Summary:
Adds support for "following" memory through MSSA PHI arguments. This will help catch more noop stores that exist between blocks.

Originally part of D79391.

Reviewers: fhahn, jfb, asbirlea

Differential Revision: https://reviews.llvm.org/D82588

A new hidden option -print-changed is added along with code to support
printing the IR as it passes through the opt pipeline in the new pass
manager. Only those passes that change the IR are reported, with others
only having the banner reported, indicating that they did not change the
IR, were filtered out or ignored. Filtering of output via the
-filter-print-funcs is supported and a new supporting hidden option
-filter-passes is added. The latter takes a comma separated list of pass
names and filters the output to only show those passes in the list that
change the IR. The output can also be modified via the -print-module-scope
function.

The code introduces an abstract template base class that generalizes the
comparison of IRs that takes an IR representation as template parameter.
Derived classes provide overrides that provide an event based API
for generalized reporting of IRs as they are changed in the opt pipeline
through the new pass manager.

The first of several instantiations is provided that prints the IR
in a form similar to that produced by -print-after-all with the above
mentioned filtering capabilities. This version, and the others to
follow will be introduced at the upcoming developer's conference.

Reviewed By: aeubanks (Arthur Eubanks), yrouban (Yevgeny Rouban), ychen (Yuanfang Chen), MaskRay (Fangrui Song)

Differential Revision: https://reviews.llvm.org/D86360

A WRITE to an unformatted sequential variable-length unit after
a BACKSPACE needs to forget its previous knowledge of the length
of the record that's about to be overwritten, and a BACKSPACE
after an ENDFILE or at the start of the file needs to be a no-op.

Differential revision: https://reviews.llvm.org/D88675

This is a temporary workaround until the new/delete situation is made
better (i.e. we don't include new/delete in both libc++ and libc++abi
by default).

Don't give false positives from INQUIRE about possible
access mode changes on connected units.  DIRECT and SEQUENTIAL
cannot be intermixed, apart from allowing DIRECT on a SEQUENTIAL
file with fixed-size records and positioning.  Nor can
FORMATTED and UNFORMATTED be interchanged.  On unconnected
files, the best that we can do is "UNKNOWN".

Differential revision: https://reviews.llvm.org/D88673

Some projects do not use the TEMP_FAILURE_RETRY macro but define their
own one, as not to depend on glibc / Bionic details. By allowing the
user to override the list of macros, these projects can also benefit
from this check.

Differential Revision: https://reviews.llvm.org/D83144

Add checking to I/O statement APIs to catch cases where the formatted
I/O data item transfer routines like OutputInteger64 are being
incorrectly used for unformatted I/O, which should use the
unformatted block or descriptor-based data item interfaces.

Differential revision: https://reviews.llvm.org/D88672

The user is expected to make the isStackSlot check before calling isPhysicalRegister
or isVirtualRegister. The APIs assert otherwise. We can improve the usability
of these APIs by carrying out the check in the 2 APIs: they become a
complete "source of truth" and remove an extra responsibility from the
user.

Differential Revision: https://reviews.llvm.org/D88598

https://reviews.llvm.org/D88310 fixed the AIX issue in LLVMExternalProjectUtils,
so we shouldn't need the workaround in the runtimes build anymore. I'm
reverting it because it prevents the target-specific tool selection in
LLVMExternalProjectUtils from taking effect, which we rely on for our
runtimes builds.

Reviewed By: daltenty

Differential Revision: https://reviews.llvm.org/D88627

Differential Revision: https://reviews.llvm.org/D88633

Reland  rG4fcd1a8e6528:[llvm-exegesis] Add option to check the hardware support for a given feature before benchmarking.

This is mostly for the benefit of the LBR latency mode.
Right now, it performs no checking. If this is run on non-supported hardware, it will produce all zeroes for latency.

      Differential Revision: https://reviews.llvm.org/D85254

New change: Updated lit.local.cfg to use pass the right argument to llvm-exegesis to actually request the LBR mode.

Differential Revision: https://reviews.llvm.org/D88670

This allows us MSAN to instrument this function. Previous version is not
instrumentable due to it shear volume.

Differential Revision: https://reviews.llvm.org/D88536

This matches the corresponding existing case in
AArch64LoadStoreOpt::findMatchingUpdateInsnForward.

Both cases could also be modified to check
MBBI->getFlag(FrameSetup/FrameDestroy) instead of forbidding any
optimization involving SP, but the effect is probably pretty much
the same.

Differential Revision: https://reviews.llvm.org/D88541

The function already has a cleanup scope that calls the same whenever
the function is exited. When reading the code, seeing that this return
codepath has an explicit call while other return paths lack it is
confusing.

In the hypothetical case of a function having a prologue that
set the HasWinCFI flag in the MF, but the epilogue containing no
WinCFI instructions, the HasWinCFI flag in the MF would end up reset back
to false.

Differential Revision: https://reviews.llvm.org/D88636

Make sure we're using getScalarSizeInBits instead of cast<IntegerType> to get Type bit widths.

This is preliminary cleanup before we can start adding vector support to the bswap/bitreverse (element level) matching.

- `-cl-fp32-correctly-rounded-divide-sqrt` is already handled in a
  per-instruction manner by annotating the accuracy required. There's no
  need to add that fn-attr. So far, there's no in-tree backend handling
  that attr and that OpenCL specific option.
- In case that out-of-tree backends are broken, this change could be
  reverted if those backends could not be fixed.

