When given the -experimental-debug-variable-locations option (via -Xclang
or to llc), have SelectionDAG generate DBG_INSTR_REF instructions instead
of DBG_VALUE. For now, this only happens in a limited circumstance: when
the value referred to is not a PHI and is defined in the current block.
Other situations introduce interesting problems, addresed in later patches.

Practically, this patch hooks into InstrEmitter and if it can find a
defining instruction for a value, gives it an instruction number, and
points the DBG_INSTR_REF at that <instr, operand> pair.

Differential Revision: https://reviews.llvm.org/D85747

we need add a "this->" inside the lambda body to workaround it. Rewrite
it to normal for-range loop.

Revert "Reland "[SCEV] Model ptrtoint(SCEVUnknown) cast not as unknown, but as zext/trunc/self of SCEVUnknown"" and it's follow-ups

While we haven't encountered an earth-shattering problem with this yet,
by now it is pretty evident that trying to model the ptr->int cast
implicitly leads to having to update every single place that assumed
no such cast could be needed. That is of course the wrong approach.

Let's back this out, and re-attempt with some another approach,
possibly one originally suggested by Eli Friedman in
https://bugs.llvm.org/show_bug.cgi?id=46786#c20
which should hopefully spare us this pain and more.

This reverts commits 1fb61042,
73246166,
aaafe350,
e92a8e0c.

I've kept&improved the tests though.

This patch adds support for the _M and _m gdb-remote packets, which
(de)allocate memory in the inferior. This works by "injecting" a
m(un)map syscall into the inferior. This consists of:
- finding an executable page of memory
- writing the syscall opcode to it
- setting up registers according to the os syscall convention
- single stepping over the syscall

The advantage of this approach over calling the mmap function is that
this works even in case the mmap function is buggy or unavailable. The
disadvantage is it is more platform-dependent, which is why this patch
only works on X86 (_32 and _64) right now. Adding support for other
linux architectures should be easy and consist of defining the
appropriate syscall constants. Adding support for other OSes depends on
the its ability to do a similar trick.

Differential Revision: https://reviews.llvm.org/D89124

replace char*+length combo with llvm::Error

Harmonize usage of LLVM components througout Flang.

Explicit LLVM Libs where used across several CMakeFIles, which led to
incompatibilities with LLVM shlibs.
Fortunately, the LLVM component system can be relied on to harmoniously handle
both cases.

Differential Revision: https://reviews.llvm.org/D87893

Differential Revision: https://reviews.llvm.org/D89307

During the import of attributes we forgot to set the spelling list
index. This caused a segfault when we wanted to traverse the AST
(e.g. by the dump() method).

Differential Revision: https://reviews.llvm.org/D89318

During the import of FormatAttrs we forgot to import the type (e.g
`__scanf__`) of the attribute. This caused a segfault when we wanted to
traverse the AST (e.g. by the dump() method).

Differential Revision: https://reviews.llvm.org/D89319

so that we could start experiment for C.

Previously, these flags in clangd were only meaningful for C++. We need
to flip them for C, this patch repurpose these flags.

- if true, just set it.
- if false, just respect the value in clang.

this would allow us to keep flags on for C++, and optionally flip them on for C.

Differential Revision: https://reviews.llvm.org/D89233

Generate (at runtime) the table used to drive getSubRegFromChannel,
base on AMDGPUSubRegIdxRanges from TableGen data.
The is a step closer to it being staticly generated by TableGen and
allows getSubRegFromChannel handle all bitwidths in the mean time.

Reviewed By: rampitec, arsenm, foad

Differential Revision: https://reviews.llvm.org/D89217

This patch updates `isGuaranteedNotToBeUndefOrPoison` to use `llvm.assume`'s `noundef` operand bundle.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D89219

Recently we started looking into sret parameters, though the issue could crop
up elsewhere. If the pointee type is opaque, we should not try to compute its
size because that leads to an assertion failure.

This revision adds a programmable codegen strategy from linalg based on staged rewrite patterns. Testing is exercised on a simple linalg.matmul op.

Differential Revision: https://reviews.llvm.org/D89374

The OpenMP 5.0 standard restricts nowait clause to appear only once on sections
directive.
See OpenMP 5.0
  - 2.8.1
  - point 3 in restrictions.

Added a test with fix.

Reviewed By: DavidTruby

Differential Revision: https://reviews.llvm.org/D88556

This relands commit 53b3873c.  The failure
of `ConvertUTFTest.UTF16WrappersForConvertUTF16ToUTF8String` detected the
first time is fixed.

Differential Revision: https://reviews.llvm.org/D88824

Differential Revision: https://reviews.llvm.org/D89365

This patch defines the MIR format for debug instruction references: it's an
integer trailing an instruction, marked out by "debug-instr-number", much
like how "debug-location" identifies the DebugLoc metadata of an
instruction. The instruction number is stored directly in a MachineInstr.

