d9b435c2)

As noted in <https://github.com/llvm/llvm-project/pull/78537>, MSVC
places import descriptors in both the EC and regular map - that PR moved
the descriptors to ONLY the regular map, however this causes linking
errors when linking as Arm64EC:

```
bcryptprimitives.lib(bcryptprimitives.dll) : error LNK2001: unresolved external symbol __IMPORT_DESCRIPTOR_bcryptprimitives (EC Symbol)
```

This change copies import descriptors from the regular map to the EC
map, which fixes this linking error.

ARM64EC import libraries expose two additional symbols: mangled thunk
symbol (like `#func`) and auxiliary import symbol (like`__imp_aux_func`).
The main functional change with this patch is that those symbols are
properly added to static library ECSYMBOLS.

EXPORTAS is a new name type in import libraries. It's used by default on ARM64EC,
but it's allowed on other platforms as well.

getExportName implementation is based on lld-link. In its current form,
it's mostly about convenience, but it will be more useful for EXPORTAS
support, for which export name is not possible to deduce from other
printed properties.

This works around ODR violations in the clang-tidy plugin we use to
perform the modules tests.

Fixes #85242

When resolving names inside templates that implement recursive
compile-time functions (e.g. waldo<N>::type is defined in terms
of waldo<N-1>::type), HeuristicResolver could get into an infinite
recursion, specifically one where resolveDependentNameType() can
be called recursively with the same DependentNameType*.

To guard against this, HeuristicResolver tracks, for each external
call into a HeuristicResolver function, the set of DependentNameTypes
that it has seen, and bails if it sees the same DependentNameType again.

To implement this, a helper class HeuristicResolverImpl is introduced
to store state that persists for the duration of an external call into
HeuristicResolver (but does not persist between such calls).

Fixes https://github.com/clangd/clangd/issues/1951

(cherry picked from commit e6e53ca8)