See https://clang.llvm.org/docs/LibTooling.html

Thanks to ExtensionSet::toLLVMFeatureList, all values of ArchExtKind
should correspond to a particular -target-feature. The valid values of
-target-feature are in turn defined by SubtargetFeature defs.

Therefore we can generate ArchExtKind from the tablegen data. This is
done by adding an Extension class which derives from SubtargetFeature.

Because the Has* FieldNames do not always correspond to the AEK_
names ("extensions", as defined in TargetParser), and AEK_ names do
not always correspond to -march strings, some additional enum entries
have been added to remap the names. I have renamed these to make the
naming consistent, but split them into a separate PR to keep the diff
reasonable (#90320)

In #70452 DAGCombiner::mayAlias was taught to handle scalable sizes, but
when it checks via AA->isNoAlias it didn't take into account the case
where the size is scalable but there was an offset too.

For the fixed length case the offset was just accounted for by adding to
the LocationSize, but for the scalable case there doesn't seem to be a
way to represent both a scalable and fixed part in it. So this patch
works around it by bailing if there is an offset.

Fixes #90559

As discussed in https://github.com/llvm/llvm-project/pull/88039, support
different strides with isSafeDependenceDistance by passing the maximum
of both strides.

isSafeDependenceDistance tries to prove that
    |Dist| > BackedgeTakenCount * Step
holds. Chosing the maximum stride computes the maximum range accesed by
the loop for all strides.

PR: https://github.com/llvm/llvm-project/pull/90036

libLTO parses options late, so at the moment the option is ignored. To
fix that, re-set it in optimize(), as at this point the options have been
parsed. When LTOCodeGenerator's constructor executes, the options
haven't been parsed by the linker to libLTO yet.

Note that we keep the value name of `%add = add..` because when the
module is imported, DiscardValueNames is still set to false (the default
when building with assertions).

I tried to improve this in libLTO, but I am not sure if there's a
suitable callback when all options have been set.

PR: https://github.com/llvm/llvm-project/pull/78705

Once https://github.com/llvm/llvm-project/issues/85613

 fixed, we can
mark this feature fully supported.

Signed-off-by: yronglin <yronglin777@gmail.com>

This flag has been enabled by default for almost two years now since
1f06398e, and at this stage we probably
shouldn't be falling back to the fixups.

This removes the flag so we always perform the assertion, as well as
making sure that CurInfo is always valid on exit: We shouldn't leave
emitVSETVLIs with an uninitialized VSETVLIInfo.

Fold:
``` llvm
define i1 @src(i8 %x, i8 %y) {
  %xor = xor i8 %x, %y
  %r = trunc nuw/nsw i8 %xor to i1
  ret i1 %r
}

define i1 @tgt(i8 %x, i8 %y) {
  %r = icmp ne i8 %x, %y
  ret i1 %r
}
```

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

As noted on #66991 - we sometimes share vector constant pool entries, referencing subvectors within them via pointer offsets

Current dir can be read-only. Use a temp path instead.

image_msaa_load is actually encoded as a VSAMPLE instruction and
requires the appropriate waitcnt variant.

The AltiVec (POWER) and ZVector (IBM Z) language extensions do not
support using the "vector" keyword when the element type is a complex
type, but current code does not verify this.

Add a Sema check and diagnostic for this case.

Fixes: https://github.com/llvm/llvm-project/issues/88399

In the test of
clang/test/Modules/no-transitive-source-location-change.cppm, there were
reports about invalid directory names in windows. The reason may be that
we may remove and create the same directory. This patch tries to avoid
such patterns for that.

91a8cb78 was originally written
before 8d538666 landed. The latter
changed how main is emitted which changed the numbering of the
suprograms in the test output.

To fix this I've added a check for the new _QQmain and renumbered
the existing checks.

…te module file for C++20 modules instead of PCHGenerator

Previously we're re-using PCHGenerator to generate the module file for
C++20 modules. But this is slighty more or less odd. This patch tries to
use a new class 'CXX20ModulesGenerator' to generate the module file for
C++20 modules.

modules

After https://github.com/llvm/llvm-project/pull/86912,
for the following example,

```
export module A;
export import B;
```

The generated BMI of `A` won't change if the source location in `A`
changes. Further, we plan avoid more such changes.

However, it is slightly problematic since `export import` should
propagate all the changes.

So this patch adds a signature to the BMI of C++20 modules so that we
can propagate the changes correctly.

This also removes the member overload in TypeSwitch.

All other users have been removed in
fac349a1 and
bd9fdce6.

Depends on #84384 and #90329

This adds support for `DW_TAG_LLVM_ptrauth_type` entries corresponding
to explicitly signed types (e.g. free function pointers) in lldb user
expressions. Applies PR https://github.com/apple/llvm-project/pull/8239


from Apple's downstream and also adds tests and related code.

