LLVM data structures like llvm::User and llvm::MDNode rely on
the value of object storage persisting beyond the lifetime of the
object (#24952).  This is not standard compliant and causes a runtime
crash if LLVM is built with GCC and LTO enabled (#57740).  Until
these issues are fixed, we need to disable dead store eliminations
eliminations based on object lifetime.

Bug: https://github.com/llvm/llvm-project/issues/24952
Bug: https://github.com/llvm/llvm-project/issues/57740
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106943

Reviewed By: MaskRay, thesamesam, nikic

Differential Revision: https://reviews.llvm.org/D150505

Leverage perf-training flow for BOLT profile collection, enabling reproducible
BOLT optimization. Remove the use of bootstrapped build for profile collection.

Test Plan:
- Regular (single-stage) build
```
$ cmake ... -C .../clang/cmake/caches/BOLT.cmake
$ ninja clang-bolt
...
[21/24] Instrumenting clang binary with BOLT
[21/24] Generating BOLT profile for Clang
[23/24] Merging BOLT fdata
Profile from 2 files merged.
[24/24] Optimizing Clang with BOLT
...
          1291202496 : executed instructions (-1.1%)
            27005133 : taken branches (-71.5%)
...
```
- Two stage build (ThinLTO+InstPGO)
```
$ cmake ... -C .../clang/cmake/caches/BOLT.cmake -C .../clang/cmake/caches/BOLT-PGO.cmake
$ ninja clang-bolt
$ ninja stage2-clang-bolt
...
[2756/2759] Instrumenting clang binary with BOLT
[2756/2759] Generating BOLT profile for Clang
[2758/2759] Merging BOLT fdata
[2759/2759] Optimizing Clang with BOLT
...
BOLT-INFO: 7092 out of 184104 functions in the binary (3.9%) have non-empty execution profile
           756531927 : executed instructions (-0.5%)
            15399400 : taken branches (-40.3%)
...
```

Reviewed By: beanz

Differential Revision: https://reviews.llvm.org/D143553

Split off from D143938. This moves the planning logic to select the
vectorization factor to LoopVectorizationPlanner as a step towards only
computing costs for individual VFs in LoopVectorizationCostModel and do
planning in LVP.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D150197

NFC. Pass affine copy options by const ref.

Differential Revision: https://reviews.llvm.org/D150507

The owner of the last two failing buildbots updated CMake.

This reverts commit e8e8707b.

The reason for this patch is to allow the MCDisassembler used in tests
to disassemble instructions that are only available when a specific
feature is enabled.

For example, on RISC-V it's currently not possible to use
decode_operand() on a compressed instruction. This patch fixes this.

Reviewed By: lhames

Differential Revision: https://reviews.llvm.org/D149523

Like done D149543 this validates the other formatter specializations.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D150041

Split off refactoring from D150197 to reduce diff.

Currently, there is no documentation on what platforms and architectures
llvm-exegesis is supported on. This patch adds in user-facing
documentation in the CommandGuide about what architectures are supported
as well as developer facing documentation detailing the technical
reasons for why certain platforms are supported and some aren't.

This is a follow-up after discussion in
https://discourse.llvm.org/t/clarification-on-platform-support-for-llvm-exegesis/70206.

Reviewed By: kpdev42

Differential Revision: https://reviews.llvm.org/D149378

The Assembler tests have been disabled for years in tree and at this
point don't test anything other than common MC infrastructure that is
already tested in other parts of the tree. This patch removes them due
to the mentioned reasons.

Reviewed By: courbet

Differential Revision: https://reviews.llvm.org/D149819

This patch fixes the man page build. It currently doesn't work as
SOURCE_DIR isn't set correctly (just undefined) within the
add_sphinx_target function. This patch also moves around the creation of
targets for autogenerated rst files so that both the man page and html
build can depend upon them as before only the html build depended on
them.

Fixes #62540

Reviewed By: tstellar

Differential Revision: https://reviews.llvm.org/D149809

At the moment, lower-matrix-intrinsics accepts mis-matches between
shapes for operations. See shape-verification.ll for an example where
@llvm.matrix.column.major.load specifies 6x1 and then the use
(@llvm.matrix.multiply) specifies the operand to have 1x6.

This patch adds verification for shapes to check if shapes match.