Actually referring to an instruction comes in a later patch, but is done
using one of these instruction numbers.

I've added a round-trip test and two verifier checks: that we don't label
meta-instructions as generating values, and that there are no duplicates.

Differential Revision: https://reviews.llvm.org/D85746

LV fails with assertion checking that UF > 0. We already set UF to 1 if it is 0 except the case when IC > MaxInterleaveCount. The fix is to set UF to 1 for that case as well.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D87679

Replace m_SpecificInt with m_APIntAllowUndef to matching splats containing undefs, then use ConstantExpr::mergeUndefsWith to merge the undefs together in the result.

The undef funnel shift amounts are getting replaced with zero later on - I'll address this in a later patch, otherwise we lose potential shift by splat value patterns.

* Add assertions to other `MutationsImpl` member functions
* `findPrevious` is a free function

Differential Revision: https://reviews.llvm.org/D89314

* Add assertions for other preconditions.
* If nothing is modified, don't mark it.

Differential Revision: https://reviews.llvm.org/D89303

Add a test to verify that 'register read' and 'register write' commands
work correctly in a multithreaded program, in particular that they read
or write registers for the correct thread.  The tests use locking
to ensure that events are serialized and the test can execute reliably.

Differential Revision: https://reviews.llvm.org/D89248

`OmpStructureChecker` is supposed to work only with `parser::OmpClause`
after tablegen changes for OpenMP and OpenACC were introduced.
Hence `OmpMemoryOrderClause`, `OmpAtomicMemoryOrderClause` and similar ones were failing
to catch semantic errors, inspite of having code for semantic checks.
This patch tries to change parser for `OmpMemoryOrderClause` and similar dependent ones
and use `OmpClauseList` which resides/comes from common tablegen for OpenMP/OpenACC eventually using `parser::OmpClause`.

This patch also tries to :
1. Change `OmpCriticalDirective` in `openmp-parsers.cpp` to support `OmpClauseList`.
2. Check-flang regresses when changes were introduced due to missing semantic checks in OmpCritical, patch implements them at the minimal level to pass the regression.
3. Change tablegen to support Hint clause.
4. Adds missing source locations `CharBlock Source` in each atomic construct.
5. Remove dead code realted to `memory-order-clauses` after moving to `OmpClauseList`.

Reviewed By: kiranchandramohan

Differential Revision: https://reviews.llvm.org/D88965

When passing SVE types as arguments to function calls we can run
out of hardware SVE registers. This is normally fine, since we
switch to an indirect mode where we pass a pointer to a SVE stack
object in a GPR. However, if we switch over part-way through
processing a SVE tuple then part of it will be in registers and
the other part will be on the stack. This is wrong and we'd like
to avoid any silent ABI compatibility issues in future. For now,
I've added a fatal error when this happens until we can get a
proper fix.

Differential Revision: https://reviews.llvm.org/D89326

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D89338

Currently one can redefine a persistent variable and LLDB will just silently
ignore the second definition:

```
(lldb) expr int $i = 1
(lldb) expr int $i = 2
(lldb) expr $i
(int) $i = 1
```

This patch makes this an error and rejects the expression with the second
definition.

A nice follow up would be to refactor LLDB's persistent variables to not just be
a pair of type and name, but also contain some way to obtain the original
declaration and source code that declared the variable. That way we could
actually make a full diagnostic as we would get from redefining a variable twice
in the same expression.

Reviewed By: labath, shafik, JDevlieghere

Differential Revision: https://reviews.llvm.org/D89310

D85703 will need to create shallow wrappers in order to track the spmd icv. We need to make it available.

Differential Revision: https://reviews.llvm.org/D89342

Instead of collecting all specializations and doing a post-filterin, we
can just get all targeted specializations from getPartialSpecializationsizations.

Differential Revision: https://reviews.llvm.org/D89220

Fixes http://lab.llvm.org:8011/#/builders/119/builds/92

Remove check for standalone and shared library mode in libcxxabi to
allow including tests in said mode. This check prevented running the
tests in standalone mode with static libraries, which is the case for
baremetal targets.

Fix check-unwind target trying to use a non-existent llvm-lit executable
in standalone mode. Copy the HandleOutOfTreeLLVM logic from libcxxabi to
libunwind in order to make the tests work in standalone mode.

Reviewed By: ldionne, #libc_abi, #libc

Differential Revision: https://reviews.llvm.org/D86540

Differential revision: https://reviews.llvm.org/D89308

Currently we only strip the Python extension when the file exists on
disk because we assumed that if it didn't exist it was a module.
However, with the change from D89334 this is no longer the case as we
want to be able to import a relative path to a .py as a module. Since we
always import a scripting module as a "python module" we should always
strip the extension if present.

Differential revision: https://reviews.llvm.org/D89352

This reverts commit c78da037.

Temporarily reverted due to https://bugs.llvm.org/show_bug.cgi?id=47837.