This adds the support for SHT_ARM_EXIDX sections to obj2yaml/yaml2obj tools.

SHT_ARM_EXIDX is a ARM specific index table filled with entries.
Each entry consists of two 4-bytes values (words).
(https://developer.arm.com/documentation/ihi0038/c/?lang=en#index-table-entries)

Differential revision: https://reviews.llvm.org/D88228

With the recent patches to the ASTImporter that improve template type importing
(D87444), most of the import-std-module tests can now finally import the
type of the STL container they are testing. This patch removes most of the casts
that were added to simplify types to something the ASTImporter can import
(for example, std::vector<int>::size_type was casted to `size_t` until now).
Also adds the missing tests that require referencing the container type (for
example simply printing the whole container) as here we couldn't use a casting
workaround.

The only casts that remain are in the forward_list tests that reference
the iterator and the stack test. Both tests are still failing to import the
respective container type correctly (or crash while trying to import).

Currently we are always recognizing the `SHT_MIPS_ABIFLAGS` section,
even on non-MIPS targets.

The problem of doing this is briefly discussed in D88228 which does the same for `SHT_ARM_EXIDX`:

"The problem is that `SHT_ARM_EXIDX` shares the value with `SHT_X86_64_UNWIND (0x70000001U)`.
We might have other machine specific conflicts, e.g.
`SHT_ARM_ATTRIBUTES` vs `SHT_MSP430_ATTRIBUTES` vs `SHT_RISCV_ATTRIBUTES (0x70000003U)`."

I think we should only recognize target specific sections when the machine type
matches. I.e. `SHT_MIPS_*` should be recognized only on `MIPS`, `SHT_ARM_*`
only on `ARM` etc.

This patch stops recognizing `SHT_MIPS_ABIFLAGS` on `non-MIPS` targets.

Note: I had to update `ScalarEnumerationTraits<ELFYAML::MIPS_ISA>::enumeration`, because
otherwise test crashes, calling `llvm_unreachable`.

Differential revision: https://reviews.llvm.org/D88294

This is a reimplementation of the overflow checks for the elementcount,
i.e. the 2nd argument of intrinsic get.active.lane.mask. The element
count is lowered in each iteration of the tail-predicated loop, and
we must prove that this expression doesn't overflow.

Many thanks to Eli Friedman and Sam Parker for all their help with
this work.

Differential Revision: https://reviews.llvm.org/D88086

9d9a11c7 added this check for predicatable instructions between the
D/WLSTP and the loop's start, but it was missing the last instruction in
the block. Change it to use some iterators instead.

Differential Revision: https://reviews.llvm.org/D88354

Usually when we enter a SWIG wrapper function from Python, SWIG automatically
adds a `Py_BEGIN_ALLOW_THREADS`/`Py_END_ALLOW_THREADS` around the call to the SB
API C++ function. This will ensure that Python's GIL is released when we enter
LLDB and locked again when we return to the wrapper code.

D51569 changed this behaviour but only for the generated `__str__` wrappers. The
added `nothreadallow` disables the injection of the GIL release/re-acquire code
and the GIL is now kept locked when entering LLDB and is expected to be still
locked when returning from the LLDB implementation. The main reason for that was
that back when D51569 landed the wrapper itself created a Python string. These
days it just creates a std::string and SWIG itself takes care of getting the GIL
and creating the Python string from the std::string, so that workaround isn't
necessary anymore.

This patch just removes `nothreadallow` so that our `__str__` functions now
behave like all other wrapper functions in that they release the GIL when
calling into the SB API implementation.

The motivation here is actually to work around another potential bug in LLDB.
When one calls into the LLDB SB API while holding the GIL and that call causes
LLDB to interpret some Python script via `ScriptInterpreterPython`, then the GIL
will be unlocked when the control flow returns from the SB API. In the case of
the `__str__` wrapper this would cause that the next call to a Python function
requiring the GIL would fail (as SWIG will not try to reacquire the GIL as it
isn't aware that LLDB removed it).

