Summary:
The `__nvvm_reflect` function is used to guard invalid code that varies
between architectures. One problem with this feature is that if it is
used without optimizations, it will leave invalid code in the module
that will then make it to the backend. The `__nvvm_reflect` pass is
already mandatory, so it should do some trivial branch removal to ensure
that constants are handled correctly. This dead branch elimination only
works in the trivial case of a compare on a branch and does not touch
any conditionals that were not realted to the `__nvvm_reflect` call in
order to preserve `O0` semantics as much as possible. This should allow
the following to work on NVPTX targets

```c
int foo() {
  if (__nvvm_reflect("__CUDA_ARCH") >= 700)
    asm("valid;\n");
}
```

Relanding after fixing a bug.

Introduced in 76ce4736

Notably, test that --ro-rosegment with a linker script may unnecessarily
make a read-only PT_LOAD executable.

Previously, `InsertSliceOpSourceCastInserter` was incorrectly applied to
a case when tensor types have an encoding attribute attached to them.
The type `newSrcType` was missing that attribute from the old `srcType`,
which made the expression `srcType == newSrcType` false, since
`tensor<2x2xf32, "foo">` is not equal to `tensor<2x2xf32>`. That lead to
an endless back and forth between `InsertSliceOpSourceCastInserter` that
would introduce a cast and `InsertSliceOpCastFolder` that would remove
it right after.

[libc] Only declare float128 math functions in the generated math.h if float128 type is supported. (#81010)

The error check should be performed after the iterator increment, not before
it. Thanks to @dcb314 for catching this!

Fixes github.com/apple/swift/issues/81119

A line table whose sole entry is an end sequence should not have the
entry's file index verified, as that value corresponds to the initial
value of the state machine, not to a real file index. In DWARF 5, this
is particularly problematic as it uses 0-based indexing, and the state
machine specifies a starting index of 1; in other words, you'd need to
have _two_ files before such index became legal "by default".

A previous attempt to fix this problem was done [1], but it was too
specific in its condition, and did not capture all possible cases where
this issue can happen.

[1]: https://github.com/llvm/llvm-project/pull/77004

Derived from this discussion:
https://discourse.llvm.org/t/prs-without-approvals-muddy-the-waters/76656

Fix buildbot failing because of missing  HLFIRTypes.h.inc

This reverts commit 9211e67d.

Summary:
This seemed to crash one one of the CUDA math tests. Revert until it can
be fixed.

See https://github.com/emscripten-core/emscripten/issues/21140

Summary:
Currently, the linker wrapper sorts input files into different link
jobs according to their architectures. Here we assume each architecture
is a unique and incompatible link job unless they are specifically
marked compatible. This patch simply adds an `all` target to represent
an architecture that should be linked against every single other
architecture.

This will be useful for modelling generic IR such as the ROCm device
libraries or the NVPTX libdevice.

Summary:
The `__nvvm_reflect` function is used to guard invalid code that varies
between architectures. One problem with this feature is that if it is
used without optimizations, it will leave invalid code in the module
that will then make it to the backend. The `__nvvm_reflect` pass is
already mandatory, so it should do some trivial branch removal to ensure
that constants are handled correctly. This dead branch elimination only
works in the trivial case of a compare on a branch and does not touch
any conditionals that were not realted to the `__nvvm_reflect` call in
order to preserve `O0` semantics as much as possible. This should allow
the following to work on NVPTX targets

```c
int foo() {
  if (__nvvm_reflect("__CUDA_ARCH") >= 700)
    asm("valid;\n");
}
```

The current implementation of aliases tries to remove all the aliases in
the module to prevent the generic version of `AsmPrinter` from emitting
them incorrectly. Unfortunately, if the aliases are used this will fail.
Instead let's override the function to print aliases directly.

In addition, the declarations of the alias functions must occur before
the uses. To fix this we emit alias declarations as part of
`emitDeclarations` and only emit the `.alias` directives at the end
(where we can assume the aliasee has also already been declared).

The custom printer for `fir.global` was eluding all the attributes
present on the op when printing the attribute dictionary. So any
attribute that is not part of the pretty printing was therefore
discarded.
This patch fix the printer and also make use of the getters for the
attribute names when they are hardcoded.

Add `scf::wrapWhileLoopInZeroTripCheck` to wrap scf while loop in
zero-trip-check.

Otherwise we will crash since target intrinsics don't have their types
legalized. Let the mgather get legalized first, then do the combine on
the legal type.
Fixes #81088

Co-authored-by: Craig Topper <craig.topper@sifive.com>

This code was correct as written prior to C++17, which allowed bases to
appear in the initializer list.

This was observable by creating non-constant aggregate initialization at
file scope in a compound literal, but since that behavior will change
soon if we implement support for dynamic initialization, I also added a
unit test for `isConstantInitializer`.

This fixes at least one part of issue #80510 .

---------

Co-authored-by: Aaron Ballman <aaron@aaronballman.com>

We run CheckLargeFunctions pass in non-relocation mode to prevent the
emission of functions that later could not be written to the output due
to their large size. The main reason behind the pass is to prevent the
emission of metadata for such functions since this metadata becomes
incorrect if the function is left unmodified.

Currently, the pass is enabled in non-relocation mode only when debug
info output is also enabled. As we emit increasingly more kinds of
metadata, e.g. for the Linux kernel, it becomes more challenging to
track metadata that needs to be fixed. Hence, I'm enabling the pass to
always run in non-relocation mode.

