This patch adds a new IRTransformations directory to llvm/examples/. This is
intended to serve as a new home for example transformations/analysis
code used by various tutorials.

If LLVM_BUILD_EXAMPLES is enabled, the ExamplesIRTransforms library is
linked into the opt binary and the example passes become available.

To start off with, it contains the CFG simplifications used in the IR
part of the 'Getting Started With LLVM: Basics' tutorial at the US LLVM
Developers Meeting 2019.

Reviewers: paquette, jfb, meikeb, lhames, kbarton

Reviewed By: paquette

Differential Revision: https://reviews.llvm.org/D69416

This reverts commit 3f594ed1.

This change has cause LLDB expression evaluation to fail on Arm Linux.

Differential Revision: https://reviews.llvm.org/D63540

This warning triggers when a class defines a copy constructor but not a
copy-assignment operator (which then gets auto-generated by the
compiler). Fix the warning by deleting the other operator too, as the
default implementation works just fine.

Summary:
getAsInstruction is the only non-const member method.
It is impossible to enforce const-correctness because of it.

Reviewers: jmolloy, majnemer

Reviewed By: jmolloy

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70113

Differential Revision: https://reviews.llvm.org/D70060

If the MOVi operand was renamable, the operands of the expanded
instructions are also renamable.

Reviewers: thegameg, samparker, zatrazz

Reviewed By: thegameg

Differential Revision: https://reviews.llvm.org/D70061

Don't try to canonicalize loads to scalable vector types to loads
of integers.

This removes one assertion when trying to use a TypeSize as a parameter
to DataLayout::isLegalInteger. It does not handle the second part of the
function (which looks at bitcasts).

This patch also contains a NFC fix for Load Analysis, where a variable
initialization that would cause the same assertion is moved closer to
its use. This allows us to run the new test for InstCombine without
having to teach LocationSize to play nicely with scalable vectors.

Differential Revision: https://reviews.llvm.org/D70075

Fixes cppcheck warning.

Additional coverage for D70079

Currently we have limited support for outer loops with multiple basic
blocks after the inner loop exit. But the current checks for creating
PHIs for loop exit values only assumes the header and latches of the
outer loop. It is better to just skip incoming values defined in the
original inner loops. Those are handled earlier.

Reviewers: efriedma, mcrosier

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D70059

We know should_stop_here is false here, so we might as well return false directly.

Summary:
This patch extracts the logic for computing the "absolute" locations,
which was partially present in the debug_loclists dumper, completes it,
and moves it into a separate function. This makes it possible to later
reuse the same logic for uses other than dumping.

The dumper is changed to reuse the location list interpreter, and its
format is changed somewhat. In "verbose" mode it prints the "raw" value
of a location list, the interpreted location (if available) and the
expression itself. In non-verbose mode it prints only one of the
location forms: it prefers the interpreted form, but falls back to the
"raw" format if interpretation is not possible (for instance, because we
were not given a base address, or the resolution of indirect addresses
failed).

This patch also undos some of the changes made in D69672, namely the
part about making all functions static. The main reason for this is that
I learned that the original approach (dumping only fully resolved
locations) meant that it was impossible to rewrite one of the existing
tests. To make that possible (and make the "inline location" dump work
in more cases), I now reuse the same dumping mechanism as is used for
section-based dumping. As this required having more objects know about
the various location lists classes, it seemed like a good idea to create
an interface abstracting the difference between them.

Therefore, I now create a DWARFLocationTable class, which will serve as
a base class for the location list classes. DWARFDebugLoclists is made
to inherit from that. DWARFDebugLoc will follow.

Another positive effect of this change is that section-based dumping
code will not need to use templates (as originally) envisioned, and that
the argument lists of the dumping functions become shorter.

Reviewers: dblaikie, probinson, JDevlieghere, aprantl, SouraVX

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70081

Preparation for: https://reviews.llvm.org/D70079

https://reviews.llvm.org/D70077

Summary:
https://bugs.llvm.org/show_bug.cgi?id=36294

Addressing bug related to returning after return type not being honoured for some operator types.

```
$ bin/clang-format --style="{BasedOnStyle: llvm, AlwaysBreakAfterReturnType: TopLevelDefinitions}" /tmp/foo.cpp
class Foo {
public:
  bool operator!() const;
  bool operator<(Foo const &) const;
  bool operator*() const;
  bool operator->() const;
  bool operator+() const;
  bool operator-() const;
  bool f() const;
};

bool Foo::operator!() const { return true; }
bool
Foo::operator<(Foo const &) const {
  return true;
}
bool Foo::operator*() const { return true; }
bool Foo::operator->() const { return true; }
bool
Foo::operator+() const {
  return true;
}
bool
Foo::operator-() const {
  return true;
}
bool
Foo::f() const {
  return true;
}
```

Reviewers: mitchell-stellar, klimek, owenpan, sammccall, rianquinn

Reviewed By: sammccall

Subscribers: merge_guards_bot, cfe-commits

Tags: #clang-format, #clang-tools-extra, #clang

Differential Revision: https://reviews.llvm.org/D69573

Summary:
swift-lldb currently has to patch the ExpressionKind enum to add support for Swift expressions. If we implement LLVM's RTTI
with a static ID variable instead of a centralised enum we can drop that patch.

Reviewers: labath, davide

Reviewed By: labath

Subscribers: JDevlieghere, lldb-commits

Tags: #upstreaming_lldb_s_downstream_patches, #lldb

Differential Revision: https://reviews.llvm.org/D70070

Reviewers: davide, xiaobai

Reviewed By: davide, xiaobai

Subscribers: davide, JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D70074

We call IsPossibleDynamicType but we also need to check if this is a Clang type,
otherwise other languages with dynamic types (like Swift) might end up being interpreted
as potential Obj-C dynamic types.