The reason for this unexpected GIL release seems to be a workaround for recent
Python versions:
```
    // The only case we should go further and acquire the GIL: it is unlocked.
    if (PyGILState_Check())
      return;
```

The early-exit here causes `InitializePythonRAII::m_was_already_initialized` to
be always false and that causes that `InitializePythonRAII`'s destructor always
directly unlocks the GIL via `PyEval_SaveThread`. I'm investigating how to
properly fix this bug in a follow up patch, but for now this straightforward
patch seems to be enough to unblock my other patches (and it also has the
benefit of removing this workaround).

The test for this is just a simple test for `std::deque` which has a synthetic
child provider implemented as a Python script. Inspecting the deque object will
cause `expect_expr` to create a string error message by calling
`str(deque_object)`. Printing the ValueObject causes the Python script for the
synthetic children to execute which then triggers the bug described above where
the GIL ends up being unlocked.

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D88302

bug 45566 shows the process of building coroutine frame won't consider
that the lifetimes of different local variables are not overlapped,
which means the compiler could generates smaller frame.

This patch calculate the lifetime range of each alloca by StackLifetime
class. Then the patch build non-overlapped sets for allocas whose
lifetime ranges are not overlapped. We use the largest type in a
non-overlapped set as the field type in the frame. In insertSpills
process, if we find the type of field is not the same with the alloca,
we cast the pointer to the field type to the pointer to the alloca type.
Since the lifetime range of alloca in one non-overlapped set is not
overlapped with each other, it should be ok to reuse the storage space
in the frame.

Test plan: check-llvm, check-clang, cppcoro, folly

Reviewers: junparser, lxfind, modocache

Differential Revision: https://reviews.llvm.org/D87596

After some recent upstream discussion we decided that it was best
to avoid having the / operator for both ElementCount and TypeSize,
since this could give the impression that these classes can be used
in the same way as basic integer integer types. However, division
for scalable types is a bit odd because we are only dividing the
minimum quantity by a value, as opposed to something like:

  (MinSize * Vscale) / SomeValue

This is why when performing division it's important the caller
first establishes whether the operation makes sense, perhaps by
calling isKnownMultipleOf() prior to division. The caller must now
explictly call divideCoefficientBy() on the class to perform the
operation.

Differential Revision: https://reviews.llvm.org/D87700

This reverts commit 506b6170.

This still causes link errors, see https://crbug.com/1130780.

For C++20 P0732R2; unused so far. Will be used and tested by a follow-on
commit.

References to different declarations of the same entity aren't different
values, so shouldn't have different representations.

Recommit of e6393ee8 with fixed handling
for weak declarations. We now look for attributes on the most recent
declaration when determining whether a declaration is weak. (Second
recommit with further fixes for mishandling of weak declarations. Our
behavior here is fundamentally unsound -- see PR47663 -- but this
approach attempts to not make things worse.)

Add operands to represent if and deviceptr. Default clause is represented with
an attribute.

Reviewed By: kiranchandramohan

Differential Revision: https://reviews.llvm.org/D88331

This patch remove the printer/parser for the acc.data operation since its syntax
fits nicely with the assembly format. It reduces the maintenance for this op.

Reviewed By: kiranchandramohan

Differential Revision: https://reviews.llvm.org/D88330

This patch remove the detach and delete operands. Those operands represent the detach
and delete clauses that will appear in another operation acc.exit_data

Reviewed By: kiranktp, kiranchandramohan

Differential Revision: https://reviews.llvm.org/D88326

strcat:
destination and source shall not overlap. (http://www.cplusplus.com/reference/cstring/strcat/)

stpcpy:
The strings may not overlap, and the destination string dest must be  large enough to receive the copy. (https://man7.org/linux/man-pages/man3/stpcpy.3.html)

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D88335

Summary:
Adding a missing directory needed for generating Sphinx documentation without
errors. Directory current contains a placeholder image just to populate the
directory.