---------

Co-authored-by: Jonas Devlieghere <jonas@devlieghere.com>

[Clang][Sema] Fix a bug on template partial specialization with issue on deduction of nontype template parameter (#90376)

Fix https://github.com/llvm/llvm-project/issues/68885


When build expression from a deduced argument whose kind is
`Declaration` and `NTTPType`(which declared as `decltype(auto)`) is
deduced as a reference type, `BuildExpressionFromDeclTemplateArgument`
just create a `DeclRef`. This is incorrect while we get type from the
expression since we can't get the original reference type from
`DeclRef`. Creating a `SubstNonTypeTemplateParmExpr` expression and make
the deduction correct. `Replacement` expression of
`SubstNonTypeTemplateParmExpr` just helps the deduction and may not be
same with the original expression.

Co-authored-by: huqizhi <836744285@qq.com>

attempt to fix
https://github.com/llvm/llvm-project/issues/68885#issuecomment-1764201896


Deduction of NTTP whose type is `decltype(auto)` would create an
implicit cast expression to dependent type and makes the type of primary
template definition (`InjectedClassNameSpecialization`) and its partial
specialization different. Prevent emitting cast expression to make clang
knows their types are identical by removing `CTAK == CTAK_Deduced` when
the type is `decltype(auto)`.

Co-authored-by: huqizhi <836744285@qq.com>

Guard object destroyed immediately after creation without naming.

We need to adjust the RHS to account for the LHS bitwidth.

Adds an example that combines loop peeling and scalable vectorisation of
`linalg.depthwise_conv_2d_nhwc_hwc`. This is similar to
transform-op-peel-and-vectorize.mlir and is meant to demonstrate how to
avoid masking when vectorising using scalable vectors.

For all means and purposes llvm.mlir.addressof acts like a constant, and
should be treated as such by passes. In particular, the operation should
be propagated rather than passed whenever possible.

Should hopefully help shave some minutes off developer debugging time in
the future.

This is part of "no transitive change" patch series, "no transitive
source location change". I talked this with @Bigcheese in the tokyo's
WG21 meeting.

The idea comes from @jyknight posted on LLVM discourse. That for:

```
// A.cppm
export module A;
...

// B.cppm
export module B;
import A;
...

//--- C.cppm
export module C;
import C;
```

Almost every time A.cppm changes, we need to recompile `B`. Due to we
think the source location is significant to the semantics. But it may be
good if we can avoid recompiling `C` if the change from `A` wouldn't
change the BMI of B.

# Motivation Example

This patch only cares source locations. So let's focus on source
location's example. We can see the full example from the attached test.

```
//--- A.cppm
export module A;
export template <class T>
struct C {
    T func() {
        return T(43);
    }
};
export int funcA() {
    return 43;
}

//--- A.v1.cppm
export module A;

export template <class T>
struct C {
    T func() {
        return T(43);
    }
};
export int funcA() {
    return 43;
}

//--- B.cppm
export module B;
import A;

export int funcB() {
    return funcA();
}

//--- C.cppm
export module C;
import A;
export void testD() {
    C<int> c;
    c.func();
}
```

Here the only difference between `A.cppm` and `A.v1.cppm` is that
`A.v1.cppm` has an additional blank line. Then the test shows that two
BMI of `B.cppm`, one specified `-fmodule-file=A=A.pcm` and the other
specified `-fmodule-file=A=A.v1.pcm`, should have the bit-wise same
contents.

However, it is a different story for C, since C instantiates templates
from A, and the instantiation records the source information from module
A, which is different from `A` and `A.v1`, so it is expected that the
BMI `C.pcm` and `C.v1.pcm` can and should differ.

# Internal perspective of status quo

To fully understand the patch, we need to understand how we encodes
source locations and how we serialize and deserialize them.

For source locations, we encoded them as:

```
|
|
| _____ base offset of an imported module
|
|
|
|_____ base offset of another imported module
|
|
|
|
| ___ 0
```

As the diagram shows, we encode the local (unloaded) source location
from 0 to higher bits. And we allocate the space for source locations
from the loaded modules from high bits to 0. Then the source locations
from the loaded modules will be mapped to our source location space
according to the allocated offset.

For example, for,

```
// a.cppm
export module a;
...

// b.cppm
export module b;
import a;
...
```

Assuming the offset of a source location (let's name the location as
`S`) in a.cppm is 45 and we will record the value `45` into the BMI
`a.pcm`. Then in b.cppm, when we import a, the source manager will
allocate a space for module 'a' (according to the recorded number of
source locations) as the base offset of module 'a' in the current source
location spaces. Let's assume the allocated base offset as 90 in this
example. Then when we want to get the location in the current source
location space for `S`, we can get it simply by adding `45` to `90` to
`135`. Finally we can get the source location for `S` in module B as
`135`.

And when we want to write module `b`, we would also write the source
location of `S` as `135` directly in the BMI. And to clarify the
location `S` comes from module `a`, we also need to record the base
offset of module `a`, 90 in the BMI of `b`.