Reviewers: spatel, RKSimon, lebedev.ri, apilipenko

Reviewed-By: apilipenko

Tags: #llvm

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D68263

In MachineCopyPropagation, when propagating the source of a copy into
the operand of a later instruction, bail if a destination overlaps
(partly defines) the copy source. If the instruction where the
substitution is happening is also a copy, allowing the propagation
confuses the tracking mechanism.

Differential Revision: https://reviews.llvm.org/D69953

Change-Id: Ic570754f878f2d91a4a50a9bdcf96fbaa240726d

E.g. the buildbot at

 http://lab.llvm.org:8011/builders/ppc64le-lld-multistage-test/builds/7259/steps/build-stage2-unified-tree/logs/stdio

failed with

/home/buildbots/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/unittests/Transforms/Utils/VFABIUtils.cpp:50:22: error: unused variable 'FnAttrs' [-Werror,-Wunused-variable]
  const AttributeSet FnAttrs = Attrs.getFnAttributes();
                     ^
1 error generated.

This converts elf-linker-options.ll to use yaml2obj instead of llc,
improves and cleanups it a bit.

This opens a road to add an additional tests for checking the broken cases.

Differential revision: https://reviews.llvm.org/D70004

SHT_LLVM_LINKER_OPTIONS section contains pairs of null-terminated strings.
This patch adds support for them.

Differential revision: https://reviews.llvm.org/D69895

Summary:
This patch introduces align attribute deduction for callsite argument, function argument, function returned and floating value based on must-be-executed-context.

Reviewers: jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: hiraditya, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69797

* Add inline to the helper functions because gcc-9 won't inline all of
  them without the hint. I've avoided `__attribute__((always_inline))`
  because gcc and clang will inline without it, and improves
  compatibility.
* Replace the byte-by-byte copy in update() with endian::readbe32()
  since perf reports that 1/2 of the time is spent copying into the
  buffer before this patch.

When lld uses --build-id=sha1 it spends 30-45% of CPU in SHA1 depending on the binary (not wall-time since it is parallel). This patch speeds up SHA1 by a factor of 2 on clang-8 and 3 on gcc-6. This leads to a >10% improvement in overall linking time.

lld-speed-test benchmarks run on an Intel i9-9900k with Turbo disabled on CPU 0 compiled with clang-9. Stats recorded with `perf stat -r 5`. All inputs are using `--build-id=sha1`.

| Input | Before (seconds) | After (seconds) |
| --- | --- | --- |
| chrome | 2.14 | 1.82 (-15%) |
| chrome-icf | 2.56 | 2.29 (-10%) |
| clang | 0.65 | 0.53 (-18%) |
| clang-fsds | 0.69 | 0.58 (-16%) |
| clang-gdb-index | 21.71 | 19.3 (-11%) |
| gold | 0.42 | 0.34 (-19%) |
| gold-fsds | 0.431 | 0.355 (-17%) |
| linux-kernel | 0.625 | 0.575 (-8%) |
| llvm-as | 0.045 | 0.039 (-14%) |
| llvm-as-fsds | 0.035 | 0.039 (-11%) |
| mozilla | 11.3 | 9.8  (-13%) |
| mozilla-gc | 11.84 | 10.36 (-12%) |
| mozilla-O0 | 8.2 | 5.84 (-28%) |
| scylla | 5.59 | 4.52 (-19%) |

Reviewed By: ruiu, MaskRay

Differential Revision: https://reviews.llvm.org/D69295

Summary: This patch introduces a new heuristic for guiding operand reordering. The new "look-ahead" heuristic can look beyond the immediate predecessors. This helps break ties when the immediate predecessors have identical opcodes (see lit test for examples).

Reviewers: RKSimon, ABataev, dtemirbulatov, Ayal, hfinkel, rnk

Reviewed By: RKSimon, dtemirbulatov

Subscribers: xbolva00, Carrot, hiraditya, phosek, rnk, rcorcs, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60897

Summary: The attached test case replicates a null dereference crash in
`yaml::Document::skip()`. This was fixed by adding a check and early
return in the method.

Reviewers: Bigcheese, hintonda, beanz

Reviewed By: hintonda

Subscribers: hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69974

The attribute is stored at the `FunctionIndex` attribute set, with the
name "vector-function-abi-variant".

The get/set methods of the attribute have assertion to verify that:

1. Each name in the attribute is a valid VFABI mangled name.

2. Each name in the attribute correspond to a function declared in the
   module.

Differential Revision: https://reviews.llvm.org/D69976

Summary:
I want to be able to specify which python framework to use for lldb in macos. With python2.7 we could just rely on the MacOS one but python3.7 is not shipped with the OS.
An alternative is to use the one shipped with Xcode but that could be path dependent or maybe the user doesn't have Xcode installed at all.
A definite solution is to just ship a python framework with lldb. To make this possible I added "@loader_path/../../../" to the rpath so it points to the same directory as the LLDB.framework, this way we can just drop any frameworks there.

Reviewers: hhb, sgraenitz, xiaobai, smeenai, beanz, labath

Reviewed By: labath

Subscribers: beanz, labath, mgorny, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D69931

Summary:
- Add llvm::SimplifyFreezeInst
- Add InstCombiner::visitFreeze
- Add llvm tests

Reviewers: majnemer, sanjoy, reames, lebedev.ri, spatel

Reviewed By: reames, lebedev.ri

Subscribers: reames, lebedev.ri, filcab, regehr, trentxintong, llvm-commits

Differential Revision: https://reviews.llvm.org/D29013

The author of the patch forgot to add -verify-machineinstrs to the RUN
lines which would have made the issue appear on all bots. Added that
as well as a fix for the undefined register issue (after the hoisting).