Reviewed By: thegameg

Differential Revision: https://reviews.llvm.org/D147438

There may be one extra warning. Just make the check less strict.
```
clang: warning: unable to find a Visual Studio installation; try running Clang from a developer command prompt [-Wmsvc-not-found]
clang: warning: argument unused during compilation: '-ftime-trace' [-Wunused-command-line-argument]
clang: warning: argument unused during compilation: '-ftime-trace=e' [-Wunused-command-line-argument]
clang: warning: argument unused during compilation: '-ftime-trace-granularity=1' [-Wunused-command-line-argument]
```

Replace some RF_ flags with integer literals.
Rewrite the isWrite/isExec block to make the code block order reflect
the section order.
Rewrite some imprecise comments.

This is NFC, if we don't count invalid cases such as non-writable TLS
and non-writable RELRO.

This lets us remove some isel patterns.

Reviewed By: fakepaper56

Differential Revision: https://reviews.llvm.org/D150463

See discussion in #56637.

Reviewed By: ldionne, jhenderson

Differential Revision: https://reviews.llvm.org/D147284

Reviewed By: thieta

Differential Revision: https://reviews.llvm.org/D150018

Memory leaks https://lab.llvm.org/buildbot/#/builders/5/builds/33657

This reverts commit 1e317c3f.

We've opened up pull requests for libcxx so we don't need this template
any more.  Also, the repo-lockdown job already adds the same comment
when closing pull requests.

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D150317

https://discourse.llvm.org/t/opening-up-prs-experimentally-for-a-subset-of-the-llvm-project/70375/11

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D150314

My newly added backtrace test (https://reviews.llvm.org/D150491)
broke the Windows buildbot (https://lab.llvm.org/buildbot/#/builders/127/builds/48103)
because they do not have execinfo.h.
I expect the same will happen with the backtrace_symbols test (https://reviews.llvm.org/D150498) as well.

This patch does a quick fix by restricting the test scope to glibc-2.27.
(A tricker fix would take into account SANITIZER_INTERCEPT_BACKTRACE,
which is defined as (SI_FREEBSD || SI_NETBSD || SI_GLIBC || SI_SOLARIS))

This is another patch for https://github.com/google/sanitizers/issues/321
(sanitizer interceptors can write to freed memory, causing corruption),
in this case for backtrace_symbols.

backtrace_symbols is already correct, hence this patch removes the
TODO note. Additionally, this patch adds a test case for it.

Differential Revision: https://reviews.llvm.org/D150498

Currenlty there is a mismatch between LoongArch gcc and clang about
handling register name in inlineasm, i.e. gcc allows both `$`-prefixed
and non-prefiexed names for GPRs while clang only allows `$`-prefixed
one. This patch fixes this mismatch by adding non-prefixed GPR names
in clang.

Take `$r4` for example. With this patch, clang accepts `$r4`, `r4`,
`$a0` and `a0` like what gcc does.

Reviewed By: xen0n

Differential Revision: https://reviews.llvm.org/D136436

Add 'REQUIRES: asserts' to test added in D150002 (53a4adc0) because it tests for a crash that is caused by an assertion failure.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716

This was reverted in d4994d0e b/c a bolt test failed after the
encoding changed.

Relanded the patch with the updated test.

This is to improve a performance bottleneck of printf for long double.

Reviewed By: michaelrj

Differential Revision: https://reviews.llvm.org/D150475

Main value of this is simplifying code, and making a few of the tests easier to read.

Differential Revision: https://reviews.llvm.org/D150474

This was reverted in 4e84149c due to a problem report which has been confirmed to be misattributed.

Original commit message:

Use a switch to avoid repeat tests on the opcode, and factor out some common code out of another switch.  (Not all branches had both common bits, but the one which didn't left the values unchanged and their starting value is the respective operand - so storing it back is a nop.)

This reverts commit d3a6a05b.

Some bots don't like it.

Boo.

Sometimes you want to see how much is being allocated in your data structure
in general.

Add statistics that show how many internal and leaf nodes have been allocated
in the suffix tree over the course of its construction.

Also add a testcase that shows that we actually get these stats out when we're
outlining stuff.

The test shows that we get the expected O(n) leaf nodes, a split, and so on.

Add if condition removal pattern for acc.host_data in a same way as
acc.enter_data, acc.exit_data and acc.update.

The condition is removed from the op if it is a true constant. If
it is a false constant then the region is inlined before the op
and the op is removed.

Reviewed By: vzakhari

Differential Revision: https://reviews.llvm.org/D150480

This makes a (possible) change to the internal representation easier in the future, and makes the code easier to read now.