Refactor the code that handles the align clause of 'omp allocate' so
it can be used with globals as well as local variables.

Differential Revision: https://reviews.llvm.org/D126426

This reverts commit 1e911498.

Pending further discussion.

This change reorganizes the majority of frame index resolution into a two strep process.

    Step 1 - Select which base register we're going to use.
    Step 2 - Compute the offset from that base register.

The key point is that this allows us to share the step 2 logic for the SP case. This reduces the code duplication, and (I think) makes the code much easier to follow.

I also went ahead and added assertions into phase 2 to catch errors where we select an illegal base pointer. In general, we can't index from a base register to a stack location if that requires crossing a variable and unknown region. In practice, we have two such cases: dynamic stack realign and var sized objects. Note that crossing the scalable region is fine since while variable, it's a known variability which can be expressed in the offset.

Differential Revision: https://reviews.llvm.org/D126403

This reverts commit ec10ac75.

See https://discourse.llvm.org/t/cmake-regeneration-is-broken/62788.
This change caused Ninja's CMake regeneration to depend on the build,
which prevented CMake regeneration from functioning properly and caused
spurious build failures on incremental builds when a CMake change
occurred.

We've observed segfaults in libunwind when attempting to check for the
Linux aarch64 sigreturn frame, presumably because of bad unwind info
leading to an incorrect PC that we attempt to read from. Use
process_vm_readv to read the memory safely instead.

The s390x code path should likely follow suit, but I don't have the
hardware to be able to test that, so I didn't modify it here either.

Reviewed By: MaskRay, rprichard, #libunwind

Differential Revision: https://reviews.llvm.org/D126343

Create a macro for this instead of duplicating the architecture checks
everywhere. (It's a little redundant to use it when we're checking for a
specific architecture, but I'm also applying it there for consistency.)

Reviewed By: rprichard, MaskRay, #libunwind

Differential Revision: https://reviews.llvm.org/D126342

Use logical instead of bitwise and to combine conditions, to avoid
propagating poison from a later condition if an earlier one is
already false. This avoids introducing branch on poison.

Differential Revision: https://reviews.llvm.org/D125898

During insertion of VSETVLI, we have two related bits of code which decide whether we can reuse a previous vsetvli result. As was pointed out in the original review, these cases can allow any prior state for which we know that VL is the same for any value of AVL.

This was originally separated out of a desire for separate tests and review. As it turns out, finding a test case for this has been quite challenging. Most of the cases I tried, we manage to already get through other chains of logic. We do have one correct test change, but that only exercises one of the two changes.

Differential Revision: https://reviews.llvm.org/D126400

Patch improves compile time. For function calls, which cannot be
vectorized, create a unique group for each such a call instead of
subgroup. It prevents them from being grouped by a subgroups and
attempts for their vectorization.

Also, looks through casts operand to try to check their
groups/subgroups.

Reduces number of vectorization attempts. No changes in the statistics
for SPEC2017/2006/llvm-test-suite.

Differential Revision: https://reviews.llvm.org/D126476

Need to handle a corner case correctly, if all elements are Undefs/Poisons,
need to emit actual values, not just poisons.

Differential Revision: https://reviews.llvm.org/D126298

Responding to a feature request from the Rust community:

https://github.com/rust-lang/rust/issues/80630

    void foo(X) {
      for (...)
	switch (X)
	  case A
	    X = B
	  case B
	    X = C
    }

Even though the initial switch value is non-constant, the switch
statement can still be threaded: the initial value will hit the switch
statement but the rest of the state changes will proceed by jumping
unconditionally.

The early predictability check is relaxed to allow unpredictable values
anywhere, but later, after the paths through the switch statement have
been enumerated, no non-constant state values are allowed along the
paths. Any state value not along a path will be an initial switch value,
which can be safely ignored.

Differential Revision: https://reviews.llvm.org/D124394

Show a missed case where the AND is currently blocks applying the
information from the assume.

The default implementations will perform a shallow copy instead of a deep
copy, causing some internal data structures to be shared between different
objects. Disable these operations so they don't get accidentally used.

Differential Revision: https://reviews.llvm.org/D126401

Reviewed By: ldionne, var-const, #libc

Spies: libcxx-commits, mgorny

Differential Revision: https://reviews.llvm.org/D123016

On Power PC we have ISA3.0 for Power 9, ISA3.1 for Power 10.
This patchs adds an ISA for mcpu=future. The idea is to have a placeholder ISA
for work that is experimental and may not be supported by existing ISAs.

Reviewed By: lei

Differential Revision: https://reviews.llvm.org/D126075

Fixes https://github.com/llvm/llvm-project/issues/55457

Ensures that attributes in the enum declaration are interpreted
correctly, for instance:

```
enum class [[nodiscard]] E {
  a,
  b
};
```

Reviewed By: MyDeveloperDay, curdeius

Differential Revision: https://reviews.llvm.org/D125848

CoreturnStmt needs to keep the operand value distinct from its use in
any return_value call, so that instantiation may rebuild the latter.
But it also needs to keep the operand value separate in the case of
calling return_void.  Code generation checks the operand value form to
determine whether it is a distincte entity to the promise call.  This
adds the same logic to CFG generation.

Reviewed By: bruno

Differential Revision: https://reviews.llvm.org/D126399

If you are broken by this change, you should remove your CMake cache and
re-run the CMake generation step.