Then the problem comes. Since the base offset of module 'a' is computed
by the number source locations in module 'a'. In module 'b', the
recorded base offset of module 'a' will change every time the number of
source locations in module 'a' increase or decrease. In other words, the
contents of BMI of B will change every time the number of locations in
module 'a' changes. This is pretty sensitive. Almost every change will
change the number of locations. So this is the problem this patch want
to solve.

Let's continue with the existing design to understand what's going on.
Another interesting case is:

```
// c.cppm
export module c;
import whatever;
import a;
import b;
...
```

In `c.cppm`, when we import `a`, we still need to allocate a base
location offset for it, let's say the value becomes to `200` somehow.
Then when we reach the location `S` recorded in module `b`, we need to
translate it into the current source location space. The solution is
quite simple, we can get it by `135 + (200 - 90) = 245`. In another
word, the offset of a source location in current module can be computed
as `Recorded Offset + Base Offset of the its module file - Recorded Base
Offset`.

Then we're almost done about how we handle the offset of source
locations in serializers.

# The high level design of current patch

From the abstract level, what we want to do is to remove the hardcoded
base offset of imported modules and remain the ability to calculate the
source location in a new module unit. To achieve this, we need to be
able to find the module file owning a source location from the encoding
of the source location.

So in this patch, for each source location, we will store the local
offset of the location and the module file index. For the above example,
in `b.pcm`, the source location of `S` will be recorded as `135`
directly. And in the new design, the source location of `S` will be
recorded as `<1, 45>`. Here `1` stands for the module file index of `a`
in module `b`. And `45` means the offset of `S` to the base offset of
module `a`.

So the trade-off here is that, to make the BMI more independent, we need
to record more abstract information. And I feel it is worthy. The
recompilation problem of modules is really annoying and there are still
people complaining this. But if we can make this (including stopping
other changes transitively), I think this may be a killer feature for
modules. And from @Bigcheese , this should be helpful for clang explicit
modules too.

And the benchmarking side, I tested this patch against
https://github.com/alibaba/async_simple/tree/CXX20Modules. No
significant change on compilation time. The size of .pcm files becomes
to 204M from 200M. I think the trade-off is pretty fair.

# Some low level details

I didn't use another slot to record the module file index. I tried to
use the higher 32 bits of the existing source location encodings to
store that information. This design may be safe. Since we use `unsigned`
to store source locations but we use uint64_t in serialization. And
generally `unsigned` is 32 bit width in most platforms. So it might not
be a safe problem. Since all the bits we used to store the module file
index is not used before. So the new encodings may be:

```
   |-----------------------|-----------------------|
   |           A           |         B         | C |

  * A: 32 bit. The index of the module file in the module manager + 1. The +1
          here is necessary since we wish 0 stands for the current module file.
  * B: 31 bit. The offset of the source location to the module file containing it.
  * C: The macro bit. We rotate it to the lowest bit so that we can save some 
          space in case the index of the module file is 0.
```

(The B and C is the existing raw encoding for source locations)

Another reason to reuse the same slot of the source location is to
reduce the impact of the patch. Since there are a lot of places assuming
we can store and get a source location from a slot. And if I tried to
add another slot, a lot of codes breaks. I don't feel it is worhty.

Another impact of this decision is that, the existing small
optimizations for encoding source location may be invalided. The key of
the optimization is that we can turn large values into small values then
we can use VBR6 format to reduce the size. But if we decided to put the
module file index into the higher bits, then maybe it simply doesn't
work. An example may be the `SourceLocationSequence` optimization.

This will only affect the size of on-disk .pcm files. I don't expect
this impact the speed and memory use of compilations. And seeing my
small experiments above, I feel this trade off is worthy.

# Correctness

The mental model for handling source location offsets is not so complex
and I believe we can solve it by adding module file index to each stored
source location.

For the practical side, since the source location is pretty sensitive,
and the patch can pass all the in-tree tests and a small scale projects,
I feel it should be correct.

# Future Plans

I'll continue to work on no transitive decl change and no transitive
identifier change (if matters) to achieve the goal to stop the
propagation of unnecessary changes. But all of this depends on this
patch. Since, clearly, the source locations are the most sensitive
thing.

---

The release nots and documentation will be added seperately.

Some of the online sync-ups on our Getting Involved page seem to no
longer be happening. Document them as no longer happening, so that
people don't get confused when dialing in to one of these.

In the debug intrinsic class heirachy, a dbg.assign is a (inherits from)
dbg.value, so `findDbgValues` returns dbg.values and dbg.assigns (by
design). That hierarchy doesn't exist for DbgRecords - fix findDbgValues
to return dbg_assign records as well as dbg_values and add unittest.

The original PR #90083 had to be reverted in PR #90444 as it caused one
of the gfortran tests to fail. The issue was using `isIntOrIndex` for
checking for integer type. It allowed index type which later caused
assertion when calling `getIntOrFloatBitWidth`. I have now replaced it
with `isInteger` which should fix this regression.