This add canonicalizer for

- extracting an element from a dynamic_tensor_from_elements
- propagating constant operands to the type of dynamic_tensor_from_elements

Differential Revision: https://reviews.llvm.org/D87525

There at least one other bug related to pow -> sqrt transforms:
http://lists.llvm.org/pipermail/llvm-dev/2020-September/145051.html
...but we probably can't solve that without fixing this first.

The code drops the sqrt op instead of bailing out,
so this is very wrong.

This is not a valid transform unless we can prove
that the program does not read errno after the pow
call and before some other function changes it.

This test tries to create a 2 GiB std::string, catching the bad_alloc
exception if the allocation fails. However, for no-exceptions builds
there is no way for the error to be reported, so this crashes with a
null pointer dereference.

Differential revision: https://reviews.llvm.org/D87682

With https://reviews.llvm.org/D87537 we made it an error
to import or export a mutable global with the +mutable-globals
feature present.  However the scan was of the entire symbol
table rather than just the imports or exports and the filter
didn't match exaclyt meaning the `__stack_pointer` (a mutable
global) was always triggering with error when the `--export-all`
flag was used.

This also revealed that we didn't have any test coverage for
the `--export-all` flag.

This change fixes the current breakage on the emscripten-releases
roller.

Differential Revision: https://reviews.llvm.org/D87663

Adds a new GettingInvolved page to documentation which provides details about
mailing list, chats and calls.

Adds a sidebar page which provides common links on
all documentation pages.
The links include:
-  Getting Started
-  Getting Involved
-  Github Repository
-  Bug Reports
-  Code Review

Depends on https://reviews.llvm.org/D87242

Reviewed By: richard.barton.arm

Differential Revision: https://reviews.llvm.org/D87270

This patch adds a isConditionImplied function that
takes a constraint and returns true if the constraint
is implied by the current constraints in the system.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D84545

Restrict UnnecessaryCopyInitialization check to variables initialized from free functions without arguments

This restriction avoids cases where an alias is returned to an argument and
which could lead to to a false positive change.

Setting _LIBCPP_HAS_NO_THREADS is needed when building libcxxabi without
threads in standalone mode. This is useful when target WASM. Otherwise,
you get an error like "No thread API" when building libcxxabi.

It would be better to link against a properly-configured libc++ headers
CMake target when building libc++abi instead, but we don't generate such
targets yet.

Thanks to Matthew Bauer for the patch.

Differential Revision: https://reviews.llvm.org/D60743

More remaining dependencies down to LoopCacheAnalysis.cpp

Forward declare AAResults instead of the (old) AliasAnalysis type.

These are all directly included in AliasSetTracker.h

Loop tripcount expressions have a positive range, so use unsigned SCEV ranges
for them.

Differential Revision: https://reviews.llvm.org/D87608

The "takeName" logic in ScalarizerVisitor::gather did not consider
that the value vector could refer to non-instructions, such as
global variables. This patch make sure that we avoid changing the
name of a value if it isn't an instruction.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D87685

qemu calls the "fp" and "lr" registers via their generic names
(x29/x30). This mismatch manifested itself as not being able to unwind
or display values of some local variables.

lldbUtilityHelpers does not depend on lldbSymbolHelpers. Remove that
dependency, and add direct lldbSymbolHelpers dependencies where needed.

This seems to have caused incorrect register allocation in some cases,
breaking tests in the Zig standard library (PR47278).

As discussed on the bug, revert back to green for now.

> Record internal state based on register units. This is often more
> efficient as there are typically fewer register units to update
> compared to iterating over all the aliases of a register.
>
> Original patch by Matthias Braun, but I've been rebasing and fixing it
> for almost 2 years and fixed a few bugs causing intermediate failures
> to make this patch independent of the changes in
> https://reviews.llvm.org/D52010.

This reverts commit 66251f7e, and
follow-ups 931a68f2
and 0671a4c5. It also adjust some
test expectations.

These are all directly included in SpillPlacement.h

These are all directly included in StatepointLowering.h

Reduce to forward declarations and move implicit dependencies down to the cpp files.

