rdar://117421999

These are used unconditionally by libc++ math.h.

This is related to issue #84879.

…a sparse tensor.

This patch switches from manually using the Linux syscall to get the
current thread ID to using the relevant LLVM Support libraries that
abstract over the low level system details.

This reverts commit aefad270.

This relands commit 6bbe8a29.

This patch was casuing build failures on non-Linux platforms due to the
default implementations for the functions not being updated. This ended
up causing out-of-line definition errors. Fixed for the relanding.

NAL is an assembly idiom on Pre-R6 instruction sets (which is
implemented in binutils), or an actual instruction on Release 6
instruction set, and is used to read the PC, due to the nature of the
MIPS architecture.

Since we can't read the PC directly, on pre-R6 we use a always-not-taken
Branch and Link operation to the address of the next instruction, which
effectively writes the address to $31, thus PC is read with offset +8.

MIPS Release 6 removed the conventional Branch and Link instructions,
but kept NAL as an actual instruction for compatibility on the assembly
level. The instruction has the same encoding of the pre-R6 ones, and
with the same behavior: PC + 8 -> $31.

- result variables are optional
- static members may print their values
- public/protected shows up in ptype output

.pci_fixup section contains a table with entries allowing to invoke a
fixup hook whenever a problem is encountered with a PCI device. The
hookup code typically points to the start of a function. As we are not
relocating functions in the kernel (at least not yet), verify this
assumption while reading the table and ignore any functions with a fixup
code in the middle.

`__tsan::Acquire()`, which is called by `__tsan_acquire()`, has a
performance optimization which attempts to avoid acquiring the atomic
variable's mutex if the variable has no associated memory model state.

However, if the atomic variable was recently written to by a
`compare_exchange_weak/strong` on another thread, the memory model state
may be created *after* the atomic variable is updated. This is a data
race, and can cause the thread calling `Acquire()` to not realize that
the atomic variable was previously written to by another thread.

Specifically, if you have code that writes to an atomic variable using
`compare_exchange_weak/strong`, and then in another thread you read the
value using a relaxed load, followed by an
`atomic_thread_fence(memory_order_acquire)`, followed by a call to
`__tsan_acquire()`, TSAN may not realize that the store happened before
the fence, and so it will complain about any other variables you access
from both threads if the thread-safety of those accesses depended on the
happens-before relationship between the store and the fence.

This change eliminates the unsafe optimization in `Acquire()`. Now,
`Acquire()` acquires the mutex before checking for the existence of the
memory model state.

This allows to keep fetching release branches as well.

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.

We need TSFalgs from pseudo to real.

The decoder emitter is showing some signs of age. This patch makes a few
kinds of clean-ups:
- Use ranged-for more widely, including using enumerate() for those
loops maintaining a loop index along with the items.
- Reduce the number of arguments to fieldFromInsn (removes an out
reference parameter: CodingStandards). The insn_t argument to insnWithID
can/should probably be removed soon too since modern C++ allows us to
return a local container without a copy.
- Use raw strings for the large emitted code segments. This enhances
both readability and modifiability.

Implement an abstraction to specify precise overload types supported by
DXIL ops. These overload types are typically a subset of LLVM
intrinsics.

Implement the corresponding changes in DXILEmitter backend.

Add tests to verify expected errors for unsupported overload types at
code generation time.

Add tests to check for correct overload error output.

instructions.

This debug log adds noise to a large fraction of *other* debug logs when
you run with -debug, because it prints "Verifying operation: blah blah\n"
whenever those other debug logs dump an op.

You can use -debug-only to get around this, but sometimes -debug really
is what's called for!

Previously any global under 8 bits would accidentally be considered 0
sized, which is considered a large global.

Before it gets too unwieldy, add a common header for all MachO types
that are used across InstallAPI. Also, break up the types in
`InstallAPI/Frontend`. This both avoids circular dependencies and is
logically easier to maintain as more functionality gets added.

Fixes https://github.com/openxla/iree/issues/16475

Proof: https://alive2.llvm.org/ce/z/TAFmPw

This is a lemma for clearing up some of the regressions that #84688
causes.

Closes #84868

Spinning off from #79321 / 35f45926 - looked like the comparator could be
simplified & made more clear/less risk of leaving hidden bugs.

--compress-sections <section-glib>=[none|zlib|zstd] is similar to
--compress-debug-sections but applies to broader sections without the
SHF_ALLOC flag. lld will report an error if a SHF_ALLOC section is
matched. An interesting use case is to compress `.strtab`/`.symtab`,
which consume a significant portion of the file size (15.1% for a
release build of Clang).

An older revision is available at https://reviews.llvm.org/D154641 .
This patch focuses on non-allocated sections for safety. Moving
`maybeCompress` as D154641 does not handle STT_SECTION symbols for
`-r --compress-debug-sections=zlib` (see `relocatable-section-symbol.s`
from #66804).

Since different output sections may use different compression
algorithms, we need CompressedData::type to generalize
config->compressDebugSections.

GNU ld feature request: https://sourceware.org/bugzilla/show_bug.cgi?id=27452

Link: https://discourse.llvm.org/t/rfc-compress-arbitrary-sections-wi...

Handles the INSERT_SUBVECTOR(INSERT_SUBVECTOR(UNDEF,SUB0,0),SUB1,N) pattern

Currently limited to v8i64/v8f64 cases as only AVX512 has decent cross lane 2-input shuffles, the plan is to relax this as I deal with some regressions

A new function attribute named amdgpu_num_work_groups is added. This
attribute, which consists of three integers, allows programmers to let
the compiler know the number of workgroups to be launched in each of the
three dimensions and do optimizations based on that information.

---------

Co-authored-by: Jun Wang <jun.wang7@amd.com>