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.

Also fix directives not covered by D125604.

reapply 62a9b36f and fix module build
failue:
1: remove MachineCycleInfoWrapperPass in MachinePassRegistry.def
   MachineCycleInfoWrapperPass is a anylysis pass, should not be there.
2: move the definition for MachineCycleInfoPrinterPass to cpp file.

Otherwise, there are module conflicit for MachineCycleInfoWrapperPass
in MachinePassRegistry.def and MachineCycleAnalysis.h after
62a9b36f.

MachineCycle can handle irreducible loop. Natural loop
analysis (MachineLoop) can not return correct loop depth if
the loop is irreducible loop. And MachineSink is sensitive
to the loop depth, see MachineSinking::isProfitableToSinkTo().

This patch tries to use MachineCycle so that we can handle
irreducible loop better.

Reviewed By: sameerds, MatzeB

Differential Revision: https://reviews.llvm.org/D123995

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D125604

The Transform dialect uses the side effect modeling mechanism to record the
effects of the transform ops on the mapping between Transform IR values and
Payload IR ops. Introduce a checker pass that warns if a Transform IR value is
used after it has been freed (consumed). This pass is mostly intended as a
debugging aid in addition to the verification/assertion mechanisms in the
transform interpreter. It reports all potential use-after-free situations.
The implementation makes a series of simplifying assumptions to be simple and
conservative. A more advanced implementation would rely on the data flow-like
analysis associated with a side-effect resource rather than a value, which is
currently not supported by the analysis infrastructure.

Reviewed By: springerm

Differential Revision: https://reviews.llvm.org/D126381

Fixes failure seen when building without X86 backend:
https://lab.llvm.org/buildbot/#/builders/171/builds/15124

These shows that the cost of a @llvm.vscale is indeed 1, not 10.

Reviewed By: var-const, #libc

Spies: libcxx-commits, mgorny

Differential Revision: https://reviews.llvm.org/D123681

When updating the branch instruction outside the loopduring non-trivial
 unswitching, always skip trivial selects and update the condition.

Otherwise we might create invalid IR, because the trivial select is
inside the loop, while the condition is outside the loop.

Fixes #55697.

We didn't implement RISCVELFStreamer::reset and cause some very strange
section output for attribute section...just reference D15950 to see how
ARM implement that.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D125905