This patch recommits "[ConstraintSystem] Add helpers to deal with linear constraints."
(it reverts the revert commit 8da6ae4c).

The reason for the revert was using __builtin_multiply_overflow, which
is not available for all compilers. The patch has been updated to use
MulOverflow from MathExtras.h

When packing function results into a structure during the standard-to-llvm
dialect conversion, do not assume the conversion was successful and propagate
nullptr as error state.

Fixes PR45184.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D87605

Changing directory name to reflect naming convention discussed here:
https://llvm.discourse.group/t/vectorops-rfc-add-suite-of-integration-tests-for-vector-dialect-operations/1213

Differential Revision: https://reviews.llvm.org/D87678

This reverts commit cfff88c0. Sends
instcombine into an infinite loop.

```
define i1 @foo(i32 %arg, i32 %arg1) {
bb:
  %tmp = udiv i32 %arg, %arg1
  %tmp2 = mul nsw i32 %tmp, %arg1
  %tmp3 = icmp eq i32 %tmp2, %arg
  %tmp4 = select i1 %tmp3, i32 %tmp, i32 undef
  %tmp5 = icmp sgt i32 %tmp4, 255
  ret i1 %tmp5
}
```

We're now getting close to having the necessary analysis/combines etc. for the new generic llvm smax/smin/umax/umin intrinsics.

This patch updates the SSE/AVX integer MINMAX intrinsics to emit the generic equivalents instead of the icmp+select code pattern.

Differential Revision: https://reviews.llvm.org/D87603

Fixed a small error in an if condition to prevent usat/ssat being generated if (upper constant + 1) is not a
power of 2.

960cbc53 immediately removes nodes that won't be used to avoid
compilation time explosion. This patch adds the removal to constants to
fix PR47517.

Reviewed By: RKSimon, steven.zhang

Differential Revision: https://reviews.llvm.org/D87614

Helps Visual Studio check include dependencies.

Drop the pow2 vector limitation for AVG generation by padding the vector to the next pow2, creating the PAVG nodes and then extracting the final subvector.

Fixes some poor codegen that has been annoying me for years.....

Our implementation of stack sizes section dumping heavily uses `ELFObjectFile<ELFT>`,
while the rest of the code uses `ELFFile<ELFT>`.

That APIs are very different. `ELFObjectFile<ELFT>` is very generic
and has `SectionRef`, `RelocationRef`, `SymbolRef` and other generic concepts.
The `ELFFile<ELFT>` class works directly with `Elf_Shdr`, `Elf_Rel[a]`, `Elf_Sym` etc,
what is probably much cleaner for ELF dumper.

Also, `ELFObjectFile<ELFT>` API does not always provide a way to check
for possible errors. E.g. the implementation of `symbol_end()` does not verify the `sh_size`:

```
template <class ELFT>
basic_symbol_iterator ELFObjectFile<ELFT>::symbol_end() const {
  const Elf_Shdr *SymTab = DotSymtabSec;
  if (!SymTab)
    return symbol_begin();
  DataRefImpl Sym = toDRI(SymTab, SymTab->sh_size / sizeof(Elf_Sym));
  return basic_symbol_iterator(SymbolRef(Sym, this));
}
```
There are many other examples which makes me thing we might win from
switching to `ELFFile<ELFT>` API, where we heavily validate an input data already.

This patch is the first step in this direction. I've converted the large portion of the code
to use `ELFFile<ELFT>`.

Differential revision: https://reviews.llvm.org/D87362

This is a follow up to c1f2fb51.

`ELFFile<ELFT>` has many methods that take pointers,
though they assume that arguments are never null and
hence could take references instead.

This patch performs such clean-up.

Differential revision: https://reviews.llvm.org/D87385

Update TargetMachine.Options with function attributes before we start
to generate MIR instructions. This allows access to correct function
attributes via TargetMachine.Options (it used to access attributes of
the function that was translated first).
This affects some existing tests with "no-nans-fp-math" attribute.
Follow-up on D87456.

Differential Revision: https://reviews.llvm.org/D87511