This was missing in the gn build for some reason, causing build errors like http://45.33.8.238/linux/130337/step_4.txt after 3b57b647.

Cleanup some dead variables. In addition, switch to a `MAKE_CASE` macro,
similar to other targets, to reduce boilerplate.

MCPhysReg is 2 bytes, while Register is 4 bytes.

DWARFLinkerImpl::DWARFLinkerImpl initializes
DebugStrStrings/DebugLineStrStrings/CommonSections using GlobalData
but GlobalData is initialized after the three members.
Move GlobalData before.

Fix #81110

Currently symbol info is generated from a linking section or from export
names. This PR generates symbols in a WasmObjectFile from the name
section as well, which allows tools like objdump and nm to show useful
information for more linked binaries. There are some limitations:
most notably that we don't assume any particular ABI, so we don't get
detailed information about data symbols if the segments are merged
(which is the default).

Covers most of the desired functionality from #76107

Deprecate `TestVectors`, since no one uses it.

This affects the output order of ExecVectors.
The current impl emits sorted by binary value of ExecVector. This impl
emits along the traversal of `buildTestVector()`.

LLDB has a setting (symbols.enable-background-lookup) that calls
dsymForUUID on a background thread for images as they appear in the
current backtrace. Originally, the laziness of only looking up symbols
for images in the backtrace only existed to bring the number of
dsymForUUID calls down to a manageable number.

Users have requesting the same functionality but blocking. This gives
them the same user experience as enabling dsymForUUID globally, but
without the massive upfront cost of having to download all the images,
the majority of which they'll likely not need.

This patch renames the setting to have a more generic name
(symbols.auto-download) and changes its values from a boolean to an
enum. Users can now specify "off", "background" and "foreground". The
default remains "off" although I'll probably change that in the near
future.

This adjusts the isSubVectorExtractCheap callback to consider any
extract which fits entirely within the first VLEN bits of the src vector
(and uses a 5 bit immediate for the slide) as cheap. These can be done
via a single m1 vslide1down.vi instruction.

This allows our generic DAG combine logic to kick in and recognize a few
more cases where shuffle source is longer than the dest, but that using
a wider shuffle is still profitable. (Or as shown in the test diff, we
can split the wider source and do two narrower shuffles.)

Reverts llvm/llvm-project#80890

Currently, a method exists to get the count of the operation objects
which are still alive. This helps for sanity checking, but isn't
terribly useful for debugging. This new method returns the actual
operation objects which are still alive.

This allows Python code like the following:

```
    gc.collect()
    live_ops = ir.Context.current._get_live_operation_objects()
    for op in live_ops:
      print(f"Warning: {op} is still live. Referrers:")
      for referrer in gc.get_referrers(op)[0]:
        print(f"  {referrer}")
```

1. Add parsing methods for block[n, m].
2. Encode n and m with the newly extended 64-bit LevelType enum.
3. Update 2:4 methods names/comments to n:m.

Add a SPIR-V target-specific intrinsic for creating handles, which is
used for lowering HLSL resources types like RWBuffer.

`llvm/lib/TargetParser/Triple.cpp`: SPIR-V intrinsics use "spv" as the
target prefix, not "spirv". As far as I can tell, this is the first one
that is used via the `CGBuiltin` codepath, which relies on
`getArchTypePrefix`, so I've corrected it here.

`clang/lib/Basic/Targets/SPIR.h`: When records are laid out in the
lowering from AST to IR, they were incorrectly offset because these
Pointer attributes were defaulting to 32.

Related to #81036

Fixes https://github.com/llvm/llvm-project/issues/80910.

Per the documentation in ISDOpcodes.h, for BUILD_VECTOR "The types of
the operands must match the vector element type, except that integer
types are allowed to be larger than the element type, in which case the
operands are implicitly truncated."

This transform was assuming that the scalar operand type matched the
result type. This resulted in essentially performing a truncate before a
binop, instead of after. As demonstrated by the test case changes, this
is often not legal.

[AMDGPU] Compiler should synthesize private buffer resource descriptor from flat_scratch_init (#79586)

This change implements synthesizing the private buffer resource
descriptor in the kernel prolog instead of using the preloaded kernel
argument.

LLDB has a setting (symbols.enable-background-lookup) that calls
dsymForUUID on a background thread for images as they appear in the
current backtrace. Originally, the laziness of only looking up symbols
for images in the backtrace only existed to bring the number of
dsymForUUID calls down to a manageable number.

Users have requesting the same functionality but blocking. This gives
them the same user experience as enabling dsymForUUID globally, but
without the massive upfront cost of having to download all the images,
the majority of which they'll likely not need.

This patch renames the setting to have a more generic name
(symbols.auto-download) and changes its values from a boolean to an
enum. Users can now specify "off", "background" and "foreground". The
default remains "off" although I'll probably change that in the near
future.

The following test case in
`clang-tools-extra/test/clang-tidy/infrastructure/diagnostic.cpp` is
failing:
```
#ifdef PR64602 // Should not crash
template <class T = void>
struct S
{
    auto foo(auto);
};

template <>
auto S<>::foo(auto)
{
    return 1;
}
// CHECK8: error: template parameter list matching the non-templated nested type 'S<>' should be empty ('template<>') [clang-diagnostic-error]
#endif
```

#80864 fixes a bug where we would (incorrectly) append invented template
parameters to empty template parameter lists, which causes this test to
fail.