These are no longer necessary since D69686.

Add a flag to getPredicateAt() that allows making use of the block
value. This allows us to take into account range information from
the current block, rather than only information that is threaded
over edges, making the icmp simplification in CVP a lot more
powerful.

I'm not changing getPredicateAt() to use the block value
unconditionally to avoid any impact on the JumpThreading pass,
which is somewhat picky about LVI query order.

Most test changes here are just icmps that now get dropped (while
previously only a result used in a return was replaced). The three
tests in icmp.ll show some representative improvements. Some of
the folds this enables have been covered by IPSCCP in the meantime,
but LVI can reason about some cases which are hard to support in
IPSCCP, such as in test_br_cmp_with_offset.

The compile-time time cost of doing this is fairly minimal, with
a ~0.05% CTMark regression for ReleaseThinLTO:
https://llvm-compile-time-tracker.com/compare.php?from=709d03f8af4da4204849a70f01798e7cebba2e32&to=6236fd503761f43c99f4537121e057a01056f185&stat=instructions

This is because the block values will typically already be queried
and cached by other CVP optimizations anyway.

Differential Revision: https://reviews.llvm.org/D69686

If -enable-constraint-elimination is specified, add it to the -O2/-O3 pipeline.
(-O1 uses a separate function now.)

Reviewed By: fhahn, aeubanks

Differential Revision: https://reviews.llvm.org/D88365

D69686 will be able to determine that the icmp is always false.
As this is not the purpose of the test, use a different modulus
that doesn't trivialize the condition.

The lattice value returned by getValueInBlock() holds at the start
of the block, not at the end. Also make it clearer what the
difference between getValueInBlock() and getValueAt() is.

Require CxtI in getConstant() and getConstantRange() APIs.
Accordingly drop the BB parameter, as it is implied by
CxtI->getParent().

This makes sure we don't forget to pass the context instruction,
and makes the API contract clearer (also clean up the comments to
that effect -- the value holds at the context instruction, not
the end of the block).

This fold was the only place not passing the context instruction.
The tests worked around that fact by introducing a basic block split,
which is now no longer necessary.

To hopefully help improve the codegen delta in D87976

This is a setting used by SimplifyCFG, LoopUnroll, and InlineCost,
but there is apparently no direct test coverage for any of those
cost model values.

As discussed in D87877, instcombine already has this fold,
but it was missing from the more general ValueTracking logic.

https://alive2.llvm.org/ce/z/PumYZP

This shows missing analysis in ValueTracking's isKnownNeverInfinity().

Remove usages of special error reporting functions(error(),
reportError()). This patch is extracted from D87987.
Errors are reported as Expected<>/Error returning values.
This part is for COFF subfolder of llvm-objcopy.

Testing: check-all.

Differential Revision: https://reviews.llvm.org/D88213

RegInfoBasedABI::GetRegisterInfoByName was failing because mips/mips64 ABIs
don't use ConstString in their register info array.

Reviewed By: #lldb, teemperor

Differential Revision: https://reviews.llvm.org/D88375

This was supposed to be done in the first place as is currently the case for
G_ASHR and G_LSHR but was forgotten when the original shift legalization
overhaul was done last year.

This was exposed because we started falling back on s32 = s32, s64 SHLs
due to a recent combiner change.

Gives a very minor (0.1%) code size -O0 improvement on consumer-typeset.

Use +/-Inf or +/-Largest as neutral element for nnan fmin/fmax
reductions. This avoids dropping any FMF flags. Preserving the
nnan flag in particular is important to get a good lowering on X86.

Differential Revision: https://reviews.llvm.org/D87586

[AArch64][GlobalISel] Use the look-through constant helper for the shift s32->s64 custom legalization.

Almost NFC, except it catches more cases and gives a 0.1% CTMark -O0 size win.