ScatterVectorize nodes should be handled same way as gathers in
reorderBottomToTop function, since we can simple reorder the loads in
this node. Because of that need to include such nodes to the list of
gathered nodes to fix compiler crash.

Differential Revision: https://reviews.llvm.org/D126378

This is a preparation for D125804, which makes test_errors.py test
warnings the same way it already tests errors, i.e., assert that the
emitted and expected errors are identical. The following changes are
made to the test:

 - Add the WARNING directive where warnings are expected.
 - Remove -Werror in the RUN line. It does not serve much purpose here:
   with -Werror flang makes compilation fail in the presence of
   warnings, but warnings are still printed as warnings and not as
   errors. And I anyway find it better to test the warnings as warnings
   instead of promoting them and test both warnings and errors as
   errors.
 - Update the header comment describing the test case, mostly in
   response to the removal of -Werror.
 - Remove the reference to 'issue 458', referring to
   https://github.com/flang-compiler/f18/issues/458, from the header.
   I think the relevant reference here is to C1120 of the standard,
   and references to bug trackers from other projects (from before
   upstreaming) can be confusing.

Reviewed By: PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D126176

CUDA requires that static variables be visible to the host when
offloading. However, The standard semantics of a stiatc variable dictate
that it should not be visible outside of the current file. In order to
access it from the host we need to perform "externalization" on the
static variable on the device. This requires generating a semi-unique
name that can be affixed to the variable as to not cause linker errors.

This is currently done using the CUID functionality, an MD5 hash value
set up by the clang driver. This allows us to achieve is mostly unique
ID that is unique even between multiple compilations of the same file.
However, this is not always availible. Instead, this patch uses the
unique ID from the file to generate a unique symbol name. This will
create a unique name that is consistent between the host and device side
compilations without requiring the CUID to be entered by the driver. The
one downside to this is that we are no longer stable under multiple
compilations of the same file. However, this is a very niche use-case
and is not supported by Nvidia's CUDA compiler so it likely to be good
enough.

Reviewed By: tra

Differential Revision: https://reviews.llvm.org/D125904

With large compare constant:
(X u/ Y) == C --> (X == C) && (Y == 1)
(X u/ Y) != C --> (X != C) || (Y != 1)

https://alive2.llvm.org/ce/z/EhKwh6

There are various potential missing icmp (div) transforms shown here:
https://github.com/llvm/llvm-project/issues/55695

This is a generalization for part of the udiv + equality.
I didn't check in detail, but some of those may only make sense as
codegen transforms.

This results in one extra instruction in IR, but it is better for
analysis, and looks much better in codegen on all targets that I tried.

Differential Revision: https://reviews.llvm.org/D126410

This covers a generalization of one of the transforms
suggested in #55695.

Like we have been doing for libc++ for a while now, start using
from-scratch testing configurations for libc++abi.

As a fly-by fix, remove the LIBCXXABI_NO_TIMER macro, which was defined
but never used.

Differential Revision: https://reviews.llvm.org/D125242

Remove local (uniform) constant folding and rely on getNode() to perform it

Minor cleanup step toward adding non-uniform shift amount support

Fixes https://github.com/llvm/llvm-project/issues/55610.

Reviewed By: MyDeveloperDay

Differential Revision: https://reviews.llvm.org/D126096

Amends 681c50c6 and hopefully fixes:

https://lab.llvm.org/buildbot/#/builders/109/builds/39347
https://lab.llvm.org/buildbot/#/builders/188/builds/14634
and others

Post-commit feedback on https://reviews.llvm.org/D122895 pointed out
that the diagnostic wording for some code was using "declaration" in a
confusing way, such as:

int foo(); // warning: a function declaration without a prototype is deprecated in all versions of C and is not supported in C2x

int foo(int arg) { // warning: a function declaration without a prototype is deprecated in all versions of C and is not supported in C2x
  return 5;
}

And that we had other minor issues with the diagnostics being somewhat
confusing.

This patch addresses the confusion by reworking the implementation to
be a bit more simple and a bit less chatty. Specifically, it changes
the warning and note diagnostics to be able to specify "declaration" or
"definition" as appropriate, and it changes the function merging logic
so that the function without a prototype is always what gets warned on,
and the function with a prototype is sometimes what gets noted.
Additionally, when diagnosing a K&R C definition that is preceded by a
function without a prototype, we don't note the prior declaration, we
warn on it because it will also be changing behavior in C2x.

Differential Revision: https://reviews.llvm.org/D125814

Dependent patch adds UnarySymExpr, now I'd like to handle that for SMT
conversions like refutation.

Differential Revision: https://reviews.llvm.org/D125547

Fixes https://github.com/llvm/llvm-project/issues/55241

Differential Revision: https://reviews.llvm.org/D125395

This patch adds a new descendant to the SymExpr hierarchy. This way, now
we can assign constraints to symbolic unary expressions. Only the unary
minus and bitwise negation are handled.

Differential Revision: https://reviews.llvm.org/D125318

Depends on D124758. That patch introduced serious regression in the run-time in
some special cases. This fixes that.

Differential Revision: https://reviews.llvm.org/D126406

Resolves part of
https://github.com/llvm/llvm-project/issues/38652

Reviewed By: dp

Differential Revision: https://reviews.llvm.org/D125700

This ensures that a deduced type like __auto_type matches the correct
association instead of matching all associations.

This addresses a regression from e4a42c5b

Fixes #55702

Prep work as I'm investigating some cases where TLI::convertSetCCLogicToBitwiseLogic should accept vectors.