Differential Revision: https://reviews.llvm.org/D88424

Removed hasSideEffects from SSAT and USAT so that they are no longer
marked as unpredictable.

Differential Revision: https://reviews.llvm.org/D88545

Differential Revision: https://reviews.llvm.org/D88650

This patch fixes the bug report in https://bugs.llvm.org/show_bug.cgi?id=47659

Reviewed By: sameeranjoshi

Differential Revision: https://reviews.llvm.org/D88597

Remove some checks that have already been done in the only caller.

This reverts commit 30d07b14.

Test failures have (hopefully) been fixed.

This reverts commit 79fbcbff.

The fallback command fails to parse for the test files if there's no
compile_commands.json in the tree.

After this change all nodes that have a delimited-list are using the
`List` API.

Implementation details:
Let's look at a declaration with multiple declarators:
`int a, b;`
To generate a declarator list node we need to have the range of
declarators: `a, b`:
However, the `ClangAST` actually stores them as separate declarations:
`int a   ;`
`int    b;`
We solve that by appropriately marking the declarators on each separate
declaration in the `ClangAST` and then for the final declarator `int
b`, shrinking its range to fit to the already marked declarators.

Differential Revision: https://reviews.llvm.org/D88403

This is a tool to simply parse a file as clangd would, and run some
common features (code actions, go-to-definition, hover) in an attempt to
trigger or reproduce crashes, error diagnostics, etc.

This is easier and more predictable than loading the file in clangd, because:
 - there's no editor/plugin variation to worry about
 - there's no accidental variation of user behavior or other extraneous requests
 - we trigger features at every token, rather than guessing
 - everything is synchronoous, logs are easier to reason about
 - it's easier to (get users to) capture logs when running on the command-line

This is a fairly lightweight variant of this idea.
We could do a lot more with it, and maybe we should.
But I can't in the near future, and experience will tell us if we made
the right tradeoffs and if it's worth investing further.

Differential Revision: https://reviews.llvm.org/D88338

It's actually not safe to call TEST_BIG_ENDIAN here, since we may be
running from the builtins build (i.e builtins-config-ix) context where
TEST_COMPILE_ONLY  is set since without builtins already built we may
fail to link, and TEST_BIG_ENDIAN internally performs tests which may
fail to link without builtins.

Fortunately powerpc is the only target that uses this information here and
we actually already know the whether we are targeting the LE variant due
to earlier macro checks, so we can simply this to remove our reliance on
TEST_BIG_ENDIAN.

Reviewed By: hubert.reinterpretcast, Whitney

Differential Revision: https://reviews.llvm.org/D88608

We don't support global variables with scalable vector types so I've
changed the code to compare the fixed sizes instead.

Differential Revision: https://reviews.llvm.org/D88564

When adding an archive member with a problem, e.g. a new bitcode with an
old archiver, containing an unsupported attribute, or an ELF file with a
malformed symbol table, the archiver would throw away the error and
simply add the member to the archive without any symbol entries. This
meant that the resultant archive could be silently unusable when not
using --whole-archive, and result in unexpected undefined symbols.

This change fixes this issue by addressing two FIXMEs and only throwing
away not-an-object errors. However, this meant that some LLD tests which
didn't need symbol tables and were using invalid members deliberately to
test the linker's malformed input handling no longer worked, so this
patch also stops the archiver from looking for symbols in an object if
it doesn't require a symbol table, and updates the tests accordingly.

Differential Revision: https://reviews.llvm.org/D88288

Reviewed by: grimar, rupprecht, MaskRay

This is a simple pass that flattens nested loops.  The intention is to optimise
loop nests like this, which together access an array linearly:

  for (int i = 0; i < N; ++i)
    for (int j = 0; j < M; ++j)
      f(A[i*M+j]);

into one loop:

  for (int i = 0; i < (N*M); ++i)
    f(A[i]);

It can also flatten loops where the induction variables are not used in the
loop. This can help with codesize and runtime, especially on simple cpus
without advanced branch prediction.

This is only worth flattening if the induction variables are only used in an
expression like i*M+j. If they had any other uses, we would have to insert a
div/mod to reconstruct the original values, so this wouldn't be profitable.

This partially fixes PR40581 as this pass triggers on one of the two cases. I
will follow up on this to learn LoopFlatten a few more (small) tricks. Please
note that LoopFlatten is not yet enabled by default.

Patch by Oliver Stannard, with minor tweaks from Dave Green and myself.

Differential Revision: https://reviews.llvm.org/D42365

This test wasn't using decorators before and was missing the import, so my
previous commit broke the test.

Instead of managing two copies of the symbol lists, reuse the same list
in libc++abi and libc++.

Differential Revision: https://reviews.llvm.org/D88623

This test seems to randomly fail on Linux machines. It's only one part of the
test failing randomly, so let's just skip it instead of reverting the whole
patch (again).

This patch adds support for creating Guard Address-Taken IAT Entry Tables (.giats$y sections) in object files, matching the behavior of MSVC. These contain lists of address-taken imported functions, which are used by the linker to create the final GIATS table.
Additionally, if any DLLs are delay-loaded, the linker must look through the .giats tables and add the respective load thunks of address-taken imports to the GFIDS table, as these are also valid call targets.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D87544